Installing Solar_cells

[DR]

We have had ours installed at the office - 38 x 300W panels (LG) with 2 x SMA Inverters.

We've done it for the sheer amount of power we use to try and cut bills and of course get some FIT action.

Will it pay off? For sure, question is how quickly.

[DR]

Ours is now up and running, we've got 2 additional panels so 40 in total - 300W each. Will keep you all up to date on the performance

[1stRaven]

Nice work. We are doing the same on some of our food stores - 8-12kw depending on the size of the store but with the lighting, fridges and freezers, it all gets used during the day.

[Jace007]

Bump! great post. Do the panels have a 10 year warranty on then Peter? .. I did a quick search, British gas stopped doing the offer they had last year. Also the Sainsbury offer with British Gas has gone too :/
A Government consultation's proposing a changes to the solar panel scheme. It wants to greater reduce the amount those with panels are paid for generating electricity from January 2016, that new ppl who have them installed. http://www.solarpowerportal.co.uk/ne...tes_by_87_2324

[DR]

So come on peeps - what KWH are you generating on a daily basis and how big is your system?

[hesham1516]

Unfortunately I am not in a position where I can install a solar system, but I stumbled across http://pvoutput.org/map.jsp?country=243 last year or something. Really useful information if you want to compare your system to others in the area. They also show the size of the setup and the efficiency etc.

[peterb]

So, 12 months on and time to take stock!

In the last quarter (June - September) I generated 1.123 MWh which was to all intents and purposes, the same as the previous quarter, not helped by the relatvely poor weather in August

For the year

Sep-Dec 2014 472 kWh
Dec-Mar 2015 368 kWh
Mar-Jun 2015 1226 kWh
Jun-Sep 2015 1241 kWh

The amount earned came to a few pence short of £600.

The other side of the equation is the energy saving.

Nov 2013-Nov 2014 Electricity 2563 kWh Gas 9,200 kWh
Sep 2014-Sep 2015 Electricity 1850kWh Gas 8,309 kWh

I don't have September 2014 readings, but it is still a year.

Reduction of 713 kWh in electricity consumption and 891kWh in gas. In practice I have used 32 kWh of gas (one cubic foot) in the last 6 months as all my hot water has been generated from the solar panels via an 'intelligent' immersion heater controller.

In financial terms, my monthly energy bill has dropped from £81/month to £51/month, so the cost saving is £360/year. However I was overpaying my bill, and received a rebate, so my actual saving was about £260

So overall I am getting £860/year on my investment which is just around 8.5% (not taking into account loan interest, which reduces the net payback to around 4.5%, but that will be paid off in the next few months.

So was it worth it?

Yes, and will come a better investment as time goes on - while I remain in the house! Solar panels should make the house a more attractive sale proposition, although whether I would get back that investment is guesswork.

The reduction in feed in tariffs would tip the balance considerably, although I would expect installation costs to be falling as the technology matures.

So anyone contemplating solar - do your sums and research very carefully - it does pay in terms of energy consumption but it does take a change in routines (to make maximum use of generated power and minimise use of grid power.

[peterb]

Bump! great post. Do the panels have a 10 year warranty on then Peter? .. I did a quick search, British gas stopped doing the offer they had last year. Also the Sainsbury offer with British Gas has gone too :/
A Government consultation's proposing a changes to the solar panel scheme. It wants to greater reduce the amount those with panels are paid for generating electricity from January 2016, that new ppl who have them installed. http://www.solarpowerportal.co.uk/ne...tes_by_87_2324

The installation and panels have a ten year warranty, the inverters themselves have a 20 year warranty.

[Jace007]

I'm glad its saving you money peterb thanks for the updates. it will be intresting to see what the government does with the feed in tariff in the next few months, the proposed tariff paid for generating electricity will be cut from 12.4p to 1.6p. Just mad.

[Top_gun]

The installation and panels have a ten year warranty, the inverters themselves have a 20 year warranty.

I'm surprised inverters have a 20 year warranty because of their limited lifespan. How long do you think your inverters will last and what would be the cost of replacement?

[TeePee]

I'm going to be the negative nancy and point out the downside once again. 860GBP a year sounds like a good return. But the snag has always been the declining value of the panels. Amortized over 20 years, which is probably generous, we are down to a 330GBP return. Even without accounting for the depreciation, you'd still be better off investing the money. Had you invested that 10K into the S and P 500, you'd now have about 11066GBP (8.6% gain and 2% dividend yield).

If the market and all pricing remained stable, in 20 years your 10K investment will have been worth 18130 (inflation dirtily adjusted), compared to 75000 invested in the market.

Of course, none of these things will remain stable, and energy prices in particular will outpace inflation over the next 20 years, which will likely work in your favour. But they have to go a long way to make this a sound financial investment.

[peterb]

And a year on from installation and Ive just submitted my fifth quarter reading. Slightly down on last year at £73 this quarter, £79 for the equivalent period last year. Several reasons spring to mind, last Autumn's weather was better (more sunshine) although the warmer weather in the summer seems to have delayed some nearby trees shedding their leaves, so early morning shading seems a bit more pronounced.

Fitting the cells has made me more energy conscious. I have fitted LED lamps throughout the house (except for very low use areas) and when I do use gas for water heating (rather than solar) I only run the boiler long enough to heat about half a tank (which is what the solar panels do, through the immersion heater) and I find that is enough for the day (if it isn't, I can boost it)

I do have reasonable efficient heating controls, which were replaced a couple of years ago. I am tempted by a Nest thermostat, but I doubt it would offer much in the way of a significant saving, so a long payback period - but probably more convenient - and I like the technology.

As I said in the last report, my monthly energy bill has dropped from ~£81/month to £51/month (partly due to reduced energy costs) and I am on track to receive a rebate the end of the year.

In financial terms, as Teepee point out, the question of whether it is a good return on investment is a fine one. In terms of 'green-ness' its a good one, but that alone wouldn't persuade me unless it was at least financially neutral, or beneficial. The changes in subsidies and the feed-in tariff has changed the equations, although the installation costs have fallen - I suspect installing my system now would be around 20% less than I paid, but the returns are lower.

As ever, if you are thinking about this, do your sums carefully!

Just out of interest, I downloaded a graph for 12 months generation - no surprises, it follows the sun's diurnal declination.

[peterb]

I'm surprised inverters have a 20 year warranty because of their limited lifespan. How long do you think your inverters will last and what would be the cost of replacement?

Sorry, missed that post. The inverters cost about £90 each when they were installed. The price has dropped a bit since then, so around £70 each. The real cost of replacement though is getting onto the roof and lifting the panel to gain access to the failed inverter itself, and that might mean a scaffolding tower.

That said, when the installers came back to fit the two panel retaining clips (left off by mistake) they used a ladder and lifted with a safety harness clipped round the panel mounting rails, so it could probably be done in an hour or so.

[Noxvayl]

Ramboll UK were going to install solar panels at their Southampton office, but those plans are on hold now thanks to the changes in the feed in tariffs. There was a sound business case for doing them, neutral cost for the equipment allowing the site to be powered entirely by solar panels and then selling the excess to the grid when more is produced over the summer... but now the feed in tariff makes accountants twitch and the whole thing seems to be on hold. I'm interested to find out if the project goes ahead anyway, not like they are making use of the fields they own...

Good to see your panels are working out for you. I wouldn't be interested in getting solar panels on my roof unless I could pair them up to a battery that could power the house for at least a few hours. If I do get them in the future it would be to make sure the power supply to my house is 100% stable and has hours worth of redundancy built in so I can live comfortably without grid energy. Unfortunately that is not cost effective just yet, but it should be when I can afford the solar panels to begin with so I have no choice but to wait and see

[peterb]

The changes in feed in tariffs has changed the figures, it remains to be seen if it drives down prices. Of course there is still the saving in consumption costs.

I looked at storage system earlier in this thread

http://forums.hexus.net/home-garden-...ml#post3525440

At the moment the battery technology makes this uneconomic, but that may change as it becomes more common place/battery technology matures.

It could be an exciting development, and battery technology is being driven (no pun intended) by electric vehicles.

[Jowsey]

I appreciate the serious nature of this discussion (and its inclination into the Devil's magic, or maths as you like to call it) and I feel I am morally obligated to inform you of the damage you are doing to our beautiful planet.

If you please point your attention to the following link : here./

You will learn a great deal from a local community. Please contact me if you wish to discuss this further

/sarcasm

On a more serious note we not long ago (3/4 months) had company representative come to our property to have a chat. I live in a privately rented flat in the middle(ish) of Newcastle and apparently the roof is the source of some pretty weird situations between landlords, the Council and the ownership of the roof (I didn't really get it but my father-in-law knew what we meant)

The summary of it was the council were performing initial surveys of current residents and their landlords to see if they could install solar panels down the entire street. The agreement would stand as follows:

The landlord/tenant pays nothing to the installation or maintenance of the panels.
The panels remain the property of the installation company at all times.
The tenant gets 'first use' of the power produced by the the panels.
The right to benefit derived from the feed in tariff is surrendered to the panel owner.

It was an interesting one and I couldn't see any immediate reasons to outright refuse it so we provided a pretty positive response to the suggestion but we've heard squat of it since.

Admittedly, we wouldn't see a massive benefit in the winter as me and my girlfriends annual bill for gas and electric is pretty low, circa £550 with it being more electricity than gas, and most of that is after the hours of 7pm and before 8am, as we are both out of the house from during the day . With the small flat we only have space for one under counter unit so it has to be a washer dryer and we find ourself putting loads on over the night (my sleeping pattern is so poor I normally do a load of washing in the middle of the night as well so we can do 2 loads a night!). This obviously is the largest single contributor to our electricity bill.

I think being realistic we could save maybe £60 - £80 if we try and change our life style but any more savings would probably require further investment from ourselves. But I do think this is a situation that really benefits a certain lifestyle. In the next 9 - 12 months we could both be working from our home and in which case I would imagine our electricity and gas usage go up but we would be better placed to efficiently run our requirements from the panels if they were installed.

I'll keep people posted if this goes any further but I wonder if people have heard of similar schemes?