Solar cooling an option for our increasingly hot summers

Iwent to the Solar Fiesta held in Albuquerque at the UNM campus June 24.

I got to check out a fleet of different electric cars, talk to solar installers, and see new solar applications and designs. I met some great vendors and advocates and learned a lot.

I specifically wanted to know more about “splits.” Several of my friends who have rooftop solar have added them to their homes. Splits are heat pumps that are used for both heating and cooling.

We know that burning natural gas for residential and commercial heating contributes significantly to global warming. Heat pumps are an ingenious solution. In the winter when you use the heating mode, the heat pump works like a refrigerator, pulling air from outside into a condenser, heating it and exchanging it with cool inside air. In the summer it moves warm inside air to the outside, exchanging it with cool air. I talked with the exhibitor, Ward McCartney.

He explained that heat pumps are “like an air conditioner that works in both directions, but they are much more energy efficient.”

And the nice thing about splits is you do not have to have existing ductwork.

“To install a mini split a 2½-inch hole is drilled through the exterior wall,” he explained. But you do need a dedicated 240 outlet. And it is not a do-it-your-self job. He recommends the DIAL. They sell for about $1,200 and will heat or cool a 400-square-foot area. Installation can be very expensive, especially if you need to install 240 lines and outlets. But if you have enough rooftop solar, your heating and cooling can be cost- and carbon-free.

I have solar on my home. We put 13 panels on our roof seven years ago. That translates to a 4-Kilowatt system. We have seldom had an electric bill. However, we would need to upgrade our system if we wanted to charge electric cars or run splits just on solar.

Exhibitor Christopher Fortson from Positive Solar was very helpful. Positive Solar is one of the most reliable solar companies doing business in New Mexico. The company’s brochure states, “a typical residential solar panel system will eliminate three to four tons of carbon emissions each year—the equivalent of planting over 100 trees annually.”

Foresters say that there are 30-50 trees per acre in a forest. In 10 years of solar use, you could have the equivalent of a 20-acre forest in terms of saved carbon emissions. If every household could do that we would be well on our way to solving the climate crisis.

I asked him what a new household system would cost. I learned that the cost of solar has decreased a lot. I could get a much larger system for what I paid 7 years ago, a system that might be large enough to handle some heating and cooling or charging my car.

My option is to add more panels. I might need to add three panels or 1.2 kilowatts for car charging and other uses. That would cost about $5,000. There are still great tax incentives for residential solar.

The federal exemption is now 26% and the state exemption is 10%. That reduces the cost considerably.

With the horrid heat waves we have been experiencing, heat waves that only promise to get worse, I want to do what I can do to stay cool. That’s why splits sound so great. And like a lot of folks here, we do not have central air and just use window air conditioners.

With the accelerating heat our window units barely keep our house tolerable.

And what happens if the electricity goes out? “All that electric use for increased essential cooling might cause black-outs or brown-outs,” the worrier in me says.

“How will I stay cool?” “No problem,” says Christopher. “You just need a solar powered generator.” He pointed to the small device under his table that could keep him cool and run his displays.

“They run about $2000, and you can use them for camping or any time the electricity goes out. A solar generator could at least run fans and keep the refrigerator running.

After this summer’s heat domes and accelerating temperatures my next purchase may be a solar generator. I may never use it, but I will sleep better knowing I have an option. And a “split” may also be in my future.

Judith Polich is a New Mexico resident and a climate change columnist. She can be reached at judith.polich@gmail.com

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