Community & shared solar
See whether a flat monthly fee or a percentage-of-credit fee actually costs less at your specific subscription size.
How it works
Step 1
These determine your total credit value, which is what both fee types get compared against. If you're not sure of your subscription size yet, use the subscription size calculator first.
Step 2
Pull the exact flat fee and percentage fee figures from actual provider proposals, not estimates. Once you know which structure wins, plug it into the subscription cost per kWh tool for your full effective rate.
A $5 monthly flat fee sounds small in isolation, but its relative impact depends entirely on subscription size. On a large subscription it's a rounding error, while on a small subscription it can represent a meaningful share of your total credit value. A percentage fee avoids this problem entirely by scaling with your subscription automatically. Check the DSIRE database for any state rules on community solar fee disclosure, since a handful of states require this to be spelled out clearly upfront.
Once a subscription is large enough, a flat fee's dollar cost stays the same while a percentage fee's dollar cost keeps growing with subscription size. At a certain size, the flat fee becomes the cheaper option in absolute terms, even though it started out looking worse for smaller subscribers. Run both structures at your specific size to find which side of that crossover you're on, and check the minimum subscription size tool if you're near a program's smaller threshold. A financed rooftop system has a similar dealer-fee-versus-size question, covered by the dealer fee impact calculator.
Fee structure is one input among several that determine your true effective rate, alongside the credit rate and discount percentage. Don't let a favorable fee structure alone justify choosing a provider with worse terms elsewhere. Check the provider comparison tool for the full picture across multiple providers at once. If you want the source document behind this, the Department of Energy's community solar basics guide has it.
Confirm whether the fee is truly flat or percentage-based, since some providers use terms that sound similar but work differently in practice. Also ask whether the fee itself can change over time, since a fee that escalates works against you in the same way a subscription price escalator does, covered in the escalator rate calculator. A commercial-scale array has a comparable ongoing cost structure, covered by the commercial solar operations and maintenance cost estimator. The Department of Energy's community solar basics guide recommends getting the exact fee mechanics in writing before enrolling, not relying on a verbal summary.
Questions
A flat fee is a fixed dollar amount charged monthly regardless of subscription size, while a percentage fee takes a set share of your bill credit value. A flat fee has a much bigger relative impact on a small subscription than a large one, while a percentage fee stays proportional at any size.
A percentage fee is usually better for a smaller subscription, since a flat fee eats a much larger share of a smaller credit value. A $5 monthly flat fee on a 2,000 kWh subscription can represent over 20% of the credit value, while a 3% fee on the same subscription stays at 3% regardless of size.
Yes, a flat fee becomes proportionally smaller as subscription size grows, so a large subscriber might actually pay less under a flat fee structure than under a percentage fee. Run both fee types through this tool at your actual subscription size to see which wins for you specifically.
Not on its own, since the fee is just one factor in your total effective rate alongside the discount and credit rate. Use it as one input in a broader comparison rather than deciding on fee structure alone.