Solar panels and battery - any real world recommendations?

I'm getting some building work done which will involve replacing the roof, so I thought it would be sensible to go down the in-roof/integrated panel route so I didn't have to pay for the roof tiles.

After getting a few quotes from solar providers, the quotes for in-roof panels are between £1000 and £1500 more than the equivalent on-roof solution. That's approximately the same as it would cost to tile the area, so the overall cost would be comparable.

I'm not that bothered by the aesthetics of the panels, so I'm leaning towards on-roof panels for the following reasons:
- Slightly more efficient (due to airflow underneath them).
- Simpler installation (e.g. lower chance of leaks as the roof is already watertight, more flexibility at installation time as there can be a longer gap between roofer and installer doing their thing).
- More choice (some installers only offer a certain brand and/or size of in-roof panels because they fit the trays they like to use).
- Easier to replace the panels in future (panel sizes/mounting systems will likely have changed in 10+years, so having to change the trays as well as the panels would be a much more expensive/complex job).

Just wondered if anyone thinks I'm overlooking anything?
 
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NotAGolf said:
I'm getting some building work done which will involve replacing the roof, so I thought it would be sensible to go down the in-roof/integrated panel route so I didn't have to pay for the roof tiles.

After getting a few quotes from solar providers, the quotes for in-roof panels are between £1000 and £1500 more than the equivalent on-roof solution. That's approximately the same as it would cost to tile the area, so the overall cost would be comparable.

I'm not that bothered by the aesthetics of the panels, so I'm leaning towards on-roof panels for the following reasons:
- Slightly more efficient (due to airflow underneath them).
- Simpler installation (e.g. lower chance of leaks as the roof is already watertight, more flexibility at installation time as there can be a longer gap between roofer and installer doing their thing).
- More choice (some installers only offer a certain brand and/or size of in-roof panels because they fit the trays they like to use).
- Easier to replace the panels in future (panel sizes/mounting systems will likely have changed in 10+years, so having to change the trays as well as the panels would be a much more expensive/complex job).

Just wondered if anyone thinks I'm overlooking anything?
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I think if I had the option at equivalent cost I would go for in roof. No risk of bird issues, no risk of wind catching panels, etc.
 
NotAGolf said:
Just wondered if anyone thinks I'm overlooking anything?
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Yes, as mentioned above, the gap immediately above the panels make a great place for seagulls to nest - I have a nest between the ridge and the panels.

I'd go in roof if doing the roof, just to solve this problem.
 
Ron-ski said:
Yes, as mentioned above, the gap immediately above the panels make a great place for seagulls to nest - I have a nest between the ridge and the panels.

I'd go in roof if doing the roof, just to solve this problem.
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All the on-roof quotes I've got include bird proofing. Or are you saying they like to create a nest on the edge of the bird proofing?

Even if this were to become a problem, I still think I'd prefer to accept the risk if it means minimising a potential future bill (due to more expensive panel replacement).
 
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I have bird spikes around my older panels, last year they tried to make a nest on the spikes.

My new panels have netting, but this actually makes a nice area for seagulls to build a nest above the panels.
 
NotAGolf said:
All the on-roof quotes I've got include bird proofing. Or are you saying they like to create a nest on the edge of the bird proofing?

Even if this were to become a problem, I still think I'd prefer to accept the risk if it means minimising a potential future bill (due to more expensive panel replacement).
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I have same as Ron, but with pigeons
They were kicked out after a couple of clips came off the bird netting (I found them both eventually after the birds threw all the moss out of the gutters), so they moved at a later date to just sitting on top of the netting thats just below the ridge.

I guess in winter they will give up but they have been there since spring.
 
rtho782 said:
I'm after more battery and not sure of the best route.

I currently have:

1x Powerwall 3 (13.5kWh) with 30x445W panels in 3 strings of 10
1x Solax 6kW String inverter with 14x645W panels in 2 strings of 7 with Tigo optimisers

I will likely add more panels at some point (north roof at least), but I definitely feel I need more batteries for the periods where Octopus decide my rate isn't 7p.

I see 3 main options:

1. Add PW3 DC expansions, 1 would take me to 27kWh, 2 would take me to 40.5kWh. Cost about £5500 each. Can pay for them on 0% finance for 3y. Integrates well with existing battery, don't need to make any changes to my automations. Can then charge from grid at 8kW rather than 5kW.
2. Replace the Solax inverter (which gets some clipping anyway) with a larger hybrid inverter, and get 2x Fogstar 16kWh batteries. This would cost around £6k for 32kWh, and slightly more generation (less clipping), but does mean I have to manage two batteries that won't talk to each other, I would have to take efforts to make sure one didn't charge the other etc.
3. Go the insane route, copy that guy off youtube, replace the solax inverter as above, and mount a recovered Tesla Model 3 LFP battery pack to my garage wall. A lot more work but I think I could handle it, about the same cost as option 2 I think (£6k), but would get me 60kWh. Has all the management drawbacks of option 2.

What would others do?
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Have you checked any option is cost effective and do you actually need an additional 26kwh of batteries?

Once you have enough batteries, adding more doesn’t increase your ROI, it reduces it.

For me, option 1 or wildcard #4, rather than the DC expansion, get another Powerwall 3 and bin the Solax inverter.

I’m all about the ease of use and simplicity where possible.
 
b0rn2sk8 said:
Have you checked any option is cost effective and do you actually need an additional 26kwh of batteries?

Once you have enough batteries, adding more doesn’t increase your ROI, it reduces it.

For me, option 1 or wildcard #4, rather than the DC expansion, get another Powerwall 3 and bin the Solax inverter.

I’m all about the ease of use and simplicity where possible.
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So right now it's poor, but that's only due to the lax nature of Intelligent Go. If I were forced to have just 6h of cheap elec, I would feel it. I don't have enough battery to cover my usage, especially in winter - we use elec for heating via ASHPs (A2A).

A 2nd PW3 doesn't make sense, a) because of the G99 limit that would mean they ended up capped at like 8kW each inverter capacity, and b) because it won't like the optimisers on the 2nd array, which I am not removing as two of the panels are on a different aspect.
 
Unless you also have a huge EV overnight demand swapping to Octopus Cosy for a few months a year is likely to be more cost effective than spending ~£6k on another battery. 3 periods a day at 12p.

I’ve got an ASHP and I’ve ‘only’ got a 13.5kwh battery. It doesn’t last the day in Dec or Jan but of spending thousands to save tens of £ of peak time electric per year doesn’t really work either. My average import cost in December and Jan last year was under 10p/kwh so I don’t even go to Cosy. Last year was pretty mild mind but even then I was well below the cosy swap point.

At full rate, £6k buys you a hell of a lot of peak electricity over the useful lifespan of an inverter and battery, say 12-15 years. That’s £400/year you can spend on peak rate electricity before you even break even.

The goal shouldn’t be zero peak time usage, it’s minimal cost (IMO). Slapping another battery in isn’t minimising costs.

Of course you want to carefully look at the rates, incentives and battery costs regularly, it’s a moving beast.

There’s lots of discussion about Eon clamping down on brown export and I wouldn’t be surprised if 15p-16p flat export goes away as solar penetration continues. Particularly those with batteries exporting out to 11.30pm when the grid can be very cheap at wholesale.

I guess what I am trying to is also don’t bet the house on brown export being profitable. Even now, it’s only 7p/kwh once you factor round trip losses. That isn’t really profitable when paying commercial rates for batteries, particularly premium options like the Tesla. You are better off sticking your money elsewhere to make a better return.
 
Oh I'm not going near E.On, the 2nd array doesn't have MCS so they won't pay anything like what I export.

I currently get everything at 7p thanks to IOG. I don't cycle the battery for profit but in winter I can easily use 100kWh in a day.
 
The whole market will be in flux for many years, as more homes adopt solar and batteries, and then H2G, V2H and V2G will change things all over again as they become more common place.

For me and my situation, I don't really care about a few £K extra over so many years on something that may help reduce fossil fuel use, but not many people actually care and most only look at the £'s saved/made. I also like the ability to run of grid if needs be for a few days, we never know when we'll see an event like Spain/Portugal recently, or other local issues.
 
This week I had solar panels installed :)

The panels got delivered at 7:30am, but there were no rails, clamps, etc. Those arrived at 2:30pm and this is when the panels installation started. The two guys finished installing all 14 panels the same day, but I think they did a very rushed job. Now I'm noticing some small issues with the panels and wondering if those are normal or caused by the rushed job.

The two rows of panels are perfectly aligned on the right side, but not on the left side. Even from the street it's visible that the left top panel is not vertically aligned with the left bottom one. Also one of the DC cables has a cut through the isolation. The DC cables are not neatly attached to the wall, but just hanging around.

I uploaded some photos here: https://imgur.com/a/solar-MhLo7d7

Do you think that's something I should contact the installer about, or just normal way that panels are installed?
 
Oh, I see - this may be an old antenna cable.

There are two arrays, the misalignment is most visible on the left side of the left panel. On this photo right under the scaffolding pipe. The top panel on the right starts aligned on the right side, but gets less so on the left. And the left panel is mounted substantially higher than the one under it.

Vw9ucIA.jpeg
 
Ok, I can see it now, that is a bit out. None of the pictures were square with the issue so it’s hard to see it.

If you are not happy with it get them back to sort it out. You can see in the wide shot your roof is anything but flat but as you say, if they had more time they could probably have got it aligned better. Just bear in mind it’s not easy to get it completely aligned on an old roof so it will probably never be perfect.
 
Another thing I'm worried about is the rails are extending beyond the panels. Birds can go under the rails and nest under the panels. There is metal bird netting around the panels, but where the rails go beyond the panels there is no netting. There's enough space for a bird to pass between the railing and the roof tiles.
 
It’s normal for the rails to extend past the edge of the panels, if they didn’t, there would be nothing for the panels to mount to.

As for the netting, discuss with the installer as that at be how that system works.
 
Suspect the roof and the tiles are not square/level but they probably could have done better with more time.
Some of those tiles are anything but flat so if it just happens that the rails hit a high/low point they will not align.

Bird netting should be all the way round otehrwise its a waste of time

Are you going to fix the missing tile whilst the scaff is up?
 
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