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dozydave2

Hi


I have a 4 bed detached house with south facing roof.
Fully insulated.
Garden on slope approx 500sqm.
We cant get mains gas, dont want oil.
Have log burner but difficult ish access to house for logs etc.

What suggestions for self sufficient power and heating budget £12-15k.
Appreciate any ideas and advise.

Perfect roof for solar but am unsure about pv would it be good to do hotwater as well?
Can I store electric generated?

Thanks

milanonaj

dozydave2 wrote: »

Hi


I have a 4 bed detached house with south facing roof.
Fully insulated.
Garden on slope approx 500sqm.
We cant get mains gas, dont want oil.
Have log burner but difficult ish access to house for logs etc.

What suggestions for self sufficient power and heating budget £12-15k.
Appreciate any ideas and advise.

Perfect roof for solar but am unsure about pv would it be good to do hotwater as well?
Can I store electric generated?

Thanks

First, you have PV/thermal modules so you could have both electricity and hot water. Second, you have to calculate the best angle for your future solar array!

thenudeone

What heating system (if any) is installed currently?

You might not want oil but it may be the most efficient solution, when combined with a high-efficiency boiler.

Heat pumps are eco-friendly but can't heat water to as high a temperature as a normal boiler, so don't work effectively with a traditional heating system radiators. And they won't work when it's bitterly cold (-15C last winter) so you may need a backup.

Solar PV can provide a decent return on investment. Solar thermal much less so.

If you're using green methods to heat water, you also need some means of heating stored hot water to at least 60C to avoid legionalla bacteria.

There is a lot of information here http://www.ethicalconsumer.org/BuyersGuides/Energy.aspx and here http://www.cat.org.uk/

dozydave2

Hi Thanks for the replies.
We have bulk calor gas (very expensive) a 2 year old boiler. Small multifuel stove and electric showers.
Cant get oil near house (no good long term)
Have now ruled out air source (too noisey)
Ground source (garden no good).
Can you store electric from pv panels?
Any other suggestions?

albyota

A good quality Air source heat pump is no more noisier than a boiler flue, in fact I'd say its quieter, unless you have been listening to a cheapo far eastern unit, have you actually been close up to one? or are you going on hearsay? I know, I have one!

rogerblack

thenudeone wrote: »

Heat pumps are eco-friendly but can't heat water to as high a temperature as a normal boiler, so don't work effectively with a traditional heating system radiators. And they won't work when it's bitterly cold (-15C last winter) so you may need a backup.

The other issue is that it's hard to get a decent handle on how your system will in fact perform in the house.
It may be that you don't actually get the claimed 3.5* electricity heat output, but 1.5*.
Is there any guarantee on the performance?
Will they refund you if the system does not perform to spec? Unlikely.

In addition, I note that if saving money is the object, a electric central heating setup with a massive storage tank heated overnight on cheap-rate electricity would be more-or-less on a par with a heatpump economically, and far, far simpler.

(and yes, the siting of a couple of ton thermal store may have issues)

thenudeone

If you have no heating system at all I'd probably got for either a heat pump plus larger or fan-assisted radiators, or night storage heaters on Economy 7. If you want to be ultra-ecological you can often pick up second hand storage heaters on ebay.
For hot water you're probably looking at a large well-lagged tank, possibly with twin immersion heaters - one to heat the full tank at full blast on Economy 7 electricity, and other at the top of the tank set at a lower temperature to cut in during the day if the water loses too much heat. It's also possible to have an intermediate tank heated by the heat pump, which feeds into the main tank, but the heat losses from two storage tanks might outweigh the efficiency gains from the heat pump.

It wouldn't be be self-sufficient. If you installed solar PV you could probably create enough income from the feed in tariffs to cover the cost of the electricity, but a 4kW system would take £12k of your budget and wouldn't leave much for everything else. If access is difficult solar PV might be more expensive to install.