Over the past decade, prices for solar panels and wind farms have reached all time lows (still expensive), leading to hundreds of gigawatts worth of new renewable energy generation. As the saying goes though, the wind isn’t always blowing and the sun isn’t always shining. If, for example, it’s a beautiful sunny day and we’ve got a super abundance of electricity, we can’t use it. We need a good way to store energy for later. And the main option right now is lithium ion batteries.
The question of how to firm renewables, that is, ensuring there’s always energy on demand no matter the time of day or weather, is one of the biggest challenges in the industry.
You see them in products like Tesla’s home battery, the Powerwall and utility-scale system, the Powerpack. But though lithium ion is dropping in price, experts say it will remain too expensive for most grid-scale applications. To get to battery for the electrical grid, we need to look at a further cost reduction of 10 to 20x.
Problem with lithium ion battery
Right now, lithium ion batteries just can’t store more than four hours worth of energy at a price point that would make sense. Plus, they pose a fire risk and their ability to hold a charge fades over time. To address this, there’s acadre of entrepreneurs experimenting with a variety of different solutions.
Now we’re seeing flow batteries, which are liquid batteries. And we’re seeing other forms of storage that are not chemical or battery-based storage. And each has serious potential.
For renewables to truly compete with fossil fuels, we need to figure out a better way to store energy. From 2000 to 2018, installed wind power grew from 17,000 megawatts to over 563,000 megawatts. And solar power grew from a mere 1,250 megawatts to 485,000 megawatts. And it’s not stopping there.
Renewables are expected to grow an additional 50 percent over the next five years. We know today that solar P.V. and wind are the least expensive way to generate electricity. In particular, the price of solar photovoltaics has plummeted far faster than all forecasts predicted, after China flooded the market with cheap panels in the late 2000s.
All the Wall Street analysts did not believe that solar was going to ever stand on its own without subsidies. Well, a few years later, even the most conservative analysts started realizing that actually solar was going to become economic in most parts of the world pretty quickly.
And as solar has gotten cheaper, so too have lithium ion batteries, the technology that powers electric vehicles, our cell phones and laptops. And thanks to improved manufacturing techniques and economies of scale, costs have fallen 85 percent since 2010.
Now, wind or solar plus battery storage is often times more economical than peaker plants. That is, power plants that only fire when demand is high. Tesla, for example, built the world’s largest lithium ion battery in Australia, pairing it with a wind farm to deliver electricity during peak hours. But this doesn’t mean lithium ion is necessarily economical for other grid applications.
Basically, the market is ripe for competition. There are dozens of chemistry being looked at today. There are hundreds of companies working on scaling up and manufacturing new battery technology. Lithium ion has done remarkable things for technology, but let’s go to something far better.
Alternative to lithium ion battery
One of the main alternatives being explored is a flow battery. Unlike lithium ion, flow batteries store liquid electrolyte in external tanks, meaning the energy from the electrolyte and the actual source of power generation are decoupled. With lithium ion tech, the electrolyte is stored within the battery itself.
Electrolyte chemistries vary, but across the board, these aqueous systems don’t pose a fire risk and most don’t face the same issues with capacity fade. Once they scale up their manufacturing, these companies say they’ll be price competitive with lithium ion.
But as always, it’s going to be tough to get even the most promising ideas to market.No matter if the raw materials were dirt cheap, the initial cost of a first system is essentially astronomical. Of course, government policies and incentives could play a major role as well.
There is a production tax credit on wind. There’s an investment tax credit on solar. We in the battery community would like to see an ITC for batteries in the same way that it is in existence for solar. Implementing a storage mandate, as California has done, is another policy that many are advocating.
When we get to roughly 20 percent of our peak demand available in storage, we will be able to run a renewable-only system, because the mix of solar and wind, geothermal, biomass all backed up with storage will be enough to carry us through even some of these potentially long lulls.
With the right mix of incentives and ingenuity. We’re hopefully headed towards a future with a plethora of storage technologies. The future is not going to be a mirror of the past.