Portable Solar Power – A Primer For The Radio Amateur

The first of several posts on this topic.


6 responses to “Portable Solar Power – A Primer For The Radio Amateur

  1. Reblogged this on 3% Signal Corps and commented:
    h/t WRSA

  2. Alfred E. Neuman

    Reblogged this on The Lynler Report.

  3. Reblogged this on Starvin Larry and commented:
    Good stuff to know-everyone should have some type of solar set-up for your home-at least a few panels for charging some 12v batteries so that with a voltage inverter,you can power your important stuff that uses electricity-like lights,comms and refrigeration.
    Portable solar power generation is even better to have.

  4. I have a question.
    How EMP proof are solar panels with their on panel low voltage, high current protection and bypass diodes and the high tech controllers.

    • Deployed panels are physically fragile. When deployed, wires are antennas. When deployed, panels are subject to flying debris (intentional and not). Deployed panels are pretty obvious

      Grid-tied panels are “WTF?” in the Land of Falling Water (BPA grid-land) that only pretends to work with Zero Interest Rate borrowed money and State Mandates/Subsidy. In SoCal or Phoenix, maybe, when the Nat Gas runs out.

      Controllers are subject to everything electronics are subject to (EMP, corrosion, heat). Spares in sturdy unconnected packaging is a decent back-up. Underground in sealed packing is as good as you can do.

      The Uni-Solar flexi-panels are less fragile, but less efficient per area of panel. Their big advantage is “roll-up” capability that can put 250W (name plate) in half of a bike trailer. If you have a pu truck canopy, you can get a couple of 150W hard panels on a tilt-able rack on the roof that will be much smaller than 300W of flexi-panels. The fixed panels will get you more amp-hours, as long as you adjust to be perpendicular to direct sun (and/or add some reflectors to boost the brightness on the cells).

      MPPT is useful to be able to use panels of higher nominal voltage than your batteries without wasting the extra voltage (power not used to make charging current). The Morningstar SS-15L MPPT (msrp ~$250) is even more flexible than the video might suggest. Go to http://www.morningstar.com to find install manual. Max PV panels with 24 battery is about 400W, with 12v battery about 200W (output Amps max 15 for 12v or 24v). Max battery on a 15A output charger should be ~200A/hr @24v. Four golf car 6v batteries (190-220A, GC-2 type) will work. SLA or gel if you need to be portable, Flooded Lead-Acid if static. System does scale down (fewer pv Watts, fewer battery A/hrs) for weight and volume, but cost does not drop proportionately with power.

      I’ve been disappointed with everything from Harbor Freight, esp. anything “solar”.

      Copper is not a super conductor. Use the largest/shortest wire that will fit into the connector and reach with a couple extra inches for flex and drip-loop. It says 14 ga, but an 8 ga wire crimped to a pin will fit. Look for Voltage Drop Chart and size wire for less than 2% voltage drop in the loop.

      Batteries care very much about 2/10ths of a volt. Use an accurate digital volt meter (display with at least this much resolution: “12.58v”, not “12.6v”) and measure at the battery terminal. Adjust charge controller to deliver battery manufacturer recommended charge at the battery terminal.

      Heat shrink tubing seals and supports the connector. Build as if salt water spray is a daily event.

      Do not connect inverter to charge controller load terminals. Connect to the battery terminal directly, via a fuse and disconnect. There is plenty of power in systems like these to start fires!

      PNW I-5 valley “solar” is assumed to be 5 hours of illumination. December may be ZERO to Five Percent of late June solar . Without dust or snow. Other places will be brighter. You have a genset, right, and coffee?

  5. I read long ago that those “old fashioned” lead acid cells were unaffected by EMP. So I have equipped with a simple hand driven motorcycle dynamo / battery set up (for the unknowing a dynamo preceded the car alternator with it’s diode pack and mine produces DC 6v). Heavy, bulky, and hell on the arms but convertible for belt drive.
    Left disconnected in it’s coffee tin, it should be totally “pop” proof.