Solar cells and green roof

For this credit, according to Leed Online, you have to consider total roof area excluding mechanical equipment, photovoltaic panels and skylights. If your project's roof consist of only photovoltaic panels and green roof, in terms of this credit, 100% of this roof is a green roof and therefore you achieve it. Actually you can apply for exemplary performance with this percentage.

The project i'm looking at has a green roof with PVs sitting on a framing system slightly above the vegetative material. Is it possible to include the plan view area of PV in the roof area calculations as on other projects we've seen a better growing result in the shade of the PV than elsewhere . Sun angles etc would also mean that the green area is alos doing its job. The project's ecologist has given the all clear for walk on access for maintenance purposes. thanks

Vivian,
do you have other materials on the roof as well? Or is it only green roof with PV panels? If there is only vegetated surface and PV panels, why do you want to include it?

The reason for excluding mechanical equipment and PV panels from this credit calculation is that it would be contraproductive. HVAC systems are very often situated on the roof, because it is not possible to put it anywhere else. And without it you wouldn't achieve some other more relevant credits...

Yes there are other roof areas - two difference types of roof material and also some other plant enclosures. I'd exclude the plant areas easily enough but if we can include the area of PV within the green roof area on which the PV sits the calculations should be favourable for the 50% vegetative roof area

I see... my guess is that if you wish to do it this way, you will need to submit a CIR on this.