So now I have a solar PV system how do I make the most of it???

Martyn1981

davidanddeirdre wrote: »

Mart, well said, I could have put it like this in the first place. Why didn't I?
I am happy with overall PV results despite less than ideal direction, we achieved well over the predicted output for our first year.

Evening D&D, can I ask what your best day has been?

Only running since mid August, so not sure what to expect. At 110deg (azimuth -70), 3.6kWp, and 27deg (average), I'm guessing 20% less than a 4kWp South facing system.

Given that the holy grail of a 4kWp seems to be 30kWh in a single day, I'm reckoning 24kWh max for me, if all the oranges line up!

Did anyone get a true 'monster' last year, perfect weather late June etc etc?

Mart.

jackieblack

Best days for me last year generated 16kWh :j (several days in May & June)
As your system is approx 62% bigger than mine, 24kWh is definitely do-able. The main factor (of course ) being the weather where you are.

During last week's beautiful weather we had several days of 14kWh generation :T. The panels have had a good wash this morning, next few days not looking too promising

Martyn1981

Thanks Jackie. Adding 62% then deducting 10% for ESE, looks like 24 is do-able as you say, but very, very tough. Wouldn't be a fun target if it was easy I suppose.

Obviously I wasn't reading as much about PV this time last year, but I'm pretty sure it wasn't a great year for record days. Fingers crossed for a super day in late June!

Mart.

davidanddeirdre

Martyn1981 wrote: »

Evening D&D, can I ask what your best day has been?

Only running since mid August, so not sure what to expect. At 110deg (azimuth -70), 3.6kWp, and 27deg (average), I'm guessing 20% less than a 4kWp South facing system.

Given that the holy grail of a 4kWp seems to be 30kWh in a single day, I'm reckoning 24kWh max for me, if all the oranges line up!

Did anyone get a true 'monster' last year, perfect weather late June etc etc?

Mart.

Hullo Martyn, not sure what 110deg is in relation to S, so will just say we are 5 or 10deg E of SE, i.e. 50 to 55deg off south. We have a nominal 1.75kW system, 10 X Sharp 175s, about 40deg slope. The best day I have recorded starting March 2011 was last June 3rd at 12.0 units precisely. So far in 2012, we have 9.22 on 1st April (thankfully Apr 1 was not a joke!). I have to say I don't get the daily total absolutely every day, we don't have any recording system.
In June & July 2011 although it was I believe rated sunnier than average, there were few cloudless days, so few opportunities to get a max reading. I've also noticed that even when one can say that the sun has shone all day, total output can be reduced noticeably by intermittant translucent high cloud, although thankfully and conversely output can be surprisingly high in a day of only sunny periods if the cloud is short lived and/or only extensive in the mid to late afternoon when we don't get any direct sun.
NB I would have loved a larger system, but would have had to build an extension to put it on!

Martyn1981

davidanddeirdre wrote: »

Hullo Martyn, not sure what 110deg is in relation to S, so will just say we are 5 or 10deg E of SE, i.e. 50 to 55deg off south. We have a nominal 1.75kW system, 10 X Sharp 175s, about 40deg slope. The best day I have recorded starting March 2011 was last June 3rd at 12.0 units precisely.

NB I would have loved a larger system, but would have had to build an extension to put it on!

Hiya D&D, thanks for the post. 12 is interesting, doing the maths that gives me about 25 less the difference of -70 for me compared to approx -50 (from South) for you, so back to 24 I think. Cool. Obviously I appreciate I'm being very childish trying to guess what a 'best day' could be, but that's me I guess, a big kid at heart.

At 40 deg, does that mean you are close to optimum soon? I've got 2.4 at 30deg, and 1.2 at 20deg, so maybe a small advantage back to me for June and July.

I did kinda build an extension for mine! Could only get 4 panels on the lower roof, and that was too tight to be honest, so I ripped down the old canopy (3.5m x 0.8m) as the polycarb was cracked, had some new wrought iron brackets made, and hey presto Robert's your mum's brother - 2 extra panels plus 3 on the roof.

Got me thinking, as the brackets were so cheap (4 handmade, galvanised, 12 steel threaded rods, and a tube of bolt-fix resin for £100) could something similar be fitted to vertical walls?

Mine were made at 20deg (to match lower roof), so if fitted upside down, so to speak, they'd give 70deg panels, winter optimised, or maybe make them 60deg, and fit to a suitable wall. Would definitely need planning permission, but would open up a whole new possibility for 'PV unsuitable' houses.

Just thinking (over-thinking) out loud as usual.

Mart.

EricMears

Martyn1981 wrote: »

I did kinda build an extension for mine!
Mart.

If you have space in the garden, you could always build a new garden shed and put solar panels on that.

There are several conditions to building a shed but loosely speaking one that doesn't cover more than half the area of the garden and isn't more than 3 metres high or too close to a boundary would be a 'permitted development'. Fitting solar panels to such a shed should also be a 'permitted development'. But best to run any proposals past local authority planning dept before doing it.

If you just fail the PD rules, you can always apply for planning permission.

jackieblack

Martyn1981 wrote: »

Got me thinking, as the brackets were so cheap (4 handmade, galvanised, 12 steel threaded rods, and a tube of bolt-fix resin for £100) could something similar be fitted to vertical walls?

Mine were made at 20deg (to match lower roof), so if fitted upside down, so to speak, they'd give 70deg panels, winter optimised, or maybe make them 60deg, and fit to a suitable wall. Would definitely need planning permission, but would open up a whole new possibility for 'PV unsuitable' houses.

There's a house in the next town, that I pass every week on my way to the supermarket, that has a row of panels attached to their side wall. Have only had a quick look, in passing, but they appear to be supported on a framework.
(Have had a look on Google Maps but the photo is pre panels.)

jimjames

We've only had our panels since Nov so not been able to really see the effects with all the other changes in daylight etc but has anyone noticed that panels get less efficient as they get dusty and then when a good shower has passed over the generation improves?

We've not had any rain since early March (or much over the winter either hence the hosepipe ban) and the panels have now got a coating of dust/pollen on them. Performance has been good up to now but will it jump again once they get washed? Not that I'm intending going up with a bucket but just curious if rain will help them.

EricMears

jimjames wrote: »

We've only had our panels since Nov so not been able to really see the effects with all the other changes in daylight etc but has anyone noticed that panels get less efficient as they get dusty and then when a good shower has passed over the generation improves?

We've not had any rain since early March (or much over the winter either hence the hosepipe ban) and the panels have now got a coating of dust/pollen on them. Performance has been good up to now but will it jump again once they get washed? Not that I'm intending going up with a bucket but just curious if rain will help them.

Mine are described as 'self cleaning' in that sunlight plus a coating on them is supposed to make dirt soluble and rain washes that off. Can't say that I'm totally convinced by that - our conservatory roof makes the same claim but that never works !

However, cleaning them - by whatever means must improve efficiency. Difficult for people with steep rooves and a hosepipe ban but neither constraint applies here and I've every intention of cleaning them when viewing the conservatory roof suggests that might be worthwhile. So far I've only done that once - the day after installation - and have no definite evidence that it worked.

KevinG

jimjames wrote: »

We've not had any rain since early March (or much over the winter either hence the hosepipe ban) and the panels have now got a coating of dust/pollen on them. Performance has been good up to now but will it jump again once they get washed? Not that I'm intending going up with a bucket but just curious if rain will help them.

Yes, rain should help clear this off and we should get gallons of the stuff tomorrow!