Going Solar

I got a solar panel kit for our Burning Man adventure THAT STARTS TUESDAY!

I got it firstly to power my CPAP, Megan’s medical equipment, all our crazy bike lights, and phones. After testing it out for the last 2 nights, I now have the very satisfying feeling that we can power all of our personal medical equipment and personal electronics without the power grid for a very long time!

Yay solar!

I got the very succinctly named “Renogy 100 Watt 12 Volt Portable Solar Panel with Waterproof 20A Charger Controller Foldable 100W Solar Suitcase with Adjustable Kickstand for Power Station, 100W Panel-20A Controller, Black” for $160

It’s 2 50 watt panels, a charge controller, kickstand, a good protective case (good for packing away the panels!), with 10′ of wire and a alligator clips to go on my battery.

My math says that on a deeply overcast day, this system will just barely provide enough energy to power my CPAP. On a sunny day, I’ll have oodles of energy to spare. Here’s the math:

You usually get about 75% of the power out of a solar panel. 75% of my 100 watt system = 75 watts. Wildly guess another 10% in losses = 67.5 watts captured on a sunny day.

There’s about 8 hours of great sunshine per day = 540 watt-hours per day captured


You’ll see in the photo that I’m charging at 1.0 amps at 10am on this overcast morning in the bay area. 1.0 amps * 12 volts = 12 watts. With 8 hours of sun that’s = 96 watt-hours

I measured with a Kill-a-watt that my CPAP uses about 120 watt-hours per night. My AGM  On a sunny day.

I have a 12 volt adapter for my CPAP so I don’t need to run it though an inefficient inverter. I also got a bunch of 12 volt accessory/cigarette-lighter to USB adapters to charge my electronics and my USB AA/AAA battery charger.

In 2021, I got a 35 amp-hour AGM deep cycle sealed lead-acid (SLA) battery f0r $120 to take camping. It has powered my CPAP for a max of 3 nights. The exact model is the very succinctly named “Interstate Batteries 12V 35Ah AGM Deep Cycle Battery (DCM0035) Group 24 Rechargeable Replacement Mobility SLA AGM Battery (Insert Terminal) Wheelchair, Trolling Motor, Scooter, RV”. It’s been great.

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