Sharp to Launch DC powered mini-split Air Conditioner

[MN Renovator]

A 48v version of the super-effcient inverter mini-splits would be excellent for off-grid homes. Most off-grid folks that I've talked to, along with many Energy Fair presentations pretty much say air conditioning is out of the question but I really think that if you've got the capacity to run your stuff in the winter that you'll likely make a much more comfortable home with the additional power available in the summer without the need to use generator power.

[flavin]

It really got my interest.

[Mobile Master Tech]

It is possible to run very efficient air conditioning using off-grid solar power, since the peak demand coincides with peak availability. Precool the house a bit during peak availability and have panels on more than one azimuth at least 90deg apart to get output over more of the day, eliminating or minimizing demand at other times while extending the amount of the day you have useful output. If there are clouds, your output goes down but so does the demand.

In Hotlanta, my Nordyne 23SEER central unit which can vary its output from 1.5 tons to 3.5 tons, takes around 15kwh per day to keep all 3 floors of my 5br/3.5ba house AND my garage at 74-76F. My year round demand for other electricity is around 10kwh/day.

That's within the capability of approximately a 6kw or larger PV system according to PVwatts. A couple extra panels on another azimuth is way cheaper/simpler than any kind of tracking system and adds just as much average output.

FWIW, even with all day cloud cover, I have seen system output reports that the minimum harvest you actually get is at least 20% of full sun harvest since the panels are cooler and you always get some irradiation.