The battery technology is the one which is now replacing the entire power plant for cities
Batteries make a lot of modern techs possible, as we see around us everything from cell phones, cameras, medical devices, a million appliances, to bigger things like electric cars. We might get frustrated because our cell phone still can’t make it through the day on a single charge, but the fact is, the battery technology as a whole is leaping forward. It is improving so much that batteries aren’t just powering our phones and our cars; they are powering cities and even replacing entire power plants.
But storing energy on the power grid isn’t a new idea. In fact, batteries are joining some really whimsical technology. Tech, that might make you wonder what the definition of a battery actually is. Tesla co-founder and CTO, JB Straubel, said about the Giant batteries that are compelling to the future of power grids everywhere because they are more useful at powering bigger things like bikes, cars, and soon, entire cities. Tesla, obviously, is big into batteries for their cars, but they are also tackling city-sized energy storage, which improves on our very old school grid.
The electric grid hasn’t changed that much from 100-some years ago when Tesla and Edison were actually invented it. Most people don’t realize, but it is instantaneously matched. Every time that we turn on a light switch in our house, instantaneously, a power plant, somewhere, connected to that same grid, has to ramp up a little more power output to make the light operate. When we turn on that light, we are probably relying on a big old gas or coal-fired plant. Fossil fuels account for about 60% of electricity in the U.S and another 20% comes from nuclear. Big plants are steady but are not flexible. Generally, to power something, we have these huge bases load gas plants that are running all the time; no matter they are pretty slow; they can’t really adjust how much energy they are creating. When the demand is too low, these big, slow plants actually lose money. And when the demand is too high, quicker, dirty plants called Peaker Plants have to switch on to keep up and they are pretty wasteful. So, traditional plants aren’t super efficient, but they are consistent and therefore, predictable.
Renewable energy can be another story. Solar and Wind power is cheap, clean and plentiful but only when the sun is shining or the wind is blowing. So, inconsistency is a big worry that something that no one really wants. What makes batteries so promising is that they can solve all these problems. When paired with big power plants, they can supply energy during peak times without polluting the way that Peaker Plants do. And when paired with renewable, they can jump in when clouds roll over a solar farm. Energy storage really is the missing piece of the puzzle for renewable energy.
But when we say storage, we don’t just necessarily mean these. On a super broad level, a battery is like a bank for energy. You deposit energy into it when you don’t need it and withdraw it when you do. We use electrical energy on the grid, but we can store it as any kind of energy. For instance, the Hoover Dam in the USA that is in the News recently, because of plans to turn it into Giant Battery. It would work by converting excess electricity into gravitational potential energy. So, essentially there are two lakes, one at the bottom and one at the top. And then, when the energy is cheap, the water is pumped from the bottom to the top where it just stays there in the reservoir. Then, when there is a need for energy, the reservoir opens up and the water goes crashing down, turning the turbine and creates the extra energy that might need for high demand. This is called Pumped Hydro-electric Storage and is actually in use all the country today.
There are other options still; Flywheel Storage works the same way. Engineers use power to start a heavy flywheel spinning and that power gets stored via Inertia. You can later harvest that Inertia to generate electricity again. And the weird part is the compressed air storage. Cheap power is used to force air into a Cavern or a Canister, building up the pressure. When power gets pricey or scarce, you can release the air to spin a turbine and power a generator.
There is another big newcomer, Gridscale Chemical Batteries. In the past few years, the price and durability of batteries have improved fast, making them suddenly useful for variable energy sources like Solar that was quite unheard of about 10 years ago. Batteries are still a tiny fraction of the energy storage market.
This is roughly the market share that pumped Hydro Waves. Batteries are growing fast, partly because they work at any size. Well, the biggest thing is scalability. Batteries have this beautiful ability to very economically, scale from gigawatt-hour all the way down to 10-kilowatt hours in your house. Batteries do have their weaknesses, they degrade over time, which probably noticed by our cellphone. And we can’t run them indefinitely, the way a fuelled power plant. Once the charge is depleted, that’s it. But their flexibility sets them apart from pumped hydro which is really only practical on the scale of a lake.