Building interior windows insulation panels

[Weatherlawyer]

(Liked the link though.)

[harryagain]

Shouldn't think so, it took Drayton years to perfect the system.

[harryagain]

Things was even worse when there were smokers and non-smokers in one office.

[harryagain]

The best solution is a revolving door.

[harryagain]

The windows are three feet X twelve feet on the South side where all the frequently occupied rooms are.

[harryagain]

Bungalows have a bigger footprint than houses, hence more room on the roof for PV panels. Also less scaffolding needed, reducing the cost.

Energy generated/captured depends on many factors. PV panels are more efficient than they once were. Even more efficient ones are in the pipeline. The house was selected as ideally situated for solar energy captureof all types as well as ideal for conversion to passive house standard.

[harryagain]

Been on the go for forty yearst o my knowledge.

[Nightjar]

Not if you are pushing a wheelchair.

Colin Bignell

[The Natural Philosopher]

rotating knives?

[Nightjar]

Against which, the larger surface area will have greater heat losses and a roof is far from the best angle for a solar panel in mid-winter, when you are likely to need the output most. Hanging them on the wall at around 15 degrees from the vertical will give the best output in SE Britain in December.

IME, scaffolding has never been particularly expensive.

The point is that none are going to give 4000 kWh pa from a 4kWp installation, especially after the first year's drop in efficiency.

We obviously have different views about what makes a house ideal for that.

Colin Bignell

[Chris J Dixon]

If you put the numbers into one of the output estimators, does this actually increase to annual output though?

Seems to think that, for SE England, 4 kWp, the optimal slope is

38 degrees at -1 azimuth, producing 3860 kWh. At 15 degrees slope the output is 3650 kWh, about 5% less.

The breakdown of kWh by month shows the opposite to what you suggest:

38 Deg 15 Deg Jan 145 107 Feb 184 153 Mar 323 291 Apr 450 435 May 468 484 Jun 467 494 Jul 472 494 Aug 419 419 Sep 359 331 Oct 266 223 Nov 171 129 Dec 131 94.5 3860 3650

Chris

[Chris J Dixon]

Just realised your 15 degrees was to the vertical, so 75 for the simulator.

Here it is.

38 15 75 Jan 145 107 156 Feb 184 153 188 Mar 323 291 304 Apr 450 435 378 May 468 484 350 Jun 467 494 333 Jul 472 494 340 Aug 419 419 332 Sep 359 331 321 Oct 266 223 265 Nov 171 129 185 Dec 131 94.5 141 3860 3650 3290

Chris

[Nightjar]

No, because a typical roof slope of 30 degrees is best for the summer months, when you get most sunlight. That will give you maximum annual output, but most of it will be in months when you are least likely to need it.

It all depends upon whether you wish to maximise the income from FIT or have maximum output when you need it most. FIT is fairly recent, so whenever I have looked at self-sufficient houses, which I first did in the 1970s, I have worked on the latter.

If you wanted to maximise both annual and monthly output, you would have to fit the screens on 2-axis motorized mounts and track the sun. However, hinged mounts regularly adjusted would be better than fixed mounts.

Try inputting 75 degrees, which is 15 degrees from the vertical. It gives an annual output of 3190 with the December output as 138. Only 5% more, but in a cold, dark month that may be significant. You will find that many Victorian greenhouses have glass at a similar angle, thanks to the work of a Victorian clergyman, whose name escapes me.

This site will calculate the optimum angle for each month:

Colin Bignell

[Nightjar]

I must have been typing my reply when you posted this. I got slightly less at 75 degrees, using London as the location, but you can clearly see the gain from choosing that angle in the winter months.

Colin Bignell

[Tim Lamb]

Interesting to note that the performance for the 15 deg. slope found on agricultural/industrial barns tails off significantly outside the summer months. Doubly unfortunate in that the locations might best suit supply connections.

[dennis]

I looked at doing off grid solar on it..

just doing june-oct it said it would cost me £46k and I would need 110 sq metres of panels, it doesn't say where I find somewhere to put them.

And then there is the batteries about 6000 Amp hrs worth.

Somehow I don't think solar is the way to go.

[Nightjar]

You bury the house, which simplifies things by giving you a constant external temperature, then use the land above it for the panels.

You may be right :-)

Colin Bignell

[John Rumm]

How about a big motorised reflector as used in solar thermal power stations. ;-)

[Nightjar]

That would make an interesting planning application.

Colin Bignell

[John Rumm]

It would be smaller than a windmill, and make less noise.