Solar panels - pros and cons ?

S

Setanta12

Registered User
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Mrs. Aetius are back from a well-earned break. On the continent, admittedly in warmer countries, we noticed fields of panels - and at home here in Ireland, we've noticed one or two houses with them on the roof.

Are they worthwhile ? Any real savings here?
 
Kildavin
you have to ask more specific questions

define worthwhile ?

and set the parameters for enviro/cost/comfort savings ?

btw:
PV create elec &
solar thermal heat your water

both have 'real savings'

why not review the SEAI website

come back then
 
Ok, a little more research done.

We have a typical home but ... are usual utility bills mostly taken up with costs of heating water ? Summer, and Winter ?

Puff pieces suggest 70% savings at least in the Summer months with payoff coming in Year-6.

Pipes (evacuation tubes) seem a much better bet than panels.

Am I correct so far?
 
Yup except for most of utility bills accrued to hot water, 70% savings & pay back in year 6.
 
Mixing up two types of panels here. The ones you are seeing on a field scale in the UK and elsewhere are for generating electricity. They work because they are supported by incentives. Here there are none. So unless you can use all of the power produced, (e.g. a supermarket with a lot of refidgeration during the day), it doesn't really stack.

Solar thermal to heat water does work if you have a house that uses a fair amount of hot water. It should provide all your hot water for free during the summer months when the heating is off and the hot water comes from a more expensive immersion.
 
Thanks for the above.

To my mind, if you have the readies and a normal 3-bed home with kids - it seems like a no-brainer ? (If so, whya ren't they more popular?)
 
Kildavin said:
Thanks for the above.

To my mind, if you have the readies and a normal 3-bed home with kids - it seems like a no-brainer ? (If so, whya ren't they more popular?)
Click to expand...

Regarding solar panels to heat water.

If you get answers to 2 questions

1.How much will it cost to install?

2. How much will it save each year

You will know why they are not more popular.

Beware that while the answer to question 1 should be reliable if you get a quote from an installer, any answer to question 2 will only be an estimate, and maybe over optimistic.

The cost for a new build should be a lot less than for retrofitting to an existing property.
 
cremeegg said:
Regarding solar panels to heat water.

If you get answers to 2 questions

1.How much will it cost to install?

2. How much will it save each year

You will know why they are not more popular.
Click to expand...

From reading whats out there;

1 - EUR4,000 - EUR5,000
2 - 70% of Summertime costs / nothing ever quoted re Spring/Autumn/Winter costs - other than ...

... payoff generally guaranteed in Year 6.
So Yr7, Yr8, YrX ... ...

Still seems like a no-brainer. Better return than leaving it on deposit.
 
Regarding solar power water heating panels.

Had a company come out and do a survey of house of 4 adults and 1 child as solar heating requirments are based on water usage not house size. Cost of system was appprox 7k got the usual speal about sign in garden reduction, but basically a lot of what the guy said with regards to cost saving and how he calculated it was totally bogus.

The energy saving trust in England did a survey of houses in the UK and Ireland with solar heating and concluded that the yearly savings on a properly installed solar system is £60/year compared to using gas and £85/year over using an emerrsion.

The report was called "Here comes the sun" and can be viewed/down loaded from the [broken link removed]. There's is a lot of useful information here about all types of heating system.

In some cases, a poorly installed system the cost of running the electric pump in the solar system cost more than any savings.

In short it just ain't worth the money, you'd be far better off getting a more effiecent boiler and a lot less disruption to your house and no ugly panels on the roof.
 
Last edited by a moderator:
We installed two panels about five years ago and also connected the back-boiler of the solid-fuel stove into the system. When the sun shines, we don't light the stove and vice versa. The result is that we have never put on the immersion in all those years and have an abundance of hot water (and that's with a teenage girl in the house). It's 100% from the solar panel throughout the summer and the panels have never required any maintenance.
I've also switched the washing machine and dishwasher to use the surplus hot water, at the turn of a tap as required.
Best thing we ever did.
 
We have solar panels for 2 years now and they have supplied all our hot water needs throughout the summer months - and do warm up incoming supply on a sunny day in winter.

We have been advised that the circulating coolant needs to be replaced regularly every 2-4 or 5 years - have you ever done this?
 
I never changed the coolant or did any servicing though the installer left me a five gallon drum of the stuff. I must get a service one of these days and herself tells me that they were installed eight years ago not five.
It's amazing how much sunshine we have in the winter. Often I hear the pump whirring when you'd think it is darkest winter outside. Our panels are on a 45 degree angled roof and facing a little west of due south in a very open site.
 

No one can guarantee you payback in 6 years.
This assumes that you save 800 a year just on hot water. Are your hot water costs really that high ? If so, you should consider better tank lagging, and turning down the thermostat. Much cheaper solutions.

We have had a solar panel for 5 years now. I am glad we did it, but we have saved a lot less than 800 a year for the last 5 years.
 
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