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

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.