Have You Looked at Rooftops Lately?

Oct. 15, 2021
As the solar+storage customers increase, it’s only natural they look for ways to generate money on their investment.

As I write this month’s column, it’s raining, and everyone is enjoying it. In most of the country that isn’t big news, but in the desert southwest it is! You see, it’s monsoon season and for a few short weeks we receive just about all of the year’s precipitation. For the past couple of years the monsoon has been sparce due to a lingering drought, but this year we have been seeing a nice amount of  rainfall.

If we are lucky it comes in moderate amounts over the period. But today it’s a torrential downpour. A thunderstorm cell formed directly over the area I live in. In less than an hour, it dropped almost two inches (5.08 cm)of rain. Unfortunately, that much rain quickly caused some severe runoffs that fill our normally dry arroyos.

Arroyo means gully, wash, or dry creek bed in Spanish. In the desert southwest, arroyo says it all. For about ten months out of the year arroyos are bone dry, but when it rains they come to life and it’s not always pretty. People tend to forget arroyos are waterways that funnel these seasonal runoffs into rivers and that causes problems. With this storm, the arroyo near my house became a raging torrent with water running from bank to bank in a matter of minutes.

At first I didn’t realize what was taking shape and then I started getting flood notices from my video doorbell’s neighborhood group. It started off with complaints about the downpour and then switched to electricity outages. One neighbor after another reported lost service. A neighbor living close to the aforementioned arroyo reported seeing 7 distribution poles taken down by roaring floodwaters, which resulted in a restoration effort that lasted over 14 hours for those on the feeder.

Whoever designed and built the feeder had never seen the arroyo running bank to bank. The neighborhood group spent many hours grousing about the outage. Rooftop solar was bandied about as a solution for these outages. Interestingly, customers are getting technically savvy these days. They understand there’s an alternative with distributed energy resources (DER).

BTM Solar

I hadn’t realized how many rooftop solar panels had sprouted around the area until I started looking at rooftops after the storm. They blend into the landscape and quickly become invisible. As I was musing over the growth of rooftop solar, an email from Lawrence Berkeley National Lab (LBNL) came in. They had just completed a report on “Behind-the-meter Solar+Storage: Market Data and Trends.”

I have been on the LBNL newsletter distribution list for a long time. LBNL always comes up with intriguing research on timely subjects, but this was spooky in its timeliness. The report focused on residential and non-residential behind-the-meter (BTM) solar+storage systems in the U.S., which hit really the nail on the head for me. LBNL’s report focused on how distributed solar was a trending technology that is having a huge impact on the BTM segment.

Customers are Ahead of Utilites

So how does the BTM solar+storage stack up with the rest of the industry? Well, LBNL  found that roughly 3,200 megawatts (MW) of battery storage capacity was installed in the U.S. through 2020. Of that, approximately 1,000 MW (30%) of battery capacity was installed BTM.

Going deeper, nearly 550 MW of the BTM battery capacity was paired with solar. Overall, about 80% of residential storage is paired with solar. LBNL pointed out, “Roughly 420 MW (19%) of all utility-scale/front-of-the-meter storage capacity is paired with solar.”

It really gets interesting when you shift to individual states. Hawaii’s residential and non-residential customers have been pairing solar and storage at an amazing rate. In 2020 about 80% of residential customers and 40% of non-residential are taking advantage of solar+storage. LBNL attributes the Hawaiian customers’ solar+storage pairing to the phasing out of net metering for the past five years by Hawaii utilities.

Turns out there are several groups that are anti-net-metering and anti-solar, but with numbers like LBNL’s, solar+storage is here to stay and is growing. I wonder how FERC’s Orders 841 and 2222 are going impact the anti-net-metering crowd, since BTM aggregators can sell ancillary services throughout the grid.

It’s doubtful the aggregation trend is going away. As the solar+storage customers increase, it’s only natural they look for ways to generate money on their investment. It’s possible these customers will make utilities buy their ancillary services. FERC has opened the marketplace to DERs. It’s getting interesting.