Could the UK's gas grid be converted to hydrogen?

[NOTE: An earlier version of this piece appeared on 13 July on The Fifth Estate. This version has been updated.]

A new study claims converting the UK gas grid to carry hydrogen instead of natural gas will help to meet the UK’s carbon reduction targets and is technically feasible without much disruption to consumers. It proposes Leeds as a pilot city, but there are still major problems to be overcome before it can go ahead.

The proposal is called the H21 Leeds City Gate and the report has been produced by the North of England’s gas distributor, Northern Gas Networks, which is clearly worried by what could happen to its assets down the line, as the country reduces its greenhouse gas emissions by 80 per cent of 1990 values by 2050, which is the target.

It commissioned Kiwa Gastec, Amec Foster Wheeler, and Wales & West Utilities to assess the prospects for converting the gas network to take hydrogen instead of natural gas for cooking in heating, beginning in Leeds and eventually covering the entire UK.

The study is backed by no less than four other recent reports, all making the case for using the existing gas grid, which serves almost half the UK population, for either biogas or hydrogen or a combination.

• National Grid's Future of Gas report
• Energy Networks Association (ENA)'s Green Gas report
• The Green Gas Book backed by the UK's Labour Party
• Consultants KPMG's report 2050 Energy Scenarios - The UK Gas Networks role in a 2050 whole energy system.

A UK-wide conversion of the grid to hydrogen gas could, it’s claimed by H21, reduce greenhouse gas emissions associated with domestic heating and cooking – currently over 30 per cent of the UK’s total emissions – by a minimum of 73 per cent, as well as supporting decarbonisation of transport and local electricity generation.

The report argues that a hydrogen gas grid could use the existing underground natural gas pipe network, and that household appliances can be converted to run on hydrogen with far less disruption and expense than converting to renewable energy sources.

Dan Sadler, H21 project manager at Northern Gas Networks, said: “Households won’t be required to buy new appliances. The conversion process will be similar to that carried out in the 1960s and ’70s when 40 million appliances across 14 million households were converted from town gas to natural gas. We’d have special teams, working street by street to make the conversion as smooth as possible for customers with minimal impact in the homes and the highways.”

H21 says the project would be funded the same way as happened during that first conversion. This would allow the costs to be paid back over time and, alongside energy efficiency measures, would have a minimal impact on household energy bills.

Household appliances will, however, need to be upgraded or modified.

Pure hydrogen embrittles many pipeline steels causing cracking and many pipes are made of iron, but they are slowly being changed to polypropylene at a cost of around £1 billion (AU$1.75b) a year. This cost is spread across consumer bills.

NGN is proposing that Leeds, the UK’s third largest city, is used as a prototype test bed, and the conversion would take place from 2026-29. If successful, there would be a rollout across the UK, implemented at the pace required.

The government has cautiously welcomed the report as a contribution to the debate on Britain’s energy future.

John Loughhead, the chief scientific adviser at the Department for Energy and Climate Change, said: “Meeting the challenge of the Climate Change Act is a huge technical and business challenge. The H21 Leeds City Gate project has usefully explored one possible contribution to meeting this challenge. DECC, and wider UK government, are looking forward to seeing the full findings of the project in the final report.”

The Leeds proposal has received backing from local authorities and businesses including Leeds City Council, the Leeds City Region LEP and Tees Valley Unlimited LEP.

Councillor Lucinda Yeadon, Leeds City Council’s executive member for environment and sustainability, said: “Transforming Leeds into a hydrogen city would be a bold step. It could play a crucial role in how we heat and power our homes in the future alongside other sustainable energy sources.”

NGN is asking for £70-100 million to take the project to the next stage.

Big hurdles

There are several problems with NGN’s proposal besides replacing the pipes, to do with the energy content of hydrogen, and the process of obtaining it.

NGN is proposing the hydrogen be derived from North Sea natural gas with the carbon dioxide removed and placed securely back under the sea so that it doesn’t contribute to global warming.

But at present there is no proof this can work or will be cost-effective. 

Let’s look at this a little more closely.

Most hydrogen in the lithosphere is bonded to oxygen in water. Over 90 per cent of today’s hydrogen is mainly produced by a process called steam reforming, which uses fossil fuels – natural gas, oil or coal – as a source of the hydrogen. The carbon dioxide is removed and vented to the atmosphere.

Hydrogen produced from gas this way is two to three times the cost of the original fuel.

Of course, the energy content of hydrogen is less than that of the original fuel. The claimed energy efficiency for natural gas reforming is 75 per cent. Furthermore, by weight, a unit of hydrogen contains around three times more energy than natural gas or petrol:

• Hydrogen: 33.33 kWh/kg
• Natural gas: (82-93 per cent methane): 10.6-13.1 kWh/kg
• Petrol: 12.0 kWh/kg
• Methane: 13.9 kWh/kg

But natural gas is 7.857 times more dense than hydrogen, and we buy it by volume. Since natural gas carries 41.7 per cent less energy per unit of weight, you’d need to pipe to people’s homes just over three times as much volume of uncompressed hydrogen for them to get the same amount of energy, so the pipes will be under greater pressure to compensate.

Then there’s the climate change problem. The global warming potential of producing hydrogen using the steam reforming process is 13.7kg CO2-e per kg of hydrogen produced. Coal gasification, another major production method, delivers even worse emission levels.

A typical steam methane reforming hydrogen plant with a production rate of one million cubic metres of hydrogen a day produces 0.3-0.4 million standard cubic meters of CO2 a day, which is normally vented into the atmosphere.

To fully attain the benefits of using hydrogen, we must therefore either produce it from renewable energy – or capture and store somewhere the carbon dioxide removed during steam reforming – a process called carbon capture and storage. H21 is proposing the latter.

The renewables option

There are at least eight sustainable ways of producing hydrogen. Electrolysis of water is the cheapest but currently is much more expensive, around US$1500/kWh.

A comparison of photoelectrochemical (PEC) and photovoltaic-electrolytic (PV-E) ways of producing hydrogen with low CO2 and CO2-neutral energy sources indicated that base-case PEC hydrogen is not currently cost-competitive with electrolysis using electricity supplied by nuclear power or from fossil-fuels in conjunction with carbon capture and storage.

They are currently an order of magnitude greater in cost than electricity prices with no clear economic advantage to hydrogen storage as of yet.

A number of possibly cheaper technical breakthroughs are in the wings but we don’t yet know if and when they will be commercially viable.

Analysts at the US National Renewable Energy Laboratory who have looked into the feasibility of hydrogen, assume that 53kWh are required for an electrolyser to produce a kilogram of hydrogen (remember that’s 33kWh when converted), so we’d need a lot of renewable energy to create all the hydrogen to feed the grid.

It might just be more effective to send the electricity straight there and use it directly for heating and cooking.

The CCS option

The H21 proposal has been welcomed by Scottish Carbon Capture & Storage, a research partnership that includes the British Geological Survey, whose director, Stuart Haszeldine, called steam reforming with carbon capture and storage “the least cost method of generating the large amounts of hydrogen required”.

So he is right. Except that no one knows how much it will cost.

The H21 report points towards the very few existing CCS projects in the US and elsewhere – but these operate under very different conditions.

Ever since CCS was first proposed over 15 years ago, I have been sceptical that it could work. It has always been seen as a get-out-of-jail card to permit business as usual in terms of fossil fuels and energy use while seeming to tackle climate change.

Every single deadline and target to get economically viable demonstration and proof-of-concept projects off the ground has been missed in Europe.

This crucial hurdle needs to be overcome – perhaps by backing a completely different and sustainable route to making the hydrogen, or by using the carbon dioxide removed as a feedstock for fuels, chemistry and polymers.

This is called Carbon Storage and Utilisation (CCU).

CCU for the production of fuels, chemicals and materials has emerged as a possible complementary alternative to CO2 storage, but the report does not mention it. Nor do the two other reports on adapting the gas network produced last week.

"CCS is basically a non-profit technology, where every step is costly. CCU however has the potential to produce value-added products that have a market and can generate a profit." says Dr Lothar Mennicken, German Federal Ministry of Education and Research.

The report CCU in the Green Economy from The Centre for Low Carbon Futures shows CCU can be profitable with short payback times on investment.

It says: "Although only a partial solution to the CO₂ problem, under some conditions using CO₂ for CCU rather than storing it underground can add value as well as offsetting some of the CCS costs."

But what are the life-cycle carbon emissions of hydrogen production using SMR plus CCS/CCU?

The latest UK government estimated LCA CO2 emission figures for NG combustion are 184.45 g/kWh plus 24.83 g/kWh emitted by the supply system, totalling 209.28 g/kWh.

But this depends on the gas source: e.g., liquefying natural gas in Qatar, transporting it in refrigerated ships, transporting it in special depots, reclassifying and compressing it into the transmission system can add around another 20 g/kWh, totalling 230 g/kWh.

The carbon footprint of SMR+CCS has been evaluated as 269 g/kWh using the lowest 184.45g/kWh figure above and assuming an efficiency for the process of 68.4%. But applying this to the more accurate lifecycle figure for NG of 230 g/kWh obtains 336.26 g/kWh.

If 90% of the carbon dioxide emitted by combustion is captured by CCS or CCU this still leaves [184.45/0.687] x 0.1 + 20 + 24.83 g/kWh = 71.68g/kWh emissions of carbon dioxide equivalent gases – a not insignificant amount.

H21Leeds puts the figure higher, at 85.83g/kWh. Hardly zero carbon – so H2 generation by renewable energy + electrolysis might be a necessary option in the future.

So, for the time being H21 is an interesting dream – but we must wait to see if it can become a reality.

David Thorpe is the author of:

• Best Practices and Case Studies for Industrial Energy Efficiency Improvement (with Oung, K. and Fawkes, S. UNEP, 2016)
• A London Conversation: Business Briefing on Green Bonds (The Fifth Estate, 2015)
• The One Planet Life (Introduction: Jane Davidson. Routledge, 2015)
• Earthscan Expert Guide to Energy Management in Buildings (Earthscan, 2013)
• Earthscan Expert Guide to Energy Management in Industry (Earthscan, 2013)
• Earthscan Expert Guide to Solar Technology (Earthscan, 2011)
• Earthscan Expert Guide to Sustainable Home Refurbishment (Earthscan, 2010)

British building owners can now make money by generating renewable heat

The first scheme in the world that will pay owners of domestic buildings for generating renewable heat has been launched in the UK by Energy Minister Greg Barker (seen right with MP Chloe Smith opening a 'Mr Renewables showroom' at the beginning of April).

Like feed-in tariffs for generating renewable electricity from technologies such as photovoltaic solar panels, the financial incentive scheme offers householders a fixed amount per kilowatt-hour generated from various technologies, even though the heat is only consumed in the home and not made available for others (as with home-generated electricity that is fed into the electric grid).

Called the Renewable Heat Incentive, it is based on a similar scheme for business, the public sector and non-profit organisations, that has been in operation for some time in the UK, as well as a smaller domestic scheme aimed at solid-walled, hard-to-heat homes, called the Renewable Heat Premium Payment.

Property owners apply to all schemes through the Energy Saving Trust, a government-sponsored body which promotes energy efficiency and renewable energy at the domestic scale.

The purpose of the RHI is to stimulate the renewable heat industry in the same way that feed-in tariffs have done for the solar PV industry. This has seen remarkable growth in the last four years with the cost of a typical PV system installation dropping by more than half.

The UK Government and industry body the Solar Trade Association (STA) have a target of covering over one million roofs with solar thermal and solar PV panels by the end of 2015. Over 200,000 solar thermal systems are already installed in the UK.

Global capacity for solar thermal is over 200GW - around double global installed capacity of solar power. The technology is proven and well established across Europe and elsewhere, and back in the days of previous support systems when grants were offered for installation of many types of renewable energy technologies, solar thermal was by far the most popular technology of choice for householders.

Stuart Elmes, Chair of the Solar Thermal Working Group at the STA, welcomed the launch of the RHI, saying: “Solar heating is popular with householders and quick to install, integrating easily with existing heating systems. We calculate that the returns from solar water heating are similar to those from solar power when you take into account the high price inflation for gas and heating oil.”

Paul Barwell, Chief Executive of the STA said: “With the launch of the Domestic Renewable Heat Incentive the final piece of support for household solar technologies slots into place. Together with the Green Deal for insulation improvements and the Feed-in Tariff for solar power, householders now have a great choice of Government-backed financial incentives to choose from to best suit their clean energy needs.”

Launching the scheme, the Government Minister for Energy Greg Barker (pictured right) said: "Not only will people have warmer homes and cheaper fuel bills, they will reduce their carbon emissions, and get cash payments for installing these new technologies. It opens up a market for the supply chain, engineers and installers – generating growth and supporting jobs as part of our long-term economic plan."

Technologies and payments

The technologies currently covered by the scheme are:

• Biomass heating systems, which burn fuel such as wood pellets, chips or logs to provide central heating and hot water in a home. Biomass-only boilers are designed to provide heating using a ‘wet system’ (eg through radiators) and provide hot water. Pellet stoves with integrated boilers are designed to burn only wood pellets and can heat the room they are in directly, as well as provide heat to the rest of the home using a ‘wet system’ (eg through radiators) and provide hot water.
• Ground or water source heat pumps, which extract heat from the ground or water. This heat can then be used to provide heating and/or hot water in a home.
• Air to water heat pumps, which absorb heat from the outside air. This heat can then be used to provide heating and/or hot water in a home.
• Solar thermal panels, which collect heat from the sun and use it to heat up water which is stored in a hot water cylinder. The two types of panels that are eligible are evacuated tube panels and liquid-filled flat plate panels.

Technology	Tariff
Air-source heat pumps	7.3p/kWh
Ground and water-source heat pumps	18.8p/kWh
Biomass-only boilers and biomass pellet stoves with integrated boilers	12.2p/kWh
Solar thermal panels (flat plate and evacuated tube for hot water only)	19.2 p/kWh

Only one space heating system is allowed per property but homeowners can apply for solar thermal for hot water and a space heating system.

The guaranteed payments are made quarterly over seven years for households in England, Wales and Scotland. (Northern Ireland has its own RHI scheme). The scheme is designed to bridge the gap between the cost of fossil fuel heat sources and renewable heat alternatives.
According to renewable energy expert Richard Hiblen, who has more than 14 years’ experience in this field, the RHI tariffs are ‘good for some and better for others’, but even the worst figures make the technologies more attractive than installing oil or LPG heating.

Phil Hurley, managing director, NIBE Energy Systems Ltd., a renewable heating manufacturer, called the RHI "a game changer for the renewable heating industry". He continued: “The introduction of the domestic RHI gives the industry the security and confidence it needs to realise its growth potential".

But Neil Schofield, Head of External and Governmental Affairs at boiler (furnace) manufacturer Worcester, Bosch Group, cautioned that: “the funding is weighted heavily in favour of biomass, which is one of the most expensive systems to install and one requiring the largest amount of user intervention. Questions have already been raised over whether DECC has backed the right horse in this respect."

UK Solar Strategy

Earlier this week, the UK Government also launched its Solar Strategy, which contains plans to turn the Government estate as well as factories, supermarkets and car parks in cities around the UK into “solar hubs”.

Energy Minister Greg Barker  said he believes that “there is massive potential to turn our large buildings into power stations and we must seize the opportunity this offers to boost our economy as part of our long term economic plan. Solar not only benefits the environment, it will see British job creation and deliver the clean and reliable energy supplies that the country needs at the lowest possible cost to consumers.”

The UK has an estimated 250,000 hectares of south-facing commercial rooftops, and the government believes that solar increasingly offers efficient and cost effective onsite generation opportunities to both businesses and domestic consumers.

In a further initiative, the Department for Education is working on ways to improve energy efficiency across the 22,000 schools in England, to reduce their annual energy spend of £500 million, and to encourage the deployment of PV on schools alongside promoting energy efficiency. The British Education Secretary Michael Gove said: “Solar panels are a sensible choice for schools, particularly in terms of the financial benefits they can bring. It is also a great way for pupils to engage with environmental issues and think about where energy comes from.”

Government leaves domestic biogas and microbes CCS out of its heat strategy

The Government has launched a consultation on its strategy for decarbonising heat which omits domestic biogas and the method favoured by Richard Branson for carbon capture.

This is the second consultation on the topic of heat in three years; the last one resulted in the Renewable Heat Incentive and the Green Deal. This one attempts to envisage how the market will be transformed as a result, and as part of the goal of supplying 15% of UK energy from renewables by 2020.

Launching the consultation, Energy and Climate Change Secretary Edward Davey spoke of the need to cut emissions from the way we generate heat and said that many towns, cities and communities across the UK are already switching from fossil fuels to low carbon forms of heating like biomass, heat pumps and solar thermal.

“I want to give the opportunity to others to follow the pioneers," he said, “so that in time, our buildings are no longer dependent on burning fossil fuels for heat but using affordable and reliable alternatives to help create a flourishing, competitive low carbon manufacturing industry."

Alongside the consultation DECC published a series of electronic maps which show the heat demand from buildings across England, aimed at developers so they might identify areas in most need of low carbon heating projects and local authorities.

Demand reduction

The document envisages different solutions for different locations and geographies, as households, businesses and local authorities choose the approach that will work best for their circumstances.

It proceeds logically through an examination of measures to reduce the wastage of heat and hence demand, through to an examination of means to supply the remaining demand.

In particular there is emphasis on the potential for expansion in the heat pumps market and the solar thermal market. In 2010, the UK heat pump market alone was worth nearly £50m, and the solar thermal market grew 24% to £25m.

Heat networks

There is also hope expressed that more heat networks will be installed by, for example, integrating them with local authority plans for urban growth and regeneration.

The document notes that such networks can be the most effective way of supplying low carbon heat to buildings, offering the benefit of flexibility, since a number of different heat sources, such as biomass and gas boilers, combined heat and power (CHP) plants and heat from energy-from-waste plants, can supply the same network.

However, they have a high upfront cost due to the need to install the pipework, and to their dependence on municipal vision. Hence, although widespread in Europe, there are a few examples in this country, exceptions being Nottingham, Sheffield, Birmingham, Aberdeen, Southampton and a new project in Newcastle which is to be supplied from geothermal heat.

The Newcastle borehole will eventually reach 1821m and tap into water at a temperature of 80 deg. C, which will be used to heat a new science park.

Nottingham's one of the largest district heating networks in the UK, with a 65km network serving over 4,600 homes and 100 businesses and public sector properties; roughly 3.5% of the city’s entire heat consumption.

Measures for industry

The consultation also examines the decarbonisation of process heat for industry to create a separate strategy. "By focusing on biomass, biogas and electrification, as well as innovative technologies like Carbon Capture and Storage, we have the opportunity to achieve a competitive advantage, winning contracts abroad in a new and thriving global market," it says.

It recognises six major subdivisions of industry which will need their own specialised attention. These are: Coke and refined petroleum, food and drink, pulp and paper, basic metals, non-metallics and chemicals.

It sees particular opportunities for combined heat and power, which is ironic considering that George Osborne removed support from the technology in his budget two weeks ago.

Biogas

Responding to the Heat Strategy, Energy Networks Association (ENA) Chief Executive, David Smith, expressed disappointment that “domestic use of bio-gas has not been considered. As the Strategy points out, currently 81% of the UK uses gas for its heat and hot water.

"To ignore a potential fuel source which can use existing domestic heat infrastructure seems bizarre to say the least.

“With the proposal that gas for domestic heat be phased in only a decade or so the Strategy has also failed to consider the cost implications for the public."

The ENA is undertaking a major study on domestic heat out to 2050 that will be published in early May.

The Strategy does refer to biomethane injection into the gas grid for the industrial sector. It notes that the Renewable Heat Incentive (RHI) currently only gives support for biogas from anaerobic digestion, sewage gas and syngas for heating equipment with a capacity of less than 200kWh.

It says that the Government will consult on removing this limit or setting a higher limit in September.

Hot air

The RHI is currently limited to supporting installations which generate hot water or steam through a boiler or engine, as these can be metered relatively easily.

The Government is also considering the inclusion of equipment which can heat air directly, thereby potentially expanding the type and number of industrial uses of bioenergy which the RHI supports.

Electrification and carbon storage

The strategy also notes the potential for carbon capture and storage at a small, industrial scale. But it does not seem to be aware of the latest technologies such as the use of microbes, as supported by Richard Branson's Virgin Atlantic.

In the short term it expects industry to concentrate on energy efficiency, switching to low temperature processes and sustainable biomass, using CHP and fuel switching.

After 2020 is looking for even greater efficiency of thermal processes using heat recovery or reuse between high and low temperature processes, greater use of biogas and sustainable biomass, and further electrification of lower temperature processes, for example through direct electric steam generation as the grid itself is the carbonised.

In the longer term wider deployment of carbon capture and storage is anticipated to capture the remaining inherent process emissions. Further fuel switching to electricity and biomass for the remaining high-temperature processes is also expected.

Roger Webb, director of the Heating and Hot Water Industry Council (HHIC), thought this could be a problem. "From the strategy it seems there is a big push on electricity rather than fossil fuels - so the main question is how quickly can we move forward to low carbon electricity?"

DECC expects to receive responses by May 24, expand its evidence base and produce a range of policy proposals around the beginning of next year.

Fuel poor targeted by renewable heat trials

Social housing tenants across the country are to receive £4m in the start of a trial that will help prepare for next year's Renewable Heat Incentive (RHI).

The exercise involves installing sustainable heating systems such as biomass boilers, solar water heating panels, heat pumps (ground source, air-to-water and water-to-water), in solid walled properties managed by 24 social housing providers across Britain.

These types of properties are harder to heat and insulate than more modern, cavity-walled dwellings and are typically inhabited by those classified as living in fuel poverty.

The social landlords comprise the first winners to be announced under the £15m Renewable Heat Premium Payment (RHPP) scheme competition, which was launched in August.

Participants will each receive up to £175,000 in the form of the following support for each technology:
Solar thermal hot water: £300
Air source heat pump: £850
Ground source or water source heat pump: £1250
Biomass boiler: £950.

Most of the winners are in the south west; a total of 558. Scotland, which is of course a much colder part of the UK, gets just over 400 schemes, the south east about 370, the east of England 310, Wales 290, with London getting the lowest number, because it has proportionately fewer solid walled properties: 32.

Air source heat pumps will receive the most support; they are very easy to install. Solar thermal comes close second, followed by ground source heat pumps and biomass boilers, which are the heating source of choice north of the border.

Air source heat pumps are controversial since some experience has shown that poor installation and management can lead to minuscule or dubious fuel or carbon savings.

One householder has complained to BRE that his MCS-approved air source heat pump achieved savings of only 200 watts over a 24 hour period, because of the number of motors it uses.

The results of the monitoring are expected to clarify this, together with the cost-effectiveness of ground source heat pumps, which is reduced if a trench has to be specially dug for the installation.

They are more cost- and carbon-effective if a hole in the ground is already available due to other construction activity.

One of the conditions for taking part in the scheme is that, once installed, participants permit the measures to be monitored to gauge their effectiveness, to better design the full roll-out of the domestic RHI that is expected next autumn.

Currently half of the UK’s carbon emissions come from the energy used to generate heating in buildings.

The Government estimates that the total of the measures under the RHPP and the RHI (domestic and non-domestic) are going to save the equivalent of the power supplied and carbon emitted by two new gas power stations up to 2020; that is, an average of 4.4 million tonnes of carbon per year.

Energy and Climate Change Minister Greg Barker commented that the scheme "directly targets many of the people who could struggle to pay their heating bills in the winter. It will encourage an increase in the number of new heating technologies in social housing and help people deal with expensive fuel costs.”

Karen Lawrence, director of delivery for the Energy Saving Trust, said she was well aware of a great appetite for green technologies among social landlords, to "help tenants heat their homes more cheaply and efficiently".

"We also know councils and housing associations have become increasingly proactive and knowledgeable in the field of sustainability – and this was reflected in the standard of the bids for funding that were received," she added.

“Both this and the householder strand of the RHPP will also be great learning opportunities," she said. "Real data on performance in people’s homes is absolutely key in successfully boosting the market for renewable heat technologies.”

No doubt the Government also hopes it will help them avoid the costly and damaging mistakes associated with the mis-setting of the feed-in tariff levels for PV.

The vouchers are being issued on a first come first served basis. The scheme is still open to applicants, who can apply here or by phoning Energy Saving Trust on 0800 512 012.

RHI for businesses and organisations

Meanwhile, the non-domestic RHI will start at the end of this month.

It was originally scheduled to commence at the end of September, but required state aid approval. This has now been granted, subject to a small change in one tariff.

Businesses and organisations will be able to install sustainable heating systems and receive a favourable tariff for each unit of heating produced, over twenty years, in the same way that the feed-in tariff works for electricity.

This is expected to provide a huge boost to the heating industry.

The new rates are as follows:

Small biomass <200 kW: 7.6p/kWh (Tier 1) or 1.9p/kWh (Tier 2)
Medium biomass <1000 kW: 4.7p/kWh (Tier 1) or 1.9p/kWh (Tier 2)
Large biomass >1000 kW: 1p/kWh
Small ground-source heat pumps <100 kW: 4.3p/kWh
Large ground-source heat pumps >100 kW: 3p/kWh
Solar thermal <200 kW: 8.5p/kWh
Biomethane and biogas <200 kW: 6.5p/kWh.

£15m renewable heat trial scheme gives grants to off-gas-grid householders

A ‘Renewable Heat Premium Payment’ scheme has been announced by DECC that makes available £15m of support for up to 25,000 renewable heat installations in homes, with a review to take place as the £10m limit is approached.

It will target the 4 million or so households in Great Britain not heated by mains gas, who have to rely on heating such as coal, oil and electric fires, which tend to be more expensive and emit more carbon emissions.

It is open to householders in England, Scotland and Wales, who will be able to apply for grants of up to £1,250 to install systems such as biomass boilers, air and ground source heat pumps and solar thermal panels from 1st August 2011. It will operate on a first-come-first-served basis, and will close on 31st March 2012.

Part of the purpose of the scheme is to obtain further information on the behaviour of the technologies prior to the full commencement of the Renewable Heat Initiative (RHI). Therefore installations will be monitored and any metering equipment will be provided free of charge.

Participants will be required to complete surveys and provide feedback on their experiences.

“Today starts a new era in home heating," announced Climate Change Minister Greg Barker, “because we’re making it more economical for people to go green by providing discounts off the cost of eco heaters. This should be great news for people who are reliant on expensive oil or electric heating as the Premium Payment scheme is really aimed at them.

“Getting money off an eco heater will not just cut carbon emissions, it will also help create a market in developing, selling and installing kit like solar thermal panels or heat pumps.”

The Premium Payment scheme is to be administered by the Energy Saving Trust, which has set up an information line, 0800 512 012 and a website.

Dwellings will have to have in place basic energy efficiency measures before householders can apply. The following technologies are eligible:

• Ground Source Heat Pumps - £1250 grant (for homes without mains gas heating)
• Biomass boilers - £950 grant (for homes without mains gas heating)
• Air source heat pumps - £850 grant (for homes without mains gas heating)
• Solar thermal hot water panels - £300 grant (available to all households regardless of the type of heating system used).

£3m of the £15m will be set aside for registered social landlords to improve their housing stock.

DECC will announce details of how to apply for these funds at a later date.

The Renewable Heat Incentive

The Renewable Heat Incentive is split into two tranches. The first, for industry, business and communities will be open for applications on 30th September, subject to State Aids Approval. The tariffs will be paid for 20 years to eligible technologies that have been installed since 15th July 2009 with payments made for each kWh of renewable heat produced.

Households will be able to apply a year later. The Government has confirmed that renewable heat installations installed in homes since 15th July 2009 could receive the Renewable Heat Incentive once it comes in, provided they meet the eligibility criteria.

They have also confirmed that this could include those who receive support under the RHPP scheme. The Government has not yet published its proposals for how the RHI will work in the domestic sector, including eligibility criteria.

Is anaerobic digestion an ideal sustainable technology?

Between three and five terawatt-hours of energy could be supplied by anaerobic digestion by 2020, according to the Government's new Anaerobic Digestion Strategy and Action Plan.

The Plan contains guidance on the cost and benefits of AD for developers and local authorities, and tactics for training and developing markets for the biogas and fertilisers produced by the technology.

″Getting rubbish and waste rot in landfill is madness when we can use it to power our homes and cars,″ said energy secretary Greg Barker. ″We are already making it financially attractive to turn waste into electricity under the Feed-in Tariffs scheme and soon there'll be similar incentives to generate heat too.

"The Anaerobic Digestion strategy and action plan will help us unlock the potential to get more energy from waste to reduce emissions in the fight against climate change.”

Rightly, the Strategy describes AD as a beautifully flexible technology - "plants can be built on many different scales, from large facilities treating sewage sludge or municipal waste, to smaller ones handling materials from a particular farm or a small community. The construction of AD facilities can be comparatively swift, and compared to some other waste management technologies can be relatively inexpensive.

"The inputs and outputs of the technology are also flexible, meaning that the plants can be designed to meet local requirements for feedstock or outputs, while remaining connected to the national electricity and/or gas grid."

It has further advantages, too, over other renewable energy technologies. "The energy is generated constantly, unlike wind, tidal and solar power, and can be stored in the grid (in the form of gas)" - methane.

Methane is one of the few renewable fuels suitable for Heavy Goods Vehicles (HGVs), and has the potential to reduce reliance on imported gas.

So it can process waste and produce heat and electricity.

And, "by providing low carbon fertilisers for agriculture, AD helps deliver a sustainable farming sector, where resources are reused on-farm to reduce GHGs and provide secure and sustainable inputs, particularly phosphate", the Strategy says.

The Anaerobic Digestion and Biogas Association (ADBA) said the plan "should help make it easier to grow the industry. Developments such as a best practice scheme for AD will ultimately help break down barriers to plant development, reduce the risk of investing in AD and deliver the industry's potential to UK plc."

However...

However, they qualified this by adding that the accompanying Waste Review "should have been bolder and called for as much organic waste to be treated through AD as possible.

"We are disappointed by the lack of recognition of the importance of source-segregating food waste, in reducing waste arising, allowing easier recycling of products from other materials such as plastics, and creating a quality fertiliser from AD which will help decarbonise food production. With 1.1% of overall UK emissions coming from artificial fertilisers, and oil prices increasing their costs and the cost of food all the time, this is a huge environmental and social issue."

And, the Action Plan does not offer the prospect of additional funding.

Instead "it promises that the Government is working to ensure that the financial incentives available for AD under the Renewables Obligation (RO), the Feed-in Tariffs (FITs) Scheme, the Renewable Heat Incentive (RHI) and the Renewable Transport Fuel Obligation (RTFO) provide the revenue support that investors need."

If AD is so good, it should be supported more than photovoltaics – and certainly should be made more attractive to developers.

Unsexy renewable energy technology is turned on... and will one day beat solar and wind in the UK

It's not as sexy as solar power or controversial and high profile like wind power. But a 'new' form of renewable technology is going to take off this year – the first of a series of plants was commissioned this week – and eventually it will be better value for money, more reliable and even contribute more energy to the UK's needs.

Its developers are now urging the Government to match the level of support offered to other renewable energy technologies such as wind and solar, through Feed-in Tariffs.

What is it? Well, unpleasant as it sounds, it's anaerobic digestion (AD) and it is a multiple-win technology that is set to revolutionise waste processing and energy generation.

AD also helps to divert waste from landfill, and reduce air and water pollution. Byproducts include transport fuel and renewable sources of soil nutrients and manures. These processes will all additionally create new employment.

The Coalition Government also believes AD can help the UK meet its climate change objectives by reducing greenhouse gases from waste and producing energy - including renewable heat - without significant land use changes.

AD makes power from the methane generated by composting organic food, sewage and crop waste without oxygen being present. As these materials are in abundant and continuous supply, it is more reliable than wind and solar power.

The National Grid has said that it believes that within 20 years, half the gas in the grid could come from this source. The gas can be burnt to make electricity and used to power vehicles too.

Pioneer plant opens

One of the first anaerobic digestion projects funded through the Government’s Environmental Transformation Fund was officially opened on Thursday.

The plant, at Staples Vegetables in Boston, Lincolnshire, one of the biggest producers of vegetables in the UK, will produce 11 million kilowatt hours of electricity per year by processing 40,000 tonnes of unusable vegetables and waste.

The digestate (what's left over after the composting) from the Staples plant will replace artificial inorganic fertiliser (which creates emissions) and be better for the soil (because of the organic matter it contains), the heat will be captured for office heating, innovative heat absorption coolers will chill the processing areas, and the electricity generated will power the plant.

Vernon Read, Managing Director at Staples says there is an additional benefit: “The project is giving us control not only over future pricing of power, but also over power security.”

There are three more Government-supported AD facilities opening this spring and over 30 in the planning stage. Some examples are highlighted towards the end of this article.

The National Grid has talked of the biogas from AD eventually replacing a significant proportion of fossil fuel gas in the mains in the future.

But before this can happen markets need to be created for the fertiliser, and for the gas as a fuel in transport. Different sectors, such as the water sector, need to be encouraged to process sewage this way. This was the subject of a Defra consultation last December, whose results have not yet been published.

AD is also subsidised through Feed-in Tariffs (FITs). In order to increase uptake, there is a study into the take-up of FITs for farm-based AD plants going on now at DECC, parallel to the review of Feed-in Tariffs and "solar farms".

Climate change minister Greg Barker believes there is "a huge opportunity" for farm-based AD but had been disappointed by the take-up so far. Developers agree and hope it will become eligible for FIT subsidies soon.

Pioneering AD plants

Because it is not yet cheap to set up. Gary Jones is the owner of a plant at Langage Farm, near Plymouth in Devon. He says that the project couldn't have happened without support from the ETF. "Due to the new concept involved with anaerobic digestion in the UK, the start up costs are very prohibitive.

″Hopefully when there are a few more established sites around the UK, the authorities concerned in the build and running of the sites have a better understanding, and good technology providers can be found locally the cost will reduce and the plants will become profitable without grant funding."

Several other exciting projects are nearing completion, funded by the Environmental Transformation Fund.

United Utilities and National Grid are expanding the already existing anaerobic digestion plant at United Utilities' Davyhulme Waste Water Treatment Works in Greater Manchester. Work is almost complete on converting 250 cubic metres per hour of biogas to grid quality biomethane. Half will be used to fuel a fleet of tankers and half injected into National Grid’s gas distribution network - sufficient to provide heating and cooking needs for around 500 homes.

In Driffield, East Yorkshire, anaerobic digestion company GWE Biogas Limited is constructing a plant to convert up to 50,000 tonnes of organic waste each year sourced from local authorities, food manufacturers and supermarkets, to generate approximately 2MW of electricity for export to the grid. The long term objective is to upgrade gas to bio-methane to supply a private heat and wire network for new housing.

Like Langage Farm, BV Dairy (pictured) in Dorset, which processes around 35 million litres of milk per year, is building an anaerobic digestion plant to process liquid waste and provide renewable electricity and heat for its site.

WRAP, with support from the Carbon Trust, is delivering the Anaerobic Digestion Demonstration Programme under the Environmental Transformation Fund particularly because of its role in cutting waste in the food chain. It's also supporting a Staffordshire-based AD project through its Advantage West Midlands (AWM) Programme, with an animal rendering and food waste collection business.

There is every reason to believe the claim of the Anaerobic Digestion and Biogas Association (ADBA) in ten years' time the UK will have a mature anaerobic digestion industry.

[PS - let's see how popular this post is - with words like sexy and turned on in the heading! - I noticed my post about naked supporters of Amen Awel Tawe windfarm making a calendar is my most popular so far!]

Renewable domestic heating

On a domestic level, the Government has committed to support domestic micro-CHP with £2,300* cash support. But this does not apply to district level heating schemes.

This article looks at both ideas, carbon impacts and support in the UK.

District heating

District heating is more carbon-efficient than heating individual homes where the density of accommodation is high enough. The example in Southampton is often cited.

The idea was part of last year's DECC Heat and Energy Saving Strategy Consultation. It did suggest support for these schemes.

The conclusions were published in August 2009. We're still waiting to see what the Government decides to do.... and will probably wait for some time as there is an election on.

District heating is recommended to the Government by this month's report from the Green Building Council. This says:

1. Public sector buildings should be required, where available and viable, to connect to existing or planned community heat networks, to provide an ‘anchor load’ of demand, and large businesses should be encouraged to do the same.

2. The ‘allowable solutions’ mechanism should be used as a way of providing additional ring fenced capital to support the delivery of heat infrastructure. Government has said that developers will be able to invest in so-called 'allowable solutions' in order to meet the required standard when constructing new zero carbon buildings.

It says nothing about existing non-public buildings though.

Neither is district heating part of the current renewable heat consultation. This scheme, which is due to start in April 2011, will subsidise a rapid increase in the number of homes and offices heated by woodfuel, biogas, solar thermal, heat pumps and waste-to-energy technologies. The deadline for responses to this consultation is Monday 26 April so do have your say.

District heating systems are ideal if a whole street, area or block of flats is to be renovated. Economies of scale make this form of heat and power delivery the cheapest on a per-household basis, and by far the most carbon-efficient, if low carbon fuel sources are specified.

A district heating scheme in Southampton, England, serves many residential developments from gas-fired CHP and geothermal energy, saving 11,000 tonnes of carbon a year and benefiting residents with a service price 5 per cent less than the market rate.

Systems are most efficient when servicing both homes and businesses or premises used during the day, as the two heat loads throughout a 24 hour period suit the continuous running required of a large plant.

District CHP plants may utilize fuel sources from waste to biomass, as well as geothermal where it is available. They work best where buildings are close together. A not-for-profit energy service company is usually formed to manage the system.

Micro-CHP

Micro-CHP – combined heat and power – is a nascent technology of small units for individual homes, typically the size of a fridge. They run on natural gas to produce up to about 10kW of power.

The current crop of models are based on the Stirling engine, Organic Rankine Cycle (ORC) or internal combustion engine. The first two have high thermal efficiency and output but low electrical efficiency (10 per cent) – and this is a sticking point.

Electricity output is around 1.1kW, enough to maintain back-up power in the event of a power cut or boil a kettle. A 1kWe (1kW electrical power) model from Honda called Ecowill has sold well in Japan.

A 2007 trial by the UK’s Carbon Trust concluded that micro-CHP can cut electricity bills and overall CO2 emissions by 15–20 per cent when they’re the lead boiler in larger contexts like care homes, district schemes, apartment blocks and leisure centres.

The best individual home for them therefore is a medium-to-large, moderately well-insulated one, maybe with solid walls, solid floors and no loft space that is harder to insulate well and has a relatively large heat demand.

Here, micro-CHP units can potentially deliver carbon savings of 5–10 per cent – fewer than a condensing boiler, since capacity is likely to be best matched to demand, for both heat and power.

Payback can be as little as five years. But they offer limited benefits for smaller and newer dwellings.

The key to success is matching the thermal output to the building’s pattern of use so that they operate not intermittently but for many hours at a time, making the value of electricity generated pay for the marginal investment in as little as three years in a typical family home.

It therefore works best with a buffer storage tank to save the surplus heat for later.

Grid connection for electricity export is going to be crucial to micro-CHP’s widespread acceptance. On average, half of all electricity generated by a typical 1kWe micro-CHP device is exported to the grid as it’s not needed at the time.

Reliability is also a key issue – service agreements will be essential. So homeowners shouldn’t yet trade in their condensing boilers, which have about the same overall heating efficiency – 90 per cent – without also producing electricity, but they might keep an eye on developments.

Superinsulated homes will have to wait until the next generation of machines, based on fuel cells. These generally come in two types – proton exchange membrane fuel cells (PEMFCs) and solid oxide fuel cells (SOFCs).

They have a heat to power ratio that is approximately equal so for example they could produce 5kW of heat and 5kW of electricity.

Support for micro-CHP

Under the Feed-in Tarriff scheme, from the 1st April 2010, microCHP units with a capacity below 2kW will receive 10p per kW hour generated, for a period of ten years. This tariff is available for the first 30,000 microCHP installations. A review will take place when 12,000 units have been installed.

However the Government has not followed through on commitments made in the Energy Act to support miniCHP units of up to 50 kW capacity.

* - based on 10p generation tariff and assuming a 3p pence export rate. Assuming annual generation of 2000 kWh and 50% export. Assuming import electricity price of 14p kWh-1. The total income paid to a generator over a 10 year FiT period would be £2,300 over full period of 10 years. Annual figure therefore of £230.

The Feed-in Tariff (FiT) scheme is the first phase of the Government’s Clean Energy Cashback programme - see the Energy Saving Trust website for details.

What is the most carbon efficient heating?

An independent survey conducted by the UK Energy Efficiency Partnership for Homes which looked at the carbon impact of different domestic heating and hot water systems in both houses and flats concluded that the following performed best, all other things being equal (figures in kgCO2/m2/yr):
• community heating and CHP, fuelled wholly or mainly by biomass - 4.15
• community heating without CHP fuelled wholly or mainly by biomass - 7.11
• wood burning boilers - 10.02
• wood burning boilers with solar water heating panels - 10.09
• ground source heat pumps with low temperature heat distribution/emitters (e.g. underfloor heating) - 20.83
• solar water heating panels in conjunction with gas boiler systems - 21.98

Source: Heating Strategy Group of the Energy Efficiency Partnership for Homes, January 2008