Help me be efficient - electric heating water and house?

[chrishamblin]

Hi All,

First post me for here despite looking up many a tip over the years so I hope its in the right place.

We have just bought a large chalet in the French Alps which we are rennovating for future use as a chalet holiday business. Currently the house is 100% electric, there are two large immersion heaters for hot water and a combination of electric radiators and cable underfloor for heating.

At the very least we will need to up our hot water capacity - the current setup is for family use for two bathrooms. The chalets capacity will be up to 14 adults all wanting a hot shower!

The easy option is obviously bigger immersion tanks and this seems to be the trend out in the alps. So I have some questions:

• 1) Is there a budget concious alternative? We will have limited funds so wripping everything out and starting again probably isnt an option.
  2) Is there a semi DIY route possible for some kind of biomass system (to keep the costs down)? I'm generally profficient with most building and plumbing matters but have never touched a boiler.
  3) If we have to stay all electric how can we make it as efficient as possible?
  4) Are there any particular types of immersion heaters or electric radiators etc which we should be looking out for?

Sorry for so many questions but if anyone has any experiences to share that would be much appreciated!

Thanks,

Chris

 

[dcawkwell]

It depends on what prices your fuels are.

If you are there then consider anything and work out the costs.

If it was the UK I would have said air source heating but if temperatures
are low your alternatives are ground source.

The cheap solution for the moment are immersion heaters.

 

[DeltaT2]

I certainly think you're on the right track regarding your hot water needs, a bigger tank etc.... Have a look at what you are paying for your leccy in France - what tariff are you on? There may be a cheaper one?!

 

[thatbloke]

What fuel source do your neighbours use? Or the neighbouring hotels etc? This might give you a rough idea.
I know that geothermal heat pump systems are quite popular in Switzerland where winter temps are quite cold, I dont know if this is in the Alps or the lowlands though.

 

[chrishamblin]

Not sure what the neighbours use, I will check. Certainly of the chalets we have been in used for business before most use electric immersion heaters with the odd few oil fired boilers around. This I guess is mostly down to the install costs.

I know geothermal is used nearbye, but I don't think I have the budget for that, I'm guessing I'd be talking €15-20k which just isn't going to pay back quick enough. I'd like to reduce or limit our energy bills but our budget is stretched already so upfront cost is just as important, maybe more so.

I guess in my mind there are only really two options:

1) Keep on electric but get the most efficient stuff we can - which is one of the things I would like some info on? Surely an immersion heater isn't just an immersion heater, or is it?
2) Try to put in some kind of solid fuel burner, wood pellets etc. But I fear even this could be too rich for us which is why I was wondering if a DIY install was an option? If a €3-5k investment on kit could re-pay itself in less than 5 years it would be of interest. More expensive than that with longer repayback than that isn't likely to work for our circumstances.

On electric costs, I think France is a bit cheaper than the UK, on avg. I think they are supposed to be 10-30% cheaper than the EU avg, but it still adds up!

Any thoughts?

 

[DeltaT2]

Yeah a log stove would be a great added feature to any Chalet, but if you're letting it out, then of course there's the added fire risk.

 

[chrishamblin]

It will have a wood burning stove in the main living room in any case.

What I mean is a wood or solid fuel burning boiler primarily to provide hot water but possibly also additional heating (I.e. radiators).

 

[Steve]

A 3kw heater is a 3kw heater. You wont find anything more powerful or efficient. But electric heating of any description is always terribly inefficient and expensive (think about the energy transfers involved in producing the electricity, then converting it to different voltages for dist'n and then back into heat, compared with that of a gas flame heating the water. There could be 10-15 transfers with leccy, only one with gas.)

The only thing you can really do to make it more efficient is have a highly insulated, modern tank. The bigger the better, by the sounds of it.

 

[muggles]

How about solar photovoltaic? Look into available grants in France, it may be that you can get a good deal on PV panels, and run your cylinder immersions off them. Bigger cylinders with better insulation may well be the way to go, possibly with bigger elements in them if the PV panels can provide the supply.

 

[Steve]

How about solar photovoltaic? Look into available grants in France, it may be that you can get a good deal on PV panels, and run your cylinder immersions off them. Bigger cylinders with better insulation may well be the way to go, possibly with bigger elements in them if the PV panels can provide the supply.

Using Solar PV to HEAT a tank of water - isnt this a bit pointless? Wouldnt it be better to use (cheaper?) water solar collectors and heat the tank directly with the sun's heat?

As I understand it, solar PV panels on homes only go up to about 4kw peak power (though the more you use the higher this is), so using them to power a 3kw immersion is out of the question when on average the actual power is a lot lower (500w-1kw on an overcast day). Yes you're going to shave a few pence per unit off, but in my opinion its not the best method.

I dont know the figures on water solar collectors unfortunately. But SPV is ideal for low loads - lighting, TVs, computer. Water solar must be the best method of the two for actually heating surely? Can anyone comment?

 

[HERTS P&D]

Tell her to stay at her mothers while your doing it up and she can come back when its finished.

Approx. in 10 years.


Andy