Renewables: "talking 'bout my generation"

Martyn1981

DREKLY wrote: »

Martyn, quick question, how does your Solar Edge send info to you from the loft installation?

Hi. I think you can run a cable direct, but that's gonna be hard work, so my inverter runs a cable to the nearest socket (about 3 feet away) to a home plug (thingy?) then the plug's partner is plugged into a socket by my router, to which it's plugged into.

Effectively it uses the copper leccy cabling for data transmission.

I have to say that the SolarEdge monitoring is simply fantastic, but even I (yes I) have got a bit bored, and don't look at it that often anymore - I spend more time looking at Edwinks ...... but that's another story! :shocked:

Mart.

Crowmann

EricMears wrote: »

Our inverter is in the loft. It seemed a perfectly reasonable place to put it given that the DC arrives through the roof and the AC needs to go downstairs via the TGM & CU. And of course getting the TGM as close as possible to the roof will minimise any cable losses.

The inverter is attached to a solid wall in the centre of the roofspace and underneath tiles which are shielded from direct sunshine by the solar panels. It's above an insulated floor and next door to approximately half a tonne of water that acts as a heatsink (not its real purpose of course).

I have occasionally visited it on a hot day and not found the environment that unpleasant.

But there's really no need to go up there to check out the inverter - thanks to 'Bluetooth' I get a complete view of what's going on from my computer.

The cable losses are a red herring, almost immeasurable. Your loft in summer will be unbearably hot even on an overcast day. In direct sunlight 40deg plus when outside is 20 would be my experience.


The last place anyone should fit an inverter is the loft. Simples. That folk have them there is down to expedience by installers and ignorance on the part of the client.


Did I mention house fires? Apparently caused by them over heating.... funny that an item whose size is largely formed by a through air flow heat sink being placed in seasonally the hottest part of the house and it gets too hot. Who could have predicted that eh?

EricMears

Crowmann wrote: »

. . . Your loft in summer will be unbearably hot even on an overcast day. In direct sunlight 40deg plus when outside is 20 would be my experience.

Just to avoid any confusion to other readers of this forum, nobody but myself and our PV contractor have any experience of the conditions in our loft.

pinnks

I wouldn't call myself an ignorant person, client or otherwise. As said, while the loft used to get into the thirties it no longer gets anywhere near as hot. Indeed, it is now cool enough to be up there doing looking for something or whatever. For me, the only other options would have meant excessive disruption/cabling/surface-mounted cables etc and/or placing the inverter outside. So for me the choice was - simples.

And I would agree with Eric's comment which arrived while I was typing my reply...

Crowmann

EricMears wrote: »

Just to avoid any confusion to other readers of this forum, nobody but myself and our PV contractor have any experience of the conditions in our loft.

Your contractor did a measured assessment prior to installation over the summer months prior to installing?


Wow, seriously committed contractor. Please name.

Crowmann

I find it bizarre that the simple truth that un insulated lofts (that is lift un insulated from solar gains) get hot - very hot in peak summer should be contentious.


As a chartered surveyor for nearly 25 years who has had the misfortune to inspect lofts and their structure in the summer I can assure anyone ignorant of the ambient conditions of your summer time loft - they are best avoided between June and August, even in dear old Blighty.


Yes there are aesthetics to having an inverter and the cabling out of sight which I fully understand but the loft is simply the wrong place for a list of reasons.


If you ever have a choice choose some where else, myself the downstairs cloak room.

Exiled_Tyke

Martyn1981 wrote: »

Hi. I think you can run a cable direct, but that's gonna be hard work, so my inverter runs a cable to the nearest socket (about 3 feet away) to a home plug (thingy?) then the plug's partner is plugged into a socket by my router, to which it's plugged into.

Effectively it uses the copper leccy cabling for data transmission.

I have to say that the SolarEdge monitoring is simply fantastic, but even I (yes I) have got a bit bored, and don't look at it that often anymore - I spend more time looking at Edwinks ...... but that's another story! :shocked:

Mart.

Not sure if it helps but I've run an ethernet cable from the inverter to the wi-fi/modem box for mine.

1.38O's today. Which is better than expected as the sun only peeped out occasionally. FIT reading now due but not inclined to take it in a hurry as the payment is going to be so miserly.

zeupater

Crowmann wrote: »

The cable losses are a red herring, almost immeasurable. Your loft in summer will be unbearably hot even on an overcast day. In direct sunlight 40deg plus when outside is 20 would be my experience.


The last place anyone should fit an inverter is the loft. Simples. That folk have them there is down to expedience by installers and ignorance on the part of the client.


Did I mention house fires? Apparently caused by them over heating.... funny that an item whose size is largely formed by a through air flow heat sink being placed in seasonally the hottest part of the house and it gets too hot. Who could have predicted that eh?

Hi

To be fair, the majority of properties will experience cooler mid-summer loft temperatures with pv panels providing the shading, but the extent will be down to orientation and the overall size of the roof covered ... for example, our total roof area is ~200sqm and with a ~WSW 4kWp system covering around 26sqm our loft can still get unbearably hot.

DC Cable losses actually aren't unmeasurable as the resistance in the cables is pretty high, however, longer DC run losses can be mitigated by specifying heavier gauge cables ... that's what we did. If you're interested you can use SMA's SunnyDesign software and check the effect of different cable diameters on overall generation. Now, with much reduced FiT payments the question isn't really whether losses are measurable, it's whether it's worthwhile investing in more expensive cable. Theoretically, running electronic equipment at lower average temperatures should extend the design working life - but remember that it's 'on average' so there's nothing to say that one inverter operating cooler than another would guaranty that it would last longer.

Regarding fires, my view is that a loft is generally a flammable place. Decent inverters will measure their operating temperature and use a combination of fans and power de-rating to protect their own circuits, even to the extent of shutting down in extreme conditions, so high temperature operation in the loft shouldn't significantly increase risk .... it's probably far more statistically significant that cable damage or bad mechanical connections would be the condition to cause worry, but it needs to be remembered that there are already plenty of AC cables and connections in the loft, particularly ceiling roses & lighting circuits .... if our inverter was in the loft, as long as it was well installed, I wouldn't be too worried - to place in context, just think about the last time the lint was removed from the filter in the tumble dryer or the frying pan was used, or even when the log-burner got a little warm ....

HTH
Z

edwink

Martyn1981 wrote: »

I have to say that the SolarEdge monitoring is simply fantastic, but even I (yes I) have got a bit bored, and don't look at it that often anymore - I spend more time ooking at Edwinks ...... but that's another story! :shocked: Mart.

That is true guys

0.76 O's for us today.

No rain but blooming windy today

Edwink

carbry

1.43 O's very cloudy today.