Is solar worth it in District of Columbia?
A 7.0 kW rooftop system near Washington produces about 9,876 kWh a year. Priced against the 4 residential tariffs currently on file in District of Columbia, payback runs from 12 years on the best of them to 70 on the worst.
Why the tariff matters more than the panels
Two households in District of Columbia with identical roofs and identical systems can see paybacks 12 and 70 years apart, purely because they are on different tariffs. Solar produces at midday; households consume in the evening. Only 52% of what these panels make is used as it is made — the rest is exported, and what an exported kWh earns is set by the tariff and by state net metering rules, not by the hardware.
That is why the figures here are computed hour by hour against each real tariff rather than by taking a bill and assuming solar removes a share of it. How this is modeled →
Payback by tariff in District of Columbia
7.0 kW system at $3.00/W, household using 1000 kWh a month, no incentives. A range means the export credit is not filed with the tariff and the outcome depends on net metering rules — 4 of 4 tariffs here belong to a utility that reports residential net metering.
| Utility | Tariff | Structure | Annual saving | Payback |
|---|---|---|---|---|
| Potomac Electric Power Co | Residential Apartments-Master Meter-Schedule MMA | Time-of-use + tiered | $960–$1,818 | 12–22y |
| Potomac Electric Power Co | Residential - Schedule R | Time-of-use + tiered | $990–$1,775 | 12–21y |
| Potomac Electric Power Co | Residential Apartments-Master Meter-Schedule MMA | Flat | $377–$724 | 29–56y |
| Potomac Electric Power Co | Residential - Schedule R | Time-of-use + tiered | $298–$490 | 43–70y |
Price it for your own usage and system size →
What would change this
Your roof. Production is modeled for Washington on a south-facing array at 20° tilt. Shading, orientation and pitch all move it, and solar resource varies within District of Columbia itself.
Your usage pattern. A household at home during the day self-consumes more and exports less, which shortens payback wherever export credit is poor.
Rising rates. These figures hold today's prices flat. Electricity prices have been rising, and every rise shortens payback — so treat these as a conservative bound.
State and local incentives. Not included here, and in some states they are worth more than the federal credit was. Check your state energy office before deciding.