On average, one gallon of gasoline produces 18.07 pounds of carbon dioxide. If your car gets 20 miles-per-gallon and you drive 10,000 miles in a year, you'll produce 4.5 short tons of carbon dioxide (CO2), or 9,000 pounds. The generation of one kilowatt-hour (kWh) of electricity emits 1.588 pounds of CO2 based on a Minnesota average. If ones use 10,000 kWh per year, that's 15,888 pounds (7.944 short tons).
Based on that, if a community member subscribed to enough panels to offset 100% of their annual usage, it would be the same as taking 1.77 cars off the road for a year. Since there is a 50% subscription limit, it's 0.88 cars.For every 1,000 kWh you switch to solar, you take the equivalent of 0.177 cars off the road for a year, or, roughly 11 kWh is the same as one gallon of gas.
That same 10,000 kWh customer switch to solar would offset about the same CO2 (7.944 tons) as what is absorbed by 331 mature trees (assumes 48 pounds per tree per year). There are a lot of ways to look at this (new trees versus older ones, one year versus sequestration over the life of a typical tree). 331 mature trees would cover roughly an acre. One acre of mature trees offsets roughly the CO2 emissions of about 2 cars.