how much solar for an all-electric home?

[lucy.lists]

Hello,

We have a small 2.5 bed semi-detatched house in England. A series of fortunate events has meant that we also have a bigger house in France, with land, and this is now where we have decided to base the family.

We bought the England house in July 2007 and since then have been slowly refurbishing it, and using it very occasionally as an overnight stop when working in England. We've recently installed a posh wood burning stove which - when running properly - heats the downstairs quite nicely. The rest of the house is all electric, running old electric storage heaters (which we don't use), an old electric immersion heater (also which we don't use) and an electric shower. There's also an integrated fridge/freezer, washing machine and dishwasher. The house is not connected to gas. We've upgraded as much of the insulation as possible.

So ... given that we're hardly using the house we've decided that it's a luxury we can't afford and don't really need - and it should go back into use - so we either want to sell it, for preference, or rent it out. But, as it is, and especially in the current market, it's a kind of half done up house and probably not very desirable. We've put in a fab woodblock floor and the downstairs looks great now with the woodburner. But I think the current outmoded heating system and hot water situation is a real downside ...

So, all the sensible advice is suggesting we hook up to the gas and get a combi boiler and heating system put in. But following my heart, I really don't want to do this. It feels like such a backwards step and also, what with the house being all electric, if we spent the extra money and went with solar I think that would be a real selling point for the house in both the buying and letting markets.

We've never really lived in the house so we don't know what our electricity consumption is. But I would guess that buyers/renters would be a 2 or 3 person family. We'd need between 5 - 7 electric heaters (including a towelrail) at the most to heat the rooms. We'd need to power the immersion heater too. And then the kitchen appliances.

We'd be looking at a grid-connected solar PV system for all that, I suppose. And would we need separate solar hot water, or would it be best to leave everything to the solar P.V?

Has anyone got any ideas what a good KWh output would be good to aim for on the solar pv side? If anyone has any recommendations for good electric heaters that also would be great.

We are going to have to borrow the money to do this, so it's not a case of working to our budget. Obviously the less we have to spend the better.

Any thoughts and advice much appreciated.

Lucy

[Clara]

Hi Lucy, I'm afraid to say that it would be lunacy to try and convert your house to solar pv the way it is.

Creating heat from electricity is THE most inefficient way of going about things, the guy who installed my system said it was like returning the purest form of energy to the most base.

I can't give you a figure on how much you would need panel wise or cash wise, but to give you a comparison; I just spent 13k Euros on a PV system. It will do for lights, washing machine (though it is hot filled from the solar hot water and the internal heating element is removed), computer, kitchenaid, a few hours of TV a night, occasional use of power tools and in the summer we can use a freezer (but we don't use a fridge ever). So no heaters of any kind, no hairdryers, no electric shower, etc. And here's the important bit: I live in the south of Spain, I have far more sunshine hours than you do.
I reckon you could take that 13K and triple it in the UK in order to have the set up I have, to live like a normal person the cost doesn't bare thinking about. I would say that if you are looking to sell your house then you won't make the return on an investment to convert it to solar, you would lose A LOT of money and besides a lot of people would be put off because regardless of how many panels you have on the roof at some point lack of sunshine will have an impact, you do have to live with the weather somewhat.

IMO best to save the money for converting the house you are actually going to live in to solar, and let the next occupiers make up their own minds how to power the house that is for sale.

[lucy.lists]

Hi Clara,

I hadn't realised that about electricity and heat ... duh.

After reading your post it occurred to me that the guy working on the house has not yet installed the new wood block floor for the living/dining room - we bought it (off ebay!) in 2007 so it's been sitting there 'acclimatising' for quite a while! There has been quite a bit of background damp we've been trying to get sorted first. Given that we've also had a really reasonable quote for carpeting the upstairs ... maybe underfloor heating might be a solution?

I hear what you're saying about letting a potential buyer make the choices about what heating to put in, but I really don't think putting a half refurbished house on the market is going to get us very far. I would prefer to finish the job.

Lucy

[Clara]

I think I read some of your post a bit wrongly and replied with a lack of clarity - what I meant was do the house in a conventional manner and if the new occupants want solar, let them make the investment.

Underfloor heating from the woodburner, electricity or gas, that would make sense, I believe it is more efficient than wall radiators, but again a bit of a no-no with the solar hot water. I had quotes to do a similar thing and I might consider it for a small part of the house, but again that is because even when it is cold here, it is quite likely to be sunny, though even we would have to back up with woodburners in each room (or get a massive backboiler system).

I'm no expert in conventional power, I have lived completely off-grid for about 5 years, so I have no idea what is cheaper in terms of gas, electricity or oil these days. I guess that perhaps gas would be a better option in terms of water heating and its more what people are used to.

Unfortunately until governments are prepared to start serious funding of micro-generation or energy prices run wildly out of control, solar power will never be a sensible choice in terms of money alone (esp in northern europe), unless like me you live kilometres from the nearest pylon anyhow!

[lucy.lists]

Thanks again Clara.

The house could be connected up to the gas main (£500) but I really don't think I can bear to do it. I guess it might come to that, though. If I'd known we were going to be thinking about selling I would've got a heating system linked up to the wood burner, but at that point we were doing the house up for ourselves and we don't like a really warm home.

I've emailed a couple of companies about the possibilities of using a ground source heat pump to run underfloor heating.

We have solar hot water at our house here in France. We're seriously considering running some kind of wood-fired cooker to run some radiators too.

I suppose I know we've got to sort out the heating in the U.K house *somehow* which is going to mean spending more money on it. And if it comes to spending £5000 for a gas-fired combi boiler and radiators or quite a bit more for a sustainable solution, then unless it's off-the-planet expensive I'd rather go for the sustainable solution, and feel positive about it as well as, hopefully, give our house an edge in the market.

[Clara]

I suppose I know we've got to sort out the heating in the U.K house *somehow* which is going to mean spending more money on it. And if it comes to spending £5000 for a gas-fired combi boiler and radiators or quite a bit more for a sustainable solution, then unless it's off-the-planet expensive I'd rather go for the sustainable solution, and feel positive about it as well as, hopefully, give our house an edge in the market.

I totally understand your feelings, I would never ever live with mains anything again, but then I am prepared to accept living in a seriously different manner to the norm.

I think you need to get some serious unbiased advice, perhaps somewhere like Centre for Alternative Technology in Wales might be able to give you more concrete facts and figures. But my gut feeling is that what you are looking at in the UK would be off-the-planet expensive. I'm sure you could find someone that would install a system for a few grand and promise it would be sufficient, but I doubt it would.

My solar hot water cost 2K, it provides hot water and nothing else, a couple of friends of mine have a far more conventional house just up the road and are about to install a system 5 times the size in order to deal with their heating and hot water needs, they will be incorporating their current gas system as a back up, I am interested to find out if it works. Another friend of mine, a rather more practically minded soul has built a small (30m ish) super-insulated double-glazed wood cabin and installed a system twice the size of mine to heat it. He is not living there through the hardest months of the winter and still has a Jotul in place as a back up. Even with all his knowledge and friends in the field he still feels this is experimental and may well not work out, in short he's done it for fun and is own amusement (that crazy german sense of humour!!). Remember all of this and we are still in the south of Spain with a lot more sun than you guys.

I really really hate to sound like I am poo-pooing your intentions, I'm not, I truly admire them, as i said I would never go back to living on-grid, even if it meant having to do without a lot. But I think in a level-headed manner do not make this investment on behalf of someone else, it could well be a wasted effort, they may choose to rip it all out once they realise that they will HAVE to change their habits in order to live with it (or otherwise you are selling to a seriously reduced market). House prices are falling, solar technology prices are rising. And solar power is not free forever once you have made the initial investment, panels and batteries have to be replaced and are rising in cost at a phenomenal rate as demand increases. The worse someone is at looking after the batteries (i.e. moderating their use in line with the weather/season) the sooner they will have to be replaced - I've known many an ordinary expat who wants to live like they would on-grid, trash their batteries in as little as 3 years, that's about a grand a year at current prices for decent batteries.

It might be fair to say that I tend to put the SELF in to self-sufficiency, perhaps a little too selfishly, but I really feel like my money is better put into something that I know I can keep control of and live by example - make the change, be the change and inspire change that way.

[The Riff-Raff Element]

If you don't already have radiators in place, then an air-source heat pump might be the answer.

I don't know about the Deux Sèrves, but in the Vendée virtually all new HLM housing is being built with solar water heating (there's enough sun in the winter to just about run it with a little electric back up - the new systems are that good) plus air-source heat pump for space heating.

Usually this is done through underfloor heating, but where this is not possible (retro fitting or upstairs in some properties) large surface area radiators can be installed. Plus masses of insulation of course.

Heat pumps are the only really efficient way using electricity for space heating that I've come across.

[lucy.lists]

Hi Clara,

Blimey, your solar hot water cost loads less than ours did in France. Mind you we needed a new tank and all that.

I should say that when I was talking about solar pv I was thinking of a grid connected system - so that the grid buys back unused energy but sells energy as usual when the solar supply isn't enough. As far as I can make out this doesn't require any sacrifices, just cheaper electricity and a potential to sell units back to the grid in the summer. I totally hear what you're saying with regards to not doing anything that would require potential buyers/renters to change their lifestyles!

I'm also now wondering about a heat pump running an underfloor heating system with/without solar hot water too. Now would be the time to do it cos we haven't finished the floors yet. There's plenty of garden space for a ground source pump.

Can anyone think of anything else I might have missed? Mainly thinking about warmth for the house and hot water.

Perhaps I'm kidding myself, and perhaps it's not worth it. But I can't help thinking that, with a conventional heating system (which will still cost us money but no doubt much less of it) our house will be on a par with millions of others on the market ... very nice garden, nice floor, nice stove but ultimately very average. Whereas if we could market it as a house for a more sustainable future, that saves people on their bills, well, that might put it a notch above anything else in the neighbourhood. How's that for putting the 'selfish' in self sufficiency!?

Oh Jon, yes, thanks for that .... just seen your post while I was previewing mine and you're saying what I was thinking, really. This heating solution is for our house in the U.K by the way, not for our France house. I have just commented on your blog about your Godin - something else we're thinking about but for France, this time. :-)

[The Riff-Raff Element]

Lucy - I'll post a detailled reply about the Godin this evening (I have to go and scrub the offspring!), but I was wondering whether air-source might work for your UK property. Installation I suspect might be cheaper and easier than ground source... so many choices!

[Clara]

I see you have insulated, have you got double glazing too? I've never lived in a DGed house and I was absolutely gobsmacked by how warm the house I grew up in was (without the heating on) when my Dad got round to it last year. Sometimes it's the simple things eh? But then loft insulation and DG aren't as "sexy" as solar

[Clara]

I should say that when I was talking about solar pv I was thinking of a grid connected system - so that the grid buys back unused energy but sells energy as usual when the solar supply isn't enough. As far as I can make out this doesn't require any sacrifices, just cheaper electricity and a potential to sell units back to the grid in the summer.

OK, can't say I know much about this, but sounds like it doesn't involve batteries, which would be a lot cheaper and more appealing to your average punter. Presumably you might also be eligible for grants?

The ONLY thing I have seen discussed here about this as a potential drawback, is that some contracts required a amount of energy by sold back to the grid, meaning that it was possible that on some occasions one could be obliged to sell everything you were producing and buying back anything you needed to use. Perhaps this has changed, seeing as people got wise to it, but worth checking the fine print of any contract I guess. Also be interesting to know how or if this ties you to one particular provider and therefore be at their whim when it comes to prices.

[lucy.lists]

Hi Clara,

Yes, the house is double glazed ... probably old and not brilliant quality, but it's there. We got a grant for insulating the loft up to whatever the current recommendation is, and also for cavity wall insulation on the one bit of cavity wall.

Yes, the grid-connected solar doesn't involve batteries. From what I've read it 'feels' just like a normal electricity supply, but sometimes you can watch the meter going backwards :-) Those are really good points about being tied to one provider - I'll look into it.

And yes, we'd get a bit of a grant for solar, or a heat pump. But then, being a low income family (despite having 2 houses - how bizarre is that!) we'd get a bigger grant if we installed a new 'conventional' heating system ... bah.

When it was just going to be for us, we were more than happy to curl up by the wood stove, and take a hot water bottle to bed, so we didn't feel we needed to update the heating system. But now we're thinking of selling, I think we've got to update it, somehow, or the house won't sell at anything like it's potential value, if at all.

[fruitcake]

as others have said it looks like air source heat pumps could be the way forward - easy to retrofit - basically just plastic piping with with a 'refrig unit' type thing to convert solar gain - it allows you to heat one side of the house and cool the other too - eg if you are north / south facing. I'm not good on the numbers but it's something like - with electricity you use 1kw energy to produce 1kw heat but with ASHP you can use 0.1kw energy to produce 1kw heat. (pls dont quote me on the numbers but the difference in ratio is astounding - i just cant remember exact nos off the top of ma heid)

You're better off looking at efficiency - like you have done with the insulation. Is the house airtight - biggest source of heat loss is badly fitted window / doors / skirtings / eaves etc. Make sure there's no dimmer switches etc etc
Oh and you'll need to provide an energy performance certificate now I think - certainly if you're renting - that could give some interesting findings - I dont know how much detail they go into - not seen one or been through the process.

Good luck and keep us posted with what you go for. Things are improving re renewables but it would be great to find somewhere / someone who understands all the pros and cons to give householders sensible advice - some of it is just green bling. We looked at all sorts when we were building our house but in the end the price, location, lack of access to new technology, lack of return phone calls from manufacturers meant we installed an oil condensing boiler and underfloor heating downstairs - will put a stove upstairs next year prob and would like to investigate the potential to retrofit solar panels at some point. I'm looking forward to when PVs / woodchip etc become better available.

[Big Al]

Hi lucy,

I've done a lot os searching and research, sorted out what I wanted, changed my mind, sorted it again and again and agian....

For my 2'penneth, for what it's worth I would forget all the sustainable ideas for the england house sad as it may be. Sort out the damp issues, conect to gas install a condensing gas boiler and radiators in each room, paint it up and get shot of it or rent it out. £5k on a heating system seems a lot. I'd estimate around £3500 maybe but worth checking out local prices and prices from further away ocntractors.

You might like the idea of solar power (PV) solar Thermal, wood nurning stoves etc but will the next punter ? you will be seriously limiting your market to greenies or potential greenies if you do the environmental installs. You might not be bothered about chopping logs up and lighting a fire etc but how many others will be wanting to do that when they have had a hard day at work and are used to just turning a tap and having hot running water to have a soak in the tub.

Heat pumps are expensive from what i've seen, maybe £10k or so. Fine they will be economical in the future but you won't be there for the benefits.

If I was in your position I'd certainly not go in hock to provide environmental solutions when I wasn't going to be there.

Sorry if it's not what you want to hear but the best bit is that you will be able to save money and then spend this on your french house and get the benefits there.


As for electric useage, The average home in england currently uses around 7800 kwhrs and that is with gas conected so to be carbon neutral you need to provide that amount of panels. On a house of the size you say it probably won't have enough south facing roofspace to install all the panels even if you have the money to pay for it. A roungh estimat is between £1000 and £1500 per KWhr so for an average 7800 kws you will have to spend around £8000 to £12000 and as electric is currently around 15p per kwh you will need to have the panels installed for at least 10.25 years before they start to pay back...
Not worth it for you in my humble opinion.


( having said that my electric is only 3177 kwh per year and soon to drop to a little over 2000 kwh)

HTH

Big Al

[TheGoodEarth]

Have to agree with most of what has been said, any kind of renewable heating system as a retro fit will be very expensive and will not add any value to your home - particularly in the current economic climate. People will not be paying premiums on homes for a few years to come.

You already have a heating system, although not the most energy efficient, but it is something buyers will be familiar with. If I were you I would freshen the place up and put it on the market at a realistic price for a quick sale and them spend my efforts transforming your main home in France.