Renewable energy production from solar and wind isn’t steady 24/7 like coal or natural gas. Instead, production fluctuates. This has been problematic because the grid must always be in perfect balance between supply and demand. However grid-scale batteries are increasingly solving that problem by storing excess renewable energy output, then releasing it into the grid (or elsewhere) as needed.
Why, you ask, are utilities installing renewable energy with batteries when they could just build coal plants? The answer is simple. Renewable energy is now cheaper than coal or natural gas. This trend is irreversible and is happening across the planet.
A few examples:
Scotland
An 200-room inn in Scotland installed a five ton battery. They charge the battery when rates are cheapest. It can power the entire inn for several hours and it saves them money.
The 3m3 lithium ion battery is expected to save the hotel £20,000 a year on its energy bill, and is able to power the whole venue, including the restaurant, for up to three hours at a time after a two-hour charge. The new system also allows hotel management to avoid increased peak-time energy costs and generate revenue by offering energy support services to the national grid – in essence, by being paid in exchange for taking power off the grid.
Australia
Tesla installed the world’s largest battery on the Australia grid near a wind farm. It stabilizes the grid and has generated millions in income.
I mean, it really stabilizes the grid. A coal plant there crashed. The Tesla battery injected 7 MW of power into the grid in milliseconds. Of course, other backup came online instantly too. However, the more resiliency, the better.
More megabatteries are planned for Australia, included several for pumped hydro sites.
Pumped hydro is the oldest form of stored form. Excess energy pumps water uphill into reservoirs. The gates are opened when electricity is needed. The descending water powers turbines to create energy. Now they will be able to store power in batteries, making pumped hydro even more resilient and efficient.
Four other megabatteries have been commissioned – at Alice Springs, Ballarat, Dalrymple and Gannawarra. The Snowy 2.0 pumped hydro storage project moved a step closer with board approval, at least 10 other pumped hydro projects have been announced and the NSW government launched a roadmap identifying 24 potential pumped hydro projects leveraging existing state-owned reservoirs.
Energy market analysts SunWiz estimate that 25,000 households installed small-scale battery systems in 2018, collectively matching the combined capacity of the country’s grid-scale megabatteries.
China
China, while still building coal plants, is also installing massive amounts of solar and wind energy and backing it up with batteries.
According to the government statement, the virtual power plant would have a capacity of 720 MWh and could store unused electricity for four hours. For comparison, that’s almost two thirds the capacity of Tesla’s proposed “Megapack” energy storage system, which would bring a 1,200 MWh virtual power plant to California.
With a large-scale battery storage facility, people in Gansu will be able to rely on clean energy as needed rather than having to revert to fossil fuels when the sun goes down or the wind stops blowing.