Delaware’s main 2026 rate change took effect on June 1, not October 1. Delmarva Power’s standard offer service (SOS) rate, the default supply price, rose by about a fifth. A delivery rate case is still open.
This article covers Delmarva Power in Delaware. It does not cover the Delaware Electric Cooperative or municipal utilities.
Quick Summary: Residential Standard Offer Service
| Season | Before June 1, 2026 | From June 1, 2026 | Change |
|---|---|---|---|
| Summer | 9.3569¢/kWh | 11.1063¢/kWh | +19% |
| Winter | 9.4804¢/kWh | 11.4049¢/kWh | +20% |
Residential heating customers have separate rates: 11.0159¢ in summer and 10.0515¢ in winter.
What It Means for a Bill
The State of Delaware put the impact at about $14.64 a month for a typical residential customer using 811 kWh. Delmarva described it as roughly 9.34% of the total bill.
Our check: 811 kWh × (11.1063¢ − 9.3569¢) = 811 × $0.017494 = $14.19. The official figure is slightly higher because it reflects other supply-related lines as well.
One small offset: the renewable compliance charge fell 11%, from 0.5797¢ to 0.5172¢ per kWh.
Winter Rate
The winter SOS rate is 11.4049¢, about 0.3¢ above the summer rate. At 811 kWh that is a difference of about $2.42 a month. Check your bill for the date the winter rate starts.
Why It Rose
Delmarva cited higher regional supply prices, which it does not control. The state said an independent expert confirmed the supply auction worked properly and bids reflected the market. Delaware’s Public Advocate, Jameson Tweedie, pointed to rapid demand growth from data centers.
Still Pending
- Base rate case: $67.8 million a year, filed December 2025. This is for delivery, not supply.
- “Affordability and load flexibility” application: $37 million over three years. The Public Advocate has asked for it to be dismissed.
Delmarva offers a Customer Relief Fund of up to $500 for eligible households.
What This Means for Homeowners With Solar
We did not verify Delaware’s current net metering or export credit rules for this article, so we give no export rates here. Ask your utility for its current solar tariff, and check how exported energy is credited before sizing a system. Fixed monthly charges are not reduced by solar.
Our solar payback guide shows how the retail rate and the export credit change the math.
What to Check on Your Bill
- The supply rate and whether you are on SOS or with a supplier.
- The customer charge and distribution rate, which the pending case could change.
- The renewable compliance charge.
For help sorting the lines on your bill, see our guide to reading your electric bill.
Limitations
Rates come from a State of Delaware news release and a local news report. We did not open the Public Service Commission’s orders, and we did not confirm the status of the base rate case or whether interim rates are in effect.
Sources
- State of Delaware, “Upcoming Electricity Rate Increase Adds to Cost Increases for Delmarva Customers,” April 6, 2026
- WBOC, “Delmarva Power expects higher bills for Delaware customers following new rates filing”
- Delaware Division of the Public Advocate, statement on Delmarva Power’s SOS filing, April 9, 2026
Frequently asked questions
Did Delaware electric rates change on October 1, 2026?
We found no new order with that date. Delmarva Power's supply rates changed on June 1, 2026, and those rates include a slightly higher winter price than summer price.
How much did Delmarva Power supply rates rise?
Residential standard offer service rose 19% for summer and 20% for winter, about $14.64 a month for a customer using 811 kWh, according to the State of Delaware.
Is another Delmarva increase coming?
Delmarva filed a base rate case in December 2025 seeking $67.8 million a year. Delaware's Public Advocate has also asked regulators to dismiss a separate $37 million Delmarva application.
