4KW system in South-West Cornwall

DREKLY

Hello everyone, could I have any comments on my proposed system on a south facing roof for 16 "Enhance" panels (have a tree shading issue) from a company known as "SOLARLEC" please ?

They were advertising in Morrisons store in Bodmin, had an initial quote of 8,250, but rejected that, and after some haggling, they agreed on 7,000..... ? !!

Projected annual output is stated at 3242 KW

generated income 419.00

export income ..... 79.00

electricity saving 258.00 ( the chap who quoted was most amused at my low usage!)

"Estimated" 1st year benefit = 755.00

this installation includes an "Immersun" for my immersion heater
in the hot water tank, it's an all electric bungalow, no gas.

Does this seem ok .....

I am hoping Martin 1981 will pass comment, please and thankyou

zeupater

DREKLY wrote: »

Hello everyone, could I have any comments on my proposed system on a south facing roof for 16 "Enhance" panels (have a tree shading issue) from a company known as "SOLARLEC" please ?

They were advertising in Morrisons store in Bodmin, had an initial quote of 8,250, but rejected that, and after some haggling, they agreed on 7,000..... ? !!

Projected annual output is stated at 3242 KW

generated income 419.00

export income ..... 79.00

electricity saving 258.00 ( the chap who quoted was most amused at my low usage!)

"Estimated" 1st year benefit = 755.00

this installation includes an "Immersun" for my immersion heater
in the hot water tank, it's an all electric bungalow, no gas.

Does this seem ok .....

I am hoping Martin 1981 will pass comment, please and thankyou

Hi

Not Mart, but hope I'll do until he comes along ....

First impression is that you'll do better on price - Although you've already knocked them down a little, £7k is still steep by today's standards, even with proportional diversion ...

Being all electric your diversion savings will obviously need to be valued at electricity levels as opposed to the usual gas so you should actually make a decent saving over what you're currently paying, but it looks like the pv savings quoted are simply based on a 50% of generation value ... you say that "the chap who quoted was most amused" at your low usage, so in reality we'd really need to know how low that is (in kWh/year) along with a rough idea of how much of that you reckon is currently used for DHW (water heating) to really help with some useful guidance there ...

HTH
Z

Martyn1981

Hiya DREKLY. Thanks for the positives, never had that before!

I'm with Zeup, a bit more info would be great.

The leccy savings seemed way to high, especially if you are low users, but if your water is electric, then as Z said, that will be priced in leccy not gas savings. Also any spare leccy during heating months will be high value savings too, but I'd suspect that with lower GMT generation that won't be important, as after heating water, there wouldn't be any left for heating.

Price seems high especially as it's a bungalow.

One concern though is the generation figure. Cornwall is one of the best locations, and you also say south facing, so that screams 1,000kWh/kWp at me. 3,242kWh sounds more like East or West.

Have a play with PVGIS, there's a walkthrough in section 5 of the PV FAQs. If you're not sure, post a rough location (nearest town for privacy) and confirm roof orientation and I'll have a play for you.

Good location, good property, good orientation ..... just need a good price and you'll be cooking on [STRIKE]gas[/STRIKE] leccy.

Regarding personal views, if I ever did have a headstart on others on here, and that's questionable, then I think I've been fully caught now. So there are loads of experienced PV'ers offering excellent advice and extra views and options on here. But thanks again anyway.

Mart.

DREKLY

Hi Marty, & Zeupater, appreciate your quick responses, I just got back home to check if any replies.... yes, the idea is to use excess production to divert into heating water... long story, house had a working tiny ancient Rayburn boiler, in the kitchen, next to an airing cupboard - parents used to use 5 sacks of coal a month, EVERY month !! so there's 100 pounds
out, on top of the electric heaters used in lounge and bedroom via E7 (but storage heaters dismantled long long ago....)

The Rayburn is on it's last legs (fitted in 1955 when bungalow (cornish unit, ha ha !!) was built.... plus, it's in the kitchen...

So, hence my choice of CLEAN energy, I did consider a woodburner in the small lounge, but that fireplace NEVER used at all, plus wood is not free down here, and you can't burn seagulls, it's illegal.

I get by on 90KW a month averaged over the year ( seriously)
at the moment, but I am away a lot, during colder months, the
immersion I do not run at all, as there is an electric shower in the bathroom, and a KETTLE in the kitchen if I want to wash up one plate + one cup !

The generation figure was downrated by 20% to 3242Kw, because of neighbour's beech trees - right now the roof is clear of shadows, but by autumn they will be a problem, hence
Enhance smart panels (original quote was for "J.A. panels" )
plus Solar Edge inverter, and a "free" immersun....

So yes, I anticipate a LOT more generated during summer months (when you don't need heat...) but think it will not be very good during the short days of winter, but as my friend in London with a 4Kw flat system on his garage roof says - even 300 watts is earning pennies daily....:rotfl:

I am unsure as to where they will try and position the inverter, but I am tempted to have it in the south facing lounge, as I am told they give off quite a bit of heat too; but are they noisy ??

I hope that puts you in the picture a bit more, Z, let me know if I need to provide more info, and thanks for the advice..

DREKLY

Martin, forgot to give location details, I am 7 miles east of Penzance, postcode TR20, half a mile from the sea on the south coast of Cornwall - I know this county (and south Wales) are reputed to have the best generation, as the air is so clear and free of pollution, and the sea on 3 sides creates a good
effect on scattered light, hence St.Ives becoming the artist colony centuries ago...

We DO get a lot of unpredictable sea mist at times, not sure how that affect UV levels, but sure does cool the place down quickly..

Appreciate if you will have a play on that site you suggested as you obviously know your way round, but I will try a bit later on;
internet + cellfone signal down here is very iffy usually, I often think even Western Power's electricity is a luxury too :cool:

Martyn1981

DREKLY wrote: »

Martin, forgot to give location details, I am 7 miles east of Penzance, postcode TR20, half a mile from the sea on the south coast of Cornwall - I know this county (and south Wales) are reputed to have the best generation, as the air is so clear and free of pollution, and the sea on 3 sides creates a good
effect on scattered light, hence St.Ives becoming the artist colony centuries ago...

We DO get a lot of unpredictable sea mist at times, not sure how that affect UV levels, but sure does cool the place down quickly..

Appreciate if you will have a play on that site you suggested as you obviously know your way round, but I will try a bit later on;
internet + cellfone signal down here is very iffy usually, I often think even Western Power's electricity is a luxury too :cool:

My pleasure, and had a little play, but ....

the generation figures around Penzance seem to vary more than normal, so you'll need to have a go, and place the flag on your house to be precise. However ...... :D:D

the numbers are massive, I was seeing anything from 1,080 to 1,170 kWh per kWp. I'm a little shocked.

BTW PVGIS takes account of average weather (as I understand it) so should take account of average sea mists .... I think.

Don't worry too much about PVGIS, just put 4kWp in the size box, roof pitch if you know it, but 35d default will be ok for a start, and enter orientation from south. So if 10d to the east, put -10, if 20d to the west put +20. Zoom in to your house and click on it. Press calculate and read the findings.

Mart.

PS. If I can arrange the helicopters, any chance there's a free plot nearby for me to park my house? M.

Martyn1981

DREKLY wrote: »

The generation figure was downrated by 20% to 3242Kw, because of neighbour's beech trees - right now the roof if clear of shadows, but by autumn they will be a problem, hence

It's hard to estimate shade, especially from trees. Best to not underestimate it though, so perhaps 20% is fair. But this will be during the poorer generation months, and if you have shade mitigation like SolarEdge or micro-inverters then that'll help if the shade only covers a few panels at a time.

The summer is the time people often think about PV, but spring and autumn discussions on shade are easier as folk can actually go out and see, or even take pics of the shade to get an idea of how much loss there will be in the better months Mch to October. If the shade is minimal in Mch, then the summer will be better, and the bottom months aren't as important.

Mart.

DREKLY

Hey, thanks Martyn, brilliant - roof was measured a 33 degrees, which surprised me, as I imagined it would be 45 on a bungalow - what do i know, need a protractor....

you were amazed at the output figures for this area then ? I know if you go up to Truro, there are TONS on panels everywhere, on roofs, and acres of them in fields, as well as evac tubes on properties, which is what I originally wanted to go for...

Even the ALDI store near Truro rail station has 320 panels on its roof :T

I will have a play, and see what I come up with - have a nice day in Wales, big T-storms heading this way later, enjoy!

tunnel

Way too much to pay for a 4kWp system, tell them £5300 and you'll take the deal.
That's based on a friend of mine getting a 4kWp system(on a house) for £4900 with immersion switch, the difference being that between a standard inverter and solaredge.
And it makes no difference where you are in the UK as to cost as many installers now travel the length and width of the country.

zeupater

DREKLY wrote: »

Hi Marty, & Zeaputer, appreciate your quick responses, I just got back home to check if any replies.... yes, the idea is to use excess production to divert into heating water... long story, house had a working tiny ancient Rayburn boiler, in the kitchen, next to an airing cupboard - parents used to use 5 sacks of coal a month, EVERY month !! so there's 100 pounds
out, on top of the electric heaters used in lounge and bedroom via E7 (but storage heaters dismantled long long ago....)

The Rayburn is on it's last legs (fitted in 1955 when bungalow (cornish unit, ha ha !!) was built.... plus, it's in the kitchen...

So, hence my choice of CLEAN energy, I did consider a woodburner in the small lounge, but that fireplace NEVER used at all, plus wood is not free down here, and you can't burn seagulls, it's illegal.

I get by on 90KW a month averaged over the year ( seriously)
at the moment, but I am away a lot, during colder months, the
immersion I do not run at all, as there is an electric shower in the bathroom, and a KETTLE in the kitchen if I want to wash up one plate + one cup !

The generation figure was downrated by 20% to 3242Kw, because of neighbour's beech trees - right now the roof if clear of shadows, but by autumn they will be a problem, hence
Enhance smart panels (original quote was for "J.A. panels" )
plus Solar Edge inverter, and a "free" immersun....

So yes, I anticipate a LOT more generated during summer months (when you don't need heat...) but think it will not be very good during the short days of winter, but as my friend in London with a 4Kw flat system on his garage roof says - even 300 watts is earning pennies daily....:rotfl:

I am unsure as to where they will try and position the inverter, but I am tempted to have it in the south facing lounge, as I am told they give off quite a bit of heat too; but are they noisy ??

I hope that puts you in the picture a bit more, Z, let me know if I need to provide more info, and thanks for the advice..

Hi

If you continue to use energy at that rate then you'll really need to wind the electricity savings back a little, you can't save £258/year if your unit usage is only around £150 ( 90*12*0.14) ... Looks like you'd be better working the figures on closer to £75 annual electricity savings and, from what you've posted, that'd probably be max ...

Regarding the shower ... if you currently use an electric shower and want to make use of the proportional diversion, you'll need a plumbed in unit and shower in free DHW for most of the year, else it's probably not even worth paying for an immersun which will be providing more than enough DHW to wash-up one plate+cup .... probably worth thinking about the necessity/viability of spending ~£500 on proportional diversion if keeping (and using) the electric shower is on the books ...

On the shading front, if it's only mid/late Autumn to early/mid Spring then a 20% adjustment might be a little high, but it does really depend on the effect of shade you actually get based on daily variations in the sun's arc, which many usually underestimate, particularly in the Winter months.

Regarding inverter position, some makes/models are suitable for mounting outside, in which case it's probably better to have them under some form of carport or open porch rather than pushing your luck too much in a storm, but as long as you look for a transformerless (TL) inverter you shouldn't get much of a heat/noise problem, many inverters are in the loft - not my best choice, but we had other options ... our SB4000TL is in the garage and unless you're within a couple of inches and really listening for something, you can't really hear anything, even when it's working pretty hard - as for heat, well the case is probably around body temperature at this time of year, best not to put it in a closed broom-cupboard without decent circulation, but with decent vents there shouldn't be much of an issue ... a couple of members on this forum have done this .... ask Mart, he's got a throne room specifically for visitors to watch his pennies roll in ...

HTH
Z

zeupater

zeupater wrote: »

... as for heat, well the case is probably around body temperature at this time of year ...

Just checked ...

Garage internal wall temperature = 22.5C
Inverter front plastic panel = 35.5C
Inverter top (heat exchanger) = 39.1C
Currently generating 2kW under bright, continuous cloud ...

HTH
Z