Do Winter Months Produce more PV Watts?

[jasonvanwyk]

Hi All

I was wondering, I know the sun rises earlier and sets later in the summer months. therefore we should have more sunlight hours than in winter where the opposite is true. However we have a lot of thunderstorms (Southern Drakensberg) in the afternoons and obviously cloud cover in the summer months. winter days are mostly clear sun-shiny weather days. Hence my question - do we get more sunlight hours out of winter months, or does it not work like this in practice. 

Once again

Many thanks

Jason

[___]

It depends where you live. In South East Namibia, for example, winter can be better than summer. The weather is dry (not even a wisp of a cloud, cause it's summer-rainfall area), and the temperature is cooler (PV panels don't like heat). This often makes up for the fewer daylight hours.

[jasonvanwyk]

thanks again Plonkster. I will interested to see how I fair here in the southern Drakensberg

[Richard Mackay]

No so in Germany: Their PV power output is 5 times greater in summer than winter. (see article in General section: History of energy and the way forward)

[RikH]

4 hours ago, Richard Mackay said:

No so in Germany: Their PV power output is 5 times greater in summer than winter. (see article in General section: History of energy and the way forward)

Yes that's true. Same here in NL.

[___]

14 hours ago, RikH said:

Yes that's true. Same here in NL.

Closest to Winter I've experienced was first week of November. It was -7°C the first morning, and then the rest of the week was almost "normal" (by African standards). The locals looked at me weirdly most mornings, since I'd take a brisk 3km walk to work and by the time I was halfway there I'd have my jacket over my shoulder , sporting nothing but a T-shirt underneath.

(I suppose having "Hermanus South Africa" emblazoned on it one of those didn't exactly help either... cars practically slowed down...).

[Luminous]

Summer months looks a lot better for me compared to winter. System was the same and only change might have been load shedding days with the grid-tied.

 

[___]

OK, let me answer the original question

As usual, it depends. I live in the Western Cape, which is a winter rainfall area. When it rains that is. So in summer we have clear skies and a long solar day, but the heat affects production a bit. This means the best months in the year are October and November, because the solar day is long, there is little or no rain, and the temperatures are cool. Summer generally makes more power than winter (even if it is a dry winter like in 2014-2016).

But where I grew up in Namibia, the reverse is true. This is a summer rainfall area. Again, if it rains a lot that year, winter might actually give better PV production, but it all depends. We had an off-grid system though, so we preferred winter. The system was adequately sized so that in winter we never had to start the Diesel genset... but in summer you would have too much power the one day and had to run the genset the next day...

 But in general, overall and for the most part, all other things being equal -- picture me waving my hands around a lot while saying all that -- summer makes more power than winter

 

Edited May 27, 2020 by plonkster

[Van theplanman]

On 2019/04/15 at 12:18 PM, plonkster said:

It depends where you live. In South East Namibia, for example, winter can be better than summer. The weather is dry (not even a wisp of a cloud, cause it's summer-rainfall area), and the temperature is cooler (PV panels don't like heat). This often makes up for the fewer daylight hours.

Agree, my winter is as good as the summer.  But for me 2 conditions can kill it, 1) cloudy conditions during winter and 2) panels not adjusted to winter optimum position.