30W solar panel to power a house?

Hi, have been trying to work out what type of solar setup I would need to run my house hold purely from solar, the best way I could work out my daily consumption was to record my electric meter usage, this equates to max 15wh does this mean I could run my electric from one 30w panel, 4amp charge controller and 12ah deep cycle battery? Would be glad of your input, many thanks.

Looking at your meter is certainly a good way of working out your needs. But unless you have an extraordinarily energy-efficient household it's probably reading 15kWh per day, not Wh. That's 1000 times as much.

Most households need about 4000W of solar panels provide enough power to meet their needs - a 30W solar panel won't do much more than power a single low-energy lightbulb for a couple of hours a day!

best wishes,
Andy
Midsummer Energy

Dehumidifier powered by solar array and micro hydro

I have an isolated house in the middle of France 750m above sea level in a very damp location but with a south facing garden.  The house is unoccupied for long periods of time and I want to install equipment to maintain low level heating and ventilation throughout the four story building to reduce damp and consequently woodworm activity.  There is plenty of strong intermittent sunlight in summer, however in autumn and winter I have access to the overflow from a dammed lake that gushes water - I'd like to set up a microgenerator and connect this to the batteries thereby charging them through solar power in summer and water power in winter.  If you have time to provide any tips I would be most grateful. Thanks, Malcolm

 

Hi Malcolm. It sounds a great little project - but whether it would be practical I'm not so sure! The trouble is that heating and dehumidifying equipment is very power hungry, and you would need a very large (and hence expensive) solar array to provide enough power.  The best thing to do would be to find out the power consumption of the equipment you want to run, and use our solar panel calculator to work out how big a solar array you need.

A little micro-hydro turbine may in fact be a cheaper way of generating electricity, as you are lucky enough to have a suitable location! See http://www.homepower.com/basics/hydro/ for a useful guide. Navitron sell small turbines which might be suitable. regards, Andy, Midsummer Energy

 

Solar for off-grid house in Spain

I would like the price for a full solar energy system to be installed in Spain to run 2 small 3 bedroom houses which have just been built side by side.

The system needs to be off grid, and able to run all potential electric mod cons (though not air conditioning). Thanks, Mike.

Hi Mike,

A typical household in the UK uses around 12.5kWh per day. On a
typical UK summer's day you would need an array of around 2500W of
solar panels to generate sufficient electricity over the course of a
day to replace that power.

On the one hand you have better sun resources in Spain, and with
energy efficient appliances you can reduce the 12.5kWh needed per day
considerably; but on the other hand there will be times - overcast
days in winter - that the panels produce less than 12.5kWh per day. On
balance, a 2500W array will give you a pretty good amount of power to
play with - but you do have to remember that fundamentally a battery
bank is a limited resource, and if people leave all their appliances
on over a couple of dull winter days it will run out!

Your battery bank needs to be capable of storing considerably more
than one day's power, as it's bad for the batteries to be heavily
depleted, and also you have to have a good reserve for those overcast
days when the panels are not doing very much. As a minimum, I would
say a battery bank of 40kWh for a 2500W array.

So, the system components for each house would comprise:
- 2500W of solar panels. Approx cost £9000.
- 32 x 110Ah 12V batteries (capacity= 32 x 110 x 12 = 42240Wh).
Approx cost £2500
- Solar Regulator. Approx cost £200.
- Inverter to produce 240V AC from DC battery bank. Approx cost £1500.
- Wiring, mounting system etc. Estimated cost £1500.

So total system cost is around £14700 per household, plus installation costs.

You may be able to save 10% on that as the figures I have quoted
include VAT of 17.5% - there is a lower rate of 5% on energy efficient
installations on houses in the UK, which you may qualify for.

The cost is pretty much proportional to the size of the system. It is
perfectly possible to run a household on a system half that size (and
half that cost), with careful use of electricity. Many people in
caravans and narrowboats live quite happily with solar arrays less
than a quarter that size or even smaller. On the other hand, if you
want to be able to run everything under the sun (so to speak), you'll
find that even a 2500W array per household is not enough, particularly
in the winter.

Hope that helps - Andy

Solar power in Bangladesh

Hello there, I'm interested in setting up a small kit in Bangladesh as the sun is strong and plentifull as a trial to test it's usefullness. I'm unsure what to try as a starter. Can you suggest something please for me?

Many thanks
Kind regards
Saiduz

Hi Saiduz,

Bangladesh would certainly be a good place for solar power!

It depends what you want to power from the panel. I would suggest the smallest setup that would be of much use would be a Spectra 20W solar panel, with a Morningstar Sunguard regulator; you would attach that to a 12V lead-acid battery (which I'm sure would be available locally). That wouldn't give a great deal of power, but perhaps enough to run a radio and a fluorescent light or two in the evenings. However, it would give you an idea of what could be achieved with a larger setup.