Solar Co-Op


Here’s some things we think you might find useful …


A 1970s American guide to making your own solar water heating panels. Contains lots of good tips and also shows you how to get hot water from your wood-burning stove.

American pamphlet on homebrew solar panels  (compressed)

Save this zip file to your PC and decompress. Requires Acrobat reader to view. Please observe the library’s copyright guidance.   

A guide written by a guy from Downpatrick in Northern Ireland on how to make solar water heating panels from old radiators.

Solar Panels Made from Old Radiators (compressed)

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A superb step-by-step guide to installing a Navitron evacuated tube panel. And equally valid for installing any brand of heat-pipe evacuated tube panel! Note however that the quoted annual savings of 5400Kwh from one panel in one year is beyond the realms of credibility – you should expect approx 1000KWh p.a. from a panel of this type at UK/Ireland latitudes, no matter what brand of Chinese panel is used. 

Installation Guide for Evacuated Tube Panels (Heat Pipe)

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An excellent article by Andy Wilson on solar thermal in Ireland. Andy is a well respected eco-journalist, and runs workshops in Westport on making your own flat panels.

Andy Wilson on solar thermal in Ireland

Andy’s views on flat panels versus evacuated tubes are perhaps less relevant now given the rapidly falling price of vacuum tube panels.

Some useful info on Legionella. One of the lesser known advantages of a copper tank, apart from the price, is that copper is more biofilm resistant. 

Legionella and Copper Plumbing

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There are some simple rules of thumb for sizing an expansion vessel and working out the pre-charge for solar, but if you like arithmetic, here’s a good example.

Expansion Vessel Sizing for Solar (An Example)

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An interesting paper on stagnation, and more on expansion vessel sizing – again only of use if you don’t like the rules of thumb most people go with!

Solar Panel Stagnation

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If you want to use an old style ‘feed &expansion’ tank in your loft for the solar plumbing loop, here’s some useful notes.

Feed and Expansion Tank Sizing (for open vented solar loops)


A 6watt 12v pump running directly off a 9W amorphous silicon photovoltaic solar panel in almost direct sunlight, late afternoon, mid March.

Solar PV Panel Running 12v Pump

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Plenty more downloads to come later…