Concord light plant rolls out time-of-day billing; staff report fixes, credits and ongoing solar-customer concerns

Concord Municipal Light Plant (CMLP) staff told the board May 13 that the utility has begun billing customers under a new time-of-day rate structure. The new rates took effect April 1 and the first paper bills from the migration were mailed May 8, covering roughly 3,500–4,000 customers in the initial batch.

Directors and staff said the technical migration required new hourly meters, a new meter-data-management system and an upgraded billing ERP. Director Jason explained that the project included large-scale data migration work and some configuration limits in the vendor systems, but that staff were able to complete the rollout after extensive testing and effort. “It was a herculean effort,” he said, and staff thanked customer-service and billing teams for the implementation work.

Why it matters: the time-of-day program changes how energy is priced across on-peak, shoulder and off-peak periods and can materially alter customers’ bills depending on usage patterns. Staff said the meter-interval data reporting rate for residential meters under the new program is about 99.7% — above the vendor requirement of 99.5% — giving the utility confidence in billing accuracy for most customers.

Early issues and fixes: staff reported a small number of customer inquiries and identified a handful of technical issues from the first billing cycle. Jennifer in customer service said some solar customers saw incorrect graph coloring in the online portal and a few business/EV second-meter accounts experienced unbundled line items that will be consolidated. About 40 customers whose second meters were billed under a different account structure will receive credits on next month’s bills; staff said those credits and three targeted emails will be sent to affected customers today.

On solar impacts: at public comment, customer Sven Weber said his household’s bill increased roughly 27% (about $280 a year based on his hourly logs) under the new structure and urged clearer disclosure and grandfathering for existing solar customers. Laura and Jason responded that pre-rollout analyses had projected most solar customers would see bill decreases but acknowledged that some customers — depending on production timing and prior net-metering distribution charges — could experience increases. Staff said they will continue to monitor billing impacts and consider targeted adjustments if warranted.

Communications and next steps: staff said they will issue targeted communications, fix the portal visualization issues and revise EV second-meter bill layout by the next cycle. CMLP also plans a full bill redesign with its vendor in December and will continue data analysis over the next months to assess how the new rates affect peak behavior and customer bills. The board directed staff to track impacts and return with findings for further consideration.

Board action and oversight: the board did not take any further votes on rate design at the meeting; members asked staff for ongoing updates and encouraged timely communication with customers as issues are corrected.

Closing: staff emphasized that the rollout is an operational milestone and that continued monitoring and targeted corrections are the current priorities; the board will revisit outcomes as more billing cycles complete.