Nov 30 2009
SustainX has received an award of $5.39 million from the US Department of Energy (DOE), to develop a technology and organize for a full pledged demonstration that will show how to store energy with the use of compressed air.
According to the US Department of Energy, energy storage is an important need for the Smart Grid, which is the future version of the electrical grid that will be built in the next decade or two. The main objectives of the Smart Grid are lower cost, lower pollution, and higher efficiency. Traditional grids store no energy. When the power plants track the need of the user, within seconds or minutes, ‘peaking turbines’ which run using natural gas start immediately to generate electricity. The peaking turbines are kept idle most of the time, and the power generated by these turbines are always expensive. If storage units are installed at calculated points throughout a Smart Grid, shifts in demand can be controlled flexibly, and the power generation costs and transmission costs can also be lowered. This will bring down the need for more number of peaking turbines.
Energy storage can also help the grid to support better integration of renewable energy sources. For example, solar panels generate electricity when the sun shines, and wind turbines generate electricity when the wind blows. Power from wind and solar energy can help the grid only with minimum amount of power. With the storage units, the grid will function flexibly, and the renewable generators will produce energy continuously. But, there is no low-cost technology for utility-scale energy storage in the market.
The SustainX energy storage system deal with this need by storing the energy in the form of compressed air. The hydraulic pumps are run with the help of electricity to compress air to high pressure, up to 3,000 psi, for storing above-ground in standard industrial pressure vessels. The compressed air is expanded later, and is used to power a hydraulic motor that drives an electric generator. The technology uses isothermal cycling, which keeps the air at constant temperature. The isothermal cycling is united with hydraulic compression and expansion to deliver cost-effective, efficient energy storage.
SustainX technology depends on off-the-shelf mechanical components. It contains only ordinary hydraulic fluid and no toxic components, and it does not emit pollution or effluents. The efficient air-handling techniques, which are based on thermodynamic principles, are used to save cost. Each SustainX energy-storage unit acts like a storage battery. The unit does not any fuel to run and a cluster of energy-storage units will produce megawatts of electricity.