Solar Panel optimisers

Clive_Woody

We’re having solar panels fitted in a couple of weeks (14 panels), south facing roof. At the moment there is no shading at any time of the day, but there are some big oaks to the rear of our house that may potentially in the future shade the house (not our trees so cant be pruned) - This is probably unlikely, but it’s a possible concern and my good lady is worried.

Our current quote doesn’t include optimisers, but we’re now thinking of maybe adding them in. I asked our installer and he said they would only need fitting to panels that would potentially be shaded. Is this also potentially a risky approach, or is this a reasonable attempt at cost saving? He said it would be £52/panel to add optimisers, so we could go for all 14 panels, but a few hundred quid saving would be nice if this isn’t a false economy.

Merlin139

What height are these Oaks now? I have trees about 15 meters from my roof that are around 7 meters high likely to grow to around 20 meters over the next 50 years and the only time of year I see any shadows coming from them into the garden is the middle of winter. The rest of the year the Sun is too high in the sky to effect them. Obviously Oaks will grow a lot higher. Up to 45 Meters.

I have optimisers fitted but that is due to a shadow that is cast over my house by the angle and elevation of my next door neighbour. Over a period of 8 years the difference in Panel Output goes from 2.05 MWh to 2.37 MWh. For me they were a worth while investment.

QrizB

Clive_Woody said:

We’re having solar panels fitted in a couple of weeks (14 panels), south facing roof. At the moment there is no shading at any time of the day, but there are some big oaks to the rear of our house that may potentially in the future shade the house (not our trees so cant be pruned) - This is probably unlikely, but it’s a possible concern and my good lady is worried.

Oaks are quite slow-growing trees, and if the ones you're worried about are already "big" there's a pretty good chance they won't grow enough to shade your panels in the next decade or two.

vienly

Can anyone advise why optimisers are needed if bypassing diodes do the same job for shaded panels? 

gefnew

What is Blocking Diode and Bypass Diode in Solar Panel Junction Box? (electricaltechnology.org)
May help.

vienly

Thanks I've read that but it would seem that bypassing diodes does exactly what solar optimisers do so I'm wondering why anyone would pay extra for the same thing?

gefnew

There is this though.

se_technical_bypass_diode_effect_in_shading.pdf (solaredge.com)

QrizB

vienly said:

Thanks I've read that but it would seem that bypassing diodes does exactly what solar optimisers do

But they don't. Here's an explanation that seems pretty clear:
https://www.solarquotes.com.au/blog/solar-panel-optimisation/

Pulpdiction

QrizB said:

vienly said:

Thanks I've read that but it would seem that bypassing diodes does exactly what solar optimisers do

But they don't. Here's an explanation that seems pretty clear:
https://www.solarquotes.com.au/blog/solar-panel-optimisation/

Some really good stuff in there, particularly this was useful to me:

https://www.solarquotes.com.au/blog/microinverters-vs-dc-optimisers-which-is-best-infographic/

Makes me think I should add optimisers to my panel set up for £45 a go.  Don't see why retro fitting these would impact my FIT payments?

gefnew

British Gas always ask when you send your fit readings if your system has changed. 

Clive_Woody

Pulpdiction said:

QrizB said:

vienly said:

Thanks I've read that but it would seem that bypassing diodes does exactly what solar optimisers do

But they don't. Here's an explanation that seems pretty clear:
https://www.solarquotes.com.au/blog/solar-panel-optimisation/

Some really good stuff in there, particularly this was useful to me:

https://www.solarquotes.com.au/blog/microinverters-vs-dc-optimisers-which-is-best-infographic/

Makes me think I should add optimisers to my panel set up for £45 a go.  Don't see why retro fitting these would impact my FIT payments?

Thanks, interesting read. We are having a battery so looks like optimisers are the way to go. 

Going back to my original question, does anyone know if you can just fit optimisers to panels that are likely to be shaded or is it a false economy and best to fit to all 14 panels?