In North America, a Canadian energy storage solution firm, Hydrostor, has developed a system that has the ability to store underwater compressed energy, which can deliver power when solar and wind technologies are inconsistent.
The pilot project, which started operating in November, is located at the bottom of Lake Ontario, Toronto, Canada.
The energy firm claims that this is “the world’s first underwater compressed air energy storage system,” adding that the system produces zero emissions, CNBC reported.
Energy storage innovation in six steps
The low cost, scalable underwater system is designed to store excess generated renewable power, which is sent to the Hydrostor facility. The Power is captured through an electrical air compressor that converts electricity into compressed air.
The compressed heat is then captured and stored in water tanks to be used during generation, thus increasing the system efficiency. Additional heat can be added to increase efficiency, through running it through the concentrated solar power troughs.
Once the heat has been removed, the air then travels down to an underwater air storage accumulator, which is then stored at hydrostatic pressure in a balloon-like device.
Hydrostor CEO, Curtis VanWalleghem, told CNBC: “There, we have a whole series of what are effectively balloons, that fill… like lungs under a lake.
“They fill with air, and when they’re full you stop charging the system and it can sit there indefinitely. When you want power back, again, a valve opens… air comes rushing out, we run through a low pressure turbine called a turbo expander, and that reproduces power back to the grid.”
Need for innovation
VanWalleghem added that without storage, there needs to be an increase of coal and gas power plants to meet the increasing demand and sustain the power supply.
“And if what you use to balance it is fossil fuels then you’re kind of defeating the purpose of why we’re going to renewables in the first place.
“The way the grid operates is (at) any moment the amount of demand – how much stuff is plugged in – has to equal how much is being produced, and if ever those get out of balance you start having brownouts and power quality issues, so that’s what it means to… keep the grid ‘in balance’.
He added: “As we add wind and solar… [it] makes it very difficult to do that because clouds come, gusts of wind surge.”
Home page pic credit: Hydrostor