I found your post about pv across two different angle and orientations very useful. I have recently started installing solar Pv and am finding it a bit difficult to find all the answers as the course I went on was a bit vague.

The question I have about the above post is. How do you calculate the outputs if you have two roofs. Do you do the SAP on each individual array and then add them together? Even if you are using a dual tracking inverter.

Many thanks

H

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Chris you have raised a good point, I am often finding that installers are recommending clients to install on different aspects on the roof, to make it worthwhile doing the installation, but quoting for 1 inverter only. They are not taking into account using two separate inverters, which will be required. If it’s a large system you can get away with using the SMA 4000TL with dual MPP tracking system, which can be used to install two separate arrays at different angles. You are able to install panels arrays at different pitches i.e. 4 panels at 30 degrees  and 4 panels at 5 degrees, so long as you take into account the net voltage from both arrays and make sure that sufficient voltage will be generated to make the inverter kick in at lower light levels or you will find that you panel array work inefficiently.

I am glad you have raised this point, since both installers and the general public are not aware of this. One way of find out if your installer is any good is to ask this question?

http://www.exploresolar.co.uk

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Thank you Chris Rudge and Paul Hutchens for the various comments posted regarding solar PV.

Being new to the business of posting comments I'm not certain how to kick off an 'original' blog.  I would, however, like comments from anyone who has contacts in house sales on the effect that solar PV (or thermal) is having on resale values - i.e. does it improve sales prospects or hinder them?

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