Solar ... In the news

Nicolai_Grenovski

Don't mistake my laughter at your spin for anger. I think it's healthy to laugh especially at daft comments. For instance my Guardian troll once told me that a 50d pitch for PV was 'only' suitable in the arctic, when in reality it's probably the optimum pitch for south facing PV in the UK to best match supply and demand.

Is that like a guardian angel?

I just put London into PVGIS (google it - or "renewables ninja" - very useful) and clicked the optimise button and it states the optimum is 38 degrees. (1 degree steeper than we have in Berlin)

The furthest North I have supplied solar to is Aarlborg and Oslo University (higher than the UK) and both were 42 degrees - the most you would want to tilt a pv because of ground effects (darkening).

50 degree would work badly as it would lose output for most of the year and you get a lot more of ground effect - why did you choose 50 degrees?

fwi: Were it not for snow build up we would recommend 42 degrees or horizontal for far North (usually just instrumentation) because atmospheric reflected light is more reliable than sun.

Nicolai_Grenovski

That's strange, you claim to work in solar, but you say 50d pitch works badly. I'm not sure you know what you're pretending to talk about.

What?

So, for less than a 2% annual reduction you improve the lowest months by 10%, less import, and reduce the highest month by 6.5%, less export.

The steeper the angle the greater the ground clutter (darkening) PVGIS does not know what area you are in - it assumes that the world is an oblate spheroid and cannot factor in a high 'horizon' caused by trees/buildings etc - even though theses may not pose a shadow over the panels, they limit the view of the sky unless you're on the side of a south facing hill or have your ground mount panels on the tallest building around.

You can try this effect for yourself - get a piece of frosted glass and look though its center line - the closer to vertical the more 'dark' you see unless your local buildings, trees and grass are on fire.

It is a common misconception that solar panels must see the sun - it is the total radiance (what is called insolation) that matters which is how they work on cloudy days.

If you lived on the moon with no ambient light then perhaps 50 degrees for an imagined selenic winter would be good.

I guess that explains why all of my off-grid friends installed their ground mounts at a 45d to 50d pitch.

I am sure you are immensely popular and have no shortage of adoring friends, but off grid ones who optimise for only one season?

I know a few because of work, one is a very close friend indeed -
Every person I know who off grids with a ground mount system optimises them for summer and then winter.
I'm not aware of anyone (other than an immovable system and few offgriders would tie their hands that way) who does not switch between both seasonal modes.

But I don't know any that would use 50 degrees - not only does is darken the panels (unless you're in the middle or top of a lake) but it also increases the windage which makes them harder to anchor..

Weird that you would make the very same mistake that Trolly McTrollface made, and you claim to be in the solar industry

I honestly do not understand the meaning what you're trying to say.or why you're so angry.

Nicolai_Grenovski

Actually German off-shore wind is reaching subsidy free prices, so it's less not more than HPC, just like UK off-shore wind is expected to go sub HPC in this years CfD auctions.

Fingers crossed - but why are you ttill obsessing with HPC?

What are the storage and gas costs for your idea?

Cardew

Exiled_Tyke wrote: »

I've an idea. Since this thread is titled 'Solar in the News' can we ban all discussion of Nuclear. If anyone wants a discussion on Nuclear could you have your own thread for it please?

Great idea!

Unfortunately that is not the case in this thread and any other thread where solar PV is being discussed. Any real or perceived criticism of solar and subsidies is met with a diversionary barrage of data on the cost of Nuclear.

It is usually The Guru that diverts any solar discussion to Nuclear in general, and Hinkley in particular.

Nicolai_Grenovski

Why fingers crossed are you denying the contracts for off-shore wind that have been seen lately by other European countries?

Calm down - do not be so confrontational, you're seeing everything as a challenge -
You said: "Actually German off-shore wind is reaching subsidy free prices, so it's less not more than HPC, just like UK off-shore wind is expected to go sub HPC in this years CfD auctions"
So "fingers crossed" that those price drops do materialise - two things to note
1 - that the UK CFD pricing includes transmission costs/MWh so will always be higher than LCOE so direct comparisons as you attempt are not possible
2 - that prices are by range - just because one site has a price does not mean that they all have the same price. There is a big difference between shallow offshore and deep offshore and local wind supply and regional network 'capacity'

For gas costs, they are the same as for nuclear,

Absolutely not - plus we want to avoid gas as far as it is possible.

For storage costs please see my earlier response, I thought it was quite detailed.

No, I see no storage costs from you to match a European solar (or wind) profile.
I found your Euan Mearns website - it seems okay, but you claim he is biased against renewables - are you recommending it or not?

Cardew

Nicolai_Grenovski wrote: »

Calm down - do not be so confrontational, you're seeing everything as a challenge -

I honestly do not understand the meaning what you're trying to say.or why you're so angry.

Lèse-majest! ??

Nicolai_Grenovski

You used PVGIS in your post, I used PVGIS in response. Now you are saying that PVGIS is wrong. Interesting, but I'll stick with it.

You claimed 50 degrees was the optimum angle for solar - PVGIS completely disagrees with you.
If you have a problem with the reasons for that then I suggest complain to the makers but first have a long hard think about the implications of living on an oblate spheroid.

I pointed out that PVGIS becomes increasing inaccurate at higher latitudes because it has to assume a clear horizon when the reality is that horizons are seldom clear..
I do hope you are not suggesting that PVGIS would somehow know how close, reflective or high nearby buildings and trees in your garden or field are?
It is not magic.

50d option optimises for all seasons. It raises generation when it's low (the bottom 6 months), and reduces generation when it's too high (the top 6 months). But that aside, are you really suggesting that off-gridders shouldn't optimise their PV for winter in the UK?

You seem to think that optimising PV means maximising annual generation, but a better year round spread for less than 2% annual loss sounds like optimising to me.

No, I very clearly said that 'off griders' switch between modes - they optimise for winter or summer.
They use batteries and summer excesses are frequently used to heat water or supplement EVs - an offgrid system that cannot use Wmax power in summer is badly designed - no one with knowledge would de-optimise a system to compensate for poor design.

You've decided to start mis representing what I am saying to make yourself important - I see no benefit in talking to you if you will make things up.

Dave_Fowler

I don't think the off-gridders are making a mistake when they optimise their systems for winter generation. There's no point generating the optimum amount of power in the summer months when they can't possibly use the power. It would be a waste of time changing the pitch of the panels if all they would achieve would be a system they had to throttle back. Their use of power in winter will be at the highest and so an optimised system for winter would be best.

Dave F

Nicolai_Grenovski

Dave, the ones I know (with the option) use a dual mode system - you just slacken a bolt and pull a lever, another guy I know uses a satellite dish actuator and simply changes his routine to fit the sunshine. There is a huge difference (off grid) between winter and summer, but you will not find many full time off griders (not weekend homes) who have 'excess' power problems because that would indicate a badly designed system,.

Martyn1981

Sadiq Khan's environment plan will help to promote solar in London:

Reverse solar auctions, community solar grants and TfL tenders to form new London solar strategy


Edit - not sure this deserves it's own post, so for anyone interested in the 'ickle' Tesla Gigafactory, here's a flyby of how it's doing so far:

TESLA GIGAFACTORY August 2017 Aerial Construction Update