The advent of “big battery” technology addresses a key challenge for green energy – the intermittency of wind and solar.
The twin smokestacks of the Moss Landing Power Plant tower over Monterey Bay. Visible for miles along this picturesque stretch of the north Californian coast, the 500-foot-tall (150m) pillars crown what was once California’s largest electric power station – a behemoth natural gas-fired generator. Today, as California steadily moves to decarbonise its economy, those stacks are idle and the plant is largely mothballed. Instead, the site is about to begin a new life as the world’s largest battery, storing excess energy when solar panels and wind farms are producing electricity and feeding it back into the grid when they’re not.
Inside a cavernous turbine building, a 300-megawatt lithium-ion battery is currently being readied for operation, with another 100-megawatt battery to come online in 2021.
These aren’t the only super-sized batteries that will soon be operating at the Moss Landing plant. An additional 182.5 megawatts produced by 256 Tesla megapack batteries are scheduled to begin feeding into California’s electric grid in mid-2021, with plans to eventually add enough capacity at the site to power every home in nearby San Francisco for six hours, according to the Bay Area utility, Pacific Gas and Electric, which will own and operate the system. Elsewhere in California, a 250-megawatt storage project went online this year in San Diego, construction has begun on a 150-megawatt system near San Francisco, a 100-megawatt battery project is nearing completion in Long Beach, and a number of others are in various stages of development around the state.
California is currently the global leader in the effort to balance the intermittency of renewable energy in electric grids with high-capacity batteries, but the rest of the world is rapidly following suit. Recently announced plans range from a 409-megawatt system in South Florida, to a 320-megawatt plant near London in the UK, to a 200-megawatt facility in Lithuania and a 112-megawatt unit in Chile.
Driven by steeply falling prices and technological progress that allows batteries to store ever-larger amounts of energy, grid-scale systems are seeing record growth. Many of the gains are spillovers from the auto industry’s race to build smaller, cheaper, and more powerful lithium-ion batteries for electric cars. In the US, state clean-energy mandates, along with tax incentives for storage systems that are paired with solar installations, are also playing an important role.
The mass deployment of storage could overcome one of the biggest obstacles to renewable energy – its cycling between oversupply when the sun shines or the wind blows, and shortage when the Sun sets or the wind drops. By smoothing imbalances between supply and demand, proponents say, batteries can replace fossil fuel “peaker” plants that kick in for a few hours a day when energy demands soar. As such, widespread energy storage could be key to expanding the reach of renewables and speeding the transition to a carbon-free power grid.
“Energy storage is actually the true bridge to a clean-energy future,” says Bernadette Del Chiaro, executive director of the California Solar and Storage Association.
source : BBC
