When the White House hosted its “Summit on Scaling Renewable Energy and Storage with Smart Markets” in June, it provided some high-profile government validation for something that the industry has been buzzing about for the past year: energy storage has arrived, and it’s one of the hottest topics in clean energy. From large-scale “front of the meter” systems owned by utilities to smaller “behind the meter” batteries installed by homeowners and businesses, stakeholders throughout the value chain are looking at ways storage can make our energy system cleaner, cheaper, and more reliable.
It might be surprising that the seemingly-familiar battery — often the same type of lithium-ion battery that powers your laptop and smartphone — could be at the forefront of the clean energy revolution, when voices like Bill Gates have insisted that we need new, “breakthrough” technologies to transform our energy system. But while the virtues of battery storage are subtle, their impacts will help accelerate the transformation of our energy system at every level. In a sense, you could say that storage is the “secret sauce” for clean energy — it makes everything better!
We’ll look at the ways in which batteries can help individual homeowners in a future post, but first let’s look at the big picture of how storage fits into our evolving energy system.
Getting LOTS of Renewables on the Grid
Perhaps the most commonly-cited rationale for energy storage is the fast-rising penetration of solar and wind energy generation on the electricity grid. That’s because wind and solar power are “intermittent” resources — they’re only available when the wind is blowing and when the sun is shining, in contrast to “baseload” power plants that run throughout the day and night as well as “peaking” power plants that can be started up on short notice when demand spikes. By enabling wind and solar power generation to be stored and used whenever it’s needed, batteries and other storage technologies can help these resources act like conventional, dispatchable power plants within traditional grid management schema.
While this rationale makes intuitive sense, many regions of the U.S. and Europe are proving that grid operators can successfully integrate much larger proportions of wind and solar than previously thought with a variety of non-storage solutions. For instance, while it may be difficult to predict when a single wind turbine or solar panel may be generating power, the aggregate generation from solar or wind resources can become significantly less variable when they are deployed and interconnected over a large area. Improved weather forecasting and steps to make energy demand more flexible are other effective strategies that are successfully pushing the limits of the possible for renewables integration. In fact, a new study by the National Renewable Energy Laboratory (NREL) estimates that the eastern U.S. could get 30% of its electricity from solar and wind by applying these strategies — with no added storage!
There are still long-term limits, however, and if we want to achieve a 100% clean energy future — and we do! — storage will be key. Another recent study by NREL looks at the levels of storage that would be necessary for integrating extremely large amounts of solar power into California’s electricity supply. As of 2014, solar provided about 6% of California’s power, and the study estimates that this could climb to as high as 20–25% by 2030 without the need for additional storage resources. However, to achieve a grid with 50% solar — and 66% renewables overall — by 2030, an additional 20 to 35 gigawatts of energy storage resources would need to be developed.
Thus, storage will be a big part of our long-term renewable energy future, even if the idea that we need lots of storage (or fossil fuel backup) today to keep building out our solar and wind power capacity is simply a myth. As the Rocky Mountain Institute’s Amory Lovins says, while storage is helpful for renewables, “we don’t need to wait for it, and the market isn’t waiting.”
Eliminating the Need for New Fossil Fuel Plants and Infrastructure
Still, even if batteries aren’t yet necessary to building out lots more solar and wind, they can make those resources more valuable by allowing for control over when their power is used. Currently, utilities in many regions rely heavily on natural gas-fired peaking plants that are only used rarely during short periods of very high electricity demand — think 5 PM during a heatwave, when everyone’s getting home from work and cranking their air conditioners — and are paid very high prices for those occasional kilowatt-hours. Batteries with stored renewable electricity can reduce or eliminate the need for these peaking plants by providing on-demand electricity more quickly, cheaply, and cleanly — a win for utilities, consumers, and the planet.
This type of storage application got a serious road test in Southern California this summer, as the massive Aliso Canyon gas leak left the region without much of the natural gas generating capacity it typically relies upon. Thus, to help it get through peak demand season without sacrificing reliability for its customers, Southern California Edison used “virtual power plants” — aggregations of distributed solar power, batteries, and demand-side efficiency measures that are remotely controlled and coordinated via software to behave just like a conventional power plant. Utilities in other states with high levels of renewables penetration, as well in as countries like Germany and Australia, are similarly looking to pioneer the use of these storage-enabled resources to meet peak demand needs instead of fossil fuels.
Fossil fuel power plants aren’t the only thing batteries can replace. When faced with rising demand for power and accompanying congestion on the grid, utilities have traditionally had to build new transmission and distribution infrastructure. Battery storage can defer or obviate the need for these costly investments by reducing peak demand and smoothing consumption over time, with the additional virtue of being able to be deployed more rapidly and on a modular basis compared to big construction projects. Utilities are already putting this potential into practice, led by New York utility ConEd investing $200 million in a demand management program that will likely include significant amounts of storage in lieu of a $1 billion infrastructure upgrade.
Bringing it Home
These are just the biggest, headline benefits that grid-connected storage can provide. As detailed by the Rocky Mountain Institute’s report The Economics of Battery Storage, there are at least thirteen types of services storage can provide for transmission operators, utilities, and consumers! And, while a lot of batteries and other storage technologies are likely to be owned and operated by utilities, RMI points out that the greatest benefits from storage will come from the widespread deployment of “behind the meter” batteries by businesses and homeowners. We’ll take a look at batteries from the homeowner perspective in our next blog on this topic.