Green Moneysaving - Is this an oxymoron?

RenovationMan

I've been looking at 'green' technologies to incorporate into my house in order to both reduce my footprint on the planet AND reduce my outgoings. After looking at Rainwater Harvesting, Solar PV, Solar Water Heating, Ground Sourced Heat Pump, Air Sourced Heat Pumps on here and other forums/web sites I reached a very disillusioning conclusion that for on-grid households you simply cannot beat being attached to mains water, mains electricity and mains gas.

It seems that as far as owners of mainstream houses are concerned, the best way to save money is to pack your house with insulation, buy low energy electrical products, fit a new condensing boiler and make sure that all toilets, taps and showers are water saving.

Have I come to the wrong conclusion?

Cardew

With a couple of reservations, I would agree with your post.

IMO there is no justification in replacing a working boiler with a new condensing boiler. The savings of modern condensing boilers are usually quoted as 90%+ , however in practice this is apparently rarely achieved. It also costs around £3,000 in most cases to change a boiler, and modern boilers are far more complex - and hence less reliable.

To a lesser extent the same applies to 'white' appliances. Rarely will the savings justify the capital outlay for replacement.

Without doubt the most cost effective measure is insulation, insulation, insulation!

spadoosh

You need to look at the payback periods and the longevity of the system your installing and your current systems.

Ive seen a better one but cant find it, this gives you an idea of payback periods. But like i said ive seen somewher that if you have upvc windows that are 10/15 years old you might think they need updating and will be loads more efficient but from what you gain it could take 100s of years to recover the cost. Similar to scenario as the boiler ^^^

Yeh i go with insulation and draught proofing! Unless you need to change something in which get the most energy efficient you can afford

RenovationMan

Yes, sorry I should have said 'replacing boilers & electrical appliances when exisiting ones have reached the end of their productive lifetime'.

celerity

I share Cardew's scepticism of investing in a condensing boiler, especially if there is nothing wrong with the existing one. I'd personally spend the money on a wood stove (see below).
Other than that, you are pretty much spot on for your list of priorities (in my opinion).

Solar PV would help make an "eco statement" but even with the generous FiT rates (which go down next April) you are still looking at around a twelve year payback, and you would want people in the house during the day (absolutely stack loads of threads on this forum with more details ).

I haven't looked at ROI on rainwater harvesting systems, but on a £3K install I would expect the payback period to be decades quite honestly (that is a guess though).

If you are keen on gardening, getting some cheap water butts might eventually pay dividends (and result in less chlorinated vegetables ) but they would have to be *really* cheap and well used to recoup the investment any time soon.

Heat pump tech makes way less sense if you are connected to mains gas (it's more suitable for unlucky sods like me who have to use oil!).
Thermostat "zoning" might make sense depending on the layout of your house. You can get wireless 'stats now so installation is far easier.
One thing you might want to look at is getting a wood burning stove to supplement your heating, especially if you can source cheap or free seasoned wood. Wood stoves are far more efficient than open fires, and start at around £600 to buy, and maybe £1,200-£1600 to install. Like everything, you could save a bundle if you're capable of doing the bulk of the work yourself. Unlike other eco-friendly* technologies, I'd suggest a wood stove would add lots of non-financial benefits too - it's just a very pleasing source of heat for your home .

If you need new windows, I'd look into the costs of getting more advanced double / triple glazing, especially if you have lots of large, glazed areas.

Hope that helps, and if you do make any changes to your home or usage pattrns, do post to let us know!

/\dam

* Burning wood is carbon-neutral in theory, but not in practise, as it has to be transported to your property. Provided you use wood from sustainable forests though, the carbon footprint is still considerably better than gas.

RenovationMan

I do have a multifuel boiler stove attached to a heat bank but I have started to doubt its green credentials even compared with mains gas after reading forums and websites recently.

http://www.aecb.net/new_releases/detail/?nId=10

"According to the authors, the consequences of current mainstream thinking on biomass as a fuel leads to a ‘lose-lose-lose’ situation:

· Once when the biomass is burnt, releasing twice as much carbon as burning gas for the same heat output.

· Again when the building leaks energy, because insufficient attention was paid to energy efficient building fabric and plant design – i.e., the biomass boiler "did it all".

· And further, there is a risk that the timber price is pushed so high by the competition from a growing number of biomass burners, that concrete, bricks and steel have to be created, at very high energy and carbon costs, to make building components that could otherwise have been made from wood."

Some information about the damage that particles from woodburning stoves do to people: http://burningissues.org/health-effects.html




After discounting all of the more exciting green technologies I have come around to the idea of spending my money on simply insulating the house as best as I can. So far I have had multifoil insulation installed above my rafters and 100mm kingspan installed between and under my rafters. I'll be lagging all of my hot and cold water pipes and filling the ceiling/floor cavities with rockwool. I also intend installing internal wall insulation as I have solid walls, but I need to research this a little more to make sure I am not introducing damp issues into the house, etc.

celerity

As far as I can tell, that article fails to take into account the carbon footprint of extracting natural gas / coal in the first place?
"Leaky buildings" is a red herring in the argument too - the building would be just as leaky were it being heated with oil or gas.
It also neglects to factor in that burning wood is sustainable, whereas burning fossil fuels isn't.
Finally (for now), it doesn't discuss any of the green wildlife benefits of having newly managed sustainable woodland in our country.

I can see the argument for not converting a coal power plant to use biomass to generate electricity - but I wouldn't extend that argument to conclude that using wood to heat a domestic residence is a bad idea.

Update: I googled the original paper, it is has generated a fair amount of debate as to how accurate it is, eg: http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=6241 and http://www.aecb.net/forum/index.php/topic,2649.msg10528.html#msg10528.

By the way, would you mind explaining what your "heat bank" is? It sounds interesting!

Cheers,

/\dam

RenovationMan

My heatbank was bought from these guys:

http://www.heatweb.com/Wood/index.htm

It's basically a very large cylinder of water heated up by any combination of gas, electric, solid fuel and GSHP and it provides central heating via underfloor heating or radiators and drinkable hot water via a heat exchange plate.

I have mine connected to a multifuel boiler stove, gas boiler and lelectricity for emergencies. I was considering attaching solar but I just can't make the sums work.

celerity

Cheers, that is a potentially very useful page for me.

/\dam

RenovationMan

No problem. PM me if you want any information about heat banks and I'll try my best to answer.

Ben84

celerity wrote: »

If you are keen on gardening, getting some cheap water butts might eventually pay dividends (and result in less chlorinated vegetables ) but they would have to be *really* cheap and well used to recoup the investment any time soon.

We do sometimes have hose pipe and garden watering bans here during the summer, so being able to water your plants can be worth the investment. They can also be a cheaper DIY alternative to fitting an outside tap and will give you a convenient outside water source. To consider the environment aspects someone will have to find a way to compare producing the plastic and transporting it to the potential water savings, which is somewhat subjective at best. However, many more frivolous things are made every day, so I would say buy one if you'd find it useful.