We’re one of 100 households participating in a energy conservation pilot program by our local utility - the Snohomish PUD. It’s called “FlexTime.” We qualified by agreeing to install a ChargePoint Home Flex charging station for our electric vehicles - one that allows for charging to be delayed to overnight to reduce demand on the grid.
“Devices enrolled in the FlexTime pilot will help customers save money. Customers with eligible smart devices or taking part in the Customer Choice program can also reduce energy use (turning down the lights, delaying the dishwasher, clothes washer or dryer, etc.) during the peak rate periods (weekdays 7 to 10 a.m. and 5 to 8 p.m.) to save money.”
“Customers will receive a 20% discount during nights, weekends and federal holidays, while being charged a peak rate during three-hour periods in the morning (7 to 10 a.m.) and evening (5 to 8 p.m.) on weekdays in the winter (November through February). Discount and peak hours are already defined, making it easy to make little tweaks in your day that add up to big annual savings. After the 20% discount, the nights and weekend rate will be 7.99 cents/kWh and the peak rate will be 21.37 cents/kWh. All other hours will be billed at the PUD’s standard rate of 10.4 cents/kWh.”
And here’s what our new meter looks like that records time-of-use (also known as TOU rating):
And one of the two electric vehicles (a Harley-Davidson LiveWire) plugged in and charging.
Our 2021 Ford Mach-E is a Standard Range model with a 75.7 kWh battery pack (of which 68 kWh are usable.) It can accept Level 2 charging at a maximum power of 10.5 kW, but on a NEMA 14-50 circuit like we have our ChargePoint Home Flex connected to, continuous draw is limited to 40A, or 9.6 kW (240V x 40A), so the Mach-E would take roughly 8 hours to charge from empty to full. (Charging from empty to full has yet to be needed.) By delaying charging to 10pm, a full charge can completely use Discount Rate power - the maximum charge would cost 75.7 * 0.08 or $6.06 - not bad 🙂
Our 2020 Harley-Davidson LiveWire can accept Level 2 charging at a much slower maximum power of about 1.4 kW. It has 15.5 kWh battery pack (of which 13.5 kWh are usable.) An empty to full charge of the LiveWire takes about 11 hours, which is longer than the Discount Rate power window, but - again - empty to full charges have yet to be needed. The maximum charge would be at most about $1.50, assuming most the charge happened during the Discount Rate period.
And, of course, the icing on the cake is the ChargePoint iOS app. With graphs!