Monday, February 17, 2014

Solar Panel in the Telescope Garage

We finally had sunlight in abundance in conjunction with time in abundance.  (Today is a state employee holiday.)  I had not ordered a deep discharge storage battery, because I wanted to make sure that the rest of the parts that I was going to use for this project were in good working order.  I hooked up the solar panel to the inverter (which is claimed to be 5-45W capacity).  Then I plugged in a lamp with one of the curly CFL bulbs (since these typically only consume about 23W).  Curiously, the lamp just flickered on and off.  What?

Then I looked carefully at the back of the panel.  I thought (perhaps because of absurd optimism) that this was 15W output solar panel.  No, the promised output was 5W.  I suppose that I should consider it impressive that it even provided enough current to flicker a 23W CFL.

Anyway, this at least demonstrates that these parts are working, so I guess that I will buy a storage battery.  Perhaps I will buy one with a little more capacity, since a 5W panel is going to take a long time to build up much capacity.  But this is primarily an experiment; if I can use this to operate LED lights in the telescope garage, then it may make sense to buy a 35W panel, and build up enough charge to run an electric garage door opener (which has pretty substantial peak amperage requirements).


  1. Harbor Freight has a complete solar power system for less than $200.00. Requires battery & inverter, but includes voltage regulator, which has a 12VDC "lighter style" outlet, USB port, etc. It's 45 watts capacity, which I would consider a minimum for practical uses.

  2. I already have an inverter and voltage regulator and the solar panel. I am looking for a cheap way to experiment and provide at least some power in the telescope garage.

  3. At $150 for the HF 45 watt system (I don't know the notional list price, but it's always on sale for $150) it's probably cheaper to buy it just for the panels and have a space regulator/charge controller.

    Indeed, if your existing regulator isn't also a charge controller, it may overcharge batteries, and be worse than nothing.

  4. It is a charge controller -- at least it claims to be.