Demand response
Make water heaters grid-ready when they are replaced
Equipment replacement offers a practical opportunity to build flexible demand into homes at lower incremental cost.
Originally published on LinkedIn. This article reflects the information and perspective at the time of the original post.
Update: Bill S-4 has passed the Senate and is now at second reading in the House of Commons. It would modernize the Energy Efficiency Act so federal standards for energy-using products can include not just energy consumption, but also the “interoperability or energy demand” of a product or class of products. This could pave the way for demand response capability to be a required feature of new water heaters.
Nearly every electric water heater in Nova Scotia will be replaced over the next 15 years. With about 300,000 single-family homes in the province, even if only half have electric water heaters, that represents roughly 450 MW of connected load. (Total Winter peak demand in Nova Scotia is about 2500 MW for comparison. They do not all operate at once, so the impact on peak demand is much smaller.
Even so, water heaters represent a meaningful flexible load, and centralized control could help reduce winter peaks while also absorbing excess renewable generation in the summer that might otherwise be curtailed.
The challenge is cost. Retrofitting controls onto existing units is expensive relative to the value of each individual heater to the grid. A more practical path may be to support control-integrated water heaters at the time of purchase. If the incremental cost is low, utility access is easy to enable, and homeowners receive ongoing incentives, the economics could be flipped.
This could be a valuable research challenge for students and a meaningful contribution to Nova Scotia’s energy future. Smart Energy | Halifax
