Hey, 70% round trip efficiency sounds pretty good. That’s on par with Pumped Hydro but without all that water to deal with. After all, pumped hydro simply lifts a bunch of water and stores it in a dam.
We compress the air around us into a tiny space. The greater energy density means we can put our storage just about anywhere.
But what about Li-Ion batteries. Aren’t they greater than 85% efficient and very high energy density?
Yes, batteries are really good when it comes to efficiency and energy density. Especially when they are brand new. But over a bit of time they become pretty bad. And then they need to be replaced. They are great for your phone and your car, but not for green, long-term, grid-level energy storage.
How long do you expect your storage system to last?
Life Span > 30 Years
So what breaks down?
The system compresses air mechanically and then stores it under high pressure. Although there is nothing that limits longer use, the components will have wear and fatigue that at some point might make more sense to replace than to refurbish.
What do you mean by system? What are the parts of the system?
There are two main parts. The part that compresses the air and the part that stores that compressed air. This is similar to Hydro Storage as it has the motors and pumps and it pumps the water up to a reservoir. The motors and pumps are one part and the reservoir is the other. You can double the size of the reservoir and store twice as much energy. But you can only do it as fast as the motors and pumps were designed to. If you want to store energy faster, you need more motors and pumps.
So if we wanted to store more energy, we just need more storage tanks. But if we wanted to store it faster, we would need more motors and pumps. What about the cost? Li-Ion batteries are like $135/Whr.
The storage part of our system is much less than the best battery. And when you consider our storage will not degrade over its life and that it can last 2x longer, the cost is much, much less.
Neat, but what about the cost to the environment?
That’s the best part. Our technology uses primarily steel, the world’s most recyclable material.