Help on choosing a system !!

Bobinog1972

Hi, new to adding to posts so please bear with me.

We're about to have an air source heat pump installed to replace our old oil boiler (no gas) and I'm now I'm looking at getting solar PV installed, but I've seen so many people and read so many things that I've got brain fog and still no nearer to working out if it's the right thing to do. I'm at the point where I'm looking at a shortlist of 2 quotes but can't compare and need some external suggestions.

I'm just north of Bury St Edmunds and have an uninterrupted east facing roof and a west facing roof with 2 dormers but enough space for a row of panels at the top of the roof. We're 2 stories. One quote is £8k exc VAT for 16 x 250W Bosch mono panels split between the two roofs with Enphase micro inverters and the other is £6k for 16 x Hyundai mono panels on one roof with a Sunny By 3600TL inverter. On the face of it, £8k seems to be too much having looked at all your threads, but then again I get the impression Bosch and Enphase are more expensive items and there'll be extra scaffolding. So, is the extra money worth it? Then again, our electricity usage isn't much so is it worth installing any pv arrangement?

Any thoughts and ideas will be really appreciated.

tunnel

An east facing roof will generate about 3000+ kWh a year, giving a return of £450 plus export of about £70. Add to that your electric savings(£80-£120) would be a return of £600 ayear. If you went with the £6k quote your getting a return of 10% a year. Does the maths add up for you at that?

The figures I've given you are very conservative figures for generation too. If you have the money in the bank then i'd say go for it. Even though you may be a small user, energy prices are only ever going to go one way.

Martyn1981

Hello Bobinog and welcome.

Are the roofs exactly east / west. If no difference, then generation will be similar, except of course time of day.

Is there any shading? If not the Enphase MI's seem like overkill. Also the 16 Hyundai's with a SMA TL inverter for £6k sounds like a nice deal.

You say your not high leccy users, but presumably that will change with the switch to an ASHP. So you'll be using lots of the GMT months leccy. Also, how will you now be heating water during the BST months, will it be via immersion or perhaps the ASHP, either way presumably that will use quite a bit too. So PV may make greater sense with the heating switch, and your leccy savings more than average (possibly?)

Is it worth asking the £6k installer for a quote to put half the panels on the west roof, just to spread your generation out through the day?

Mart.

bikeman

tunnel wrote: »

....would be a return of £600 ayear. If you went with the £6k quote your getting a return of 10% a year.

I think you are forgetting to factoring in the loss of £6k of capital, afterall the panels are pretty much worthless once fitted.

In other words the breakeven point is in 10 years and there is no return until after then.

If we say tha the panels will last 20 years (is that reasonable?) then the return over 20 years is 5% pa.

So would you be better off puting the money in a building society? I'd say not since elec prices are rising sharply and will probably continue to do so. The investment in self generated elec could be the best thing you ever do.

rogerblack

First you need to take a proper look at the property - and work out what you can do with the money.
For example - if you were to put the (approx) 15K into superinsulating the property - could you get similar heating bills?

superflyguy1971

I've just been through this mill myself and the system has been up 3 days.

I got 9 quotes! (may never use comparison sites again - too many people called me :mad:).

For a 4kWp system they ranged between £6k -> £9k. I started off not knowing what I wanted, then thought I knew, then confused and back again. Just the sheer variety of choices made it very difficult to compare apples with pears.

My final system for £7k was:

16 x Hyundai HiS-S250MG (250w mono black frame)
SolarEdge SE4000-16 inverter and optimisers
Immersun (immersion diversion device)
Redundant boiler chimney removed and tiled over.

I chose the Hyundai panels as I wanted a brand that I recognised and also a company that I thought might still be around to support the warranty in 10 years time. I also liked the idea that the company operated in several diverse markets which might make them more financially robust. My second choice was LG for similar reasons.

I too liked the idea of the Enphase microinverters but the more I read about them the more I got worried that there was a lot of technology on the roof to go wrong. This may be a marketing win on SolarEdge's side but there's some great comparison videos available online that swayed me in the end.

I didn't want to export anything if I could help it so hence the immersun device.

I realise that it's early days but so far I'm very pleased with how it's all going. The monitoring website is really good and I can go down to individual panel level and produce all sorts of graphs and reports.

As an aside I have to manually input stuff into my separate monitoring site of choice pvoutput.org which is a pain but it's reasonably easy to obtain the info. To be honest I may stop doing this after a while as the solaredge site does everything I want except compare it to other people which is what I get from the pvoutput site.

Hope this helps but appreciate that I'm a PV newbie myself!

Bobinog1972

tunnel wrote: »

An east facing roof will generate about 3000+ kWh a year, giving a return of £450 plus export of about £70. Add to that your electric savings(£80-£120) would be a return of £600 ayear. If you went with the £6k quote your getting a return of 10% a year. Does the maths add up for you at that?

The figures I've given you are very conservative figures for generation too. If you have the money in the bank then i'd say go for it. Even though you may be a small user, energy prices are only ever going to go one way.

Thanks for the estimated generation/export/electricity figures. It's useful to see what someone else estimates as the three quotes I eventually got were all different. I had a go at the Solar Energy Calculator on the Energy Saving Trust website to see how accurate they might be, but the latter seems to be really conservative with everything it gives.

Bobinog1972

Martyn1981 wrote: »

Hello Bobinog and welcome.

Are the roofs exactly east / west. If no difference, then generation will be similar, except of course time of day.

Is there any shading? If not the Enphase MI's seem like overkill. Also the 16 Hyundai's with a SMA TL inverter for £6k sounds like a nice deal.

You say your not high leccy users, but presumably that will change with the switch to an ASHP. So you'll be using lots of the GMT months leccy. Also, how will you now be heating water during the BST months, will it be via immersion or perhaps the ASHP, either way presumably that will use quite a bit too. So PV may make greater sense with the heating switch, and your leccy savings more than average (possibly?)

Is it worth asking the £6k installer for a quote to put half the panels on the west roof, just to spread your generation out through the day?

Mart.

The roofs are pretty much east to west, the west facing roof overlooks fields so we get sun in our garden for much longer than where we've been overlooked. But maybe that doesn't make any difference? I'll certainly get the cheaper company to quote for doing a split roof system - that sounds like a great idea.

Re shading, our neighbours have a fir tree on the boundary around 8 metres from our house and to the south east corner of East facing roof (does that make sense?). The tree is probably 7/8 metres tall at the moment and whilst it doesn't cause shade during the summer, the concern was during the winter when the sun is lower in the sky and also when the tree grows taller. Some might say the answer is to ask the neighbours keep it trimmed, but for various reasons I think this might be sensitive.

Re the issue of heating water/the house, the ASHP will be the primary source backed up by immersion. We're on dual rate, although I don't know why as there are no storage heaters, but I propose to stay on that rate so we can make good use of night time cheaper rates when there's no solar. I'm guessing an ImmerSun might be a useful device to get?

Bobinog1972

rogerblack wrote: »

First you need to take a proper look at the property - and work out what you can do with the money.
For example - if you were to put the (approx) 15K into superinsulating the property - could you get similar heating bills?

We've already upped the insulation in the property quite considerably - loft to 300mm, old broken and uninsulated flat roofs are being replaced, remaining non-pvc/double glazed doors & windows will be replaced. The decision of changing to air source is more for the fact that the oil tank is old and leaking and would have to be moved if replaced in order to conform, oil boiler is very old and only has a few years left in it and all the radiators are very, very old and inefficient so if we're going to have to spend the money we might as well pay a little extra now to hopefully save in the longer term.

I'm aware PV is not a necessity, and I'm cautious about looking at it as an investment opportunity as it certainly doesn't have the returns it used to. But I think with the ASHP it's probably a sensible option and I'm keen to try and be ethical where practical. I think my main aim with this is to get a system that's value for money and not be ripped off nor regret it in a few years' time.

Bobinog1972

superflyguy1971 wrote: »

I've just been through this mill myself and the system has been up 3 days.

I got 9 quotes! (may never use comparison sites again - too many people called me :mad:).

For a 4kWp system they ranged between £6k -> £9k. I started off not knowing what I wanted, then thought I knew, then confused and back again. Just the sheer variety of choices made it very difficult to compare apples with pears.

My final system for £7k was:

16 x Hyundai HiS-S250MG (250w mono black frame)
SolarEdge SE4000-16 inverter and optimisers
Immersun (immersion diversion device)
Redundant boiler chimney removed and tiled over.

I chose the Hyundai panels as I wanted a brand that I recognised and also a company that I thought might still be around to support the warranty in 10 years time. I also liked the idea that the company operated in several diverse markets which might make them more financially robust. My second choice was LG for similar reasons.

I too liked the idea of the Enphase microinverters but the more I read about them the more I got worried that there was a lot of technology on the roof to go wrong. This may be a marketing win on SolarEdge's side but there's some great comparison videos available online that swayed me in the end.

I didn't want to export anything if I could help it so hence the immersun device.

I realise that it's early days but so far I'm very pleased with how it's all going. The monitoring website is really good and I can go down to individual panel level and produce all sorts of graphs and reports.

As an aside I have to manually input stuff into my separate monitoring site of choice pvoutput.org which is a pain but it's reasonably easy to obtain the info. To be honest I may stop doing this after a while as the solaredge site does everything I want except compare it to other people which is what I get from the pvoutput site.

Hope this helps but appreciate that I'm a PV newbie myself!

I find it really interesting that you didn't stop being plagued by calls after using a comparison site. I had the opposite problem - 5 companies were supposed to quote and of those 2 didn't bother contacting me, one I should have never bothered letting in the house but did (true salesman who spent his time criticising other companies, didn't look in the loft or around the house, didn't look at the electrics, but told me immediately how much it would cost - funnily he never actually bothered sending the quote through). I called several companies who said they'd call back to arrange an appointment but never did. I've also had to chase 2 of the 3 quotes I did receive. So depressing I almost gave up.

Your choice in system also sounds great. The Bosch is worrying me as they're pulling and although I know they've set up a warranty service because of this, what happens if a panel needs replacing a year down the line.

Out of interest, was it the company that swayed it for you in the end or the system? I'm wondering whether I ought to get a few more quotes as with the ASHP I just knew who I wanted to be with and fortunately they gave me a range of systems and prices to choose from. Perhaps if I'm finding the decision difficult the companies don't quite fit.

tunnel

bikeman wrote: »

I think you are forgetting to factoring in the loss of £6k of capital, afterall the panels are pretty much worthless once fitted.

In other words the breakeven point is in 10 years and there is no return until after then.

If we say tha the panels will last 20 years (is that reasonable?) then the return over 20 years is 5% pa.

So would you be better off puting the money in a building society? I'd say not since elec prices are rising sharply and will probably continue to do so. The investment in self generated elec could be the best thing you ever do.

Maybe your forgetting that the biggest part of the return is index linked for 20years, the remaining "saving" from electric use will be greater each year as energy prices only go one way and its never by the same amount as the RPI.(just look at the news)

I believe the RPI is still hovering around the 3.2% marker too. Still better than in the bank.

With the rest of the energy companies probably looking at following SSE's lead before crimbo, then the RPI for December when the rate is took for the FIT then that rate could possibly increase again. Happy days:D

Bobinog,

Put your figures into here
http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php

Its what most use on here to estimate their generation. I pinned Bury St Eds and it came up at 3090kWh but rounded it down(to be conservative)