Best place for PV inverter and battery?

yp70479

I am planning on getting a small solar array  9 Trina 395KW panels, 3kw Solis inverter and a 5.2KW  Giveenergy battery with AC3.0 charger. I don't have an adjoining garage and inside space is limited for an internal installation. So where is the best place to put the inverter and battery - in the loft (hot in summer, cold in winter) or on a west facing outer wall. All units a IP65 rated. I am worried inverter efficiency could be compromised in the loft in summer, and ability to charge the battery from cheap grid tariff in the winter would cease if units went below 0'C. Which is the least worst option?

QrizB

Welcome to the forum.

Which is the least worst option?

A difficult choice. I'd prefer the loft to outdoors, although outdoors would work if you placed them in a suitable enclosure and took measures to keep them above freezing in winter, but ventilated in summer.

Maybe something like this, insulated and with a frost heater for really cold spells and a fan for hot ones?
https://www.buyshedsdirect.co.uk/2-x-2-shire-wooden-garden-store

Exiled_Tyke

I would go with the loft on this one. You should find that the panels will reflect some heat and may prevent the loft space underneath getting quite as hot in the summer. 

Magnitio

The temperature range quoted by Givenergy for this battery is -10C to 55C and the inverter's performance reduces above 45C. I would think you are more likely to exceed the maximum temperature in the loft than the minimum temperature outside. It's worth trying to find somewhere inside. If not, outside the house with a cover.

gefnew

My inverter is in the loft and has been since2011 no problems and  is transformer less type with no fan. you can add a fan to but seems to not to need it and there no noise from it. SMA 4000 TL 20 Also the loft is a lot cooler due to solar panels on the south facing roof.

EricMears

gefnew said:

My inverter is in the loft and has been since2011 no problems and  is transformer less type with no fan. you can add a fan to but seems to not to need it and there no noise from it. SMA 4000 TL 20 Also the loft is a lot cooler due to solar panels on the south facing roof.

My inverter is also in the loft and also been there since 2011. Also a 'SMA Sunny Boy 4000-TL-20'

Never been any bother (yet !   will probably crash tomorrow now I've posted that  )

Martyn1981

We put panels on our E roof in 2011, went for an inverter in the downstairs toilet. But noticed that the loft wasn't as insanely hot after the PV. Then had panels on the W roof in 2012, and put the inverter in the loft, and the loft got cooler again.

So if the direct sun is 'blocked' then you get an ambient high temp, rather than the sun on slates/tiles peak before.

Biggest temperature change difference I've noticed, ironically, is after changing inverters in the downstairs toilet. We had two smaller SMA inverters averaging 94% efficiency, but changed to a single Solaredge inverter closer to 99% efficiency. Might not sound like a big difference 94 to 99, but the heat output went from 6% to 1%, so on a really good day with 20kWh of gen, heat output would fall from 1.2kWh to 0.2kWh, which made a difference to such a small space.

Magnitio

OK. I must admit that I've not measured the temperature in our loft since panel installation, so maybe it is suitable. The only other issue is the weight at 54kg for a 5.2kWh battery, but that will be down to whether the installer is happy to get it into the loft safely.

gefnew

Eric
 Start to touch wood to be on the safe side.

yp70479

Many thanks to everyone for their help. Outside temp today was 20'C, so I put my greenhouse thermometers on the loft floor and on the outside wall (but in full sun). The wall was actually 5'C hotter than in the loft! I'll buy some proper max/min thermometers tomorrow and try to monitor over a few days at head height in the loft and full sun and with some shading on the wall. I was surprised the wall got so hot as it doesn't get sun until about 2pm and I measured at 3 and 4pm. If putting panels on the roof does reduce loft temp I might be better putting everything up there - just need the "Worlds strongest Man" to get the battery up there!

gefnew

Do you need to have the battery up there if you can put in a lower room for a practical solution.