Today's post highlights a comparison I did between Autodesk Solar Analysis and NREL PVWatts. A key takeaway is we can get accurate results using Solor Analysis, on any Revit project, in minutes... a workflow we employ at Lake|Flato!
By the way, Solar Analysis uses the Perez Solar Model, a calculation method that occurs locally within Revit.
Renewables is a great way to reduce the EUI and operational carbon load on a building. Using PV is a common strategy. There are a number of ways to calculate the PV potential for a project. In today's post I want to share our workflow, and show that the same info, entered manually into PVWatts website, yield the same results.
From what I understand, Autodesk worked with or consulted with NREL when developing their Solar Analysis add-in for Revit. So it makes sense that the results align.
Workflow
I recently wrote a post about our workflow on the Lake|Flato blog, Dogrun. Check it out here: TOOLS OF THE TRADE – PHOTOVOLTAIC/SOLAR SIMULATION AT LAKE|FLATO ARCHITECTS
Just Do it
Since this is so easy, fast and the tool/calculation is free if you have Revit, I recommend our project teams do this on every project. Even when the project is not calling for PV, we can still share the potential project impact, just like we would with any design option. Plus, this lives up to the AIA Code of Ethics and Professional Conduct to help educate our clients on climate action/sustainability topics.
"[AIA] Members should recognize and acknowledge the professional responsibilities they have to promote sustainable design and development in the natural and built environments and to implement energy and resource conscious design." Canon VI
Results
The results are within 2% and shown in this table!
Comparing Inputs
Here are the inputs/results for both Revit and PVWatts. Same location, size orientation, and utility rate...
Results in Revit...
Results in PVWatts...
Inputs in Revit/Solar dialog...
Here are the inputs in VWatts...
In PVWatts, clicking the “?” icon next to system size and used that formula to convert my PV area in Revit; thus, 42 X .15 (see image below).
the System Loss effect is literally a simple math problem. Result x 14% = modified PV potential
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