Position of solar panels

[mjc55]

Just trying to work out options for pv.

 

Not even at planning stage yet for newbuild but plans are for single storey, flat roof, house with a smallish "summer house" down the garden.  Not favouring panels on flat roof at the mo given potential problems down the line with fixings.

 

We are planning on a "walkway" between the house (To the front of the plot) and the summer house (at the rear of the plot).  I was wondering if there would be any issues with creating a "roof" for the walkway which would support solar panels?

 

Would be something like 10+ metres of walkway between the two so enough room?  It would be South facing and the property to the South is a bungalow and is also far enough away for overshadowing of panels to be an issue.

 

Putative plans have plant room on the Southern side of the house so quite a distance, don't know whether this would be an issue!

 

Any thoughts welcome.

[SteamyTea]

PVGIS is your friend here.

[ProDave]

What is the orientation of the plot and the summer house?

 

I fitted mine on an east / west split, at the time thinking it would give longer generation than south facing, but completely overlooking the tree shading issues.  So let the plot as a whole and any shading issues e.g to the east and west guide you.  If I were doing it again (and if I fit more) I would be going for near vertical panels south facing, to maximise winter production (there is always ample in the summer)

[mjc55]

24 minutes ago, ProDave said:

What is the orientation of the plot and the summer house?

 

I fitted mine on an east / west split, at the time thinking it would give longer generation than south facing, but completely overlooking the tree shading issues.  So let the plot as a whole and any shading issues e.g to the east and west guide you.  If I were doing it again (and if I fit more) I would be going for near vertical panels south facing, to maximise winter production (there is always ample in the summer)

The "walkway" would run E/W (house to the East, Summer House to the West) so panels could be oriented to the South.  

[mjc55]

33 minutes ago, SteamyTea said:

PVGIS is your friend here.

Thanks, will have a look at that.

[mjc55]

Plot is below, in correct orientation.

 

House will be to the East, front roughly lining up between houses on either side.

 

Summer House to West of plot so walkway will run near Northern boundary from East to West, hence can orient panels to the South.

 

 

[ProDave]

So make your covered walkway with a sloping roof as steep as you dare at least 45 degrees.

[mjc55]

13 minutes ago, ProDave said:

So make your covered walkway with a sloping roof as steep as you dare at least 45 degrees.

Was definitely thinking sloped roof.  I thought optimal angle was 30 degrees???

[DamonHD]

2 minutes ago, mjc55 said:

Was definitely thinking sloped roof.  I thought optimal angle was 30 degrees???

There isn't one definition of 'optimal'.

 

if it's for maximising overall annual generation even at times when there will be a glut of other solar power, it's due south and a tilt something like that.

 

If it's for maximising winter generation when energy is scarce to to even out generation between summer and winter, it's more like 70 degrees.

 

If it's for maximising generation under overcast skies, nearly flat.

 

If it's for maximising power generation when demand is highest (and you may be paid a significant premium to export excess) then actually point west-ish or southwest and probably rather steeper than 30 degrees.  I'd have to look at PVGIS and some grid pricing...

 

Rgds

 

Damon

[mjc55]

To be honest it makes absolute sense that the angle isn't fixed.  The Sun is at different angles at different times of the year so ideally moveable panels would be the best but obviously that would be an expensive option. 

[JohnMo]

2 minutes ago, mjc55 said:

To be honest it makes absolute sense that the angle isn't fixed.  The Sun is at different angles at different times of the year so ideally moveable panels would be the best but obviously that would be an expensive option. 

Really wouldn't bother doing movable panels, the complications aren't worth the effort. Just decide what you want out the system. I wanted decent winter performance, not really bothered about loads of excess generation, I can't sell in the summer. So I went vertical panels, they are good in winter (if the sun's out) and pretty good in summer.

[Conor]

What about shading? Do you have trees nearby? If my panels weren't 2.5 stories high, and instead of a single story garden room, I'd be generating 0kwH at this time of year, rather than 5kWh, as they'd be in perpetual shade due to the trees around our site.

[mjc55]

3 hours ago, Conor said:

What about shading? Do you have trees nearby? If my panels weren't 2.5 stories high, and instead of a single story garden room, I'd be generating 0kwH at this time of year, rather than 5kWh, as they'd be in perpetual shade due to the trees around our site.

In the position I am thinking about there would be no shading at all.

[mjc55]

3 hours ago, JohnMo said:

Really wouldn't bother doing movable panels, the complications aren't worth the effort. Just decide what you want out the system. I wanted decent winter performance, not really bothered about loads of excess generation, I can't sell in the summer. So I went vertical panels, they are good in winter (if the sun's out) and pretty good in summer.

Sorry, I wasn't suggesting that I was thinking of moveable panels just thinking out loud I suppose.