Estimating the Opportunity for Load-Shifting in Hawaii: An Analysis of Proposed Residential Time-of-Use Rates

Paul Bernstein, Makena Coffman, Sherilyn Hayashida, Energy Policy and Planning Group, Energy, Governing Green Power, Reports

Hawaii’s largest electric utility, Hawaiian Electric Company (HECO) and its subsidiaries recently proposed a Time of Use (TOU) pricing scheme for residential rates. The TOU scheme has three tiers of prices: daytime, on-peak, and nighttime. The proposed rates have the highest cost during the on-peak period from 5pm to 10pm. For Oahu, the lowest cost is at nighttime, from 10pm to 9am. The difference between high and low rates is $0.33/kWh. For Maui and Hawaii Island, the lowest cost is during the daytime, 9am to 5pm. The difference between high and low rates are $0.35/kWh and $0.50/kWh, respectively. It is not stated whether the rates will be implemented as an opt-in, opt-out or mandatory program. This report summarizes literature on time varying pricing for residential rates to inform Hawaii’s electricity stakeholders, including ratepayers and policy-makers, of the potential impacts and considerations regarding the potential for TOU pricing in Hawaii.