Solar Power-is it worth it?

stoney97

Yes, i know its the future with environmental impact, but financially is it worth it? Does it reduce gas and elctricity bills enough to warrant the initial outlay? My utilities are going sky high at the moment.

Cardew

Welcome to the forum.

There are loads of threads about this if you visit the 'Green Money Saving' section of MSE.

Essentially at the prices charged currently for either solar Hot Water or Solar Electricity, it is nothing more than a joke in Money saving terms.

Making matters worse the solar 'industry' is riddled with rogues that make the infamous Double Glazing salesmen of yesteryear seem like saints.

If you really do some research you will find that £30 to £40 a year are your likely savings for Solar HW if you have gas.

Don't forget also that the system needs electronics, has a pump that eventually will fail. You will need to get up on the roof and clean the panels of grime and bird droppings from time to time.

Solar Electricity is currently(sorry) even less cost effective. Although informed opinion is that when they start getting panels produced at low prices(i.e. China getting in on the act) and get rid of the 'get rich quick' merchants installing systems, it has a brighter(sorry again) future.

Personally I don't ever think Solar Hot water will ever be viable financially, but in the long term solar electricity might have a future.

landyv8

I have had solar water installed last year and for me I am very happy with the system, price paid and saving predicted.

We moved into the house last year and as part of the renovation we needed a new hot water cylinder, so that was off set agaist the cost.

The house is 5 bedrooms 3000sq ft, running on oil for both heating and hot water (solar). The boiler is less than 3 years old s running at approx 95% eff.

As part of the solar, we added cavity wall insualtion, extra lost insualtion draft excluders energy bulbs.

Our hot water is heated via via the central heating running through one of the coils in the new tank (as it was before) this also links into the AGA (but do not have that on now it EATS oil)

So if we wanted hot water in the summer (for example) we would have to have the central heating on! Not good. All radiators are on thermostatic valves except two which are just basicaly high tec pipes with metal fins. So these rooms would get hot.

We have not had the heating on scince the start of May and thefore all of our hot water has come from the solar at 60 Deg C.

Based on last year we will not switch the heating back on until September

i.e 5 months not using ANY heating oil which is currently about 45p per L

So based on my usage I would say I am now saving 1 tank per year i.e ~£450.

In addtion to this even in the months September to May, we get solar gain of upto 40 -45 deg, therfore central heating is only heating water from 40-45 to 60 rather than 15-20. ANOTHER saving.

Winter is actualy a good time for solar haeating, a bright clear day with winters sun can easly heat the tank from cold to 40 deg c, with OUTSIDE temperatures of approx ZERO.

Cardew

With respect, the above is exactly the sort of posting that confuses people.

What has saved you £450? Possibly all your extra insulation and other measures but your solar will only contribute a small part of those savings.

In fact I wonder why you even introduce all the other measures in a thread about solar as they are simply a distraction. What has not switching the heating on until Septenber got to do with solar water? What does "as part of solar we added cavity wall insulation" mean? - they have no connection.

Many people appear not to appreciate that solar water only heats domestic hot water(DHW) and does not contribute to Central Heating.

The average family uses approx 3,000kWh per year for heating DHW. That will cost approx £60 - £90 if you have gas, and around £180 for oil - although Economy 7 must be an option to be considered with oil at that price.

Despite all the outrageous claims made by some in the industry, you will be lucky to get more than 50% of that from solar.

In fact the Government tested 8 systems - details in the Green Forum - and published a lengthy report giving the average annual output for the systems as approx 1,000kWh per year.

In fact some of the better(e.g. more responsible) firms selling solar systems state that a well set up system will give an output of 1,000kWh per year.

Being generous and accepting that a system will get 50% better output than the Government tests(or the responsible firms) could achieve, you will save 1,500kWh per year. So if you have gas the savings could be £30-£40ish a year, oil as high as £90 a year.

Those are very generous estimates, I suspect few people will achieve as much as £40 or £90 a year.

Then you have to factor in the cost of running the pump and electronics.

Future repairs and maintenance? Just see how short the guarantee period is for the equipment.

Climbing onto the roof to clean the panels?

Now it makes no economic sense to pay £thousands for those very small savings.

So over to you.

If you think I am mistaken, tell me why!!

landyv8

The solar HOT water system has saved me ~£450 per year.

I have not stated that cavity wall insulation or loft insulation can heat water!!! Therfore adding these can not help the saving of £450.

I have not stated that the solar system heats the central heating, I stated that my central heating heats my hot water. i.e the boiler heats the central heating water which passes into the hot water tank coil.

Therfore by not switching on the central heating until September saves me 1 tank of oil i.e £450.

The pump is 40 w when running at full load, not much realy!

Pannels have 30 year gaurantee, pump is 2, but that can be replaced myself for £40 it is only a central heating type pump, other than that it is just a controler.

You do not need to clean the pannels, therfore no climbing onto roof, plus I am lucky mine area easy to acces of another roof extension.

Cardew

So how has solar saved you £450?

Absolute nonsense!! and you know it!

Tell me where the Government's figures are wrong.
Tell me any manufacturer that will guarantee any output from their system.
What output do your panels give?

I am afraid your posts are typical of someone who has installed a system and cannot face reality, or someone selling systems.

You apparently know that a pump is 40W(at full load) and can change pumps yourself so have some technical knowledge(in fact a lot of technical knowledge from your posts in another thread!!!) so you must have some idea of the output of your system in kWh.

You really cannot come on MSE and make statements like "Therfore by not switching on the central heating until September saves me 1 tank of oil i.e £450."

As said above - where are my figures wrong? or give some of your own.

landyv8

I will try and put it in simple terms for simple people.

I am now saving ~£450 per year!

Reason, my boiler does not have to be on to heat the hot water.

I am not selling anything, just stating my facts, that for me, I now only order 2 loads of oil compaierd to 3.

Becuse (I will try and be to the point) the boiler has not been on from the start of May and will be off untill approx September, becuase the solar is now heating the DOMESTIC hot water tank.

If solar was not avalible the boiler would have to be on to heat the DOMESTIC hot water which is heated indirectly via the second coil in the tank i.e central heating liquid / water passing through coil heats water.

YES I do have technical knowledge but I am not in the trade, nice to see you have read my other post.

mech_2

Dude, how much hot water do you use?? And with a 95% efficient boiler as well? I'm with Cardew on this one.

I did some rough calculations for a 2.6 sq. metre thermal solar collector and I reckoned it would collect maybe 1400kWh pa on the south side of my house. At 4p of useful heat per kWh of gas (rather high figure considering my boiler is SEDBUK rated at 90%) that would cost £56. Even if oil is twice the price of gas and you have 3 times the collector area (7.8 square metres!) and can use 100% of that energy you still only reach £336.

How much did the system cost?

Are you sure you don't have an oil leak?

Cardew

Well your technical knowledge doesn't extend to knowing the output of your solar panels apparently.

I will say this S L O W L Y. The average output of of a solar water system is about 1,000kWh per year.

That 1,000 kWh, should you heat Domestic Hot Water(DHW) with with oil at 60p a litre and your 95% efficiency boiler, would cost you approx £70.

So your savings by using solar to heat that DHW instead would be expected to be in that region - £70!!!!! per year!!!!!

Now I concede that if your system is better than every other solar system you might get your savings up to £100. But £450 is simply a joke!!

If you want to delude yourself to justify your expenditure on fitting solar water, that's fine.

However to post such nonsense on a Money Saving website, might persuade some people that such savings are feasible - and they simply ain't!!

If you want to debate the point, then use your 'tecnical knowledge' to explain how you are correct and I am wrong!!!

moonrakerz

landyv8 wrote: »

The solar HOT water system has saved me ~£450 per year.

To quote Victor Meldrew: " "I don't belieeeeeve it!"

Sorry !

radcon

I'm sorry this is my first post but I've got to join in on this one.

£450 seems a bit, well - generous.

I would also suggest that your system isn't piped right if the only way you can get heat into the DHW tank is by having the CH on and pumping. 'S-Plan' anyone??

Sorry - but you can't argue with the maths about the capabilities of the Solar Systems.