Topic: Solar panel angle

Solar panel angle 

We are planning our earthquake rebuild. The house will have a roof pitch of only 8 degrees facing due north. Due to aesthetic considerations for our neighbors and height limitations we cannot raise the angle of the solar panels to the optimum angle of 46degrees.
My questions are: How much will this negatively impact on the performance of the solar panels and by what proportion should we increase the amount of solar panels to compensate for this design limitation?
Regards Tony.

Re: Solar panel angle 

Have you considered a hot water heat pump? In a new house it will be a lot cheaper to install and could save as much energy.

Complete cylinder stainless steel cylinder with emergency element and heat pump on top is $4000.

Presumably you have already decided on pipes in the slab for heating - again using a hot water heat pump. No other system comes close for comfort and low running costs.

JK

Re: Solar panel angle 

Tony, the optimum angle of 46 degrees gives the best output averaged over a year.
To answer your question with 8 degrees output, you will gain considerably in mid summer, whilst will drop off approx 45% of what you would have got in mid winter.

Increasing the panel area to compensate for winter loss will get possibly drastic overheating in summer, you would require some sort of heat diversion to dump off unwanted hot water.

Panels don't have to be mounted on the roof, have you considered ground mounted on a wooden frame.

Cheers
Mike

Re: Solar panel angle 

Solar Mike,

Do tubes (or flat panels for that matter) work OK at such low angles? Presumably there is a minimum -

I would have thought that raising the angle to perhaps 20 degrees would be an acceptable solution.

JK

Re: Solar panel angle 

JK - Flat panels that have a fluid circulated by mechanical pump, can be any angle. Unlikely to have roof mounted self circulating in which case 8 degrees wouldnt work too well. Evac tubes rely upon the conduction of energy by heated vapour moving to cooler region up the tube to the condenser.
I have built heat pipes that work horizontally so there is no reason to think that similar tubes wouldnt work down to 8 degrees angle, how effective they are at that orientation would be best discussed with the manufacture or person selling them.
As to aesthetic considerations restricting higher (better) mounting angles, at least we are not like some areas in the USA where people are even not allowed out door clothes lines, so to hell with the neighbors mount them on brackets as I have done on my roof.

Mike

Re: Solar panel angle 

I have worked on projects where developers covenants prohibit visible panels on roofs so the solution has been to hide the panels using an architectural feature.

In the image attached the weatherboard box on top acts as both a thermal chimney and the parapet walls around the top hide the solar panels.