Solar energy is a clean and renewable resource that’s being used to power more and more appliances worldwide. For years, homeowners have been hoping that solar-powered air conditioning would become available and affordable. But now that it’s here, is a solar air conditioner worth the investment? We'll tell you why it may not be as efficient as you think.
What’s Actually Being Powered?
The amount of energy needed to power a central air conditioner is significant. That energy is applied to two of the AC’s parts: the fan motor and the compression motor. The fan motor takes a fairly small amount of energy to propel – just 1/8 to 1/4 HP, according to Keith Hill, Stay Comfy’s resident HVAC expert. Compare that to the compressor motor, which takes 1 1/2 to 5 HP to run. Unless you’ve got a solar panel farm out back, that’s going to be tough for most homeowners to achieve.
“Most of the solar units that I’m familiar with use a small amount of solar to power only the outdoor fan motor,” Keith tells us. “It still requires the full grid power to run the compressor motor.” As a result, most homeowners will find that the cost of the AC unit and solar panels vs the fuel savings just isn’t incentive enough – at least not yet.
What Does a Solar AC System Cost?
The answer to that depends on a number of factors. First, there’s the cost of solar panels. That’s come down in recent years and is no longer prohibitive for smaller jobs. Then there’s the AC itself, plus installation. If you’re looking at a traditional unit, the cost can be quite high. Angie’s list breaks out the cost for one top-level system at over $11,000.
Mini-Splits Might be More Feasible
Ductless systems, often used in smaller spaces, might be more feasible for some homeowners. Angie’s list profiles one product that runs in the $5,000 range. But be sure you know what you’re getting if you’re interested in this option.
According to Keith, it pays to read the fine print. “I see some small duct-free units that appear to be all solar, but according to their own literature state that they only run when it’s sunny out and still require batteries. Hot humid evenings and nights would be rough.”
The Future is Probably Brighter
As with any emerging technology, prices for solar air conditioners will no doubt be coming down in the years to come. At the same time, the technology itself will likely advance and improve. But for the present, Keith sums it up pretty clearly. “I see this being a real thing in the future when batteries and solar panels improve. But for now, it's not even a topic of conversation in HVAC circles.”