Energy saving on new build

Although it might be a couple of years before I begin building, I am currently looking into things to try to save on energy costs due to the alarming rises seen recently.

I have read many reports on the solar panels and geothermal heating, and there seems to be various pro's and con's of both. There seems to be a high installation cost and very gradual returns on them, although in the long term they would probably pay for themselves?

Has anybody installed solar panels as an add-on to their property?

Has anybody got a few years experience of geothermal heating?

Does anybody use a wind turbine? If so, what do they cost and what savings can they provide?

Any feedback welcomed.

Geothermal needs electricity to work. Every unit of electricity used in Geothermal might produce 3 or 4 units of heat.
So if you spend €100 heating your house with Geothermal, you get the same heat as spending €400 Euros if heating your house with electricity powered radiators.

If you know how many Kilowatts of heat your house will need annually, then some fairly simple maths will tell you the payback time for your investment in Geothermal.


If you want to cut down on energy costs, the most economical thing to do is to build a very energy efficient house.
You want the heat produced in your house to be retained. It's got to be very well insulated, and airtight. Do a google on "Passive House" to see some info on a German standard of energy efficient building.

If you build a house to this standard of insulation and energy efficiency etc, you won't be bothered if the price of a unit of heating goes up, because your house won't need much energy.
A Passive house may need only 15kw/square metre of energy per annum. If you build to this standard, the payback time for Geothermal will be very long, because you will use very little energy.

Fixate on this list...... frompriority working downwards

1. workmanship
2. insulation + u values of elements of construction
3. air tightness
4. maximise passive solar design
5. efficiency of heating system
6. control over heating system

from this list you can see that it you have a well made, highly insulated air tight house, it doesnt matter what fuel you consume to heat the house once the heat is trapped within.
The 30,000 spent on a geothermal UFH system would go a long way towards making your dwelling passively heated.

highly insulated air tight house, it doesnt matter what fuel you consume to heat the house once the heat is trapped within.

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This is exactly right, you can use any traditional fuel, but not a lot of it, Im building at the moment and this is the attitude I’m using, save your money as new renewable energy’s are overly expensive in Ireland, The only one I see that has a reasonable payback time in hot water from solar panels - Insulate, Insulate, Insulate!

i installed solar panels last october,am very pleased with them as they saved me money straight away.
the one thing i noticed when researching is the price veriation,so be carful,one co' quoted twice the price for the job i had done and they also wanted me to get my own plumber as they didn't do the final fixing;lol,then they all blame each other if you have problems,i don't know if i can mention companies so i wont at this stage but the after sales service was fantastic and still is from the co' i chose.
anyway getting back,they heat the water in the winter between 30-40 degrees,on average,the lowest was about 18,the hardest and most expensive water to heat is between 0-10 degrees,my point is i can have a tank of hot water in 10-15 mins which is very little oil usage,so i've saved in excess of a tank of oil last winter.
on a second note a lady was telling me about geotermal,where they lay the pipes in the ground and draw the heat from the earth,well the husband didn't believe it,"not here in ireland",so insisted on having the oil installed,that was two years ago,they haven't used a drop of oil.wish i had done it.

I have a small wind turbine and solar photo voltaic panel on my site. Both charge a battery bank, from which I power some outside lights, and other appliances. I installed these more as a hobby than anything else though, as the pay-back period is way too long - if indeed there is any pay-back at all, due to the cost of replacing lead-acid batteries, etc. Until the government provides grants for a setup like this, I don't feel it's worth it. You will never generate the kind of hWhr's that the people selling the products claim.

Solar water heaters are another proposition though. As other posters have said, I think these are well worth the investment. Once you understand that the savings are to be made by lifting the temperature in your tank by only a few degrees (and not heating water to showering/washing up temperature, which will never happen in this country), then you'll appreciate that the investment is worthwhile. Its all the more attractive because of the SEI-administered grants.

Folks..I keep reading these posts advocating solar & the return on the panels, & the more I read, the more confused I get. Given that we require some form of space heating in this country for 9+months of the year, don't we have DHW as a byproduct of having the boiler running. Therefore, we only require energy exclusively for providing DHW less than 12weeks of the year? My logic then is that the significant capital costs of installing solar are not justified to cover the relatively modest annual cost (in the grand scheme of total energy costs for the year) for providing DHW for these circa 12 weeks? Anybody concur with my thoughts or am I incorrect? Thanks, apple1

apple1 said:

concur with my thoughts or am I incorrect? Thanks, apple1

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I've always thought that way. The pay back on solar panels (even with the grant) at the prices we pay is simply too long. If you are paying cash for them then maybe it makes more sense but if you are building a house this is likely to be borrowed money that will incur interest. What is the actual life span of the panels because I don't believe there is any hard evidence on this.

I'm still putting them in (for green reasons) but I will be stunned if they ever pay for themselves.

yob said:

the hardest and most expensive water to heat is between 0-10 degrees

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Is this true ?
Does it take more energy/time to raise the temp of water from 0 to 10 degrees than from 25 to 35 degrees ?
What's the explanation for this, or do I need to go back to my Physics class, or my common sense class ?

hi louiscribben,
well this is what i'm led to believe from the experts,and i do believe it because to heat water from cold takes a very long time,yet i can heat water from 25degrees to say 50-55 in 10 mins,there the practical facts.yob

yob said:

i installed solar panels last october,am very pleased with them as they saved me money straight away.
the one thing i noticed when researching is the price veriation,so be carful,one co' quoted twice the price for the job i had done and they also wanted me to get my own plumber as they didn't do the final fixing;lol,then they all blame each other if you have problems,i don't know if i can mention companies so i wont at this stage but the after sales service was fantastic and still is from the co' i chose.
anyway getting back,they heat the water in the winter between 30-40 degrees,on average,the lowest was about 18,the hardest and most expensive water to heat is between 0-10 degrees,my point is i can have a tank of hot water in 10-15 mins which is very little oil usage,so i've saved in excess of a tank of oil last winter.
on a second note a lady was telling me about geotermal,where they lay the pipes in the ground and draw the heat from the earth,well the husband didn't believe it,"not here in ireland",so insisted on having the oil installed,that was two years ago,they haven't used a drop of oil.wish i had done it.

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Thanks everybody for your feedback.

It is mostly along the lines that I have been reading on the net when I was researching. It appears that the most important thing is great insulation and retaining any heat that you pump into the house in the 1st place.

I am also slightly skeptical of any of the new energy saving devices such as wind turbines, solar panels etc. I believe that they are just too expensive and would take a long long time to pay for themselves, thats if they ever did!!

And finally on to GeoThermal. The poster above mentions that they haven't used a drop of oil since installing it. But I thought that this was the whole idea. If you install GT then you don't need to install oil heating. They are mutually exclusive. It has nothing to do with Ireland being a cold hole, as the heat is coming from many metres under the ground, where it is warm no matter what country you are in. But the problem I see with GT is the huge outlay in the 1st place. I know a few people who have installed it and it ranged from €24k to €30k - that would buy a whole lot of oil, even at todays prices. And you have to remember that it still uses a lot of electricity and costs approx 30%-35% of the price of oil anyway when electricity use is factored in. And you hear about a lot of maintenance problems with the pumps as well.

So I think that I when I finally start to plan my build I will be looking at insulation as the 1st port of call, and forget about the really expensive energy devices.

LouisCribben said:

Is this true ?
Does it take more energy/time to raise the temp of water from 0 to 10 degrees than from 25 to 35 degrees ?
What's the explanation for this, or do I need to go back to my Physics class, or my common sense class ?

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No- it takes the same amount of energy to raise it from 1 deg. to 11 deg. as from 80 deg. to 90 deg.

(Unless there is a change of state - e.g. ice turning to water).

Apple:
By having solar heat your water, you reduce the heat load on your heating system, so you will use less fuel even in winter.