Solar cost per kWh is not a price readily available in a proposal. Here is how to estimate that.
The formula is Cost of the Solar System divided by Solar Energy Produced
So how do we know what the Solar Energy Produced is? Here is a standard calculation for Solar energy produced over 20 years:
5kW x 5.62kWh of sun daily x 365 days x 20 years x 80% efficiency = 164,000kWh
Now that the Solar Energy Produced number is estimated the Sales Rep just needs to divide it by the Cost of the Solar System. Here is an example:
$14,500 / 164,000kWh = 9¢/kWh (this is rounded up from 0.088)