An Urban Permaculture Passivhaus Eco-Community

A plan of the development generated by architects RG+P.

We can get a glimpse of a sustainable, one planet urban community might be like by looking at existing projects. Presently, the largest permaculture-based, Passivhaus urban eco-community in Europe, is being developed in Leicester, England. When finished, the settlement will contain 68 homes for rent at affordable rates for essential workers. 

It is happening on the site of former, disused Whittier Road land on Heathcott Road, Leicester. The developer is East Midlands Homes, a provider of affordable housing, in partnership with Westleigh Homes. Westleigh is taking on new apprentices to learn building skills to help construct the homes.

At the edge of the site will be a farm, to be run on Permaculture principles, on which residents will be encouraged to work, to grow their own fruit, vegetables, other foodstuffs and supplies. When finished it will provide an urban oasis. The field pond will be refreshed, and hedgerows reinstated to connect a wildlife corridor on Saffron Heath, creating a diverse wildflower meadow and planting 800 new trees, many of which will be fruit trees, on the site.

Saffron Lane Neighbourhood Council (SLNC), a charity and social enterprise, is behind the “Building a Greener Future” project.

The site already contains a community garden, and has produced everything from striped beetroot and blue pumpkins, supplying a range of local restaurants with specialised herbs and vegetables and supporting local community projects, including their own brand and jam. This work is expected to expand upon completion of the estate.

The Neighbourhood Council exists "to provide a range of services to support disadvantaged residents of the Saffron Lane Estate and environs to reach their full potential". Its resource centre is around the corner from the 12 acre site.

Passivhaus homes

The 68 houses will be constructed according to Passivhaus principles which means that the annual running costs per year for heating will be just £13 per home, according to Standard Assessment Procedure software calculations (used by all developers to comply with Building Regulations). The majority of homes in the UK are constructed to level 3 of the Code for Sustainable Homes, meaning that homes comparable to these would use about 8801kWh per year and cost £735 per year to run.

Passivhaus is a standard for energy use in all building types. The homes will be of energy-efficient design, oriented to face south with increased south facing glass, super-insulated and with effective window shading and ventilation and moisture control, plus minimized building surface-to-volume area, protected from wind and with the cooler service spaces located on the northerly side.

The Standard requires the following:

• Space heating: less than 15 kWh/m²/yr;
• Total primary energy use (heating, hot water and electricity): no more than 120kWh/m²/yr;
• Air leakage: no more than 0.75 m³/m²hr @ 50 Pa (0.6 air changes per hour);
• The specific heat load for the heating source at the desired temperature is recommended, but not required, to be less than 10 W/m².

Neil Hodgkin, Head of Development at Saffron Lane Neighbourhood Council, said that "the original plan had been for the 68 homes to be built around the farm so that they would look onto it in a village green type construction, but this was not approved by the planners".

He added that since the houses are to be rented, the residents will have to sign a contract with the housing association, but "it will not be a feature of the contract that they have to do work on the farm, nevertheless they will receive encouragement and training".

It is very unusual to see a development which includes all of these features, and they are in line with the principles of 'one planet living' as espoused by the One Planet Council which notes that there are many benefits to this approach. They include:

• Sustainable, low impact homes;
• Sustainable livelihoods;
• Reduced ecological footprint for the community;
• Local food and products, with micro-enterprises and employment;
• Affordable housing;
• Increased land productivity;
• Skill training;
• Increased biodiversity at the site;
• Increased feelings of well-being and good health from residents;
• Increased sense of community;
• Efficient use of natural resources.

Watch a video about the community project up to now:

David Thorpe is the author of:

• The 'One Planet' Life: A Blueprint for Low Impact Development
• Solar Technology: The Earthscan Expert Guide to Using Solar Energy for Heating, Cooling and Electricity 
• Energy Management in Buildings: The Earthscan Expert Guide
• Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, and
• Energy Management in Industry: The Earthscan Expert Guide.

The Cities Aiming for 100% Renewable Energy For Cities – Webinar Report

On 24 June I hosted a webinar on Can cities go 100% renewable energy?

The answer is not only 'yes' but 'many already are'. Below is my report of the webinar, but first is a podcast. The Twitter Storify account of the highlights is here (with graphics).

Listen to the audio: (length 00:60:00)

Context

Arthouros Zervos, chair of REN21 launching the new Renewables 2015 Global Status Report said "Renewable energy and improved energy efficiency are key to limiting global warming to two degrees Celsius and avoiding dangerous climate change".

The report says that at least 145 countries have supportive policies in place for renewable energy and as of the end of last year renewables comprised around 28% of the world's total power generating capacity and new investment in the sector around the world was over twice that of investment in net fossil fuel capacity.

Amidst this is a growing numbers of cities, communities and regions are proving that meeting all of our energy demand with renewable energy is viable. As urban areas are responsible for 70-75% of energy related CO2 emissions and 40-50% of global GHG emissions, this is an encouraging trend.
Here to discuss this were:

• Anna Leidreiter, of the World Future Council,
• Manuel Valdes Lopez, Deputy Manager of Infrastructures and Urban Coordination, City of Barcelona,
• Asoka Abeygunawardana, the CEO of Strategic Enterprise Management Agency (SEMA) - Sri Lanka and Executive Director of Energy Forum

However unfortunately Asoka did not make the webinar due to a technical hitch.

Anna's presentation

Renewable energy broke a record last year - account >60% net addition to world power capacity, >19% of final consumption.

IRENA (International Renewable Energy Agency) said since 2000 renewable energy capacity has grown 120%, and countries with policies increase every year.

Renewable energy is taking over, local governments and regions around the world are leading this movement, 100s of them have 100% renewable energy or electricity targets and many have already achieved this.

The map shows which local governments have this policy in place. If yours is not on this map yet, get in touch.

In Germany, a pioneering country, 100% renewable energy has been a movement for a few years and the national framework empowered cities to transform their energy systems. In this map is the cities which have set targets. 140 regions - 1/4 of pop, have set one type of target or another.

Across these regions, the network facilitating the dialogue have sought the drivers for this move, and the main one is value creation. I.e., even though climate protection is important, they see the advantage in increasing local value.

Frankfurt is leading this and their strategy was to set a target for the city to be achieved from generation in the region. Munich's strategy was to achieve it from trading electricity and by investing abroad, for example in Scottish offshore wind. Frankfurt, however, is looking within its hinterlands for the source of its energy.

The Fraunhofer Institute has modelled that it is feasible for Frankfurt to achieve 95% RE in power heating, cooling, local mobility from its hinterland, with the rest coming from outside the region.

So it is feasible, using local resources. But this approach needs to have a local perspective. A regional approach is needed. The policy of moving from Petropolis to Ecopolis, from importing resources to making use of local resources is where the added value comes in.

What enables this to happen is the target setting itself. Doing so demonstrates political will and commitment to stakeholders. It catalyzes change for investors and helps to ensure efficient utilization of resources of all sorts, financial and technical too, creating investor security.

Once the target is set a roadmap is needed. It contains five policy principles.

These are derived from actual successful actions around the world.

Energy efficiency must be prioritized first. Consumption must be minimized. Heating and cooling and transport be electrified makes it easier. Local policy makers must help local citizens develop new business models. And educating stakeholders is vital. We should adopt an integrated approach into all policies.

One of our projects is the development of a global 100% RE label, and we need your help to decide how it is defined and measured and verified. The label could enhance the policy dialogue and highlight best practice.

Burlington in Vermont set a 100% target that it has already achieved, but only for the energy the administration purchases. This is different from Germany and Barcelona which want the target to cover everything. This exemplifies the purpose of the label – to say what it means and give guidance to local governments willing to go down this path but struggling. We are envisaging a global network of these cities and regions for those with such targets.

How is the planning developed? With participation from utilities, public, investors. We are trying to develop indicators, evaluation and operationalization. We have 12 indicators already under revision.

The tool should motivate municipalities to be part of the movement to compare their progress with other cities. Cities can gain visibility on the global stage by adopting the target. For example Vancouver, San Francisco, Barcelona, Frankfurt and Sydney are known but others not and they can gain visibility by doing so.

Manuel's presentation

Barcelona is trying to produce all its energy in the municipality. Our idea is to move from 2%, the current level, and reduce total consumption.

It is important therefore to take into account two points: reducing the impact in the city and changing the models of consumption. The people need to be convinced of this

Energy generation is increased by implementing renewable energy, mainly solar, also micro-wind, covering different places with a transformation project in the public space. City lighting (10%) has LED technology and there are 250 street lamps that produce their own energy.

We are transforming step by step all municipal buildings: a new public library is producing 80% of the energy it consumes.
A market with underground parking, will be finished next year and be a symbolic example. Walls can be transformed by covering them with solar panels.

One of the biggest efficiency projects is a new contract with suppliers to promote savings, in 122 buildings owned by the municipality.
The contract with suppliers will guarantee the saving of energy by saying that we will not pay over a certain amount per year. We can influence them because the municipality is a big bill payer.

The lighting plan implementation shows the investment in public space in the last 5 years. LEDs are being rolled out.

Electric fleets of moto-sharing and car-sharing is being rolled out. It will be implemented over the year by private enterprise, 250 electric motorcycles for sharing first. then car sharing next year.

The police will have electric motorcycles, and there will be more electric buses. We have three now and more are on the way – 80 metre buses with the batteries inside. Chargepoints are being installed in public spaces and terminals,. We are electrifying taxi fleets – 20 now with electric cars and a rapid charge network with 12 units – the will be 30 within a year. 300 altogether in public spaces.

The system also needs transforming. There are technical, economic and legal challenges. The graph show how the price changes if you don't produce. A big challenge is that the national government taxes the generation of energy by households, penalising them for installing renewable energy instead of using the existing, dirty, grid. Our promise is to pay for half of the cost of installing renewable energy like solar panels, to counter this disincentive.

City Hall has created a new system for managing energy in the city. Terfa is an organization which is turning garbage into electricity via incineration. There is a district heating network in the first stage and being developed. Distribution is private and so we must implement new ways to distribute.

An app or tool helps people understand the production and consumption of energy, so that people can help the project. Using it, people can see the quality of their power and produce their own, e.g. in some houses 50% of generation paid for if people initiate.

Discussion

Can developed nations help developing countries like India in terms of technology transfer to grow cities 100 % RE?

There are different realities in developing countries. The advice from Anna was to link the 100% RE strategy to the development strategy, i.e. making it a tool for development is key to accessing international funding sources. It's not necessarily only a technology transfer issue but a means for new income sources to come in. There is the additional advantage of securing energy security and developing new business models for local jobs.

Furthermore the value of the energy stays in the city area. With the traditional model, this capital leaves the city to flow to the utilities, to pay for fossil fuels, having contaminated the city and contributed to climate change. Instead, distributed production can be implemented and citizens rewarded with a competitive structure. It's an important way of reducing energy poverty too, by implementing a plan for offering RE to families affected by this issue.

New York is in the leading edge here.

Are the skills there in the workforce?

World Future Council is working in Morocco and elsewhere, taking an integrated approach across policy areas, to help with upskilling.

A holistic approach helps the education system and a national economic development plan for a country or region can create jobs and train young people in learning the skills required.

Bringing people to existing places of excellence, perhaps as interns or trainees, will help them learn how this works.

Developing countries

Question from Simge Aydın: These are wonderful progress indicators in the Renewable Energy area around the world/Europe, congrats. Since I am participating to this webinar from Turkey, from a problematic/chaotic city Istanbul, I am wondering whether the ongoing urbanization process here could create or not an opportunity for increasing the use of renewable energy, especially in the new buildings. What would you suggest to the local authorities on how they can incentivize the investments on RE and create public-private partnerships?
Manuel - using network participation, to find out how do they consume? To offer the chance to energy consumers to compare their consumption patterns so they can see they can save money. If we can explain and offer not just economic or technical help but understanding.

What is the usual job title of the officer in a municipal administration responsible for the 100% RE strategy?

Anna: There is no common job title. Even an energy manager hardly exists in most of them. So Manuel also works on infrastructure. Others work on climate or environment.

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David Thorpe is the author of 

• Solar Technology: The Earthscan Expert Guide to Using Solar Energy for Heating, Cooling and Electricity 
• Energy Management in Buildings: The Earthscan Expert Guide
• The 'One Planet' Life: A Blueprint for Low Impact Development
• Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, and
• Energy Management in Industry: The Earthscan Expert Guide

---

Related posts

• Meet the Businesses Aiming for 100% Renewable Energy
• East Asia Cities Go 100% Renewable Energy
• South Australia Reaches 100% Renewables Electricity
• Burlington, Vermont: A City Powered by Renewable Energy
• Renewable Energy and Urbanism
• Energy Efficiency Markets Outflank Renewables 

 

 

 

 

 

I'm at Hay-on-Wye Literature Festival This Month - Come See Me

I'm very excited because this month I am to achieve a long-time ambition of being on stage at a literary festival. Not just any literary festival, but Hay, and not just once but twice! I'm not at all nervous, no.

Both events are part of the festival's 'green' strand.

The first will be about my new non-fiction book The One Planet Life where I will be in conversation with Jane Davidson, director of INSPIRE and a fellow patron of the One Planet Council. We'll dicuss the work of the Councl and the practice and definition of one planet developments – sustainable homes and eco-villages.

The second will be to do with children's writing and climate fiction, where I will be joined by Saci Lloyd, Jane, and climate change campaigner George Marshall. I hope other members of the Facebook group of cli-fi authors will be there, too.

What are the Best Indicators for Measuring the Sustainability of Cities?

All over the world, individuals, groups, towns and cities are struggling with the knowledge that in total, humanity's activities breach the ability of the planet to support them. There is a wide variety of initiatives and programs which are being developed to try to address this and in my last post I asked if we could define a universal standard for the environmental aspects of sustainable towns and cities.

This post builds upon some responses I have received to that post.

I have just begun a project to encourage towns in Wales and hopefully later the UK to declare themselves as One Planet Towns in the same way that Bioregional is encouraging cities like Brighton and Bristol to become one planet cities. We in the One Planet Council believe that One Planet Town status is what transition towns might be or could be transitioning to.

The advantage of this is that there can be measurement, goals and verification. The advantage of having an objective and universal standard is that it enables comparisons to be made. One can compare one town's performance against another, just as one can compare the energy performance of a building or the health of its occupants against that of another building.

These comparisons need to be made against baselines, which should be established for each town at the beginning, but while it is useful to deal with percentage reductions or increases of particular indicators against those baselines, these are not absolute measurements. Absolute measures enable one area to be compared with another.

Carbon accounting is a form of absolute measurement. It is now relatively easy to both state the annual carbon emissions of a country or a city (absolute) and the percentage improvement on previous years (relative). A measurement of the overall sustainability of a town or city would incorporate this indicator amongst others.

The European Union's sustainable towns and cities program built around the Aalborg process is predicated upon monitoring. It uses:

• The Integrated Urban Monitoring in Europe (IUME) initiative by the European Environment Agency (EEA) – which hasn't been updated for four years; and
• The Reference Framework for Sustainable Cities (RFSC), a still-active online toolkit for European local authorities working towards an integrated management approach. It includes a broad collection of indicators in order for cities to compile their individual set. This uses 28 indicators of which five are environmental:

15 Greenhouse gas emissions – in tons per capita
16 Share of renewable in energy consumption
17 (Percentage of) Areas designated for nature protection and biodiversity under either municipal, communal, national or local schemes
18 The number of times that the limit PM10 permitted by the European directives on air quality is exceeded
19 Soil sealing (m²) per capita.

These are all absolute indicators, enabling proper comparisons to be made between cities of different sizes.

ISO 37120

Objective indicators are also the intention behind ISO 37120 Sustainable Development of Communities: Indicators for City Services and Quality of Life. It includes 46 indicators covered under these headings:

• Economy
• Education
• Energy
• Environment
• Finance
• Fire and emergency response
• Governance
• Health
• Recreation
• Safety
• Shelter
• Solid waste
• Telecommunications and innovation
• Transportation
• Urban planning
• Wastewater
• Water and sanitation.

Of the 46 indicators, these are explicitly about environmental matters:

1. Total residential electrical use per capita (kWh/year)
2. Energy consumption of public buildings per year (kWh/m
²)
3. Percentage of total energy derived from renewable sources, as a share of the city’s total energy consumption
4. Fine particulate matter (
PM2.5) concentration
5. Particulate matter (
PM10) concentration
6. Greenhouse gas emissions measured in tonnes per capita
7. Percentage of city population with regular solid waste collection (residential)
8. Total collected municipal solid waste per capita
9. Percentage of city’s solid waste that is recycled
10. Percentage of city population served by wastewater collection
11. Percentage of the city’s wastewater that has received no treatment
12. Percentage of the city’s wastewater receiving primary treatment
13. Percentage of the city’s wastewater receiving secondary treatment
14. Percentage of the city’s wastewater receiving tertiary treatment
15. Percentage of city population with potable water supply service
16. Percentage of city population with sustainable access to an improved water source
17. Percentage of population with access to improved sanitation
18. Total domestic water consumption per capita (litres/day).

Few of these are absolute measures that relate to planetary limits, the point of the ecological footprint method. Only numbers 6 and 8 are: greenhouse gas emissions measured in tonnes per capita and collected municipal solid waste per capita. 18 is also an absolute measure but not related to ecological footprinting since the amount of water available to a population for consumption will vary by location; what is perhaps interesting from an environmental sustainability angle is the water's life-cycle impact or energy intensity.

It is claimed that ISO 37120:2014 can be used by any city, municipality or local government wishing to measure its performance in a comparable and verifiable manner, irrespective of size and location or level of development. It is being developed as part of an integrated suite of standards for sustainable development in communities by the Global City Indicators Facility, a program of the Global Cities Institute.

It is early days for the standard since it was only published in May 2014 following a development period using input from international organizations, corporate partners, and international experts from over 20 countries. Nine pilot cities, including Bogotá, Toronto, São Paulo and Belo Horizonte originally helped to devise a list of some 115 initial indicators; eventually there were 258 participating cities across 82 countries.

ISO 31720 is meant to provide a comprehensive set of indicators and a methodology that will enable any sized city in a developed or a developing economy to measure its social, economic, and environmental performance in relation to other cities. The standard includes 54 other supporting indicators.

New additional indicators on sustainable development and resilience are currently being developed within the ISO, led by the GCIF. As of December 2014 the standard is being piloted by just one city: Mexico City.

Ecological footprinting

I also mentioned ecological footprinting in my last post, because this seems to be fundamental, and I compared it to life-cycle analysis. In response to this, Mathis Wackernagel, president  of the Global Footprint Network (GFN), got in touch to say that the GFN is "trying to make the Footprint more relevant to cities" and welcoming any suggestions.

He said that far from being professional or commercial secrets, the method and calculations behind the footprinting method which they use are publicly available. For example here: http://www.footprintnetwork.org/en/index.php/GFN/page/methodology/.

"And we make the templates available for free to academics. (we only charge for commercial use)," he says. "

The underlying concept is quite simple: add up all demands on nature that compete for space".

"Life cycle assessment is not a competitor of Footprint.," he continued, "Footprint is an aggregator, an interpretation lens. To calculate the Ecological Footprint of a product, you need a life cycle assessment first. With those LCA data points then you can calculate Footprint."

It is also worth pointing out, of course, that the Footprint is a measure of ‘unsustainability’, not a measure of sustainability.

I have also heard from the British Standard Institue's John Delaney who has alerted me to this and to more issue-specific standards like PAS 2070 for city GHG footprint; process standards like BS 8904 (referred to in the prrevious post), a management system ISO that is in development; or some combination of both, like the European Reference Framework above.

He writes:

"What option cities choose depends on what suits them and/or what they are most comfortable with. Process standards can be more powerful, and help develop strategy, vision, objectives and targets, but they take commitment and resources. Reporting standards give a quick indication of how your city is doing against a raft of issues that are commonly agreed to be important, and they allow ranking of city performance.

"There is also a split between [new] development standards [systems] like One Planet Development, BREEAM Communities, etc. and standards for sustainable development of existing communities and cities. 

"We have talked for some time about developing a general footprinting standard, but it has never gained enough momentum/interest to get going. I’d be very happy to have a chat about how you could get involved in standards development and/or how we could re-boot the footprinting idea. Maybe cities and communities would be a good sector to focus on first."

Anyone who would you like to be involved in this process is welcome to contact me.

David Thorpe is the author of:

• Solar Technology: The Earthscan Expert Guide to Using Solar Energy for Heating, Cooling and Electricity 
• Energy Management in Buildings: The Earthscan Expert Guide
• The 'One Planet' Life: A Blueprint for Low Impact Development
• Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, and
• Energy Management in Industry: The Earthscan Expert Guide.

Could We Define a Universal Standard for Sustainable Towns and Cities?

My book The One Planet Life contains a chapter arguing for a change in our attitude to planning, land and development to enable truly sustainable development, but prerequisite to this is a way of measuring when we have got there.

The trouble is that currently there is a paucity of validated research enabling us to determine what, in practice, actually is sustainable. Indeed, we even lack a common definition of the word, apart from the vague UN one about meeting present needs without compromising those of our descendants.

We urgently need more research on this topic. So much money is being invested on so-called 'sustainable' infrastructure and developments without any measurement of its true ecological impact.

The following is a non-exclusive discussion of various options and approaches already existing, as a way of scoping the field.

Ecological footprint analysis

At first glance ecological footprint analysis seems to offer much of what we need, but there are several definitions of this.

It originated from the Global Footprint Network, which crunches the numbers for WWF's occasional Living Planet Reports.

Although a non-profit, GFN is a consultancy which sells its footprinting services. It uses publicly available data but the way it then calculates the impact of a country or city in terms of global hectares per person is obscure, because if it wasn't they wouldn't be able to sell their services. (A global hectare per person is the composite global average of an area, productivity (yield) and equivalence factor that is used as an aggregation of total impacts, which therefore means that it is open for misinterpretation and confusion by uninformed users.)

The Stockholm Environment Institute (SEI) was behind work done for the Welsh Government's calculation of Wales' ecological footprint, used as a basis for its One Wales: One Planet policy document. But the data has not been updated since 2008. To calculate EFs, SEI uses a set of spreadsheets called the Resources and Energy Analysis Programme.

The SEI came up with Reap-Petite that applies this on a smaller scale with the output being in carbon emissions, but again the methodology is not obvious.

The Welsh Government itself commissioned a small team to use SEI's data to build a separate spreadsheet that would help to determine ecological footprint at the smallest possible level, that of a household.

This micro scale involves very different calculations and assumptions to the macro level deployed by GFN. At the national level, reporting is often done on a production basis, whereas on an individual or household level it is done on a consumption basis.

The Welsh government has a stated policy aim (in One Wales: One Planet (the research behind it is here)) of aiming to only use the resources commensurate with there being one planet within one generation, but is currently working out how to get there.

One Planet Development

The above spreadsheet is used as a planning tool in Wales to determine whether planning applications to build a home and a smallholding on agricultural land should be permitted. This is called a One Planet Development, advocated by the One Planet Council of which I am a patron. Applicants must satisfy the requirement that within five years the ecological footprint would be reduced to 1.88 global hectares per person.

In this case, household expenditure is used as a proxy for ecological footprint. But, again, the data and the methodology behind the spreadsheet are old and obscure.

The One Planet Development policy allows for the possibility of edge-of-settlement One Planet Developments but these are not defined. The One Planet Council has begun work on a definition which would also enable towns, villages and even cities to work towards declaring an aim to become a One Planet Town or City.

One Planet Cities

One Planet Cities are also championed by the consultancy Bioregional, which has worked with Brighton, the world's first declared one planet city, and is working with this year's European Green Capital, Bristol, to persuade it to make a similar declaration.

But Bioregional's methodology is also obscure and out of date. It does not publish its criteria and make them available for critique.

Therefore it is not possible to verify the scale of the ecological footprint of a city or development and the extent to which it is being reduced.

A New Scientist piece written by Fred Pearce in 2013 criticized EF, remarking that it didn't take into account certain variables, which, if they were taken into account would make our ecological footprints even larger.

There have been a number of confidential reports circulated by WWF and Friends of the Earth debating the value of ecological footprinting.  While everyone agrees that ecological footprinting is a great concept for public relations, as it is an easy thing for the public to understand, the methodology is problematic and the data is difficult to keep up-to-date.

But if we do not use this methodology, what might we use?

The need for verifiability

Whatever it is, it must be verifiable and transparent. In a fast urbanising world with a growing population that is already living beyond the means of the planet this is an urgent task: to create, using open data, easily updatable info and present it in a way that people can actually use at all levels from government downwards to determine what is sustainable, i.e. what the planet can fairly provide.

In energy management, it is well known that "what gets measured gets saved". Energy management is a field that is well advanced in establishing baselines, monitoring and performance, with all sorts of software and technology geared to measurement and improving efficiency. There are international standards, the principal one being ISO 50001.

Our final set of metrics must be just as robust.

Carbon footprinting

Carbon footprinting might be one solution, or part of it. This has the advantage of being kept up-to-date on an annual basis, because national and international legislation supports it, but it does not capture other kind of impacts such as biodiversity loss or gain, pollution, etc.

Life Cycle Analysis

The real target of sustainable activity should be overall lifetime impact. This means that life-cycle analysis is another potential serious contender that could be deployed but again the data and the methodology is not quite up to what we actually need.

A Life Cycle Assessment (LCA) quantifies and assesses the emissions, resources consumed, and pressures on health and the environment attributed to different products over their entire life cycle. It quantifies all physical exchanges with the environment, whether these are inputs (resources, materials, land use and energy), or outputs (emissions to air, water and soil).

The advantage of using it is that life cycle assessment is already standardised through a range of ISO documents, including ISO 14040:2006 and ISO 14044:2006, which cover principles, framework requirements and guidelines and, published six years later, ISO/TR 14047:2012 and 14049:2012, which help with applying the earlier standards the impact assessment and inventory analysis.

The LCA process may be divided into four key steps:

• identify goal and scope by defining boundaries and the functional unit
• model the processes and resources involved in the system, collate the life cycle inventories of these processes and resources and generate any new inventory required
• adjust life-cycle impacts in terms of mid points and endpoints
• evaluate and interpret results and generate the report for decision-making.

Life cycle assessment is complicated enough for a single product. A building is an assembly of many different products, and a town or city may contain millions. Clearly this approach by itself from the bottom up will be impractical.

There is, however, an attempt ongoing to apply life-cycle analysis to land use.  The Joint Research Centre (JRC)'s Institute for Environment and Sustainability (IES) leads the European Platform on Life-Cycle Assessment.

WWF have sponsored this work in an effort to assess the impact of human activities on biodiversity, something which is also not captured by ecological footprint analysis and is therefore, in One Planet Development planning applications, treated separately.

Applicants must demonstrate that they are improving the biodiversity of the land they occupy.

UNESCO Biospheres

UNESCO Biospheres are another attempt to find a sustainable way for human activities to live alongside nature, but they are a special case.  These undergo periodic reviews, but these are labour intensive, yet they do represent work in progress in terms of developing tools, testbeds for sustainable development on a wider scale.

Conclusion

Research for WWF conducted in 2010 found that many experts believe that it would be advantageous "to align the Ecological Footprint with the UN System of Environmental and Economic Accounting", and that it should be "part of a basket of indicators". Although one aggregated indicator is seen as essential for communication, it does not "provide enough detail to undertake a meaningful assessment of regenerative capacity compared with demand" (Wiedmann and Barrett, 2010).

The SEEA utilizes the principles of economic accounting, building on the existing System of National Accounts (SNA) to help reveal the relationship between the environment and well-being not revealed by GDP and national income.  See graphic, right.

It does not propose any single indicator or basket of indicators but is an approach to integrating statistics to allow for multiple purposes and multiple scales of analysis. However, there are several key aggregates and indicators that are directly derived from the accounting tables and are of interest to policy analysis

In a similar way, as part of its work towards its Well-Being of Future Generations Bill, The Welsh Government has placed ecological footprinting as one of five overarching indicators for Sustainable Development, under which more specific indicators can sit:
1.         Economic output – Gross Value Added
2.         Social Justice - percentage of the population in relative low-income households
3.         Biodiversity conservation – status of priority species and habitats
4.         Ecological footprint – national EF against the UK and global average
5.         Wellbeing - a standard set of 36 health questions which ask respondents about their own perception of their physical and mental health.

This seems to be a sensible approach. But WWF has argued that "Accounting for our actions in terms of carbon and footprint reduction, however statistically difficult, should be a pre-requisite of a nation aspiring to One Planet living", and therefore should be given more weight in this mix at an increasing level of detail.

Genuine Progress Indicator

An approach similar to this is undertaken by the Genuine Progress Indicator (GPI). Applicable to existing settlements, it uses 26 indicators: seven economic, nine environmental and ten social, combined into a single framework. From the costs of crime, pollution, commuting and inequality to the value of education, volunteer work, leisure time and infrastructure, the GPI helps us understand the true impacts of policies. But again, it is far from complete, particularly on the biodiversity side (no credits for improving it). In a sense it does complement the SEEA approach.

Realistically, since every area of land is different, every development would need to conduct a survey to establish a baseline from which biodiversity changes caused by the development could be measured. This is already part of the criteria for many planning applications.

BS 8904:2011 

The standard BS 8904:2011 might also be of interest in this context. It provides guidance for community sustainable development, a framework of recommendations and guidance to assist communities to improve their sustainability. But as far as I can make out it does not actually collect data on performance. Rather it is a community engagement tool.

Next steps

A recent piece of research which I received privately concluded:

"The EF has cemented its place as a pioneering and important step towards providing a framework and metric for measuring environmental limits.  We can expect to see it continue to be used. However, it will be increasingly important to understand what it can and can’t do, and how to make the most of it alongside the significant and growing generation of new tools now emerging." 

It is clear then that much more research needs to be done to develop a proper basket of indicators that is sufficiently mature, objective, transparent, open and verifiable to match the importance and effectiveness of carbon and energy accounting methodology.

I would love to hear of any work being done towards this end.

David Thorpe is the author of:

• Solar Technology: The Earthscan Expert Guide to Using Solar Energy for Heating, Cooling and Electricity 
• Energy Management in Buildings: The Earthscan Expert Guide
• The 'One Planet' Life: A Blueprint for Low Impact Development
• Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, and
• Energy Management in Industry: The Earthscan Expert Guide.

INTERVIEW: Dan Bloom on CliFi – Can We Save the World Through Fiction?

Fancy some climate change with your popcorn or bedtime read? Climate fiction, or cli-fi, is a new genre of fiction that was first identified as a distinct concept by Dan Bloom, a freelance writer who has been based in Tokyo and Taipei since 1991. It is, basically, fiction which touches in some way on the topic of climate change.

Dan recently sat down with me, SCC chief consultant and author David Thorpe of the cli-fi novel Stormteller, and I picked his brains about the cream of the genre and particularly what the writers of these works think will happen to cities in the future. This is what happened:

David: First, Dan, tell me, what is cli-fi?

Dan: Cli-fi is a new genre term for novels, short stories and movies that stands for works of art and storytelling that deal with climate change and global warming concerns: "cli" stands for the first thee letters of ''climate,'' and "fi" stands for the first two letters of ''fiction.'' Just as sci-fi stands for science fiction, cli-fi stands for what might be called "clience fiction," or novels and movies where climate change is a major theme, although not always the main theme.

Many sci-fi novels and movies also delve into climate themes, so in many ways cli-fi is a sister genre to sci-fi, but with a specific focus on climate change concerns. You could say that sci-fi and cli-fi are cousins.

But in the world we are living in today, where both scientists and the general public is well aware of what the future might look like if we do nothing to stop CO₂ emissions and runaway climate change, cli-fi serves a very important function for writers, literary critics, book reviewers, film directors, scriptwriters and movie critics.

Jeffrey Newman in London has told me that in his view of things, cli-fi is a "reframing" of the national and international discussions we are having on climate issues. Scott Hill in Los Angeles has referred to cli-fi as "a cultural prism" in which to view global warming and its possible fallout, if we do nothing to stop it. I also like to think of cli-fi as a critical prism: a way to focus on what the future might hold.

In the end, what is cli-fi? It is a literary and cinematic ''platform'' for artists and writers to use to say what's on their minds.

David: Can you give examples of how cities are portrayed in cli-fi novels and films?

Dan: Cli-fi novels or movies can deal with large cities, or with smaller cities and towns as well. In "The Odds Against Tomorrow" by New Orleans writer Nathaniel Rich, the setting is Manhattan in the near future, where rising sea levels put the entire area under water, and people are seen canoeing down major streets and avenues. In "Flight Behavior" by Barbara Kingsolver, the setting is the rural countryside where a massive butterfly die-off brings in scientists from the big cities to study the problem.

In "Polar City Red" by Jim Laughter, the setting is Fairbanks, Alaska in 2075 after heat waves in the Lower 48 states of the USA have made that part of the world uninhabitable and climate refugees take refuge in so-called "polar cities" – domed or underground cities – in the Arctic regions to serve as "breeding pairs" for future generations, an idea that was originally put forth by British chemist James Lovelock.

Dan Bloom and Ah-Lin, an actor playing JERKY, in a scene from POLAR CITY RED the movie during location shooting in Alaska.

David: Do you regard the way LA is portrayed (constant rain) in Blade Runner as a clifi feature?

Dan: Yes. That's a very cli fi feature of that movie. And I lived in Tokyo City for five years in the 1990s.....thirty million population....it was Blade Runner to me for five years especially at night and especially in the spring rainy season.

But it doesn't have to be all dark and depressing in cli fi novels or movies. I also hope to read and see cli fi works that portray positive, hopeful ways of coping with what is arguably the most pressing existential threat humankind has ever faced. I am an optimist, myself. I hope cli fi can help readers and movie-goers break through to the side of optimism and hope. But there is a lot of ground to cover, and not all of it is going to be a pretty picture.

In "Finitude" by Scottish novelist Hamish MacDonald, the setting is a city much like London in some un-named country much like Britain in the near future, where all hell breaks loose and a group of people search for a safe haven, against all odds. It's all one of the first cli-fi novels written by a gay author and with a major gay romance in the story.

So cli-fi is an open genre that serves as a platform for writers and film people to explore the future, not in a sci-fi but in a cli-fi way.

David: In some cli fi novels or movies, cities are abandoned. Do you think this is likely?

Dan: Yes, I do. I can't see the future, and I don't have a time frame for when all these things are going to happen, it's anybody's guess and my instinct tells me it's still 300 to 500 years away before the shit hits the fan, so to speak, but if we cannot curb the problems that are causing man-made global warming and runaway climate change, then cities will have to be abandoned and climate refugees will have to seek food, shelter and fuel in northern areas of the Arctic. Goodbye Manhattan, goodbye London, goodbye Paris, goodbye Beijing, goodbye Sydney.

Possible refuges might be New Zealand, the island of Tasmania, and all of the Arctic from Alaska to Canada to Greenland to Scandinavia to Russia and northern China. This is all fertile ground for storytellers to explore with the cli-fi platform.

David: Are all cli-fi films and novels dystopias? Or are there examples of how we might cope positively with climate change in the future?

Dan: "Cli-fi" movies and novels are emerging as a niche genre, taking the pomp of doomsday science-fiction films and novels and mixing it with an underlying message of environmental awareness. Cli fi works do not have to be dystopian, and I hope to see utopian cli fi as well.

Margaret Atwood (right, reading her book Year of the Flood) has coined a term she calls "ustopian" for novels and movies that are both ''u''-topian and dys-''topian'' in theme. Most of what I have read and seen so far in literature and cinema has been what I call dystopiana. But I really hope to see cli-fi take on more optimistic approaches to what ails the Earth these days.

Fabien Cousteau, the grandson of famed oceanographer Jacques Cousteau and a filmmaker himself, believes that cli-fi movies allow people to view a changing part of the world through what he calls ''the prism of an anecdote.'

By relating the scientific part of a cli-fi story in a way that people can be entranced by it, cli fi storytellers can win their audiences over, he believes. I like the way he frames it.

What I hope to see in the future are cli fi movies and novels with the power of Neville Shute's 1957 novel "On the Beach," which painted a wake up call picture about the dangers of nuclear war and nuclear winter. We need an "On the Beach" about the dangers of climate change and with, hopefully, a hopeful, positive ending, to raise awareness and also to goad people to take action in ways they see fit.

We need to go beyond abstract, scientific predictions and government statistics and try to show the cinematic or literary reality of a painful, possible future of the world climate changed. I do believe that cli-fi is a veritable cultural prism, a powerful critical prism, that we need to cherish and nurture among our artists and visionary storytellers. Time will tell.

David: What are your favorites?

Dan: For me, "Finitude" and "Polar City Red" resonated deeply. Neither novel is well known, and neither novel was reviewed by the mainstream media critics in London or New York or Los Angeles and both were released by small presses. But I read them both three years ago, and the stories they tell still remain with me. I'd love to see either of them turned into a movie. Hollywood, are you listening?

David: Do we have an idea of how popular they are and who reads them?

Dan: Cli-fi is still such a new term that only ten per cent of the population has ever heard of it, and such novels and movies – classified as cli-fi – are not on the radar of mainstream book reviewers or movie critics.

So for the time being, the publishing industry and the Hollywood establishment has largely ignored the rise of cli-fi (even with major news stories about the genre in Time magazine, the Guardian, The Financial Times and the New York Times).

I believe the public is hungry for cli-fi – both movies and novels. But how to get such storytelling distributed to the public is a question I cannot answer. I'm looking for the answer now but it still eludes me.

Follow #CliFi on Twitter to keep up.

David Thorpe's novel Stormteller is available from the publisher here. or on Amazon.com. 

How we can keep global warming to 2°C or below

There is no greater challenge for the world this year than to reach an agreement at Paris' climate change talks in December that will limit global warming to within 2°C. This is the threshold, moving beyond which scientists agree would create terrible and irreversible damage for our planet and all who dwell upon it.



Amongst the main issues to be solved is the long-standing difference of opinion between poor and rich countries over who pays for the required mitigation measures. The poor countries' view is that since the wealthy nations put most of the planet-warming gases into the atmosphere, then they should pay for it. These rich nations in turn do not dispute this, but argue that many of the poorer countries are now producing a huge and growing amount of the gases, and themselves must accept a share of the responsibility.

Then there are the extent to which all nations will be bound by whatever agreement is reached, and, crucially, how it will be monitored, since many nations, such as China, have said they would regard it as a breach of national sovereignty were their emissions to be scrutinized by outsiders. Instead, they demand to be trusted, something which others are uncomfortable about.

Then there is the collapse in the price of oil, which is almost back at $50, previously thought unreachable again. This makes the cost of renewable energy and energy efficiency measures seem much more expensive by comparison. It is leading some to call for stronger taxes on carbon to redress the balance.

On the positive side, the evidence of the reality of climate change is now hitting home in peoples' minds, despite the increasingly hollow-sounding voices of sceptics. 2014 was the hottest year on record - and 10 of the warmest have been since 1998.

Graph of yearly global temperature increases.

We are increasingly seeing more of a push by cammpaigners, scientists, artists, writers and musicians, as well as religious leaders such as the Pope, to build a mass, global consensus that we have to act, and do what the science demands.

If an agreement is reached then we can expect a huge mobilization of activity, but not staight away because an agreement reached in Paris in eleven months would not become binding for another four years.

In order to achieve the 2 °C climate target with a likely probability (>67%), cumulative global CO₂ emissions in the 2010–2100 period need to be constrained to about 1000 GtCO₂ (range of 800–1200 GtCO₂). The projected global 2020 greenhouse gas emission level is now around 10% above the 2010 level.

The ‘least-cost’ 2°C scenarios show lower 2020 emission levels, in the range of 38 to 47 GtCO₂eq. But these typically assume immediate implementation of mitigation policies in all countries and sectors.

If large emission reductions by 2020 are unlikely it will become increasingly harder to reach the 2°C target; global emission reduction rates will need to be much higher, and so, therefore, will the mitigation costs.

This in turn raises the risk of missing the 2°C target and the requirement for deploying technologies that often meet with public resistance.

A new analysis of the models (Long-term climate policy targets and implications for 2030  a Dutch PBL Policy Brief) shows that achieving the 2°C target critically depends on well organised international policies, in the short term, to realise stringent reductions during the 2020–2030 period.

This means formulating ambitious mitigation goals and increasing the participation of all parties in climate policy.

And it necessitates taking real action; implementing long-term incentive structures to reduce emissions (given the inertia in economic and energy systems) and stimulating innovation.

The biggest challenge is, in a tough economic climate, with a low price for oil, how to increase the motivation to implement ambitious climate mitigation policies.

It is therefore useful to look at ways of doing so that additionally achieve synergies with other policy areas, such as job creation, poverty relief, food provision, energy security, economic opportunities and risks, air pollution and ecosystem degradation.

The costs of meeting the 2°C target would be lowest if the global emissions level were to peak within the next 10 years.

Can we achieve this? Right now, emissions are increasing, but the rate of increase is slowing. The average growth in emissions over the last decade – excluding the global financial crisis between 2007-2012 was 3.8% per year. A 2.5% growth is projected by PwC and the International Monetary Fund in 2015.

What can cities and regions do? They can set unilateral targets and work with partners on their own strategies. Individuals can put pressure on their local representatives. All can help to put pressure on national governments to reach a firm and proper agreement in the Paris talks.

To borrow two clichés: all hands on deck – it will be touch and go.

David Thorpe's book, The 'One Planet' Life: A Blueprint for Low Impact Development has received the following praise:

"An excellent and immensely practical step by step guide" – George Marshall, author of Don't Even Think About It, Why Our Brains Are Wired To Ignore Climate Change.

“This year’s must have book.” Jane Davidson, former Environment Minister for Wales and Director of INSPIRE

"There is much inspiration to be had from this comprehensive and beautifully illustrated book. David Thorpe is a master of lucid writing on one of the most important topics of our time.  I highly recommend this book to anybody who is interested in assuring that we leave a habitable planet to our children." Herbert Girardet, founder of The World Future Council.

"Makes the irrefutable case for ‘one planet living’" – Oliver Tickell, editor, The Ecologist

Living the One Planet Life at the UK's 15 year old sustainable community

The view from the south looking over the lake towards the terrace.

Not far from the minster town of Southwell, Nottinghamshire, in England's Midlands (Robin Hood country to you) Hockerton housing cooperative is one of the UK's best-known example of communal one planet living. Five households have been forging a new way of living there for 15 years that is more sustainable than most, and self-sufficient in energy, water, sewage treatment and much food. They also run courses, both online and offline, and accept site visits.

When I went to see them it was a lovely late summer’s day. All of the trees and bushes were laden with fruit.

 

Part of the vegetable garden at Hockerton Housing Project.

I was taken on a tour by Bill, a resident who’d been living there for about seven years with his family. We explored the ten acres of orchards and fields where residents grow 40% of their food, keeping bees, sheep and hens. The community is about two-thirds self-sufficient in vegetables but less for fruit and meat. The hives most years generate more honey than can be eaten so surplus is exchanged. Wine-making makes use of some fruit/vegetable excesses.



Hockerton looking east from the roof of the terrace. On the left is the earth covered rear of the homes, which merges into the orchard. To the right is the lake. The chimney is for natural ventilation. At the top of the glazing can be seen the photovoltaic array.

Water supply

I was taken next to a pond that collects water filtered for use in their washing machines, sinks and toilets. Drinking water is collected from the glass roof of the conservatory in front of the row of houses via copper pipes, which are slightly antiseptic, and stored in a tank with a capacity sufficient to last around 100 days. The water is passed through a five-micrometre string filter, a carbon filter and a UV-light filter. The community is self-sustaining in water and energy.

All of the effluent is purified using an attractive reed bed at the side of the homes, buzzing with dragonflies and other insects, whose outflow enters a long lake situated along the front of the terrace, which is stocked with carp that is harvested for food or sale, and on which the children go boating. The whole is a haven for wildlife.

The houses

The houses themselves are partly earth-covered on the north side, for insulation, and constructed of a shell of dense concrete. The idea is to create thermal mass to hold the sun's heat that is captured by the south-west facing conservatories, which are also used for clothes drying.

Nowadays we know more about the carbon cost of using concrete and there are carbon-saving alternatives that do the same job. Each house is six metres deep, not so deep that it’s dark at the back, and 19 metres wide, fronted by a sunny conservatory accessed by French windows.

The rooms at the back are reserved for functions requiring less use and light, such as bathrooms and utility rooms. The homes are spacious, light, warm and comfortable.

Right: The two wind turbines and willow for coppicing.

Electricity

Electricity is provided by 7.65 kW peak arrays of PV panels on the roof and new ones on the office to help power that and charge an electric shared car, and by two nearby wind turbines;

• a 6 kW Proven wind turbine installed early 2002 year (upgraded in 2008) and
• a 5 kW Iskra wind turbine installed in 2005 as part of the construction of a community building. 

The wind turbines have produced only 40-50% of their projected output (partly due to turbulence and poorly matched inverters), some heat pumps failed, and energy use has been higher than expected (put down to teenagers, more people working from home and food processing).

This is why more PVs were installed in 2012.

The typical energy use for a house is around 10kWhrs/day (all electric).

The community has on balance more electricity than it needs and the surplus is exported to the grid for profit.

Hot water is produced partly via a heat pump and super-insulated thermal stores, but since they mainly failed, mostly by electricity.

Below: the view looking directly down across the solar electric panels, a solar water heating panel, and into the small patch of private front garden each dwelling has, with a raised bed and composting area.

Educational role

Part of Hockerton's mission is to spread the word about how it is possible to live more lightly on the earth. Although residents own their own homes they are all members of a cooperative and agree to spend 300 paid hours per year supporting a joint business which runs a programme of tours and educational events, workshops and consulting on both new and retrofit energy efficient building.

Finance for the building and land purchase came from the Co-operative Bank & Ecology Building Society. If you wanted to live there it would not be cheap: despite construction costing just 15% more than an average house of comparable size (£95,000 in 1998), recently one of the four bedroomed homes sold for £500,000. So it's not for everyone, and rather the opposite of much of what we think of as 'low impact housing' in the UK.

"My kids love it here," says Bill. "And, after the initial suspicion, the local council and residents like us too. In fact, they are very proud of us."

The planning conditions

Planning permission was initially granted with great difficulty, despite the involvement of senior academics Robert and Brenda Vale, from Nottingham University’s Architecture Department, who had built and lived in the country’s first autonomous, self-sufficient home in a Conservation Area in nearby Southwell. This is because the founders wanted to build on agricultural land, something not permitted in the UK without good reason because of the fear of land speculation and 'unfettered development'.

Permission eventually came with a condition (a 'Section 106' requirement), whereby a fixed number of hours (300 per year per household) must be spent on the land, in addition to the same number of hours spent on the community's business.

This condition seems to me to be both fairer, more achievable and manageable, than having to provide a percentage of food supply from the land, as with One Planet Developments in Wales. It also helps to secure the planners' prime directive of preventing such developments becoming owned by people who do not want to use the land, and who will instead commute to jobs elsewhere.

300 hours per year is just about six hours per week, which is quite do-able and leaves time for other work and leisure, plus the other 300 hours of Co-op work.

The project had to be viewed by the planning department as “a move towards Sustainable Development”, which “could be seen as complimenting the council’s (Newark & Sherwood District Council) own energy / environmental activities”. Account was taken of the social provisions of the scheme – “(it) is not just for the houses in an isolated situation but as a whole living project…the occupants of the dwellings will work on the site towards a system of self-sufficiency through sustainable employment with low impact on the environment”.

Besides owning a shared electric car, some families have fossil-fuel powered cars, two share one of these, and there are many bikes for local journeys.

To improve biodiversity over 4,000 trees have been planted around the site, including willow for coppicing, wild cherries for birds, and oak and hazel.

Because of this and the lake/wetland, biodiversity is flourishing, with several pairs of regular breeding waterfowl on the lake, including little grebe.

A number of passing bird migrants have been seen including green sandpiper, hobby and water rail. The ponds are monitored by the local agricultural college (Brackenhurst) who are pleased about a flourishing population of the endangered water vole.

Many people have visited this inspiring place and attended workshops, but so far, despite individual homes being modeled on aspects of the project, no community has yet emulated it in full.

Why is this, I wonder? Perhaps it’s due to the difficulty of finding the right combination of land, motivated, experienced architects, pioneers and finance. It’s notable that three of the community-scale projects I looked at in the course of writing my book The One Planet Life (of which this article is an extract) – BedZED, Hockerton and Lammas – have been led by visionary architects.

We need more of them.

More info at http://www.hockertonhousingproject.org.uk/.

David Thorpe's book, The 'One Planet' Life: A Blueprint for Low Impact Development has received the following praise:

"An excellent and immensely practical step by step guide" – George Marshall, author of Don't Even Think About It, Why Our Brains Are Wired To Ignore Climate Change.

“This year’s must have book.” Jane Davidson, former Environment Minister for Wales and Director of INSPIRE

"There is much inspiration to be had from this comprehensive and beautifully illustrated book. David Thorpe is a master of lucid writing on one of the most important topics of our time.  I highly recommend this book to anybody who is interested in assuring that we leave a habitable planet to our children." Herbert Girardet, founder of The World Future Council.

"Makes the irrefutable case for ‘one planet living’" – Oliver Tickell, editor, The Ecologist

How to use solar energy for air-conditioning, save billions and cut emissions

Question: if you can use solar power for cooling and air conditioning then why doesn't everybody do it? After all it's a match made in heaven: just when it's so hot you need the aircon, there's lots of solar energy around.

Answer: it's fairly new, not well known and there is a relatively high upfront cost. This makes it a candidate for some sort of net metering or feed in tariffs to kickstart the market, if ever I saw one.

Yesterday I wrote about how architects can use passive solar techniques to design zero carbon buildings and/or drastically cut the need for air-conditioning in warm/hot climates.

In this article I'm going to run you through the technology principles and alternatives for active solar cooling, but first let's look at the problem.

The problem: we want to be cool

It's hot. You turn on the aircon or the fan. Your energy bill goes up

According to the NREL, "air conditioning currently consumes about 15% of the electricity generated in the United States. It is also a major contributor to peak electrical demand on hot summer days, which can lead to escalating power costs, brownouts, and rolling blackouts".

The picture is the same in Europe. For example, according to a national market survey by the Hellenic Ministry of Commerce, about 95% of air-conditioning sales in Greece occur in the period of May-August and reach about 200,000 units (primarily small-size split-type heat pumps) every year. The use of air-conditioning units in summer causes peak electric loads that periodically result in power shortages in large areas of metropolitan cities like Athens.

In southern European countries there is a well-established connection between the growth of peak power electricity demand in summer and the growth of air-conditioning sales in the small and medium-size market.

The picture is the same throughout the world whenever there is hot weather. It leads to ugly city views like this one (right).

The fact that peak cooling demand happens at the same time as high availability of solar energy offers an opportunity to exploit solar thermal technologies that can match suitable solar cooling technologies (i.e., absorption, adsorption, and desiccant cooling), cut emissions from the burning of fossil fuels and in the longer run save billions of dollars in fuel costs.

The technical solutions

Space cooling uses thermally activated cooling systems driven (or partially driven) by solar energy. The two systems are:

1. Closed-cycle:  a heat-driven heat pump that operates in a closed cycle with a working fluid pair, usually an absorbent-refrigerant such as LiBr-water and water-ammonia, or an adsorption cycle using sorption such as silica gel; two or more adsorbers are used to continuously provide chilled water;
2. Open-cycle: solar thermal energy regenerates desiccant substances such as water by drying them, thereby cooling the air. Liquid or solid dessicants are possible. a combination of dehumidification and evaporative cooling of air.

Desiccant cooling system assisted by solar energy from air collectors and PV moduls. Pompeu Fabra Library (Mataró, Spain) | Source: AIGUASOL

More case studies below the techy section, next.

Absorption NH₃/H₂O

The single stage, continuous absorption refrigeration process works as follows: The working fluid (WF), mainly ammonia and water, is boiled in the generator, which receives heat from the solar collectors at 65–80°C. Mainly ammonia, but some water leaves and is condensed at the water cooled condenser (25–35°C). The boiling working fluid in the generator has therefore to be exchanged continuously using the pump to deliver strong working fluid with a concentration of 40% ammonia, from the absorber via the working fluid heat exchanger, which heats it to 50–65°C taken from the weaker fluid leaving the generator.

The latter, now cooler, is led to the absorber, and leaves the absorber at c.35°C. Meanwhile, the condensed refrigerant ammonia has left the condenser and is injected into the evaporator by the refrigerant control valve. This works at low pressure level (2–4 bar), and the refrigerant boils and evaporates. The cold vapour flows into the absorber which absorbs it, combines it with the working fluid, and sends in back to the generator.

The thermal coefficient of performance (COP_thermal) describes the relation between the profit (cooling capacity) and the expense (heat from the collectors): COP_thermal = Q_cooling / Q_heating

Absorption H2O/LiBr

This system employs a refrigerant expanding from a condenser to an evaporator through a throttle in an absorber/desorber combination that is akin to a “thermal compressor” in a conventional vapour compression cycle. Cooling is produced through the evaporation of the refrigerant (water) at low temperature. The absorbent then absorbs the refrigerant vapour at low pressure and desorbs into the condenser at high pressure when (solar) heat is supplied. In this a single-effect absorption system liquid refrigerant leaving the condenser expands through the throttle valve into evaporator taking its heat of evaporation from the stream of chilled water and cooling it.

The vapour leaving is absorbed by an absorbent solution entering dilute in refrigerant (strong absorption capability) leaving rich in refrigerant (weak absorption capability), where it is pumped via a heat exchanger to a desorber which regenerates the solution to a strong state by applying heat from the solar-heated water stream, causing the desorption of refrigerant. It condenses in the condenser to liquid, then expands into the evaporator. The absorber and condenser are cooled by streams of cooling water to reject the heats of absorption and condensation respectively.

Adsorption

Adsorption substances are working pairs, usually water/silica gel. The solid sorbent (gel) is alternately cooled and heated to be able to adsorb and desorb the refrigerant (water). A sequence of adsorbers in deployed to use the heat from one to power another. The cycle is (refer to the schematic diagram, right): refrigerant previously adsorbed in one adsorber is driven off through the use of hot water (may be solar-heated) (right compartment).

It then condenses in the condenser and the heat of condensation is removed by cooling water. The condensate is sprayed in the evaporator and evaporates under low partial pressure, producing cooling power. The refrigerant vapour is adsorbed into the other adsorber (left) where heat is removed by cooling water.

Open cycle liquid desiccant cooling

Humidity is removed from the process air by the desiccant, which is then regenerated by heat from an available source, e.g. solar. Both solid and liquid hygroscopic materials may be used in the dehumidification of conditioned air.

Liquid desiccant systems can store cooling capacity by means of regenerated desiccant. Solar thermal energy is used whenever available to run the desorber and its associated components (hot water-to-solution heat exchanger, air-to-air recuperator, pump) to concentrate hygroscopic salt.

Later, when needed, this is used to dehumidify process air. This method of cold storage is the most compact, requires no insulation and can be applied for indefinitely long time periods.

Solid desiccant air handling unit 

Here, two air channels are mounted on top of each other. The outdoor air enters (A) where the sorption wheel with a silica gel surface dehumidifies is (B) and transfers heat from the outgoing air (C), rehumidifies it to the correct level then enters the conditioned space, increases its enthalpy by internal heat sources and moisture, and leaves as return air (G) where moisture (H and J) and heat (I) are removed as necessary and it is expelled (L).

Highly effective solar collectors should be used for the heat regeneration. The Middle European climate allows an enhancement of the adiabatic cooling mode.

Relation between the cooling capacity and the regeneration heat: COP_{thermal, plant} = Q_c,plant / Q_heat

Relation between the cooling load and the regeneration heat: COP_{thermal, build} = Q_{c, build} / Q_heat

Desiccant-Enhanced Evaporative (DEVAP) Air Conditioner

NREL, AILR Research, Inc. and Synapse Product Development have developed the DEVAP air conditioner. This consists of two stages: dehumidifier and indirect evaporative cooling.

Water is added to the tops of both; liquid desiccant is pumped through the first. Some outdoor air is mixed with return air from the building to form the supply air stream, which flows left to right through the two stages. In the dehumidifier, a membrane contains the desiccant while humidity from the supply air passes through it to the desiccant, which is also in thermal contact with a flocked, wetted surface that is cooled as outdoor air passes by it, causing the water to evaporate and indirectly cooling the desiccant.

In stage 2, the supply air passes by a water-impermeable surface that is wetted and flocked on its opposite side, providing indirect evaporative cooling. A small fraction of the cool, dry supply air is then redirected through the second-stage evaporative passages to evaporate water from the flocked surface and is then exhausted.

Evaluation

More information and a simplified evaluation tool called "Easy Solar Cooling" can help assess the cost performance of different technologies and system designs under different operating conditions. See: http://www.solair-project.eu/218.0.html

Two examples of solar cooling in practice

Video of a large scale solar cooling in South Africa:



Solar cooling in Italy

Solar cooling for a department store in Rome: The 3,000 m^{2</"600"sup> of collector area run a 700 kW chiller. Photo: Metro Cash & Carry} 

The Italian minister for economic development, Claudio Scajola, inaugurated this innovative, energy saving project in Rome on a Metro Cash & Carry building. The installation uses solar energy to cool down the wholesale outlet during summer and to heat it in winter. With its 3,000 m² of solar collectors – provided by the Italian Riello Group – this system on the store's roof is one of the biggest in Italy. It reduced the store's energy consumption by 12%, Dominique Minnaert, managing director of METRO Cash & Carry Italy, was quoted saying in the press release.

The system was designed by the British company AP Engineering Services. The chiller, with a power of 700 kW, was provided by the US-American Carrier Corporation, a leader in the areas of heating, ventilation, air conditioning and refrigeration systems. The cooling tower came from Evapco Europe, a specialist for industrial and commercial cooling equipment with headquarters in Belgium and Italy. The installation in Rome is part of Metro´s project “Energy Saving Today”. Its goal is to optimize performance of storage technology and therefore reduce energy consumption.

I fervently hope that many companies and organisations, not to mention individuals take up this exciting range of technologies.

David Thorpe is the author of 

• Solar Technology: The Earthscan Expert Guide to Using Solar Energy for Heating, Cooling and Electricity 
• Energy Management in Buildings: The Earthscan Expert Guide
• The 'One Planet' Life: A Blueprint for Low Impact Development
• Sustainable Home Refurbishment: The Earthscan Expert Guide to Retrofitting Homes for Efficiency, and
• Energy Management in Industry: The Earthscan Expert Guide