Assumptions
Go Green College (GGC) currently has a fleet of 100 gas & electric golf and utility carts being used on campus, primarily by the physical plant and housing departments.  The fleet at GGC is comprised of 50 gas powered and 50 electric powered carts.  Both types of vehicles are driven 10 miles a day on average or 70 miles per week.

Current Transportation Carbon Footprint for Go Green College

Gas Carts:  GGC fleet of 50 gas carts generates 161,200 pounds of CO2 a year!
According to the U.S. Environmental Protection Agency, the typical passenger vehicle is assumed to produce 8.8 kilograms (or 19.4 pounds) of CO2 per gallon of gasoline.  Given the stop and go nature of driving gas powered golf carts, on average they get approximately 22 miles per gallon.  Using these figures, 70 miles divided by 22 miles per gallon, GGC is currently using 3.2 gallons of gas a week per vehicle, thereby producing 62 pounds of CO2 per vehicle a week.  Consequently, for its fleet of 50 gas powered carts, GGC is producing 3,100 pounds of CO2 a week or 161,200 pounds of CO2 a year.

Electric Carts:  GGC fleet of 50 electric powered carts generates only 41,700 pounds of CO2 a year!

According to the U.S. Environmental Protection Agency, the 1999 national average output rate by power companies to generate 1 kilowatt of energy was 1.34 pounds of CO2.  A 48 volt electric cart has six 8 volt batteries with approximately 6,000 watts of power when fully charged.  On average, this electric cart can be driven 35 miles on flat, asphalt terrain before having to be recharged.  Using these figures, it takes roughly 171 watts per mile so GGC is currently using 11.97 kWh per electric cart per week, thereby producing 16 pounds of CO2 per vehicle a week.  Consequently, for its fleet of 50 electric carts, GGC is producing 834 pounds of CO2 a week or 41,700 pounds of CO2 a year.

Reducing Go Green College’s Current Transportation Carbon Footprint

Solar Electric Carts:  By solarizing 50 electric carts GGC eliminates 25,058 pounds of CO2 a year!

Solar produces no CO2. So, for this analysis, for every 1.0 kilowatt-hour of electricity generated by solar energy, nearly 1.34 pounds of carbon dioxide is not released into the atmosphere.  Every solar panel will have both an STC (standard test conditions) and PTC (PV USA Test Conditions) rating.  The PTC rating involves more extreme, real world test conditions, so you’ll find it to be lower than the STC rating and more indicative of how a solar panel will hold up.  The Eco Trans Alliance (ETA) Sunray Solar Top has a 230 Watt STC and 207 Watt PTC rating. For this example, we will assume that approximately 90% of the maximum PTC solar power generated by the ETA Sunray Solar top is converted into useable energy (we are factoring in some potential loss here due to variable shading from trees, clouds, etc.).  Assuming 5.5 average peak sun hours, the sun provides about 1.02 kWh per cart a day or 374 kWh per cart a year.  Consequently, converting a fleet of 50 electric carts to solar will further reduce GGC’s carbon footprint by 25,058 pounds of CO2 a year. 

   Climate Neutral Plan: By solarizing its entire fleet, GGC eliminates 211,316 pounds of CO2 in 5 years!       

By taking advantage of solarizing its fleet of electric carts and incrementally converting its gas carts to solar electric carts, Go Green College can significantly reduce its overall carbon footprint.  In year one, GGC could convert all of its electric vehicles to solar and convert 10 of its gas carts to solar, thereby eliminating 62,310 pounds of CO2 in the first year alone!  By following this same incremental solar conversion program over the next 4 years GGC can reduce its overall transportation carbon footprint by 211,316 pounds of CO2 in 5 years.

If your college or university is interested, please contact Dan Hoffe, Regional Director, at Eco Trans Alliance, 941-355-6371.