Ground mounted solar PV installation project

[Gareth J]

Regarding your guesstimate of what to do with all the excess energy, I think you're on the right track. Which is no surprise considering the level of monitoring you do.

As a comparison, as a two person house, 4kWp and a 200l tank, we used to divert almost enough electric to do all our summertime hot water. Some consecutive foggy days required a boost. In a similar period, with a similar house and occupancy, this year, our neighbours have used about 300-400l of oil.

In summer, there is extra excess too so expecting a modest amount for modest battery sounds sensible. Bear in mind as we get to autumn, that in purely financial terms, it might be best to prioritise filling EV or batteries as this energy is (presumably) more valuable than the alternative water heating energy. You can, with the right widgets, choose different export thresholds to prioritise different energy sinks. But it can all get a bit fiddly!

We've now got excess from 8kWp and 2.5kW of wind turbine going into hot water/heating. The solar has, this summer been upgraded from 4-8k, it will be interesting to see how far into autumn the extra will take us and how much lower the oil consumption over winter is. I can probably forget any heating potentially from the panels over winter, but the extra may help shave a bit off the electric bill.

 

[Matrixx]

kW, mW (milli) & MW (megga) , kVAr, kVA, mA, the capital is because it is a name.

G98 is less than 16A supply to the grid above this it G99 (loss of mains protection), to prevent back feeding into the grid, and prevent out of synch mains coming back and blowing up your incoming breaker.
what you do when isolated (island) is up to you, as long as you are isolated from the mains.

 

[brewdexta]

The panels just arrived, I was out walking the dog on the canal when the delivery driver called. I thought it was unannounced but I missed the second email so my fault. They were on a big lorry that couldn't get up the hill so I had to get the driver to deliver to the joiners shop at the bottom of the hill. I arrived just as he was dragging them off the tail lift. I had just done a tip run so I had no straps in the back of the pickup so had to scrounge some from the joiners, he only had one decent in the shop, all the other were out on fitters vans. her had no forklift so we took them off the pallet. may not have fitted between the wheel arches anyway as it was a bespoke pallet.

They don't over-package, apart from the outer layer of card board, they just have a cardboard corner, that's it. One strap with minimal tension and we got up the hill ok. Battery arrives this evening.

 

[fizzy]

I still fail to be convinced of the viability of solar in the UK as we are so far North. Totally different in Portugal etc of course.
Will be interesting to see Andy's results over this Winter.
His location is probably pretty similar to ours in Wales.

 

[daleyd]

....and right on cue.

 

[brewdexta]

Winter will not be the benchmark for success. So far this summer since I turned the CH off I have gone through about 1.5 tonne of pellets to keep the boiler going just to provide hot water. Just hot water is not its sweet spot. That's about £450, and that is at last year's pricing, its about £700 now. So if it just provides HW during the summer it will be a good way towards justifying itself. 10 years pay back just on HW before any other output is quantified. Obviously the pellet price may come down again, The value of investments and the income from them can go down as well as up and you may not get back the amount originally invested

 

[fizzy]

....and right on cue.

No I am genuinely interested. I know he will be unbiased and tell the truth. Anything that saves me money is worth doing!

 

[fizzy]

Winter will not be the benchmark for success. So far this summer since I turned the CH off I have gone through about 1.5 tonne of pellets to keep the boiler going just to provide hot water. Just hot water is not its sweet spot. That's about £450, and that is at last year's pricing, its about £700 now. So if it just provides HW during the summer it will be a good way towards justifying itself. 10 years pay back just on HW before any other output is quantified. Obviously the pellet price may come down again, The value of investments and the income from them can go down as well as up and you may not get back the amount originally invested

If you just want summer hot water wouldn't roof mounted water thermal panels be better? Almost every house in Spain and Portugal uses them. Not much good when it's overcast though.

 

[fizzy]

....and right on cue.

And in the Spring I will be investing in a 4 to 6kw array and a forklift battery for my place in Portugal.

 

[Kayos]

....and right on cue.

But but it's sunnier in Portugal

 

[fizzy]

But but it's sunnier in Portugal

Only a tad!

 

[Kayos]

Only a tad!View attachment 362117

Yes but a few points

It's not England
@brewdexta is in England
Despite your many, many protests solar PV does in fact work in England
No one cares you have a place in Portugal

 

[fizzy]

Yes but a few points

It's not England
@brewdexta is in England
Despite your many, many protests solar PV does in fact work in England
No one cares you have a place in Portugal

I will rely on his feedback thanks.

 

[Gareth J]

I still fail to be convinced of the viability of solar in the UK as we are so far North. Totally different in Portugal etc of course.
Will be interesting to see Andy's results over this Winter.
His location is probably pretty similar to ours in Wales.

You could wait to see how his goes, or, if you were curious and didn't want to wait, you could just plug your details into PVgis. It's scarily accurate. Have I already mentioned this?

 

[fizzy]

You could wait to see how his goes, or, if you were curious and didn't want to wait, you could just plug your details into PVgis. It's scarily accurate. Have I already mentioned this?

Yes I did try it. Not looking good for our place as its down in a valley. I would consider it for my warehouse but we get awful winds right by the sea. Roof sheets often get blown off so I doubt it would be safe.

 

[fizzy]

Anyway this is Brewdexters thread not here to argue! The way he is setting it up is interesting to watch.

 

[500e]

Hot water panels work had a Solar Co in the 70s (SeS) but packed it in.
People were claiming all sort of magic things for them & we saw the fall out at the time.

 

[dobbslc]

Hot water panels work had a Solar Co in the 70s (SeS) but packed it in.
People were claiming all sort of magic things for them & we saw the fall out at the time.

So do they work or not? It's something else I have been thinking about.

 

[Gareth J]

Yes I did try it. Not looking good for our place as its down in a valley. I would consider it for my warehouse but we get awful winds right by the sea. Roof sheets often get blown off so I doubt it would be safe.

You're right, this is the wrong thread hopefully so long as things stay more or less relevant and positive brewdexta won't mind. Happy to delete any of my posts if contrary.

There's a calculator/app on the "K2" website that will spec required fixings for a specified windspeed. It's a brand so they obviously spec their own fixings but you can apply it to whatever mount system. If you're relying on fixing to tin, you can fix enough that you'll rip the tin off the roof before the panels blow off, or, if going into purlins, you could potentially fix enough that it'd hold your current roof sheets on.

Regarding your home, valley shading, that might be an issue. If you go deeper into PVgis, you can specify a "horizon profile" it's a bit clunky and takes a bit of maths to figure out what numbers are required to represent a tree 10m away, a building 50m away and a hill 500m away. But not that tricky.

 

[500e]

They can be very efficient but you have to look at your demand to decide how to plumb