Community Solar Farm Calculator

Revenue from subscriber count and credit allocation.

Farm capacity (kW DC)

Peak sun hours (PSH)

System derate factor

Number of subscribers

Retail electricity rate ($/kWh)

Subscriber discount (%)

Installed cost ($/W DC)

Annual subscriber churn (%)

Tab to move between fields

Net annual revenue ($)

$306,729.00

≈ 7 Teslas

Annual production (kWh)2,847,000

kWh per subscriber14,235

Gross annual revenue ($)$314,594.00

Subscriber savings ($/yr)$278.00

Total project cost ($)$2,000,000.00

Simple payback (years)6.5

25-year ROI (%)283.4%

How to Use This Calculator

Enter the farm total DC capacity in kW and peak sun hours.
Set the number of subscribers and the retail electricity rate they currently pay.
Enter the subscriber discount percentage and installed cost per watt.
Set the annual subscriber churn rate.
Review net annual revenue, subscriber savings per year, and simple payback to evaluate project viability.

How the result changes with Farm capacity (kW DC)

Farm capacity (kW DC): Total DC capacity of the community solar farm.
Peak sun hours (PSH): Average daily peak sun hours for site location.
System derate factor: Overall system efficiency including all losses.
Number of subscribers: Total subscribers allocated shares in the farm.
Retail electricity rate ($/kWh): Local utility retail rate subscribers would otherwise pay.
Subscriber discount (%): Discount off retail rate offered to subscribers. Industry standard: 10–20%.
Installed cost ($/W DC): Total installed cost per watt before incentives.
Annual subscriber churn (%): Percentage of subscribers who leave per year.

Net annual revenue ($): Developer revenue after subscriber discount and churn.
Annual production (kWh): Total farm electricity output per year.
kWh per subscriber: Annual energy allocation per subscriber.
Gross annual revenue ($): Revenue at full subscription before churn.
Subscriber savings ($/yr): Annual bill savings per subscriber.
Total project cost ($): Pre-incentive construction cost.
Simple payback (years): Years to recoup investment from net revenue.
25-year ROI (%): Return on investment over 25-year project life.

Identify Input Parameters
4 parameters
Farm capacity (kW DC) = 2000, Peak sun hours (PSH) = 5, System derate factor = 0.78, Number of subscribers = 200 = 8 input(s) provided
Calculate Net annual revenue
Net annual revenue = grossAnnualRevenue * avgSubscriptionRate
306729 = $306,729
Calculate Annual production
Annual production = capacityKW * peakSunHours * 365 * systemDerate
2847000 = 2847000
Calculate kWh per subscriber
kWh per subscriber = annualProductionKWh / subscriberCount
14235 = 14235