New Build - best roof orientation for solar

pile-o-stone

If you were building a new home, how would you orient the roof to get the best use of solar? Traditionally, the advise would be to go south facing, but some experts are now saving that a split roof East/West orientation would be better as you get longer generation times, from dawn to dusk. I was therefore wondering what people on here thought?

Given that we don’t get FiT payments or even export payments anymore, would a lower peak, longer generation be better for self consumption?

If we throw batteries into the mix, is it better to have higher south oriented generation to charge batteries?

What do we reckon?

JKenH

From my limited experience with an east west system, the penalty in winter is huge as the sun gets nowhere near its optimum orientation for east/west panels. I have a relatively steep roof at 39* pitch which aggravates the situation.

Exiled_Tyke

East/West will probably generate more overall but it is far more beneficial to get as smooth a production curve (across the year) as you can. In other words gaining a couple of KWhs a day in winter is more useful than an extra 10 in summer (give or take) because unless you have very exceptional circumstances you won’t get anywhere near to using your summer production but will be desperately short in winter.

Martyn1981

Something I've pondered a lot, just as a mental exercise, but keep changing my mind.

I think SE + SW would be good, but that involves a more complex roof, meeting at 90d, and possibly triangles, aesthetics etc.

Maybe shallow pitch East and West rooves, plus some very steep pitched south facing panels on a ground mount, or even wall mounted in the future (Planning permission is required).

As per others with E/W, the winter needs to be considered, so south and steep is the essential starting point I think, but multi orientation would be fun.

pile-o-stone

JKenH wrote: »

From my limited experience with an east west system, the penalty in winter is huge as the sun gets nowhere near its optimum orientation for east/west panels. I have a relatively steep roof at 39* pitch which aggravates the situation.

I'm totally with you on this one, though my East/West generation also suffers from shading in winter due to the sun being so low and the house (in front of the array) is so high.

This is the house style I had in mind for a new build:



The roof would be completely covered with PV panels and the glass gable end would face south. The glass would be inset deeper into the gable to allow the roof to shade it in summer, but allow direct light in winter. This would allow a patio seating area to be placed at the front of the house, partially sheltered under the over-hanging roof.

The design I saw (but can't find now!!:mad:) was actually two stories and had a glass balcony at the front. I was pondering if the glass balcony could be solar glass and help out in winter.

I'm having a rethink about the whole design now after your comments.

pile-o-stone

This would be the front of the house:



But with the glass set deeper into the gable end, giving a larger 'porch' area. The main idea is to enjoy summer sun outside, wich a bit of shelter from wind and winter sun inside as it peeps under the roof into the gable end glass.

If I orient the gable end differently, say South West (to catch the evening sun after work) then I would have a south east facing roof aspect and a north West roof, which would be bad.

I guess a gararge at the rear of the house with a high incline south facing roof would help in winter.

Exiled_Tyke

I’d also bear in mind when you want the sun on the decking/balcony. We love to sit out in the evening in summer so bought a house with a west facing back so we could enjoy sitting out in the garden after work.