The exact amount elsewhere will depend on many other factors, but be at least as great. This is good news for efforts to fight climate change.
The figure is in a study from the Electric Power Research Institute (EPRI) published last week. It suggests that by enabling greater integration of renewable technologies, as well as reducing consumption, the smart grid could cut US 2030 carbon emissions by a staggering 58%, against a 2005 baseline.
Over here, the EU could be powered almost entirely by renewable energies in 2050 without power disruptions by using smart grids and building new cross-border connections, according to a study by Greenpeace and the European Renewable Energy Council (EREC).
It's big business
This is going to mean very big business indeed.
Last week General Electric announced it is buying a small Irish smart grid company FMC-Tech in just one example of an intense level of business activity that is set to increase over the coming decade as the smart grid really begins to take off.
GE is acquiring the company to give it expertise in distribution automation - FMC-Tech has developed a suite of services for automating management of power distribution from the substation to the customersmeter.
The EPRI report also says that over 20 years the investment required to create the smart grid may be up to $476 billion in the US alone - that's $17 billion to $24 billion a year.
But the benefits to society will far outweigh the costs - up to $2.028 billion, EPRI says. In Britain, the savings to consumers are calculated at £7.3 billion.
The savings come because smart grid technologies will reduce the annual growth in electricity consumption to less than 0.7% over the 2008-2035 period, below the 1% projected by the US Department of Energy's 2010 energy outlook.
Put another way, if we do not smarten the grid, the average electricity bill will probably rise by 400% over the next 20 years; if we do, the increase will be only around 50%, according to Clark Gellings, EPRI fellow.
By using smart grids, utilities will also be able to lower the system voltage level and make meter-reading redundant, argues Chris King, chief regulatory officer at smart grid software provider eMeter.
Ian Marchant, chief executive of Scottish and Southern Energy, has put the cost of a European smart grid at over £150 billion and proposed that funding come from growing European pension investments. After deducting necessary costs like the installation of smart meters and new software, the net benefit to Europe would still be Euros 31 billion per year, King said.
Speaking to an IT Forum last Wednesday GE Energy Services chief technical officer Eric Gebhardt explained how his company is making "the journey to a smart energy ecosystem.”
As more renewable energy sources such as solar and wind are plugged into the power grid, their intermittent nature is forcing IT operations to change, he said.
“Infrastructure in place today has reached the end of its design life,he added. 鼎ustomers are looking to operating longer and longer with the same equipment while changing operating modes.”
General Electric's view
So General Electric is buying FMC-Tech because its technology, by providing real-time data about conditions on the grid, is able to control energy management and demand and outage management systems.
This will give much cheaper load balancing for utilities, recuing demand and managing distributed supply. FMC describes its services as "a system that delivers dramatically improved network performance at lower cost. The system consists of sensors fitted on cables throughout the network, both overhead and underground, measuring current and conductor temperature.
"Local controllers (X-NET) gather this information and deliver to a web-controller via GPRS. The overhead sensors are line powered, and the X-NET Controller can be powered by a low voltage supply or a solar panel. The system provides a platform for continuous network improvement through the application of new and enhanced software development."
General Electric's Bob Gilligan, vice president of transmission and distribution, has said that GE is developing compatible household appliances such as refrigerators that could reduce their energy use by about 25% by adjusting the timing of their automatic defrost.
He also said that the key issue for smart grids is that they will have to accommodate the gradual introduction of millions of electric cars, which will be able to store energy and also release it back when required from their batteries.
Successful smart grid trial
Practical results on developing the smart grid have come from a trial involving 25 Dutch households in the Hoogkerk district of the City of Groningen, called PowerMatching City, showing t it is possible to create a smart grid with a corresponding market model using existing technologies.
This is the first time in Europe that the results of a live smart grid community have been researched at this technological scale.
The pilot's aims were energy optimisation for the end user, reducing the grid load for the network operator, and reducing imbalances for the utility. A second phase will concentrate on the system integration into market processes like billing, charging electric transport and congestion management at the district transformer.
The underlying coordinating mechanism in PowerMatching City is PowerMatcher, a software tool that balances energy demand and energy supply.
In another indication of the scale of developments, energy and home management company AlertMe, which signed a £20 million deal with British Gas last year, is completing trials in many different countries including Germany, Spain, the Netherlands, Brazil, the US, Portugal and Mexico, and is looking for partners in other countries.
Its CEO, significantly, used to be head of broadband firm Tiscali, signalling how the convergence of software developers, telecommunications industry and energy that is the hallmark of the smart grid.
Mary Turner appointed a new chairman earlier this month, Ron Mackintosh, who was CEO of Computer Science Corporation's European business.
The company has a smartphone app that allows users to control their domestic appliances. This is likely to become commonplace as part of the smart grid revolution.
Some are still sceptical that consumers will be interested in managing their domestic energy in this way.
Others respond that they said the same thing about personal computers back in the 1970s who would want one?
Now, almost everyone has one.