We’ve got high pressure to our west generating northerly winds, so the solar panels are facing south, an ideal situation for a little angle on the panels. With the sun due to arrive over the equator in a few days we eyeballed 45 degrees. The results were immediate and positive.

At 1030 sun time (1130 local with daylight savings still messing up the real world) we are seeing as much as 54 amps at 26 volts, when the sky is clear and the stern pointed south. Of course we are swinging at anchor, and there are some cumulus clouds, so this number actually jumps between 20 and 54 amps. But it does make you think about a tropical lagoon, long days, and a line ashore to a coconut palm holding the boat in position.

For comparisons, the data above equates to 1350 Watts. Divide by your voltage for amps at your system voltage. These panels are rated at 320 Watts, before loss for conversion at the MPPT controller, line loss, etc. The rated output is 1280 watts so this is about 5% better than nominal maximum. As the panels have in the range of 10% built-in fudge factor, this is in line with what we expected from optimal conditions.

Before you get too excited, however, a few daily totals, based on flat panels, rain, sun, and in between weather. The numbers which follow are off the daily log of kilowatt hours from the Outback 80 MPPT controller, and represent the kWh that has gone into the DC system, after conversion from the solar panels’ higher voltages to battery charging voltage: 7.3, 7.3, 5.9, 4.6, 4.1, 5.5, 2.4, 2.7, 2.0, 2.4, 7.0, 5.4, 5.5, 4.0, 5.4, 1.7, 4.7.

A few takeaways from this data:

• Pointing the array to the south helps enormously.
• Angling the panels pays big dividends if you can hold the stern of the boat pointing south.
• Ideally the entire array, all 4 panels, would be on a single mast support (Wind Horse‘s are on two separate masts), making angling the array to point south, or better yet towards the sun, easy.
• If you go with the point above, adding a tiller to the mast, and then a “Tillermaster” type of auto pilot would really kick up the output without the stern anchor/line ashore.

As we were about to upload this post we noticed the sun streaming in through the deck hatch over the “office”. Just an hour shy of local apparent noon, amps are up to 60.4. or 1.5kW per hour!