New To Solar

[solar_crazy]

Hi all,

My wife and I have finally saved sufficiently to invest in some solar cells for our roof. We have a medium sized house and were wondering what kind of performance and savings we can expect. I've done some caluclations (probably too many!) and used various tools online but I just wanted to get a real life idea of how these things work. If there was anyone who could give us advice on the following questions I'd be more than grateful:

1. Which supplier of PV cells do you use? Are they all similar in performance?

2. How does the feed-in tariff work?

3. What do you typically see in terms of energy production?

4. How does the performance vary over the year?

5. What kind of savings do you see over the year (%) of typical energy bill?

I'm aware these are some pretty intense questions! I hope someone may be able to help!

Thanks,

John

 

[roys]

Welcome to the forum.

No regrets about getting solar installed, I got mine done 3 years ago.

I am not one for long answers, so here is my short answers

1. Chinese manufacturer something like Ying Lee (235W panels)

2.Paid for every unit you generate, plus a payment for a persumed 50% export. for example if you generate 100 units, payment = 100 x FIT RATE pence plus 50 x FIT RATE export pence.

3 10 X 235W panels give me about 1800 generated unit per annum

4 Huge difference between summer and winter production. For example 10 units per week generated in winter compared to 10 units a day in summer.

5.Not sure on my my annual savings.  There are certain products on the market that divert any surplus production to addition household loads such as immersion heaters in order to maximise savings.

 

[binky]

OK that's a big one!

The best Chinese panels usually have a link to Europe or North America for R&D. The thing to look for is low light performnace (irradiance) which means higher outputs in Winter and on cloudy days. Perfomance back-up from other testing is also worth looking for, such as a good test evaluation from Photon International and also worth looking at PTC ratings which is a test developed by the Californian Sate Energy department to simulate 'real world' conditions. Google 'PTC ratings' and click the link saying 'Go Solar California' . My current favourites are Candian Solar, Phono Solar and Solar World for those who want German quality. Very good, but relatively expensive panels can be had from LG and Panasonic, but I;ve not really seen these outperform what I normally fit. I am currently evaluating Seraphim - v competitive price and some good write-ups with extened warranties for performance 30 years rather than 25 years at 80%.

Inverter wise, do not accept Chinese units, they are cheap, seem to break down after only a few years and back-up service is shoddy from those I've encountered so far. SMA, Power One, Fronius and my favourite Stecca are the units you want.

Energy savings will depend on your life style but tend to be more like 30% than the 50% suggested by SAP calculation unles you have an immersion heater or wish to install a simple convection heater controlled by a gadget like Immersun or Solic 200

What size is your house roof, orientation and pitch? do you have any shading issues?

Energy production - a 4kW system should geenrate over 4000 kWh per year depending on roof orienation and pitch. Best from one of my systems has been 4500 kWh in a year. (Stecca Grid 3600 and Canadaian Solar ELPS panels)