Solar heating....very basic questions

Hi I WAS JUST READING THE THRED ON SOLAR PANEL AS I AM CONSIDERING GETTING THEM , AND I AM AMAZED TO SEE THAT THE ROI IS ABOUT 20 YEARS I WOULD HAVE THOUGH IT WOULD BE ALOT LESS THEN THAT THE COST OF HEATING WATER IN MY HOUSE HAS WORKED OUT @ €70 PER MONTH IN THE SUMMER ONLY SAY 6 MONTHS SO THEREFORE SOLAR WOULD SAVE € 420 PER YEAR, NOT EVEN TAKEN INTO CONSIDERATION THAT THEY DO CONTRIBUTE ABOUT 25% TO 40% OF THE WATER HEATING COSTS IN WINTER ,SO WOULD BASED ON THE SUMMER SAVINGS ALONE WOULD IT NOT TAKE 7 YEARS,
THE FIGURES WE HAVE MUST BE COMPLETELY WRONG IF 20 YEARS IS THE ESTIMATED ROI
 
Crikey! €70 per month for hot water? You must be all be squeaky clean. I assume you are using an oil boiler set to hot water only? It may be a very (very very very) inefficient boiler and with a lousy uninsulated cylinder, yes, that's possible.

In calculating payback, people often forget that almost half the cost of an install is changing the cylinder, which usually also offers savings for the whole year.

You can put in a 40 tube 200L system for just under €3,500 after the grant. The payback on that should be well less than 20 years on that... Q
 
Can I ask if there is any benefit in having geothermal and solar panels installed in a new build or is it pointless? The geothermal will be heating the house and water, I just wondered if solar panels would be more economical in the summer months for heating the water?
 
bartbridge said:
Can I ask if there is any benefit in having geothermal and solar panels installed in a new build or is it pointless? The geothermal will be heating the house and water, I just wondered if solar panels would be more economical in the summer months for heating the water?
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Geothermal isn't great at getting water right up to the temperature required for domestic hot water, so there is usually a more expensive top-up measure. Also, you probably won't want to use the geothermal at all for most of the summer time, and that is when solar works best.

Installing solar on a new house isn't expensive, and will help your BER assessment and help you meet your Part L compliance etc. as well.
 
DavyJones said:
€500 seems a bit high, remember you will only get useable hot water for half the year, doing well, this in effect doubles your payback time.

Most if not all installers won't want your help. they will have a fixed way of doing something and will want to get on with it.
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You are assuming that the panels do nothing all winter.
The water coming into your tank from the cold water supply is approx 12 degrees. Our solar panels heated our water to at least 22 degrees all last winter, which significantly reduced the cost of water heating all winter.
One day last winter there was snow on the ground, and the panels were working and the water was 30 degrees.

I do agree with the estimates of payback time of 6 to 10 years, at current oil prices but I dont see the price of oil going down.

I dont get why people think that the tubes are ugly and the flat panels are alright. I think both are slightly ugly, but unless you are standing on the pavement across the road looking up, you dont notice it anyway.
 
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