Kentucky Utilities client in Lexington. The account is metered on the secondary side of a utility-owned transformer. KU applies a transformer loss adjustment that adds approximately 2.5% to the metered demand. So if the meter reads 400 kW, the billed demand is 410 kW. The 10 kW addition is transformer losses that the utility says occur in their transformer. But if the transformer is utility-owned, why is the customer paying for utility equipment losses?
Transformer losses adding to billed demand ? client or utility responsibility?
Kevin ? transformer loss adjustments are standard when the meter is on the secondary side. The utility delivers power to the primary side of the transformer. Some energy is lost in the transformer as heat. The meter on the secondary side only measures what comes out. The adjustment adds back the losses so the customer pays for what was delivered to the transformer, not just what came through it. Its tariff-approved and technically correct.
Diane ? I understand the technical justification. But heres my issue: the standard loss factor KU uses is 2.5% for all transformers regardless of age, size, or loading. A new high-efficiency transformer might have losses of 1.5%. An old overloaded transformer might have losses of 4%. Using a flat 2.5% for everyone means some customers overpay and some underpay. My client has a new transformer installed 2 years ago. Actual losses are probably closer to 1.5%.
Wesley ? thats exactly what I was hoping to hear. If KU will perform a transformer loss study and apply actual losses instead of the 2.5% standard, my client could save 1% on every demand and energy charge. At 410 kW demand and 180,000 kWh monthly consumption thats approximately $250 per month or $3,000 annually. Not huge but its free money for filing a request.
Kevin ? also check whether your client should be metered on the primary side instead of secondary. Primary-side metering eliminates the transformer loss adjustment entirely. The demand and energy charges per unit are lower for primary-metered service in most KU tariffs because the utility doesnt have to add back losses. If the client owns their own transformer, primary metering is the correct configuration.
Robert ? the transformer is utility-owned so primary metering isnt an option. But I filed the request for an actual transformer loss study. KU agreed to perform it. If the actual loss factor is lower than 2.5% theyll apply the lower factor going forward. No retroactive adjustment but future savings are automatic. Good catch on an often-overlooked billing component.
Kevin raises a valid point. From my 30 years in Duke Energy metering ? transformer loss factors are set by tariff and rarely reflect actual transformer efficiency. The tariff loss factor is an average across all transformers in that voltage class. Individual transformers vary significantly. Some utilities will perform a transformer loss study on request and apply the actual loss factor instead of the tariff standard. Its worth asking.