Solar hot water heating basics

[Nikki]

Hi everyone,

After a long absence (filled with emigrting and discovering baby on the way!) I'm back online. I've been looking forward to getting back to you green folk.

I had been considering solar panels for ages, (known as photovoltaic s right?) but it turns out they're just too expensive for us right now. However, I just came across solar water heating panels. Could someone please explain if these are essentially the same thing? And if they're roughly the same cost.

I googled them and saw a few pics where they appeared slightly different to the usual solar panels I think of. They were like pipes. I guess I'm hoping they're more affordable.

[Clara]

Photovoltaic panels generate electricity, whereas the "pipes" (I´m assuming these are actually vacuum tubes) make hot water. So, completely different things!

We have both, but the PV panels we inherited with the house we are about to replace and upgrade so that we can have more mod cons - at a cost of €12K, whereas the 270l vacuum tube hot water system only cost €2,200. We love the solar hot water, especially as the other option is to use butane bottles (which we have to carry 1km to the house) and have found that it pays great rewards - since having it installed we have gone from using 1 bottle of butane every 3 weeks to one every 3 months, that´s a lot less gas and a lot less back breaking carrying.

If you have sun I´d also suggest a solar cooker as a good return on any investment. I bought a commercial model from www.sun-co.pt for €150, I use it everyday there is sun and I´m sure this has been a great help to in reducing our gas use - especially as its really good for slow cooking things like casseroles and chickpeas etc.

[Martin]

very different! http://solarwind.org.uk/content.php?content.4

[snapdragon]

and different prices too if I remember right

[Muddypause]

At the moment, solar water heating is a more efficient way of capturing the sun's energy (photovoltaics may improve in the foreseeable future), and is generally easier to store and use, too. Conveniently, water requires a lot of energy to heat up, so using the sun to do it will make comparatively large savings in conventional energy supplies.

[Nikki]

Thanks guys. I did see one image where they looked liked tubes and wondered if the water was being heated directly.

But Martin, that link is what confuses me. It just looks like a solar panel in use. ??

Thanks for the solar cooker tip Clara - I'm considering that as well. We have tons of sun here!

[Martin]

here's a picture of a typical vacuum tube system -

[Martin]

just to further confuse you.........this is a "flat panel" solar hot water collector

From certain angles these look very like solar pv (the electricity generating ones).
Generally, we'd always advise vacuum tubes in preference for performance reasons, but sometimes planners insist on flat panels......(they think they "look better" and are like Velux windows......... )

[Nikki]

Thanks a bunch Martin. That totally clears it up. So I'll be looking for a vacuum tube system. Just need to source it over here. *shrug*