Solar power battery storage is the future: Don't panic | Real Estate | santafenewmexican.com

Kim Shanahan

Building Santa Fe

Those of us of a certain age remember when lithium, which is ubiquitous and probably on your lap or in your hand right now, was whispered about in hushed terms. Like hearing your beloved crazy aunt finally got on lithium and her manic and depressive moods seem better.

These days, those opposing battery energy storage systems on a utility scale while also claiming to support society’s transition to solar, while perhaps not needing medication, do need to recognize solar and lithium are inseparable.

I’ve written about challenges Public Service Company of New Mexico faces with possible excess solar power going backward from houses on PNM lines that can cause hot spots and failures. It’s a real problem and bound to get worse as more panels go on more roofs.

PNM also knows, and acknowledges, one of the key solutions to the problem is more batteries, lots more. It knows this especially in Santa Fe County and especially for close-in areas like La Cienega and exploding developments south of Interstate 25 and along N.M. 14.

Unfortunately, there is no PNM plan, timetable or budget for installing necessary batteries, but there are three kinds of PNM localities where they could go immediately. First and foremost: on small solar fields PNM installed in the past few years in Santa Fe County, most notably by the National Guard base south of town along the interstate.

At the time, it seemed a progressive move on PNM’s part toward its pledge of 100% renewable energy by 2040. Critics say the intended consequences allowed PNM to argue its solar panels maxed out existing distribution system capacity, making new applications for rooftop solar (and minuscule PNM bills) harder if not impossible to allow.

Excess solar capacity going backward on PNM lines can be captured and stored by batteries. The greatest excess solar power is created between the hours of 10 a.m. and 3 p.m. in March, April and May, and then again in September, October and November — the months with the least demand for heating and cooling but plenty of sunshine.

The second most logical spot for PNM batteries would be at the entry point into a subdivision with a lot of solar panels. Twenty-five percent of the 70 homes in the Campo Conejos neighborhood south of Rabbit Road have them, which is close to what PNM considers maximum capacity for that stretch of its lines.

If an 8-megawatt, self-contained battery pack were placed in a PNM easement near the neighborhood connection point, which is enough storage for the entire neighborhood facing a day of outage, the excess backflow problem is solved.

The battery pack is about the size and shape of a shipping container. During the hours and months of maximum solar generation, it captures and prevents excess solar going back up the lines. It can then flip and flow power back to the neighborhood when the sun goes down and cars (with lithium batteries) are getting charged. It’s then ready to recharge the next day.

The third logical places for batteries are in big substations with transformers and switches, like the one along Richards Avenue. They step-down power from transmission lines into distribution lines. The transmission lines are federally regulated and do not allow power to go backward from distribution to transmission lines. Batteries there would be the failsafe to ensure no excess solar power got past the other two examples of logical battery placement.

The newest, best and safest batteries are not cheap but are investments that must be made for the all-electric future. Lithium is in our lives. Let’s not panic.

Contact Kim Shanahan at [email protected].

Kim Shanahan

Building Santa Fe

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