Micro hydroelectric energy recovery in municipal water systems: A case study for Vancouver

Throttling water pressure transforms useful mechanical energy into heat via a thermodynamically irreversible process. Alternatively, energy recovery hydro turbines or pumps as turbines can be used to generate power from excess water pressure. This study investigates the influence of water system and turbine characteristics on the economic feasibility of energy recovery turbines and develops general design principles that benefit infrastructure planners who may consider energy recovery within water systems. Results indicate economic feasibility is predictably influenced by a variety of factors. For instance, service reservoirs can decrease the levelized cost of electricity in the range of 10% and provide some generation dispatchability. Smaller turbines decrease the levelized cost of electricity in the range of 30%, but sacrifices energy recovery potential. Although challenges exist, energy recovery turbines can be an economical, flexible, and renewable option for controlling pressure and deserve serious consideration within some water supply systems.