By Rob Day

September 2, 2018 - People who talk and write about renewable energy technologies and climate change often declare that the next Big Breakthrough that is needed is in batteries connected to the electric grid. Even mainstream publications like The Boston Globe are fascinated by the possibility of a big battery breakthrough in the years ahead.

Because solar and wind generation are not constant (the sun doesn’t always shine and the wind doesn’t always blow) and don’t always match up with electricity demand, it’s become commonplace to declare that cheap energy storage is what’s needed to unlock a truly significant level of adoption of renewables in the global electric grid. Especially as solar and wind power now already often match the cost levels of incumbent fossil-fuel based generation (coal and natural gas), the availability of such cheap batteries is talked about as a “silver bullet” that would finally allow the entire system to go over to renewables.

Very smart people regularly talk up the corresponding need for big investments into battery technology breakthroughs, and very wealthy investors are listening.  From high net worth individuals like Bill Gates to the biggest oil companies in the world, numerous big venture capital bets have been made around promising new battery chemistries and energy storage systems. In a period when venture capital investments into “cleantech” remain depressed, such bets on energy storage have been the exception, attracting hundreds of millions of dollars of investment.

And various governments have been listening as well. From New York to California to Ontario, very large governmental incentives programs have been put in place to encourage the deployment of batteries onto the grid, and it’s helped lead to a booming industry for “grid-scale storage”.

But are batteries actually the singular climate savior we need? The answer is actually not nearly so simple.

Let me first note that I am personally a big fan of all of the above investment, policy and innovation efforts. But I’m going to have to circle back around to explain why. Because there are some real reasons to be a healthy skeptic about both the need for -- and the effectiveness of -- such a strong, near-term focus on the technology.

First of all, while batteries remain costly, there are already much cheaper available alternative solutions for the same matching-renewables-to-demand problem. Namely, software-based and other “load shifting” is entirely available and vastly underutilized. This involves moving the consumption of high wattage loads to different times within an hour or within a day or even within a week.

“Load shifting” is basically about minimizing the generation capacity required by an electric system by changing the consumption of high wattage loads from when the electricity would otherwise be used, to when it is more available. Software-based load-shifting is already being undertaken in hundreds of major industrial and office buildings across the U.S., with the goal of helping the owners can save money on their electricity bill. Done right, it can have zero impact on productivity or comfort in many cases. Additionally, many users ranging from big factories to individual homeowners have already demonstrated they are happy to automatically reduce their electricity consumption if they’re paid enough to do so. All of which, if well-coordinated, can significantly free up capacity on the electric grid in the same way batteries can. But much more cheaply.

The problem is, few utilities and regulators have gotten their act together to roll such programs out at sufficient scale and with sufficient coordination. Some “demand response” programs have been implemented, and have largely been successful. Nevertheless, it’s an underutilized resource that could go a long way even without needing any big technological breakthrough.

Of course, you can only shift loads around so much without eventually having a big impact on productivity. For example, you can’t shift loads around to eventually zero consumption, of course. Thus, battery tech enthusiasts are often quick to push back on me when I make the above point in public. And in some ways they’re right to do so -- in the long term we’ll need battery breakthroughs.

But I have also seen first-hand where a huge factory with a massive solar array on the roof was offered a massive battery to help manage the resulting intermittency, and yet when they ran the numbers they found that by utilizing load-shifting software instead they didn’t actually need a battery at all. Load-shifting is not a panacea. But it can be deployed today, much more widely than it is, and in automated fashion.

Even more potentially concerning is that some researchers have come to the conclusion that adding batteries to today’s grid actually can often result in INCREASED carbon emissions. This counter-intuitive point is still subject to much debate, and isn’t simple to understand.

But it comes down to these two concepts:

1. Batteries lose some electricity for every “round trip” (i.e.: charging and then discharging). When you have an electric grid that is still largely made up of fossil fuel based generators, any battery tied to the grid will be charging up with a mix of power from both zero-carbon and carbon-emitting generation. Remember, the battery doesn’t actually generate any power itself, it’s just being used to shift the times power is available. So if it’s the same old power generator mix, and each “round trip” leads to losses, you’ve just increased the overall amount of power generation needed, and thus increased carbon emissions.

2. Electricity generation is also roughly divided into two types: Baseload and peak. Baseload power generation is often coal-fired plants, the heaviest emitters. Peak power is often natural gas (still an emitter, but less so) and solar. Here’s the rub: If you own a battery tied to the grid and you’re trying to make money, you will usually charge it up during lower-demand times (when the overall generation mix is more heavily based on the dirtier baseload power that runs constantly), and in fact you will be reducing the need for peak power generators to run at all. The net result, however, can be that the battery is subsidizing baseload (coal) power and competing against peak (natural gas and solar) power.

Taken together, these two concepts suggest that simply throwing batteries onto today’s electrical grid actually leads to higher carbon emissions, and may actually disincentivize the use of solar as a peak power generator.

In light of this, why am I still a supporter of investments in battery innovation and deployment?

Because I think it’s an important part of the overall story of how we eventually get to a zero carbon emissions electricity system in the United States. This week we saw the passage of historic legislation in California which aims to achieve zero carbon emissions across their electric generation mix by 2045. Such bold thinking was greatly enabled by California’s early experiences with rapid deployment of batteries. Which have had their bumps, but by and large have been successful.

And also, the above critiques of energy storage deployment as both unnecessary and perhaps boosting carbon emissions are both completely voided under scenarios where low-carbon power sources are used more widely. If solar and wind achieve much greater “penetration” levels within the generation mix, software-based load-shifting can’t handle it alone. If zero-carbon generators are prevalent for both baseload and peak power, then the carbon emissions “penalty” for using batteries as a load-shifter is nullified.

So, if battery deployments today and investments in battery technologies for the future help enable policymakers and investors to get on board with a largely zero-carbon generation future, then I’m all for it.

But the question of whether batteries will actually prove to be our climate savior is simply not as cut and dried as many experts make it out to be. Moreover, there’s danger this talk about future "silver bullet" breakthroughs could encourage policymakers and investors to sit on their hands, waiting for future innovations rather than concurrently taking immediate action.

If there’s one big takeaway from the complicated issue of energy storage, it’s that policies to encourage the long-term innovation and deployment of energy storage technologies are laudable… but the more important and immediate goal should be replacing our current generation mix with more renewables, load-shifting, and other zero carbon power capacity. This is the real way for batteries to become a valuable enabler. Without this shift batteries may end up doing more harm than good.