Is solar power financially viable?

(Mat Davies) #1

solar-panels-943999_640

What are your current thoughts on installing solar panels - do you consider them to be financially viable?

On a full house renovation including a new roof - would you do it? The house would be run entirely on electricity including a swimming pool.

I think they look pretty ugly but if the reward is significant I could perhaps overlook this.

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(anon54681821) #2

if you have land near your property and good sunlight the solar companies actually pay you and you get free energy too although that is a massive installation.

its something we are looking into

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(stella wood) #3

Please be very careful … great-sounding figures are bandied about…some true, some “questionable”… and there have been many instances of wrong-selling and even downright fraud in certain cases. :zipper_mouth_face:

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(anon54681821) #4

https://www.edf.fr/en/the-edf-group/industrial-provider/renewable-energies/solar-power

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(Jane Jones) #5

We looked into it when we renovated, and because we were replacing the roof anyway the numbers would have stacked up had only the house been better orientated. Our only option would to have an array of panels down the field, so that didn’t work as well financially.

There are products that are visually more appealing than panels now, and the range is ever growing.

Previous discussions here…

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(Bill Morgan) #6

Can’t imagine it is, had panels on boats, they produced very little ‘leccy’, compared to the wind genny for the investment.

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(anon54681821) #7

its come a long way since then bill and some folks I know in England their house runs mainly off solar then again they have no computer or tv, just a little laptop. yes allot of their products are based on lower power usage but they have a pretty good life.

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(Andy Boyd) #8

I run my whole house on solar and solar water heating in the Netherlands and will do the same in France we are mid renovation. We product 1 MegawattHour per quarter year (mean) and try to minimize selling back any surplus by selling in on the new customer to customer exchange in NL.
We have been at this for years and the return on investment (break even) is now down to 7 years (pay off initial installation costs) where as when we stated that was about 18

You need battery storage to make it work over night and the new Lithium Ion sets are very good
The latest inverters are also impressive as the balance each cell individually in the circuit

In France we are considering a self build frame in the land that tracks the sun this gives you up to 30% more output. But we have not decided as we have an ideal south facing roof with 4.5 x 7m surface enough for 24 of the latest 2m x 1m black panels we have in NL which will give on NL sunlight about an average of 30 KWHours per day.
I will eventually have an electric car that becomes part of the system when parked and either charges or Discharges into the house as needed.

As you can tell I am very serious about this and we are designing a super insulated renovation VMC to circulate the heat. thermal heat sink to store heat and a fully electric house. We will not go off grid as we will need to sell back the surplus. The market to sell back is very immature in France As you have a choice if one sho to sell it back to, but that will change.

The only part I am not sure if yet is how well solar water heating will heat the swimming pool. We are planning a double glazed roll back roof and a thick insulating cover for when it is not being usedBut I have little experience of this so we shall see. The garage/studio/workshop from which the swimming pool will tangentiallly emerge will again have an ideal south facing tough enough for 18 x 80cmx120cm vacuum tube systems but I have no real world experience of the heat losses for a 8mx4m swimming pool are with a flowing swim lane - Does anyone out there shave any experience on heating pools this way

Overall now if you have a well orientated roof with the latest tech self owned not hired it is very feasible if you can afford the initial outlay

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(Mat Davies) #9

Thanks Andy for the very useful information.

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(Paul Bradford) #10

In 2007 I installed a solar hot water system from Navitron. The system saved us 500 litres of fuel oil per year and paid for itself in three to four years. About four years ago I changed the tank to a larger 500 litre one, designed for solar. (Effectively paid for by the annual savings). We immediately noticed our water was hotter. It has little or no maintenance to do, apart from checking the systems is at the correct pressure from time to time. Solar hot water was the best investment we could have had. And we are still ahead on savings.
In 2011 we had installed a solar pv system and we sell the excess electricity back to ERDF. The four kwh system generates a annual cheque for between €1340 to 1450. We took out a loan with our bank with a favourable interest rate for eco projects. The loan was for twelve years. The contract with ERDF to buy the electricity is for twenty years, with an excellent feed in tariff.
The panels will generate electricity for years beyond the contract. At the point the contract ends, if we were still here, I would have a battery storage system to save the electricity.
Our friends in the UK have a three kwh system which actually generates more electricity than our one 25% larger. Ours faces due south, but there are two problems. The first being the roof pitch at around 34° is not ideal. Ideally, the pitch of the panels should be that of your degree of latitude (approx 46°) to take advantage of the angle of the sun. Roof pitch in the UK is higher. The second problem is that French planning permission calls for the panels to be integrated into the roof. This doesn’t allow for good cooling and the hotter the panels are, the less they generate. With hindsight, we should have had both systems installed at ground level.
The inverter for the solar pv failed three weeks before the five year guarantee ran out. Fortunately, I got a new one free, apart from the installation cost.
Would I do it again? Not sure. The solar hot water, yes, without question. The outlay for the solar pv (You should really look at it as an investment in your future power costs. Our monthly direct debit to ERDF for the power is still less than we were paying before 2011, so we have gained there) was high. Our house is modern with good insulation as I had already increased it, but the double glazing is 26 years old, so could be more efficient. I think we will come out ahead, but these days with the lower feed in tariff, the payback time will be longer. Having said that, a lot of the installation companies (ours included) have gone bust. You have big name companies such as Ikea installing systems in the UK (not sure about here), so those that are around now, might still be here in years to come.
We have a surfeit of hot water in the Summer and I have often wondered if that surplus heat could be used to heat a pool. (We don’t have one). Navitron sell stainless steel heat exchangers for their systems, so some people must use it.
For us, solar power is definitely viable, but you have to weigh up your cost to change.
Just thought of this addition:- You will be told about tax rebates for such systems, but you need to look closely at it. We were told that we would get 50% off the cost of our solar hot water system, when we were looking at installers for that. That wasn’t true. It was 50% off the cost of just the panel. They were almost six times the cost here than elsewhere. Check upon what you might receive. That’s why I went for self installation (I did the course in the UK for £175 at the time. My total outlay including the costs of the system, travel, hotel bills and the course, as well as paying a plumber to connect to our boiler as I didn’t have the brazing equipment was less than £1500. Against quotes of €6000 and more to have the system fitted here.

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(Mat Davies) #11

Our main expense seems to be on hot water so I am very interested by this.

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(Bob Sivell) #12

I have 4 panels for hot water that I’ve been meaning to install for a number of years.
I’ve a few bits & pieces that could be cobbled together to make a workable system (according to a friend here) so I may get round to trying when the workshop roof is finished.
As for PV, I would only ever install something to be independant of the grid (I resisted referring to the Matrix) & hopefully be free of EDF.

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(John Withall) #13

I like navitron as I do other manufacturers as well but the heat exchangers on their site I do not like, better cheaper alternatives are available.

Very roughly speaking, if you have an abri cover around 30 tubes or 60 tubes if not. As I said on another thread you need somewhere to dump the hot water when the pool is up to temp. Some form of blind to prevent light from getting to the tubes.

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(Teresa Shipley) #14

I don’t want a heated pool but would like solar power for the pump but I imagine it would be overkill.

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(Paul Flinders) #15

I could do with a small off-grid setup to provide lighting for the shed. a 2-300W panel would do - it’s so shaded by trees down there that I doubt I’d get more than 20-30W off one but that would actually be fine to charge a battery for some low voltage LED lighting.

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(Mat Davies) #16

Paul - do you need a lot of light, would battery led work which may work out a lot cheaper.

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(Paul Flinders) #17

I like  a lot of light as my eyesight is crud and for the money that panel+controller+battery would cost I’m probably not too worried about savings.

i am starting to realise there are a few things I should have done sooner because in the event of no-deal there will be customs paperwork to complete if I buy in the UK and take to France.

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(John Withall) #18

Teresa it depends as powering a large power hungry pool pump with solar requires a larger investment in solar, inverters, battery backup etc. There are some pumps I have seen that have been flogged to owners that are stupidly expensive yet they still sell. I go down the ultra low energy route and use mains power because the break even point for the solar equipment is so far off. I did an install in Spain where the only way to get power to the pool was to tunnel under a road so very expensive. Using solar and ultra efficient eco there was no problem. If I am not busy this year I will put same in for me just to demonstrate it to customers as I the power requirements for my pool are so low anyway.

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