Solar panels are tough. I use Ecotect to check the solar reflectance and
solar gain of a specific item. You can set individual planes to different
sets of properties and watch the reflection of sun rays. It also helps with
shadow studies (Parapets, roof top equipment, buildings near by). There is a
button called solar exposure which is really what you are looking for.
I have never done solar panels in eQuest. Also when filling out the LEED
form we used calculated method. I would check into a software that studies
solar exposure or just use PV Watts calculator. I don't really understand
the reflectivity of the roof as it relates to solar panels, but then again I
love to learn.
To be honest there really is no good way to model the solar panels. PV watts
is really good because it calculates panels all over the state using
averages. It also depends on what system you are using. If you use a roof
mount system that has a specific tilt you get a certain efficiency. If you
use a system has trackers it becomes more efficient but the price might go
up. Different states have different tilt angles to make their panels more
efficient with the better degree of tilt. The thing I would do if you wanted
to put it in eQuest is use PV watts calculator and apply it as a direct load
that gives electricity to the building.
PS: check to see what inverter you are using because different inverters
have different efficiencies.
Alan,
Solar panels are tough. I use Ecotect to check the solar reflectance and
solar gain of a specific item. You can set individual planes to different
sets of properties and watch the reflection of sun rays. It also helps with
shadow studies (Parapets, roof top equipment, buildings near by). There is a
button called solar exposure which is really what you are looking for.
I have never done solar panels in eQuest. Also when filling out the LEED
form we used calculated method. I would check into a software that studies
solar exposure or just use PV Watts calculator. I don't really understand
the reflectivity of the roof as it relates to solar panels, but then again I
love to learn.
Thanks,
PETER HILLERMANN
Alan,
To be honest there really is no good way to model the solar panels. PV watts
is really good because it calculates panels all over the state using
averages. It also depends on what system you are using. If you use a roof
mount system that has a specific tilt you get a certain efficiency. If you
use a system has trackers it becomes more efficient but the price might go
up. Different states have different tilt angles to make their panels more
efficient with the better degree of tilt. The thing I would do if you wanted
to put it in eQuest is use PV watts calculator and apply it as a direct load
that gives electricity to the building.
PS: check to see what inverter you are using because different inverters
have different efficiencies.
PETER HILLERMANN
Does ASHRAE 90.1 allow the use of solar panels when calculating the proposed
bldg? if so how do you model them?
Alan Crittendon, PE, LEED AP