Solar quotes, Cheshire

pigglypots

Hi Martyn
Thanks for that...I have done the PVGIS and to be honest with the potential 20%+ shading (chimneys and winter trees) at the back, the figures come out almost the same with the front, so might make sense to spread it over, not too much extra cost to install (about 150-250 they say, for extra scaffolding)

As for the pitch its about 30 degrees

It was just a thought as we don't think that 14 panels are quite viable for my roof with interfering chimneys, so a split might be the way to go...just not sure I want to go above 4KW...not at all a big electricity user so no big savings, but if I could get more generation at teatime, early evening etc that would help spread things. (But hey ho, might just look at the figures!! - this is addictive!!)

Also off topic...apart from the Solaredge monitoring, is there some other monitoring (with online app) that would tell me exactly how much electricity I am generating/using at any one time...would help me know when to plug things in?
Thanks again!

Martyn1981

Hiya Piggly. Unfortunately there's no simple rule for going bigger. You'll have to get quotes for various sizes, perhaps 4kWp and 5kWp then calculate the generation which will give you a reasonably solid FiT and export figure. Not forgetting to use 11.71p for the over 4kWp systems.

For leccy savings a larger system will save a bit more, but with diminishing returns. I'd simply say £120 for each to make it easier.

Then divide the income by the cost and compare the gross ROI, eg.

500/5000 = 10%
600/5,900 = 10.2%

If the bigger system has a better ROI, and you have the extra money available, then it makes sense. It'll work for you because you won't need to exceed the 3.68kW export limit, as an E/W system won't all be generating at the same time.

Happy to do some number crunching for you, as the quotes come in, but as I said, no simple rule, you'll have to do some scribblings. It might work, it might not, but crucially you can't really do it later as you'd then duplicate too many costs, such as scaffolding, profit, paperwork. So worth considering, if only to rule out.

BTW my roof pitch is 30d too, that's fine. If you haven't already, try changing the WNW pitch to 40d and 50d and see how it drops off. Ouch! A south roof only drops slightly, but will shift some generation between winter and summer.

Mart.

EricMears

pigglypots wrote: »

. . . . . Also off topic...apart from the Solaredge monitoring, is there some other monitoring (with online app) that would tell me exactly how much electricity I am generating/using at any one time...would help me know when to plug things in?
Thanks again!

Many on this forum swear by Wattson where it has a local results facility called Holmes and an online version too. I've never been very impressed with the accuracy of the Wattson/Holmes set up but perhaps my unit is older & less accurate than those who are happier ?

If you have an Immersun unit, I find its new(ish) 'MyImmersun' application to be rather more accurate than Wattson/Holmes although still not as accurate as I'd like. It's a bit early for my full review of the MyImmersun system but FWIW, during the month of July (the only full month I have available yet) its report of total generation was 6% greater than my TGM and its report of imports was 10% higher than my meter readings. I assume its report of the amount diverted to Immersion heater must be accurate but I've no independent estimate of export or local usage (all of which figures are presented by MyImmersun).

pinnks

I have gone with the myimmerSUN and am pleased with it so far. 2 full months of data and I am also seeing slightly elevated generation and import. About 3.5% and 5% respectively.

Doesn't have an app but uses a webpage, so works on pretty much anything that can view a website. Updates every 15 seconds for the real time display of what is going on and the chart updates every hour. Chart views are day, week, month and year. Export to a CSV file works in Chrome and Firefox but not IE11, or the new Win 10 Edge. Irritating but I have logged that with the developers.

I like the fact that it shows export (presumably similar error rate to import as it is the same sensor), computes house use and identifies what has been diverted. If you are cascading immerSUNs (which I do) to mop up more generated leccy then the slave units just show as part of the house consumption.

I half thought of the Watson, so interesting to hear some views on its accuracy and others experiences with myimmerSUN having opted for the latter.

Ageing_Stick_Insect

Hi Pigglypots,

I rarely visits these pages but when I saw Cheshire I read the thread.

My array is on 3 roofs with 6 on ESE and 5 each on SSW and WNW making a total of 3.84kWp. I have Panasonic panels and SolarEdge inverter.

Very pleased with the install and monitoring capabilities of the SE software. Micro-optimisers for each panel so each can be monitored. Bit more pricey but it means that if any panel plays up it can be spotted quickly.

JLeaf did my install. Very happy to recommend a family-run business. If you want any more info (including a home visit if close) feel free to PM me.

LATER: Just finished some calculations for 2015 generation over my 3 roofs:-

WNW = 26.24%
ESE = 39.41%
SSW = 34.35%

So panels on a WNW roof are definitely worthwhile especially for the small additional cost of them against the labour costs.

pigglypots

Hi Ray
thanks for that...think i have enough quotes form local firms...and definitely thinking about splitting the array.
Appreciate the breakdowns.
Think that it will help for longer use of available 'free' electricity.

Ageing_Stick_Insect

Hi pigglypots,

Okay, no worries. Hope your install goes well.