Community Solar Calculator

It starts from your allocation size in kW multiplied by a standard rule-of-thumb annual production figure for a typical solar installation (roughly 1,300 kWh per kW per year, consistent with a typical US solar capacity factor), converted to a monthly production estimate, then priced at your community solar provider's rate per kWh. This is a planning-level estimate -- actual production varies by your farm's specific location, weather, and system performance, so treat it as a reasonable estimate rather than a guaranteed monthly figure.

Many community solar programs credit your utility bill at somewhat less than the program's full per-kWh rate -- this discount is effectively how the program captures its margin for managing the shared solar farm, billing, and administration. The size of this discount varies by provider and state regulation, so always check your specific program's actual published bill-credit rate rather than assuming a 1-to-1 pass-through of the community solar rate.

If a program's flat monthly subscription fee exceeds your discounted bill credit for that month -- which can happen with a small allocation, a low community solar rate, or a larger discount -- this calculator caps monthly savings so it never dips below zero, on the reasoning that a well-structured community solar subscription generally shouldn't cost you more than doing nothing. If you're seeing zero savings, it's worth reconsidering whether your allocation size and the specific program's fee structure actually pencil out for your situation.

It's specifically aimed at people who can't or don't want to install rooftop solar -- renters, condo and apartment owners with no roof to install on, homeowners with a shaded or structurally unsuitable roof, or anyone who wants solar savings without the upfront cost and commitment of a rooftop installation. The trade-off is that community solar typically delivers a smaller net savings percentage than owning a rooftop system outright, since the community solar provider retains a margin that a self-owned rooftop system does not.

Total contract savings simply multiplies your annual savings by the number of years in your subscription contract, so a longer contract compounds the same annual benefit over more years -- which is also exactly why it's worth scrutinizing a long contract term carefully. A 20-year community solar contract locks in your rate structure for two decades, so changes in your household's electricity usage or a move to a different address during that period could affect whether the subscription remains a good deal for the full term.