Information from EEnergy Informer
Li-ion batteries are expensive, but they do a great job if you are trying to store limited amounts of electricity for a few hours. That makes them great candidates for use in handling daily fluctuations in supply and demand, but lots of funding and effort is going into developing affordable, large-scale long-duration storage.
Li-ion batteries also work well following the grid operator’s signals to ramp up or down, something no conventional thermal plant, not even a natural gas peaker, can remotely match. But if you are trying to store the excess solar, wind or hydro energy when it’s plentiful for use , you need something totally different, both in terms of scale and the duration of storage. Instead of 100 MW for two to four hours, for example, you will need multiple GWs for two to four months. Conventional batteries simply are not up to the task.Among the developers of this technology is Breakthrough Energy Ventures (BEV), an investment group whose members include billionaire celebrities like Bill Gates, Jeff Bezos, Richard Branson, and Michael Bloomberg. BEV says its ultimate aim is to fight climate change. It does this by supporting companies which specialise in clean energy innovation in grid-scale storage, liquid fuels, micro- and mini-grids, alternative building materials and geothermal energy.
Form Energy is among those which initially received US$9-million from BEV, followed by additional funding later. The company’s website says its mission is to “build a successful business that enables a safe, affordable, reliable, 100% renewable grid by commercializing long-duration, system-level energy storage.” It says it is “investigating new chemistries that could store energy for weeks or even months, rather than mere hours or days.” Form has a team of experts including Mateo Jaramillo, who developed Tesla’s energy storage business; Yet-Ming Chiang, an MIT professor who worked with the Department of Energy’s Joint Centre on Energy Storage Research, and Ted Wiley, a veteran of Aquion, a long-duration storage company.
Form talks about large-scale 100-plus hour storage, something the industry sorely needs. According to the trade press, the company’s goal is to find solutions to store energy for weeks, months, and perhaps across seasons at a fraction of the cost of current technology. One potential candidate is a sulphur-flow battery, whose main ingredient is plentiful, and cheap lithium-ion and offers long-term energy storage capabilities with little loss.
Another company, which received $6,4-million funding from BEV is Quidnet Energy, which is developing an alternative form of pumped storage. Instead of relying on two large natural hydro reservoirs at different elevations, however, it pumps water at high pressure into abandoned gas and oil reservoirs underground. According to its website, “Water is pumped down the well to apply pressure to a body of rock, and in doing so, store energy in the compression of the rock,” adding, “When it is time to discharge back onto the grid, the compression in the rock is released, which pushes the water back up the well and through a turbine to generate electricity.”
Quident claims that the scheme can be employed anywhere – presumably so long as there is a suitable underground cavity – it is scalable and cost-effective, at least relative to the alternatives. Another alternative is liquid air.
Highview Power, another storage developer, has designed a cryogenic energy storage system that it claims delivers reliable and cost-effective long-duration storage. It uses liquid air as the storage medium and can deliver anywhere from 20 MW/100 MWh to more than 200 MW/2 GWh of energy with a lifespan of over 30 years. Using existing components from mature industries, it says it can deliver pumped-hydro capabilities without the geographical constraints.
As these examples illustrate, there is no shortage of ideas, nor funding. If one idea does not succeed, another will.
This article was first published in EEnergy Informer, and is published here with permission.
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