Thursday, 25 March 2010

Soaking up the Sun

Last night we fitted our solar panel, and as we speak, the batteries are being happily, quietly, and renewably charged by the sun. It makes us very happy!

We began by checking that it would fit. And, in a way that makes it feel like the boat was designed for a 5486 x 394 panel, there were millimetres to spare in every direction. Then we rolled it back up, and I prepped the roof - cleaning and sanding it to key the surface. As I did this, James installed the Steca regulator, with its much simpler display than the one we had for the wind generator. It simply has four LEDs, from red through orange and yellow to green which show the status of the batteries. But it is capable of handling two of the large panels like ours, so no need for a new one if we decide to get another panel later. It optimises battery charging and is considered to be one of the best solar charge controllers about.

The next stage was to stick it on. We were glad to have the help of (big) James who has experience with this from installing his own similar panels last summer. We stuck 6 inches on while flat, then rolled it back up to carefully unroll it again, which took three of us, me unsticking the backing, and both Jameses controlling the panel as it unrolled, carefully avoiding the mushroom vents. Sticking it on in the cool of the early evening was the best time to do it according to big James, who struggled to install his in the hot sun, with the glue melting! Unfortunately the very end of the panel is under the cratch cover, but modification of the cover would allow light through, and in the meantime, the panel has by-pass diodes, which allow shaded panels to be ignored with no ill effect.

Connecting the panel to the batteries was probably the biggest job. The kit we bought from Midsummer Energy came complete with rolls of copper wire, and these had to be crimped on to the wires which connect to the panel. We decided to enter the cabin through the pigeon box right next to the panel, and then took down part of the inside of it to allow access to the roof void. This was interesting in itself, as the Duck has two roofs, the top one covering the old one underneath, and we were finally able to answer the question of what insulation existed between the roofs if any.

You can see the wires are going through between the two roofs here, andthe rockwool insulation between them.

We used a coathanger wire to bring the wires across the roof, to the side hatch, where they dropped down to below gunwhale level and from there to the back of the boat and regulator/battery bank.

We celebrated getting everything connected up with a trip to the Elm Tree with (big)James, Elisabeth and Steven (a rower) who was enjoying his last night in the pub before heading off to Greenland for a field trip today.

This morning wewoke to a bright day, and 13.8V from the panel, and the batteries (which were 12.2V last night) at 12.6V. Very pleasing.


  1. Looking good, Amy. Why did you reject the wind generator in favour of solar? Was it the noise of the turbine, the accentuated rocking of the boat in the wind or the fact that you can't cruise with the wind generator up? Or was there a planning issue at your mooring?

  2. Noise was one issue- despite taking a lot of time and effort to accoustically isolate the turbine mast, it would still howl. It was a good sound- it meant "free power!"- but it did start to get on the nerves!

    The main issue was location. Out in the wilds of our old mooring, there was very little obstructions to the wind but even so we still only got a little help from the turbine. I'm sure that if you were on the coast, or were weekending, then you'd see a larger difference, but for us it only made an appreciable difference to the charge of the batteries on a particularly windy day, and there weren't that many of them.

    So silent, discreet solar it is!

    The old turbine's off to the FIrth of Forth, where I'm sure it'll give a very big boost to the batteries of the new owner's yacht!

  3. I meant to add that in the centre of town, where we are now, it's less windy than out in the Fens, so we'd probably see even less benefit from it.

  4. Just ordered some PVL-68W (2,849 mm × 394 mm) panels that Maplin have at the moment: + £249.99 (N69JK - 68W Flexi SolarPanel) + £0.05 (JZ76H - JZ50/JZ47 11mm Cap B) - £20.00 (SECRET20 - voucher £20 GBP off £250) = £230.04/each with free delivery. Rinse, repeat; comes to £3.38/Wp.

    They're top exit, but for a 30% discount, I can cope… Mainly these are to try and passively increase the PV production in the winter period.