What price would tempt you to go solar?

luckat

I saw a couple of guys installing vacuum tube solar panels the other day and stopped to talk to them.

They said the installation normally costs from €4,000 to €6,000, and there's a government grant in some cases of €750 to €1,500.

They said - but didn't actually whip out any ESB or Airtricity bills to prove it - that heating the water using solar panels could save you up to €1,000 a year on your electricity bills.

I thought, hmm, I'll think about it but wait until the price is a bit more doable - maybe it'll come down with economies of scale, or as better technology is produced.

What price would tempt you to install solar panels?

Cookie_Monster

TBH I don't think I would at any price at the moment. the technology just isin't good enough yet and is likely to improve a lot over the next few years. I don't really see the point in putting up panels that only heat water rather than generate power.

I know our house really uses very little hot water. Power shower, no need for immersion etc. Maybe if it could be linked to the heating system.

homer911

Look at it this way: Do you have 5k sitting in a deposit account?
5k @ say 5% interest=€200 after DIRT pa

If you save more than €200 in water heating bills pa, (at current energy costs) then you are generating a return on your investment

maniac101

luckat wrote: »

They said - but didn't actually whip out any ESB or Airtricity bills to prove it - that heating the water using solar panels could save you up to €1,000 a year on your electricity bills.

..assuming you're using electricity to heat your water. Even so, that seems like a lot of electricity just for water heating. We heat our water using the boiler only (smallish highly insulated ss tank). I reckon this costs us much less than €300 per year (I'll have to do an accurate calculation). So solar would need to be a lot cheaper before it would save us money. That said, we did consider it a couple of years ago, but the space needed for the solar tank would have involved knocking and rebuilding internal walls, and we didn't need the grief. Those fitters probably weren't taking those potential additional building costs into account.

homer911 wrote: »

Look at it this way: Do you have 5k sitting in a deposit account?
5k @ say 5% interest=€200 after DIRT pa

If you save more than €200 in water heating bills pa, (at current energy costs) then you are generating a return on your investment

Not sure if this is a good way to calculate the return. After ten years you'd still have €5k in the bank (if the bank didn't go bust in the meantime), whereas your solar panels would probably need replacement. But your €200 figure for potantial annual savings is a lot more realistic than what some installers would promise. That's a 25-year payback by the way.

jobrok1

Cookie_Monster wrote: »

TBH I don't think I would at any price at the moment. the technology just isin't good enough yet and is likely to improve a lot over the next few years. I don't really see the point in putting up panels that only heat water rather than generate power.

Using solar water heaters is far more efficient than using solar PV to produce electricity.
Granted! You'll need to suppliment it with another heating option during the colder 5 - 6 months of the year and dull days during the warmer 6-7 months. But for the most part of the warmer months you will have mostly free hot water. All it costs is the equivalent of 1 conventional light bulb to power a circulation pump.

Cookie_Monster wrote: »

I know our house really uses very little hot water. Power shower, no need for immersion etc. Maybe if it could be linked to the heating system.

That statement is kinda flawed. By power shower I presume that it has a heating element to heat the water, or else you have oil or gas to heat the water before hand. With solar water heaters you eliminate or reduce the amount of fuel/energy needed to heat heat it in the first place.

Cookie_Monster

jobrok1 wrote: »

Using solar water heaters is far more efficient than using solar PV to produce electricity.

Thats my point, solar for leccie just isin't efficient enough yet...yet... /crosses fingers in thwe hope that it will be:)/

jobrok1 wrote: »

That statement is kinda flawed. By power shower I presume that it has a heating element to heat the water, or else you have oil or gas to heat the water before hand. With solar water heaters you eliminate or reduce the amount of fuel/energy needed to heat heat it in the first place.

Shower unit both heats and pumps it all in one device... you still need the pumps so the water heater is a bit irrelevant by itself, it just wouldn't be cost effective. Dishwasher, washing machine both heat their own water. Other than having a shave or washing the odd pot i've no need for hot water (to justify such a large cost)

jobrok1

Cookie_Monster wrote: »

Shower unit both heats and pumps it all in one device... you still need the pumps so the water heater is a bit irrelevant by itself, it just wouldn't be cost effective. Dishwasher, washing machine both heat their own water. Other than having a shave or washing the odd pot i've no need for hot water (to justify such a large cost)

And that's my point. You say you don't need much hot water from the tap, except for washing up or shaving. Fair enough.
But you DO need hot water to shower also! The electric shower is a very inefficient method of heating water as it needs to use a lot of power to heat the incoming cold water to the desired temperature. When you have a whole family using it every day it adds up on your ESB bill.

Whereas in our house we don't have electric showers at all. And all our hot water needs are met for significantly less than the cost of yours.

Yes! It's a big capital investment, but for half the year at least you won't have to worry about having to switch the immersion on every day, or timing the heating to come on, or relying on an electric shower for your hot water needs.

Tipsy Mac

If there was a break even point on them after 10 years and little to go wrong with them in that time I would be interested, otherwise I'm not.

bogtreader

I would need to be more convinced to have solar panels installed at the cost it is at the moment.What about the lifespan of the panels internal corossion an the like

luckat

What's solar PV, please?

jobrok1

luckat wrote: »

What's solar PV, please?

Solar Photo Voltaic Panels.
These are the type that produce electricity.

Much lighter and easier to install that the water heater type, but unfortunately far more expensive. This is they type of solar panel that needs to be developed further to become more effeicient and cost effective.

Glowing

Solar PV = Solar Photovoltaic, generating electricity from the sun using PV panels. Not cost effective or efficient yet.

Solar Thermal Collectors/Evacuated Tubes/Flat panels - use the sun to heat your hot water. A much cheaper option for Ireland and the UK.

yop

Solar Photo Voltaic Panels, are there better technologies in other countries do you think or is it just all countries which are behind?

Never heard of them at all, thats interesting. I presume though we would need another fuse board with back up (ESB) available also.

jaycen

Personally I would want a grant of upwards of 50% of the cost before I'd consider it, I would also need to know for sure that it was worthwhile installing them at all.

homer911

Couple of points - DIRT has gone up, so you will get less on your 5k, rates are coming down and energy prices are very definitely going up (checked your ESB or Gas bill recently?), and what about EIRGRID spending €4b on upgrading the network and adding a further levy on your bill.

What might start out now as a poorish return on your investment over 25 years, will become a better return as prices go up and (hopefully) improve the value of your property when we all need to get energy ratings in order to sell them..

Should also add that I have three teenagers in my house...

GG66

Agreed Solar PV is currently uneconomical !!

I've got Solar tubes and we've had free hot water since April.... NO additional heat source except

a couple of periods of very dark overcast weather of about 6 days where we had to turn on heating (wood pellet). You don't need direct sun to get heat from it

We only just started putting on the heating last week due to temperature..

Long Term it is definetly worth the 3k or so that I paid.

10-10-20

It's doesn't matter what price you pay for the system, it's the time it takes for you to see a ROI.
Before the major price jumps (mid 2006), I calculated this as being 17 years. Hardly worthwhile when the system warranty only covers 10 years!
But, given the more recent price increases, the ROI may now be more like 14 years or so.

jobrok1

10-10-20 wrote: »

It's doesn't matter what price you pay for the system, it's the time it takes for you to see a ROI.
Before the major price jumps (mid 2006), I calculated this as being 17 years. Hardly worthwhile when the system warranty only covers 10 years!
But, given the more recent price increases, the ROI may now be more like 14 years or so.

How do you come up with 17 years?

That seems a bit high! More like the ROI time for solar PV panels.

saibhne

Check out the document on this page - it is a Good Practice Guide from the energy saving trust in the UK. There are figures which detail the percentage of energy different households use heating water.

The biggest use is space heating but coming in close is water heating. This percentage rises to as high as 25% of the total energy use the more well insulated the house is.. As passive heating design and insulation techniques advance as do prices of carbon based heating fuels this percentage will increase to the point where it will eventually cost more to heat your water if you continue to use fossil fuels, than it will to heat your house .

Solar water heating is a highly advanced global industry with the technology being very mature, any advances in technology will only provide mimimal increases in energy efficiency. There is nothing in the pipeline technology wise that is going to change the economics of these systems drastically. What will change the economics will be the price of gas, oil and electricity which will only increase by large percetages in the next few years as these resources dwindle.

Germany and Austria began their solar thermal industry about 15 years ago and their solar thermal market has continued to grow since. The Irish solar thermal market has tripled in the last two years but it's penetration per capita is miniscule in comparison to Continenatal Europe. Crucially northern Europe like Austria and Germany have the same basic solar resource as Ireland, there is no reason why it would make more sense there than here. This can be seen here
. Check the document on this site out and you can see the growth in per capita installations over the last 10 years throughout Europe.

It is now Irish law that any new house granted planning permission from September this year must provide for 10Kwh/m2 of its' floor area by a renewable source e.g. a 120m2 house must beable to provide 1200KWh per year from a renewable source - the easiest and most cost effective way to install this ability is to use solar thermal. Every house in Ireland will eventually have a solar water heater installed, it is only a matter of time..

10-10-20

jobrok1 wrote: »

How do you come up with 17 years?

That seems a bit high! More like the ROI time for solar PV panels.

I'm really sorry - I made a mistake.
This was a calculation for photovoltaic solar and not solar heating tubes.