Solar power

Discussion in 'Off-Topic Chat' started by Mesmerist, Apr 5, 2008.

  1. Mesmerist

    Mesmerist Well-Known Member

    No not a thread about solar powered brass instruments though there is an idea for Dragons Den - charge up your bass in the midday sun and listen to it sound like a sop.


    Has anyone got solar powered hot water? We are thinking of getting it but know zero about it so would appreciate your comments please.

  2. geordiecolin

    geordiecolin Active Member

    Some doubt as to whether its financially worth it, at the moment anyway.

    The planning laws change on Monday which will allow you to install panels in most cases without planning permission.

    However, government grants aren't set to increase, with the max being I believe around £400. Its difficult to get panels installed for less than £3k and at best offer a £300 saving per year on fuel bills. Most panels currently have a lifespan of around 10 years.....
    Last edited: Apr 5, 2008
  3. Aussie Tuba

    Aussie Tuba Member

    we have it on some of the building where I work.
    It's ok in summer, in winter you'd need a back up electric or Gas. We need a back up and that's in Brisbane Australia so in uk you'd definatly need a back up system.
  4. Cornet Nev.

    Cornet Nev. Member

    Its a few years since I last visited the Centre for Alternative Technology near Machynlleth in mid Wales but they had a demonstration set up using nothing more than black painted domestic radiators to collect heat from the sun, I was lucky the first time I saw it as it was bright sunny day mid year. The water from the system was actually near to boiling point, however some time later I visited on a grey winters day with no heat available at all. Thus proving that when it is hot and you really want cold water, or when it is cold and you want hot water?? Er what is the point????
  5. Mesmerist

    Mesmerist Well-Known Member

    The point is to be "greener" Cornet Nev, doing our little bit to save the planet and all that. Just an idea at this stage but am interested in all of your opinions as most of tmp users seem a bright well informed bunch about a variety of subjects.
  6. johnmartin

    johnmartin Active Member

    A common misconception about solar panels is that they rely on heat from the sun. They don't. They utilise photovoltaic cells which work using light from the sun.
  7. Mesmerist

    Mesmerist Well-Known Member

    Is it quite common in Australia then? I did read that China and Japan are the biggest users of solar power.
  8. Aussie Tuba

    Aussie Tuba Member

    Yes it is quite common here as are wind farms and the like.
    The one we have does not have a back uo and in winter the water is barly warm, most home that use solar have a back up system to.

    Australia is leading the way in this technology, but evan we get cold mornings in winter and that does affect performance of the solar panels,
    That comes from the experiemce of using them not out of books.
    not sure what previous post meant about the panels
    ours is panels and they are affected buy temperature.
  9. NeilW

    NeilW Member

    Having had a shock at the price of (heating) oil recently, we're thinking about a number of options for greener energy:

    • solar water
    • ground source heat pumps
    • air source heat pumps
    • wood chip burning boiler (+ growing the wood)

    or a combination of them

    Looks like a windmill wouldn't be an acceptable idea to the planning dept, in an "area of outstanding natural beauty" though.

    I think the next thing we need to do is figure out how much heat the house needs (a SAP assessment) to find out which options are viable and which aren't (GSHP's are marginal for "conversions" and only really work in well insulated houses)

    For solar water, the best option seems to be the tube versions (as opposed to panels, or matte black painted radiators like they use at CAT - you don't lose heat to a cold wind blowing past as they have a vacuum surrounding the heated element. Someone at work has a system like this and is very pleased with it. Being able to use them to "preheat" water in the winter is still worthwhile, even if you have to do the final heating with another source.
  10. barroweuph

    barroweuph New Member

    Solar Hot Water works by using radiation from the sun (not direct sunlight), a solar collector is used to transfer the maximum amount of energy possible, which is then used to indirectly heat water in a storage cylinder. Solar Hot Water systems are different than Photo Voltaic Systems because the water system will only heat water whereas Solar PV systems produce electricity.

    As solar hot water systems do not work on direct sunlight but on solar radiation, it can work as efficiently in our climate to provide around 65% of annual domestic hot water requirements.

    Further information about grants is available from

    Remember when installing to face south, even a 10 degree difference could reduce the efficiency by 30%.

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