Tue, 19 Dec 2023 05:33:45 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225846#Comment_225846 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225846#Comment_225846 Tue, 16 Jun 2015 22:19:12 +0100 SteamyTea 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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225848#Comment_225848 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225848#Comment_225848 Tue, 16 Jun 2015 22:56:35 +0100 Ed Davies Posted By: joe90Rather than the ethical issues raised above, some (me) may also be concerned with the pay back period for a typical PV installation.100p/W. Generates for, effectively, 800 hours a year so 0.8 kWh/year. 15p/kWh so 12p/year if you can set up to use it all. Be nice to know of anything else which pays 12% interest. Payback in 8 years and four months. If we assume a 25 year lifespan it then pays back another two times after that.

Or it breaks even against E7 rates or gas “just” giving security of supply, protection against inflation (and a warm feeling that you're not effing things up for future peoples in far off countries - but we're ignoring ethical issues.)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225853#Comment_225853 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225853#Comment_225853 Wed, 17 Jun 2015 09:43:19 +0100 GarethC
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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225856#Comment_225856 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225856#Comment_225856 Wed, 17 Jun 2015 10:12:51 +0100 Ed Davies http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225857#Comment_225857 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225857#Comment_225857 Wed, 17 Jun 2015 10:19:31 +0100 SteamyTea
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).]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225861#Comment_225861 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225861#Comment_225861 Wed, 17 Jun 2015 10:43:40 +0100 joe90 ]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225863#Comment_225863 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225863#Comment_225863 Wed, 17 Jun 2015 10:55:46 +0100 SteamyTea
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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225864#Comment_225864 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225864#Comment_225864 Wed, 17 Jun 2015 11:00:12 +0100 djh Posted By: SteamyTeaThen there are EnPhace (micro-inverters), but as you are building new, you should be designing shadows out.
So you're advocating cutting down trees? How do you suggest rerouting clouds so they don't pass overhead? Admittedly I doubt the behaviour under clouds makes much difference, but I'm certainly happy to pay the fairly small premium for the response to tree shadows and for the 25 year warranty.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225865#Comment_225865 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225865#Comment_225865 Wed, 17 Jun 2015 11:12:22 +0100 SteamyTea
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.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225871#Comment_225871 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225871#Comment_225871 Wed, 17 Jun 2015 11:37:41 +0100 fostertom Posted By: SteamyTeaNo harm is cutting down trees and sequestering the CO2.Assuming N Cornish coast was once wall to wall Sesile Oak, like the rest of Britain, but totally stripped by man, it's a bit time-lapse to call Tehidy woods man-made as if that confers the right to create/destroy at will.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225873#Comment_225873 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225873#Comment_225873 Wed, 17 Jun 2015 12:06:56 +0100 joe90 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225877#Comment_225877 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=225877#Comment_225877 Wed, 17 Jun 2015 12:41:13 +0100 ringi http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229148#Comment_229148 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229148#Comment_229148 Fri, 28 Aug 2015 12:59:39 +0100 joe90 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229181#Comment_229181 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229181#Comment_229181 Fri, 28 Aug 2015 23:14:17 +0100 SteamyTea Existing buildings is a bit harder to call.
Couple of 'off gas' pensioners may benefit, as may people that heat water with E7.
The people that will probably not benefit are the 'young aspirational' that work hard and play hard and intend to make a fortune by moving every couple or three years.

The really hard things to predict are the future price of energy. We do know that nuclear is going to be about £100/MWh (and rise with inflation), Wind is between £120 and £150 (not linked to inflation I think), coal, which is dirt cheap is being phased out or will be taxed more.
Gas will always be volatile, as will oil (not that much electricity is made that way).
If we say that the last two years are just a market correction, after the previous 2 or 4 years being higher than normal, then expect electrical generation from gas to be about £60/MWh.
Fracking will only limit the volatility, it will not reduce the price in the UK in my opinion.

The big difference is going to be political, they could tax fossil fuels highly, but doubt this government will.
They could also put a general tax on energy, regardless of how it is generated (I think this is likely).

I think as a general rule, domestic energy expenditure will account for about 5% of median household income. It has been around this point for a couple of decades now, I can't see anything on the horizon to change this (no new 'wonder' technologies or 'economic' systems).

But take my last quarter bill, I used 6 kWh/day at a gnats under 13p/kWh. Not bad value really.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229184#Comment_229184 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229184#Comment_229184 Fri, 28 Aug 2015 23:51:01 +0100 ringi
It is a shame that we still don't have any mass market roof integrated PV to save roofing costs.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229186#Comment_229186 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229186#Comment_229186 Sat, 29 Aug 2015 06:53:17 +0100 SteamyTea We can't have any old DIYer connecting whatever they like to the grid or nailing modules to a roof.
MCS was more than just approving the hardware.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229187#Comment_229187 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229187#Comment_229187 Sat, 29 Aug 2015 07:23:41 +0100 richardelliot http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229189#Comment_229189 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229189#Comment_229189 Sat, 29 Aug 2015 08:01:30 +0100 Peter_in_Hungary Posted By: SteamyTeaI think as a general rule, domestic energy expenditure will account for about 5% of median household income. It has been around this point for a couple of decades now, I can't see anything on the horizon to change this (no new 'wonder' technologies or 'economic' systems).

At 5% of income there will be no incentive or driver to change any thing.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229197#Comment_229197 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229197#Comment_229197 Sat, 29 Aug 2015 16:11:01 +0100 djh 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)?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229201#Comment_229201 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13433&Focus=229201#Comment_229201 Sat, 29 Aug 2015 17:32:42 +0100 richardelliot