Solar panels (UK based)

[Thorin]

A local solar panel business asked me to design their website for them, and on one of the pages is a guide on prices and paybacks values. From this an estimate of how long it would take to return your investment can be calculated.

http://www.affordablerenewables.org.uk/pv.html

Go further down the page to see it, maybe this could help your decision.

 

[Richard Schollar]

Thanks Andy

 

[Richard Schollar]

I ended up going with a 3.525 kWP system using Sanyo HIT N series panels. Most expensive system quote I had, but does maximise the array size.

 

[chuckchuckit]

About 3 years ago I sold a cabin property I had that was about 3 miles as the crow flys from the end of the power lines. Out in the middle of nowhere in Northern California. So the years I had it, had to design and install my own solar system for electricity.

It was a small system only 500 watts but it worked great for all the lights and such. 12 volt DC system as the lights were 12VDC bulbs too. Panels and controller charged four large 6V deep cycle batteries for power storage to run the lights etc. Each battery was a 125 pound monster.

Was a lot of fun to research and design. Lot of work though too. Drilling holes, roof work etc. So much easier to just run it as they do these days with the inverters for 110VAC uses. Or likely 220VAC in England and South Africa.

Sure miss that weekend cabin. The getaway weekends usually ended up being working weekends. Worth it though.

Chuck

 

[shg]

I ended up going with a 3.525 kWP system using Sanyo HIT N series panels.

3.5kW, wow. Is that peak power at noon on a cloudless day at the Equator? (Which would not be an unreasonable way to rate systems).

Do you have anything that can log actual power output as a function of time of day? That would make a very interesting spreasheet.

 

[Richard Schollar]

Yep that's what I understand (first point).

I am getting a monitor system that can store up to 28 days' worth of readings including both generated electricity and electricity usage of the property. I hope to download these and make some comparisons with my neighbour who also has an array of similar size. I am turning into a sad old git because I am quite excited by the prospect!

 

[shg]

Is it correct that the system will always generate all the power it can, and put unneeded power on the grid?

 

[Richard Schollar]

Yes - because we are in the UK we don't get as much sun as if we were in Spain (or Florida) for example, but it will always generate to its maximum potential. That's assuming the array is ushaded which can cause problems if it is shaded.

The economic return in the UK (and Germany) is mostly based on the Feed In Tariff (FIT) which is linked to the power generated rather than what you do with it (ie use it for feed it back to the grid).

 

[shg]

OK, we'll need you to post a workbook with power output by date and time of day. Use a dropdown-box to note the weather each day:

Cloudy
Low overcast
Drizzle
Light rain
Drenching rain

 

[chuckchuckit]

Those panels must be pretty big. The ones I had were 55 watts each X10 bought off of ebay about 10 years ago. So your 3.5KW system must be at least 100 watt panels? Take up a good portion of the roof I would imagine.

Mine were at about a 30 degree angle on the roof and sometimes get snow there covering them. If the angle gets too steep though, then the sun angle is not as efficient. I had to decide if I was going to pick the winter angle of the sun, or the summer angle. So I chose a lower winter angle so most of the snow might slide off, and so to get my best efficiency in the winter when there was less sun with the sun lower on the horizon and not there as many hours of the day.