Community & shared solar

Credit allocation estimator

See how your community solar credits break out month by month, whether your provider allocates them evenly or follows the array's real seasonal output.

Your numbers

1 Project details Optional
Shown on your exported report. Leave blank to skip.
2 Your subscription share
Your yearly kWh allocation from the shared array. Check your subscription agreement or use the subscription size calculator.
The dollar value your utility applies per kWh of allocated credit.
3 Allocation method and climate
Check your subscription agreement. Most community solar providers use seasonal allocation.
Only used with seasonal allocation. Affects how sharply credits shift between winter and summer.
4 Rollover check Optional
Enter your typical monthly electric charge to flag months where your credit may exceed or fall short of it.

How it works

Three steps to your monthly breakdown

Step 1

Enter your annual share and credit rate

Your annual subscription share comes from your enrollment agreement. If you're not sure how large your share is, run the subscription size calculator first to pin it down.

Step 2

Pick your allocation method

Most community solar providers use seasonal allocation that tracks real production, but a few use an even 12-way split instead. Your enrollment paperwork or utility statement should say which one applies to you.

Step 3

Compare your credit against your bill

Add your typical monthly bill amount to flag months where your credit runs short or over. Pair this with the annual true up estimator to see how the year nets out.

Understanding how your credits get allocated

Why allocation timing matters as much as the total

Two subscribers with the same annual credit total can have very different monthly experiences. A 10,800 kWh annual share under seasonal allocation might swing from roughly 640 kWh in December to over 1,180 kWh in June, while the same share under even allocation stays flat at 900 kWh every month. Your winter bills feel the difference directly. The DSIRE database has the current version, so check there before you rely on a summary.

How seasonal weighting actually works

Solar output follows the sun's angle and day length, so production climbs from spring through midsummer and drops through fall into winter. A northern climate pattern swings harder between seasons than a southern one, since northern latitudes see a bigger gap in day length and sun angle across the year. This tool applies typical regional weighting to your annual total to model that swing. The seasonal tilt adjustment calculator covers this same seasonal curve from a rooftop system's design side.

What to do if your winter credit falls short

If your community solar credit runs below your usual bill in the low-production months, the gap gets billed at your normal utility rate. This is expected and usually evens out once summer allocation runs above your usage. The billing cycle alignment tool shows how your utility's billing dates interact with this pattern. The Department of Energy's community solar basics guide covers this monthly settlement structure in more general terms if the underlying mechanism needs unpacking.

Rollover and how leftover credits carry forward

When your monthly credit exceeds what you owe, most utilities carry the excess to the next bill rather than paying it out in cash. Some programs cap how long unused credit can roll over before it expires. Check the credit rollover calculator and credit expiration calculator for how this plays out over a full year.

Confirming the numbers against your actual statement

This tool models a typical seasonal curve, not your specific array's real production history. Once you have two or three months of actual utility statements, compare them against this estimate and adjust your expectations for the rest of the year using the annual true up estimator. A grid-tied rooftop system's monthly true-up follows a related but distinct process, covered by the net billing versus net metering comparison. Check the DSIRE database for your state's specific rollover and settlement rules if you want to confirm the mechanics behind your own statement.

Questions

Frequently asked

No. Most community solar farms use seasonal allocation, so credits run higher from May through August and lower from November through February, following the sun. A 10,800 kWh annual share might generate around 640 kWh in December but over 1,180 kWh in June.

Even allocation divides your annual credit total into 12 equal monthly amounts regardless of actual production. Seasonal allocation credits you based on the array's real monthly output, which is higher in summer and lower in winter, matching how solar panels actually generate power.

Solar output drops in winter because of shorter days and a lower sun angle, so a shared array under seasonal allocation produces less energy in December and January than in June and July, even though your subscription share percentage never changes.

Most utilities roll over unused community solar credits to the next billing cycle, sometimes with an expiration window of 12 months. Check the rollover terms with your specific utility, since policies vary by state and by provider.

Related tools

Keep exploring community solar

Subscription savings calculator Subscription size kWh calculator Billing cycle alignment tool Credit rollover calculator Credit expiration calculator Annual true up estimator Credit rate vs utility rate All community & shared solar tools