FAQ for Solar Design in St. Louis Region
StraightUp Solar recently gave a talk to the American Institute of Architects St. Louis Chapter. We greatly appreciate the opportunity to present solar guidelines and concepts to such a distinguished and progressive group of professionals. We appreciate Don Koppy spearheading the event and the rest of AIA’s efforts to include solar as part of their continuing education.
As part of the material we were asked to provide a FAQ / general guidelines one page document to the group which is included here.
St. Louis region receives 92% of the solar resource of Miami.
New Jersey is #2 in the US for solar installation – policy matters.
Each kWh produced from solar saves approximately one pound of coal.
Southeast / southwest orientation produces 5% less energy compared to due south.
Estimate daily production in kWh by multiplying array size in kW by 4.
- 5 kW X 4 = 20 kWh / day
Estimate yearly production in kWh by multiplying array size in W by 1.25.
- 5000 W X 1.25 = 6,250 kWh / year
PV Watts calculator (http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/)
Estimate flush mount array size by multiplying square feet X 15 watts X 0.7.
PV system lifetime production is expected to be 30+ years.
PV module warranty = 25 years for 80% production.
PV modules are tested for 1 inch / 50 mph hail.
Flexible solar laminate is approximately 50% efficient compared to crystalline.
Crystalline solar modules are 14 – 19% efficient (similar to modern car).
Inverters are 96% efficient.
Grid-tied solar arrays automatically shut down when the grid is down.
When solar produces more than a building uses the meter spins backward at a 1:1 credit within that billing period.
- 30% federal tax credit (commercial projects – grant 60 days from paperwork)
- utility rebate = $2/watt up to max of $50,000 (within 30 days from paperwork)
- 100% depreciation year one for commercial projects