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Posted

When I started my project the PV did not cost out as so close to gas main and flat roof forced by planning...now the lecy and gas has gone up the sums add up a lot better for PV.

Due to roof I was thinking of building 18m fence south facing with pv panels. Obviously I will loose efficiency in summer but gain in winter which is really when I need it most. Has anyone else used vertical panels? How was the output? How do the panels cope with wind?

Posted (edited)

Have you run it through PVGIS to see how it compares to putting modules flat on the roof?

You may be better off with an East West fence with modules on either side.

Edited by SteamyTea
Posted
  On 04/02/2022 at 12:05, SteamyTea said:

Have you run it through PVGIS to see how it compares to putting modules flat on the roof?

You may be better off with an East West fence with modules on either side.

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thats presuming  i had a suitable east/west fence without shadowing and the roof slopes back towards North with restriction on roof height with no permitted development rights.

Going the fence route... its a fence if anyone asks.

Posted
  On 04/02/2022 at 11:54, gravelrash said:

When I started my project the PV did not cost out as so close to gas main and flat roof forced by planning...now the lecy and gas has gone up the sums add up a lot better for PV.

Due to roof I was thinking of building 18m fence south facing with pv panels. Obviously I will loose efficiency in summer but gain in winter which is really when I need it most. Has anyone else used vertical panels? How was the output? How do the panels cope with wind?

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Yes, for off grid.  Output is good considering location, but half what it might be because in shadow from the house until nearly noon.

 

Rgds

 

Damon

 

https://www.earth.org.uk/expanding-off-grid-PV-system.html#20160722

Posted (edited)
  On 04/02/2022 at 18:04, Marvin said:

18 degrees off vertical is about optimum for UK winter PV power. Watch outforthelong shadows though..  

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Make a wall/fence/frame that is tilted.

Edited by SteamyTea
Posted
  On 04/02/2022 at 12:05, ProDave said:

@Stones fitted some vertically at the same time as I did my ground mount system.  Perhaps he will come along and say how they are doing.

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They have performed as PVGIS suggested, lower output compared to mounting on the roof, but reasonable none the less. The array I have produces circa 20% less compared to being roof mounted at 45 degree pitch.  Mine are fixed to the garage wall so no issues with wind (which can get quite brisk here!)

  • Like 1
Posted
  On 05/02/2022 at 08:30, gravelrash said:

I thought the 9m2 rule was just for commercial not domestic

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The 9m² is for domestic.

Commercial is totally different legislation. Mainly because they are dealing in hectares, 10,000 m², rather that a few m².

Worth remembering that for every rule that says you should do something, there is another that says you can't.

Posted (edited)
  On 05/02/2022 at 13:26, SteamyTea said:

The 9m² is for domestic.

Commercial is totally different legislation. Mainly because they are dealing in hectares, 10,000 m², rather that a few m².

Worth remembering that for every rule that says you should do something, there is another that says you can't.

Expand  

bit of a conundrum. when is a fence not a fence...would keep a solicitor in fancy cars for years.

Edited by gravelrash
Posted
  On 05/02/2022 at 16:05, gravelrash said:

when is a fence not a fence..

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Or how low is a roof.

Generally a fence can be 6 foot high I think.

Modules are usually 1m wide by 1.6m tall.

If you tilt that fence as I suggest, you will get more modules on it, and better yields.

Say it is to deflect noise. Works by quantum effects.

 

Posted

That's good for maximising summer (and overall) generation in the UK with south-facing panels.

 

If you want to have the least short-fall / best putput in winter then the optimum angle is much nearer vertical as described above for south facing, or likely much nearer horizontal if facing other than fairly south.

 

Rgds

 

Damon

Posted

Don't get power (kW) and energy (kWh) mixed up with changing module angles.  Energy yield was good when you got paid for generation and a deemed export, but now power may be more useful, even if only for a limited time during the winter.

Posted
  On 10/02/2022 at 14:58, SteamyTea said:

Don't get power (kW) and energy (kWh) mixed up with changing module angles.  Energy yield was good when you got paid for generation and a deemed export, but now power may be more useful, even if only for a limited time during the winter.

Expand  

This is interesting, how would you recommend siting the panels? I’m trying to work out (sear Stroud) what angle would be best for all year round use (4kW array, 3.6kW inverter). 

Posted (edited)
  On 10/02/2022 at 21:17, CotswoldDoItUpper said:

This is interesting, how would you recommend siting the panels? I’m trying to work out (sear Stroud) what angle would be best for all year round use (4kW array, 3.6kW inverter). 

Expand  

Assuming no shading, I would just run the angles though PVGIS and initially see which gives the best energy yield.

So something like this:

 

00

 

image.png.8d87ad12d73fefefee8b467697e4dd70.png

 

250

 

image.png.4905e17c504520af351f581bbcd88091.png

 

500

 

image.png.24900df642c3a84d13f0bc67b05d5b4b.png

 

750

 

image.png.cd1bdbfb5a4b74eb5262ce56be8968d7.png

 

900

 

image.png

 

Then decide when I need the energy most i.e. 750 gives best yield in winter.

Then I would look at the hourly data for that month i.e. December.

Initially the mean, min and max by hour of day.

Chart title is wrong, it is just showing December data.

image.png.b92f7521a0d41dba231b84a2e8720760.png

 

Then the percentage frequency that those powers (W) actually happen.

 

image.png.a5047ca1ed526887716da81225900a14.png

 

Then decide if I can find a use for those power levels.

 

(I based this on Stroud and a 1 kWp grid tied system for simplicity)

 

 

 

Edited by SteamyTea
Posted

I guess we would look at maximum yearly usage. We have an annual use of around 20,000kWh (2 x EV) so will easily self use. 
 

I’ll have a look at PVGIS and work done things out. Didn’t realise it could do hourly data too! Does it take into account average sunny/cloudy days?

Posted
  On 10/02/2022 at 23:11, CotswoldDoItUpper said:

We have an annual use of around 20,000kWh (2 x EV) so will easily self use. 

Expand  

There may be a minimum power requirement to start charging them, so they may have to be topped up from the grid at the same time.  That time slot may be expensive.

Posted

Generally car charging standard need minimum 1.2kW to work. Zappi charger we have will keep charging paused until it has 1.2kW surplus. Under that it goes into hot water via tank.

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