Maryland Pepco customers keep asking the same question we heard in Washington, DC:
“Are SOS electric supply rates rising, and where does it hit hardest?”
In this post, we break down:
- The latest MD SOS schedules using the tariff’s native windows and look at total all-in $/kWh (generation + administrative + transmission) across the most common classes—Residential (R), Type I (T, GS), and Type II (MGT LV II, MGT 3A II).
- Large commercial buildings classified as Hourly Priced Service (HPS) will be touched on as well.
- The short story: R/GS/T show mild seasonality, while the Type II classes see a pronounced summer spike with only a partial fall giveback.
By “seasonality,” we mean recurring, weather-driven patterns across the year—prices firm up as summer demand tightens wholesale markets, then ease as temperatures and load fall, buffered by steadier administrative and transmission components; for R/GS/T that shows up as gentle, predictable waves, while Type II sees a sharper summer surge tied to peak-hour market exposure with only a partial reset in the fall. Below, you’ll find clear charts for each class and simple percent-change callouts so you can budget 2025–2026, plan contracts, and target load-shaping where it matters most.
Rate Class “R”
Classification: Residential
Percent Changes:
10/01/24–01/31/25 → 02/01/25–05/31/25: +1.6%
02/01/25–05/31/25 → 06/01/25–09/30/25: –2.4%
10/01/24–01/31/25 → 06/01/25–09/30/25: –0.9%
Rate Class “T”
Classification: Type I Non-Residential
Percent Changes:
10/01/24–01/31/25 → 02/01/25–05/31/25: +1.8%
02/01/25–05/31/25 → 06/01/25–09/30/25: –3.1%
10/01/24–01/31/25 → 06/01/25–09/30/25: –1.3%
Rate Class “GS”
Classification: Type I Non-Residential
Percent Changes:
10/01/24–01/31/25 → 02/01/25–05/31/25: +1.7%
02/01/25–05/31/25 → 06/01/25–09/30/25: –3.0%
10/01/24–01/31/25 → 06/01/25–09/30/25: –1.3%
Rate Class “MGT LV II”
Classification: Type II Non-Residential
Percent Changes:
03/01/25–05/31/25 → 06/01/25–08/31/25: +44.6%
06/01/25–08/31/25 → 09/01/25–11/30/25: –12.7%
03/01/25–05/31/25 → 09/01/25–11/30/25: +26.3%
Rate Class “MGT 3A II”
Classification: Type II Non-Residential
Percent Changes:
03/01/25–05/31/25 → 06/01/25–08/31/25: +44.9%
06/01/25–08/31/25 → 09/01/25–11/30/25: –12.7%
03/01/25–05/31/25 → 09/01/25–11/30/25: +26.4%
Seasonal Comparison of Residential, Non-Residential Type I, and Non-Residential Type II
| Rate Class | 10/01/24–01/31/25 → 02/01/25–05/31/25 | 02/01/25–05/31/25 → 06/01/25–09/30/25 | 10/01/24–01/31/25 → 06/01/25–09/30/25 |
| R | 1.60% | -2.40% | -0.90% |
| GS | 1.70% | -3.00% | -1.30% |
| T | 1.80% | -3.10% | -1.30% |
| Rate Class | 03/01/25–05/31/25 → 06/01/25–08/31/25 | 06/01/25–08/31/25 → 09/01/25–11/30/25 | 03/01/25–05/31/25 → 09/01/25–11/30/25 |
| MGT LV II | 44.60% | -12.70% | 26.30% |
| MGT 3A II | 44.90% | -12.70% | 26.40% |
Hourly Priced Services
Rate Classes Included: MGT LV III, MGT 3A III, GT LV, GT 3A, GT 3B, and TM-RT
For MGT LV III, MGT 3A III, GT LV, GT 3A, GT 3B, and TM-RT, riding Hourly-Priced Service (HPS) means your supply cost floats with PJM’s locational marginal price every hour—then Pepco layers on admin and ancillary charges, plus a separate monthly capacity charge. There’s no cap, and heat waves, grid constraints, or market events can push costs multiple times higher within days. In our MD analysis, even fixed Type II SOS totals jumped ~+45% from spring to summer; HPS tracks the market directly and can move more and faster, creating real budget risk
Wrap Up
Maryland Pepco SOS rates aren’t moving in lockstep. R/GS/T show mild seasonality with small ups and downs, while Type II (MGT LV II, MGT 3A II) see a pronounced summer spike with only a partial fall giveback. Window definitions differ by class, so apples-to-apples comparisons matter when you’re budgeting. The practical takeaway is simple: if you need predictable operating costs, favor fixed pricing—and that’s especially important for HPS-eligible buildings, which ride hourly PJM prices and can swing far more than the fixed SOS classes. If you’d like a quick sanity check on your class, load profile, or fixed-rate options, Honeydew Energy Advisors can help—no heavy lift required. Feel free to reach out: 240-722-1405 or honeydewadvisors.com.