Connecticut clients with electric heating have winter demand peaks that exceed summer peaks ? unusual for most commercial accounts. A medical office building on Eversource Rate 57 peaks at 310 kW in January from electric baseboard heating and heat pumps. Summer peak is only 240 kW from cooling. The tariff ratchet uses the highest peak regardless of season, so the January peak sets the floor for the entire year including mild spring and fall months when demand is 150 kW.
Winter demand peaks from electric heating ? different than summer peaks
Virginia ? electric heating demand is a growing issue in New England as buildings convert from oil and gas to heat pumps. The heat pump demand profile is the opposite of cooling ? highest demand during the coldest hours when the compressor works hardest and auxiliary electric strip heat activates. A building that was summer-peaking before heat pump conversion becomes winter-peaking afterward, often at a higher peak than the old summer peak.
Alice ? exactly the dynamic. And the winter peak is harder to reduce because you cant defer heating the way you can defer cooling. In summer you can pre-cool and coast. In winter if you reduce heating the building temperature drops quickly and pipes can freeze. The operational flexibility for demand management is much more limited in winter.
In Duluth this is our primary demand issue. Minnesota Power rates are actually designed for winter-peaking systems ? their demand ratchet is seasonal with separate summer and winter provisions. Winter ratchet is only 50% because they recognize winter peaks are driven by weather, not discretionary load. Check whether Eversource has seasonal ratchet provisions. Not all utilities treat all months equally.
Clifford ? Eversource Rate 57 does NOT have seasonal ratchet differentiation. Same 80% ratchet year-round regardless of season. Thats disadvantageous for winter-peaking accounts in New England. Ill check if there are alternative Eversource tariffs with seasonal provisions.
Virginia ? Xcel in Minnesota has seasonal demand provisions similar to what Clifford described. Winter billing demand calculated separately from summer. For accounts that winter-peak from electric heating, the seasonal separation means the winter spike doesnt inflate summer demand charges. The regulatory theory is that winter peaks are weather-driven and shouldnt penalize customers during moderate months. Progressive tariff design.
Idaho Power also has seasonal demand billing. Winter demand and summer demand are billed independently. A client with 200 kW winter peak and 150 kW summer peak is billed at each seasons peak rather than 200 kW year-round. For accounts with significant seasonal variation this structure is more equitable than a single annual ratchet.
Researched alternatives. Eversource does offer Rate 58 for space-heating accounts that has a separate winter demand provision with a lower ratchet percentage. My medical office client qualifies because more than 50% of winter consumption is for space heating. Switching from Rate 57 to Rate 58 reduces the annual demand charges by approximately $4,800 because the winter peak is treated differently. Another win from reading the full tariff book.