Not going to be too much of a problem down in Cornwall. Probably get 10% more generation compared to most places.
Your North Coast as well, so generally less misty (though that does depend on altitude too).
The rain will keep then clean too

Thing to remember is that there really is very little difference in modules.
Many are rebranded (you can search that on google).

Inverters are what they are, generally you only have a choice of 3.
SMA
Fronius
Aurora/PowerOne

Then there are EnPhace (micro-inverters), but as you are building new, you should be designing shadows out.

Stecca is a good make, but again, you should not need to use one on a new build (they work better at lower voltage).

Trick is with PV is to not be sucked in my fancy sounding technology. PV is really simple, proven and tested.

12% is great but, as I think ST's mentioned in the past, you need a whacking great "illiquidity premium" relative to savings and investment products to compensate for the inability to get your capital back quickly if you need it (and the hassle vs. buying an ISA).

Being dull, I'm fascinated by what that needs to be to drive - mass- uptake. I think 10-12% is probably a minimum, less for those that value the issues you mention, but potentially up to 20% (five year payback) for those that don't.

If your system costs you £5,000 and it takes 8 years to get your money back, that is when you have to start counting it as an 'investment', until then it is a cost.

Do people consider other things, like new cooker, or a shower, as an investment?
Which brings me neatly onto a second point.
If you think that PV supplied energy is 'free' or paid for, you may end up using more.
There has been some research about the short term drop in energy usage, but it soon rises again.

The biggest driver to get more RE onto/into homes is traditional supply price.
If energy was priced at the same level as PV, we would need to pay about 20p/kWh (assuming 5% interest and 14p/kWh and no fuel price rises).
Which is really not that high, most people count afford this (they would soon cut usage).

At 20p/kWh I would pay about £800/year, or about a 60% rise (not so far from government prediction over the next 20 years).

So it looks like I should wait about 10 years before I install.
This does assume that you use all your generation. If you only use half of it, then it is still too expensive.

The other things is that we have become accustomed to low saving rates, but this cannot last forever.

One problem with PV installation costs is that it is not linear, it costs about the same to install 3 kWp as it does 4 kWp.
You save on 3 or 4 modules and a bit of rail, a tiny bit on the inverter, but the rest is the same.
There is an advantage of fitting it on a new build, you can roof integrate, saving on tiles, design in the location of the inverter, run cabling easier, you probably have scaffolding already there and if you can convince an installer that you only want an install (off your drawings), then you should save on the salesman's commission (they used to get about £800/sale when I was involved).

Just a matter of doing the sums.

Compare the overall cost of installing PV against the cheapest E7 you can get away with.

The occasional visitor is not really a worry, just turn the immersion on. Get them to pay for at least one decent meal per visit.

a kWh of electric is about 14p/kWh, a MacDonald's is about £2.40/kWh.
Even lentils are a £1/kWh, but you don't want to eat 2 kg of them a day.

No harm is cutting down trees and sequestering the CO2.

I was being specific to Joe90's new build. Not sure there are any trees on North Cornish Coast.
The only ones of note I know of are Tehidy woods, totally man made.

I have no trees involved but a tall beech hedge to the west and that is to be trimmed down anyway.

With the recent announcement of fit being reduced big time I thought I would resurrect this thread, not sure it will be worth it for my build now. ( still fancy buying that Harley instead).

What we don't know is how much the cost of PV will come down once the FIT reductions kick in......

It is a shame that we still don't have any mass market roof integrated PV to save roofing costs.

Even though CFSH has gone Councils largely still seem to be setting energy targets for new builds, and to reach this target some form of renewables might still be needed. Won't keep the PV industry going, but you might well find it still gets installed without FIT

Posted By: richardelliotEven though CFSH has gone Councils largely still seem to be setting energy targets for new builds, and to reach this target some form of renewables might still be needed.

I haven't really followed CfSH stuff, but I thought recent changes meant councils could not impose additional standards/burdens (i.e. Merton rule is dead)? Where have renewables been required as a condition of building (in the domestic arena, not commercial)?