Put your solar panel questions to the Energy Saving Trust

grumpyoldsteve

Cardew wrote: »

I think it depends on the make/model of meter.

There is one anti-tamper meter made by Siemans that actually runs the meter forward i.e you generate say, 6kWh use 2 from the mains and the meter advances 8kWh.

I think I have read a post somewhere else where somebody had that problem.
Happy to say my meter is definitely not doing anything like that, because my spreadsheet would have detected the escalation instead of a drop in my predicted next bill
I have one of those energy monitors which is pretty useless during daylight hours (like that Siemans meter) as it isn't able to differentiate between current coming into or going out of our supply.
Having said that, if the solar PV is generating a reasonable output and only low power stuff is running in the house, then it gives an instant real time readout of what is being exported and when that is a decent amount ):idea: it's time to get the washing machine or dishwasher on:j (assuming of course there is actually was some washing to do)

orrery

grumpyoldsteve wrote: »

(assuming of course there is actually was some washing to do)

Hell, its free - run them empty!

jimjames

orrery wrote: »

Hell, its free - run them empty!

Not if you're on a water meter lol

For reference we are looking at a 12 panel Sharp system 2.94kWh and quotes so far are between £9k and £10,750, roof is quite high so more complex scaffolding needed than on our lower roof

cheesyhoward

HalloweenJack wrote: »

no , thats been mentioned above - your fits are set at the current output - so if you increase a 2 kw system to a 4 kw system it would need to be re - certified at the higher output , and fits would be paid at the new output at the lower (future ) rate.

The reason for the question is I have a hip roof where the current ridge line is around 1.5m across and the bottom of the roof is 6m across. So not a great deal of space. The front of the house faces SSW and I can fit around 1.5kWp of panels. I can also fit roughly 1.3kWp on the ESE side of the house as well. In a couple of years (when savings allow) I plan to have a loft conversion (hip to gable and rear dormer). The result of that would be losing the ESE side and gaining more space on the SSW side (new area would be 30sq m). Rather than lose the panels I would like to move them from the ESE side to the SSW side. I will not add any additional panels. But I presume the output will go up slightly due to the more favourable position. Would this cause a problem with my FIT?

Brummie71

cheesyhoward wrote: »

The reason for the question is I have a hip roof where the current ridge line is around 1.5m across and the bottom of the roof is 6m across. So not a great deal of space. The front of the house faces SSW and I can fit around 1.5kWp of panels. I can also fit roughly 1.3kWp on the ESE side of the house as well. In a couple of years (when savings allow) I plan to have a loft conversion (hip to gable and rear dormer). The result of that would be losing the ESE side and gaining more space on the SSW side (new area would be 30sq m). Rather than lose the panels I would like to move them from the ESE side to the SSW side. I will not add any additional panels. But I presume the output will go up slightly due to the more favourable position. Would this cause a problem with my FIT?

Shouldn't do - so long as they aren't moved from the original installation. Your FIT tariff is set by the rated output of the system, regardless of what it actually generates. So the 1.3 kW system on ESE might only produce at around 92% of efficiency, but would still be rated at 1.3kW. Shifted to the SSW, it might increase to 93% efficiency, but would still be rated at 1.3 kW.

mirrorimage0

ok so was looking inot solar panels and thought i had pretty much got the jist of it after having a few quotes but after reading through here im as confused as i was before lol, how do you choose?

Martyn1981

Mirrorimage - don't worry, be happy!

The great thing about solar PV is its predictability. If you can give some specs regarding your circumstances, then it will be easy to get an accurate 'guess' on your annual generation. The big unknown, will be shading, so that's up to you to assess, but now is a great time to start looking at the roof, as the sun is so low, this is when most shading rears its ugly head.

If you can post, general location, orientation, roof angle, expected system size, then we should be able to take a pretty good stab at annual generation using the following site (don't be intimidated, it gets easy quick, and I can run through it for you if you want);

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php#

If you don't mind posting any prices you've received, then MSE's should be able to place them in context with similar quotes.

Also worth thinking about your consumption patterns, if the house is empty all day then you may only use 20% to 25% of generation. If in use all day, or high consumption then maybe nearer 50%.

As and when you decide on a system, then there's lots more to help, regarding getting the most out of it etc.

Hope this helps.

Mart.

PS - Congratulations (x3)!

orrery

Martyn1981 wrote: »

The big unknown, will be shading, so that's up to you to assess, but now is a great time to start looking at the roof, as the sun is so low, this is when most shading rears its ugly head.

And remember - any shading will take out the whole string of panels. You'll usually have two strings - particularly if you have two different roof aspects.

I have a Leylandii in a neighbours garden, currently at about the same height as the panels. The shadow just touches the lower string at about 9.05 +/- 20 minutes. The graphs are consistent with the lower one of the two strings being missing.

davidanddeirdre

I wondered what are solar panel users' general experiences with snow? We've had our first last saturday since panels installed in 3/11 , c. 3 in of the stuff, and I was delighted to note that none of it settled on the panels, I was dreading getting getting up there to sweep it off. This meant we could take immediate advantage of the enhanced light levels around due to lying snow- even when cloudy/foggy we have got no less than about 30% of max output at this time of year every day since. The slope of our panels is between 35 & 40 degrees. We are in East Yorkshire.

orrery

davidanddeirdre wrote: »

I wondered what are solar panel users' general experiences with snow?..

It killed my generation for 2 days. The covering readily slid off the upper row, to form a pile at the bottom of the lower row. Mine was the only roof that still had snow on the second day!

Interestingly, the voltage on the lower (partially covered) panels was higher that the working panels, but little current was being generated.