Breaking my last solar power taboo…

Really longtime readers know that the original solar power system at the Secret Lair was a comically inadequate mishmash of scrounged worn-out parts which barely worked on bright sunny days. Evenings, I read by carefully rationed lamplight and most mornings I could only use electric lights if I also wanted to listen to the low-voltage alarm blare. I put up with that – and also burned a lot of kerosene – for my whole first winter in the Lair. By the end of that winter I vowed I would not rest until I’d built a better and more adequate mishmash of parts that were not entirely worn out.

And with a lot of help from neighbors I did, and it has done nothing but improve and expand in the seven years since. Therefore it is really not necessary for me to be quite the lightswitch nazi I was during the winter of ’11-’12. But old habits die hard.

Now it’s high summer, the days are long and bright and power is plentiful. Since Monsoon has seemingly decided to hold off for a while, it’s also quite hot. Unlike in the old days, the Lair is now equipped with ceiling fans – a monster 120 VAC fan for the main cabin that some neighbors were going to throw away because it got dropped and its case cracked, and a 12 VDC fan in the bedroom…


…donated by BB early last year*. Between them they quite efficiently keep the Lair from getting nearly as hot and stuffy as it used to. Very nice. But it’s still my habit to shut them off at bedtime, because of course I do. Solar power needs the sun, and the sun don’t shine at night, and batteries are expensive.

Last night, though, we didn’t get any evening breeze to cool the cabin down for sleeping. It’s really not an especially hot summer but it’s still summer in the desert and if you can’t cool off your sleeping space you’re going to just lay there and sweat. And I decided that since I’m planning to replace the batteries soon anyway it really doesn’t matter if I wreck the ones I have in a criminally reckless experiment: Let’s leave’em on.

And I did – and it made virtually no difference to the resting voltage of the batteries. Oh, it pulled them down over a tenth of a volt in use by morning, sure. But shut the fans off, wait a few and then record the voltage, and the actual difference was surprisingly – negligible. Measurable in hundredths of a volt if at all.


The difference is so negligible, in fact, that I don’t trust my figures. So assuming we don’t suddenly shift to cool evenings – unlikely – I’ll be experimenting with this more scientifically for the next few nights. I may have been sweating unnecessarily in the name of sparing my batteries.


*It also contributed something I never thought the Secret Lair would ever have: Its very own remote control. But it’s really nice.

About Joel

You shouldn't ask these questions of a paranoid recluse, you know.
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2 Responses to Breaking my last solar power taboo…

  1. Mike says:

    Just a thought… Since you’ve proven the draw is minimal, you should consider getting one of these window fans. I’ve had one of these for a few years and it has worked out very well. Turning it on an hour before bedtime, brings in the cool night air making sleeping a lot easier.

    https://www.amazon.com/gp/product/B00EKW4TBK/

  2. Jim Wilkins says:

    Having lived on a sailboat for something like twelve years, eleven of which we used solar to charge our batteries, I have a couple of suggestions. First is 12 volt computer muffin fans. They are inexpensive and draw very little power. They are much more efficient than 12 volt fans sold to truckers for instance. Another is your computer. I found that a Toshiba laptop computer would run fine on between 11 volts and 17. The battery is marked as 11 volts while the charger is rated for 17. That meant I could just tap into our 12 volt house system without the inefficiency of both an inverter and a charger. When the house system was above 12V the computer batteries would charge. The higher the voltage the faster the computer charges.

To the stake with the heretic!