Mystery sounds - solved ?

We had noticed that under certain conditions we would get some odd rattling sounds from the roof, this only started after the solar panels were installed so we knew it was something to do with them and was rather worrying as it seemed something was loose. The sounds only happened when there was a strong wind blowing from a south or south-east direction which is quite unusual so this has only happened about three times since the panels went up.

I contacted our supplier (EVO energy) after a stormy day in February when the sound was very apparent and they said they would send someone to inspect. The earliest day available was in early March so we booked that up and waited. I re-confirmed the appointment a few days before and they asked if we had scaffolding still up, we of course hadn't as the system had been up for nearly 6 months. The day before the inspection was due some contractors turned up an erected scaffolding, I was a bit surprised.

Scaffold goes up again !

On the day a team of three turned up first thing at 8am and took a good look at the installation. After about 30 mins one of them team came down and explained that the tiles and mountings were very secure and couldn't be the cause of the sound. They suspected that the cable runs were the cause as the slack cable had been laid on the tiles between the panels. I went up and took a look and it was easy to see how the loops of cable could be whipped up by the wind and hit the panels, mountings and tiles. A quick experiment flicking the loose cable against the panels was able to produce a metallic sound something like that we had heard - mystery solved maybe?

The team then removed the bottom row of tiles and cable tied all of the loose cable runs to the mounting rails so that they couldn't flap around any more. They were finished and on there way by around 9:30am. Only time will tell if this was the cause, we will listen carefully next time there is a strong south or south-easterly wind.

Having the scaffolding in place did allow me to take a close look at the condition of the panels and see if they needed cleaning. They were not that dirty but there was a thin film of grime from the damp winter months and some residue from bird droppings, we get rather a lot of resident seagulls in the winter ! I took a bucket of soapy water and a telescopic window cleaner with me and gave the panels a wipe over to see how much effect this would have. It did remove a fair bit of grime so I guess it will make some improvement, I am wondering how easy it will be to clean them without the scaffolding. We have a garage with a flat roof on that side of the house so access is quite easy and relatively safe so I will probably give them a wipe over a couple of times a year.

Panels still looked quite clean after 6 months in place

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Winter quarter savings

I have now had a chance to sit down and calculate how much energy we saved from our winter quarter electricity bill. The bills for this quarter over the last three years have been very similar averaging around 1240 units so any saving was going to be quite easy to see. The bill shows that our usage this year was just 780 units which is around 63% of the previous years - very impressive. This amounts to a saving of around £55 on our bill, I have already arranged for our monthly electricity payment to be reduced significantly on the basis of this.

We have made a very big effort to make use of the solar generated electricity, my wife has been doing everything possible to use power hungry devices during the daytime. We used to run the dishwasher in the evening or overnight but this and the laundry, vacuum cleaner are now used during the daytime. In the winter it has also been possible to use the electricity to cook meals during the daytime. Stews and casseroles need cooking slowly over a few hours so they are excellent to cook during the day and then warm up for dinner.

The longer days will give us even more opportunity to make use of our own electricity. I am looking forward with interest on how the system will perform during the summer months. We had the system installed at the autumn equinox so we have only seen how it works on the shorter winter days, the next 6 months will show us just what the system is capable of.

The first FIT payment arrives !

We finally received the FIT payment from our electricity supplier (SSE) on the 31 January, exactly one month after submitting our meter reading. Not too bad given the stories that are circulating about other suppliers and the need to chase them for payment. The amount was just over £300 although this did include the last 10 days of September which were not strictly part of this quarter and accounted for around £60 of the total. Our FIT registration hadn't been processed in time for them to pay this in the previous quarter.

I am still waiting for our electricity bill for the winter quarter, the meter reading was submitted last week but they usually send the bill out in the first week of February. Once I have this I can make an estimate of how much our electricity bill has been reduced. The number of units used during this quarter over the last three years are very similar so any difference will almost certainly be down to using our own electricity.The meter reading indicated it would be something like one third less than previous years. Of course it would have been much easier to measure how much we had saved if we had an export meter.

I will post a summary of the earnings + savings for the quarter once the bill arrives.

Good news is that February has started very sunny if rather cold, the sunshine is at least some compensation for the cold weather.

FIT payment is finally on it's way

We finally had a response from our electricity supplier to confirm that they had processed our first meter reading and we would be receiving our FIT payment soon - hurrah ! We have also just had the first full quarters electricity bill since the system was installed, this looks very promising. We have only used around 65% of the electricity compared with the same quarter over the previous three years. This would mean a saving of at least £50 on our electricity bill this quarter and should mean a saving of around £200 over the full year. I will calculate the exact figures once I receive the FIT statement which should arrive in the next week.

I have just updated the statistics page and added a couple more useful links - take a look !

Back soon with some more accurate figures once our FIT payment arrives and we have our electricity bill.

Our first quarter

The end of the year meant that it was time to submit our first quarterly meter reading to our electricity supplier and then wait for our first payment to arrive. This is where the system finally starts to pay us back in a tangible way, the meter reading on the 31 December was 679 units which should work out at just over £300. The website said rather gloomily that payments may take up to 65 working days, if that is true then we may well be submitting our next reading before getting paid for this one. I will post an update when payment arrives and I can say how long they actually took, reports of other suppliers taking months and needing to be chased doesn't bode well.

The other part of the equation that we are currently missing is how much of our own electricity have we been able to use as this will result in savings on our bill. There is an assumption by our supplier that we will use 50% and export 50% but this seems hard to believe. When the sun is out the system generates something between 1 and 3 kW during the day. The household devices that are always on like the fridge etc. only consume a total of 200-300W so unless we are running the dishwasher, laundry, vacuum cleaner or other high power devices we are only likely to be consuming 10-25%. I have am going to compare the electricity usage this year with the previous two or three years and see how much less we are using and try and calculate the savings. This will probably take a full years worth of reading before we will get a clear picture.

Another thing worth exploring is getting an export meter installed by our supplier. This will not only tell us how much electricity we export but also allow us to calculate exactly how much we have used. I am guessing that we will probably export something like 70% or more so it would enable us to get paid for anything more than the 50% estimate. It only comes to 3p a unit but it would still be nice to have.

We are now looking forward to 2012 and the longer days of spring, its going to be very interesting to see just how well the system does in prime months from April to September when it should really start to pay us back.

A happy 2012 to everyone.

The last minute rush

Perhaps not surprisingly there has been a last minute rush to get systems installed before the 12 December deadline to qualify for the current FIT rates. In our own immediate neighbourhood there are at least another three systems that have gone up, the installers were working on Saturday and Sunday last weekend.  A neighbour of ours who had been thinking about installing a system had their system put up on Saturday. I just hope she can get her application in and accepted on time - fingers crossed for her.

Our own system has been doing nicely since the weather got a bit brighter in mid November, we just managed to achieve the predicted yield for November and seem to be doing very well so far in December. Our generation meter has just passed the 600kWh mark. I am regularly updating the information on my daily statistics page so do take a look at them if you are interested in how the system is doing.

I am still unsure how much of the energy generated we manage to use ourselves, we will probably only find out when the next quarters bill turns up and I can compare with last year. It seems likely that we are probably  using most of it at the moment as it is only a few hundred watts on the cloudy days and the PC, central heating pump and fridge  will probably consume that amount.

Keeping up with neighbours

We took the dogs for a walk around the neighbourhood on Saturday and counted how many houses now have solar panels, there are now nine on our regular route. It seems that once one house has installed panels others nearby have quickly followed suit. My wife took  photos of some of the systems, it's quite interesting how different each system is. These are all within half a kilometre of our house.

   The house on the left was the first to install panels in late spring and was followed by the neighbour on the right a few weeks later.

They were followed a few weeks later by their neighbour and in the last couple of weeks the next house along has installed an identical looking system, the scaffolding is still to be taken down.

A little further down the road another house had a system installed in the last two weeks.

A bit further down the road and another house had a system installed in the last week.

With the reduction in the feed in tariff rates due in the next three weeks it will be interesting to see how many more appear before the deadline.