Energy's future is solar plus storage

Doron Amiran ( doron@climateprotection.org ) is electric vehicle program manager at the Center for Climate Protection. Powering the Bottom Line ( nbbj.news/powering ) is a regular column by staff at the center.

Solar power is growing in California, but is it growing too fast?

Because solar power is generated only when the sun is shining, it is reasonable to ask: “Can we have too much of a good thing?”

The simple side of the answer is no, we need to continue to grow our renewable energy capacity, but the complex side of the answer is that we can only do so if we plan correctly and make a range of necessary investments.

Recent reports show that the phenomenal growth of solar power in California has caused issues. Because electricity must be used or stored when it is produced, and because surplus energy creates costly problems on the grid, we currently have to throttle back production when the supply grows too large.

Last April, for example, the state’s electrical system operators shut down or dialed back almost 95,000 megawatt hours of solar generation, mostly from large solar farms. This would be enough to power 30 million homes for an hour.

The problem is largely one of timing.

We produce the most solar power on cool sunny days, but that’s not when we use the most power. Furthermore, if we do not address this issue, it will only grow. California law requires that 50 percent of the state’s energy come from non-carbon producing sources by 2030, and starting next year all new homes in California will be required to include solar panels. This will mean a continued massive growth in solar and wind power.

From the perspective of reducing carbon emissions and addressing the climate crisis, this is a very good thing. But to successfully grow our renewable energy capacity, we need to plan accordingly.

The good news is that there are a variety of technologies available right now that can help us address this growing solar surplus. These can all be summarized in the phrase “solar plus.” Solar plus means combining solar with technologies that make use of or store the electricity for later use, so, solar plus batteries, solar plus electric heating, solar plus electric vehicles, and more.

Simply put, we must electrify everything, from cooking and heating, to transportation. Electricity can be an extremely clean way to provide the power we need for our homes, businesses and transportation.

In Sonoma County, Sonoma Clean Power delivers 100 percent local, renewable green power to its Evergreen customers, and some of the cleanest energy in the country to everybody else. Even for folks who still rely on utility power, such as PG&E, their energy is cleaner than 10 years ago, and getting cleaner all the time. It is therefore imperative that we electrify our homes, our businesses and especially our cars.

As California grows its fleet of electric cars from the current half million, to the 5 million or more called for in current regulations, those large batteries offer a great place to store massive amounts of electric power. The amount of power we can store in vehicle batteries will expand even further as we electrify buses and trucks, whose batteries are far larger than those in passenger cars.

In the future there will be three critical components of a 21st century solar project: storage, storage and storage.

Made popular Elon Musk of Tesla, the idea of on-site energy storage is growing. It offers the ability for a grid-tied solar system to provide power to the customer when the power goes down, and it allows homes and businesses alike to draw power from their batteries to keep utility bills low, which reduces grid load during peak times.

By “peak shaving,” or avoiding the high charges for electricity during peak times, these battery storage systems are able to pay for themselves over time. Businesses and large commercial solar installers are finding that installing solar plus batteries makes both financial and environmental sense.

“The solar industry realizes it is creating issues as we move forward with installing more solar on the grid,” says Jeff Mathias, co-owner of Synergy Solar in Sebastopol. “We address these issues on two fronts: smart inverters and storage. The smart inverters which are now required, detect high voltages on power lines and curtail power during these times. Partly as a result of this, our new solar installations include storage 25% of the time, a 10x growth in just the last 2 years.”

The future of solar, wind and other renewable energy in California is robust. The industry will continue its rapid pace of growth as we transition into a 21st century energy system. But these systems will look different than the early solar projects of decades past. The system of the future will be solar plus, and that is indeed a plus for us all.