The world’s first hybrid plant which combines batteries with gas turbine
This week, General Electric (GE) and Southern California Edison (SCE) announced that they had retrofitted a natural gas peaker plant with a 10 MW, 4.3 MWh battery installation to create the world’s first hybrid electric gas turbine. Peaker plants only run when demand for electricity is high, and they can be used to fill in the gaps between baseload energy and intermittent renewables.
The trouble with natural gas peaker plants, however, is that they can waste a lot of fuel in standby mode and when getting ramped up to the point where they can be put on the grid. But GE’s battery solution cuts out the fuel used during those times.
“The energy storage capacity of the battery has been specifically designed to provide enough time coverage to allow the gas turbine to start and reach its designated power output,” GE writes. This eliminates the need to burn fuel while the gas turbine is kept spinning in standby mode.
The hybrid natural gas plant came about after California ordered Southern California Edison to invest in utility-scale solutions. The state did this to avoid a potential natural gas shortage in the wake of one of the biggest natural gas leaks in US history, which took place at the Aliso Canyon natural gas storage facility north of Los Angeles.
The natural gas shortage never hit California consumers like experts suggested it could, but the situation prompted utilities to contract with Tesla, AES Energy Storage, and GE to build battery installations. Last October, GE said a second hybrid electric system would also be completed for SCE in 2017.
The Tesla and AES installations are separate from peaker plants, and they dispatch energy when the California Independent System Operator (CAISO) sells it. But the GE hybrid peaker plant produces energy from burning natural gas and uses the battery system to complement the gas turbine. That’s possible through a new control system that GE says “seamlessly blends output between the battery and the gas turbine.”
The natural gas plant was also fitted with new emissions controls so that, when combined with the reduced fuel consumption needed while the turbine is in standby mode, greenhouse gas emissions and air pollution are reduced by 60 percent. The amount of water needed to operate the plant is also reduced by 45 percent, which reflects 2 million gallons of water annually.
Fast-ramping power sources are also becoming increasingly important as regions incorporate more and more intermittent renewable energy like solar and wind into their grid. A recent study of East Coast grid operator PJM Interconnection determined that PJM could add 7 GW of offshore wind power capacity to its grid without making major changes. But PJM could add nearly 36 GW of installed offshore wind capacity if improvements were made to the grid and if fast-ramping power generators were added to pick up the slack if the wind suddenly cut out.