Net Metering Calculator

They represent genuinely different policy decisions that vary by state and utility. The retail rate is what you'd pay to buy a kWh from the grid, while the export credit rate is what your utility actually pays (or credits) for a kWh you send back. Some programs set these equal (full retail-rate net metering), but many utilities now pay a separate, lower avoided-cost or wholesale rate for exports, so keeping the two rates independent lets the calculator reflect your actual program's terms.

No -- net metering and net billing policy varies enormously by state and even by individual utility, ranging from full retail-rate compensation to a much lower avoided-cost or wholesale rate, and some utilities have moved away from traditional net metering entirely. Always enter your own utility's actual published export compensation rate rather than assuming this calculator's default reflects your program.

Self-consumed energy is the portion of your solar production used directly on site during the same billing period, up to the amount you actually consumed, valued at the full retail rate since it directly offsets a purchase you would have otherwise made. Excess production beyond your consumption is treated as exported to the grid and valued at the separate export credit rate instead.

Once your monthly production covers your monthly consumption, this calculator's modeled bill is already floored at your fixed monthly charge -- any additional export credit beyond that point has nothing left to offset within that same month, since this simplified model does not roll banked credit forward to a future month or pay it out in cash. In many real net-metering and net-billing programs, unused credit instead carries over to offset a future month's usage or gets settled at an annual true-up, so producing more than you consume can still have value that this single-month snapshot does not capture.

This calculator models a single simplified monthly snapshot using flat retail and export rates, but real utility billing often involves time-of-use rate periods, seasonal rate changes, tiered pricing, annual true-up reconciliation for banked credits, and program-specific rules about credit expiration -- none of which this simplified model captures. This calculator is best used to compare scenarios side by side, not to predict the exact dollar figure your next bill will show.