It seems like ages ago that we started to put up the new vacuum solar tubes. The rain and the corn planting and hay cutting have stopped us getting on with the installation but today we finished it !
I've used a photo of a pump as an introduction to today's blog post because DC pumps like these are really difficult to find - at least in France.
Someone searching the 'net for a solar powered pump (As I've done so often !) will get the information here that they need to find the right pump. The installation and operation manual of our pump is available on the 'net in the Laing website
Our old flat plate solar collectors worked by thermosiphon - that is the hot water rose and circulated without the need for a pump. (Note the English and the American spellings differ) I prefer that system as there's nothing to go wrong but as I wanted to put our new panels on the back roof of the conservatory where they wouldn't be seen which is higher that our hot water cylinder, we couldn't use thermosyphon and have to pump the hot water around the circuit.
This little pump is powered by a little 20 watt photovoltaic panel which of course only works when the sun shines and the water is being heated - so it's perfect for a solar water heating system !
The photo above shows Fabrice fitting the last of the 16 vacuum tubes which each heat a little copper bar at the top of them. They fit into a manifold where they heat the water. That was the last step in the fitting process after we'd tested the pump and bled the hot water system.
I haven't lagged the pipes or insulated the water cylinder yet just in case there's a leak, so the system isn't as efficient as it will be when it's insulated but so far everything is working as planned and the water is warming up nicely.