Renewable energy to save money? Sorry It doesn't work.

[Traffic]

Evanivitch said:

Unless the Sun over the south of Sweden is drastically different to the Sun over Scotland, I find it quite hard to believe that the sun is "almost overhead" and that you're generation is peaking at 21kW unless you have something approaching a 30kW installed capacity.

I should rephrase it, the sun gets pretty high in the summer, not overhead. But both modules will see sun on them at the same time in the middle of the day, it also is daylight for around 18 h through the middle of summer.

I doubt we will see peak 21Kw utilization, but even on this past Saturday afternoon we hit 32%.

Edited by Traffic on Monday 21st February 10:22

Edited by Traffic on Monday 21st February 10:24

[wombleh]

We have a fairly big roof for a UK house and our array covers the entire side, it's 4.8kW, possibly could squeeze an extra 2 panels on if we didn't have an extension gable. The North side would only see the sun for about an hour each morning at this time of year, due to the angle then not sure it'd generate that much in summer either. Don't normally see panels on more than one side here.

Have Swedish houses got large roofs that extend down over the first floor too? Can't work out how you fit such a massive array on it !

[4Q]

wombleh said:

We have a fairly big roof for a UK house and our array covers the entire side, it's 4.8kW, possibly could squeeze an extra 2 panels on if we didn't have an extension gable. The North side would only see the sun for about an hour each morning at this time of year, due to the angle then not sure it'd generate that much in summer either. Don't normally see panels on more than one side here.

Have Swedish houses got large roofs that extend down over the first floor too? Can't work out how you fit such a massive array on it !

A north facing roof at 35deg pitch will do about 55-60% of what a south facing one does. As the pitch gets shallower then this increases, at 20- 25 deg pitch it’s about 70% of a South facing roof at optimum pitch.
The reason we don’t generally see panels on both north and south is that we are limited by regulations to a 3.68kW inverter without getting permission from the DNO first and you can fit 4kW to go with that on one side of the roof.

Edited by 4Q on Monday 21st February 18:25

Edited by 4Q on Monday 21st February 18:27

[wombleh]

Interesting stuff

[Traffic]

wombleh said:

We have a fairly big roof for a UK house and our array covers the entire side, it's 4.8kW, possibly could squeeze an extra 2 panels on if we didn't have an extension gable. The North side would only see the sun for about an hour each morning at this time of year, due to the angle then not sure it'd generate that much in summer either. Don't normally see panels on more than one side here.

Have Swedish houses got large roofs that extend down over the first floor too? Can't work out how you fit such a massive array on it !

We went 3 panels high, which literally covers from the gutters to the ridge tile almost!