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Energy Policy & Planning Group


Hawai`i sits on the precipice of an energy revolution. With plentiful and increasingly competitive renewable wind and solar energy, combined with the nation’s highest electricity prices and generous subsidies, Hawai`i  is poised to become 100% renewable by 2045.


Hawai`i’s green energy transformation brings new opportunities and challenges. How we manage the transition could serve as a model for the rest of the world. With the right policies, the State could eliminate most greenhouse gas emissions while reducing energy costs and becoming an innovation hub for renewable energy integration technologies.


The Energy Policy & Planning group at UHERO uses data analysis together with economic, engineering, and planning models to evaluate the consequences of current and prospective policies governing Hawaii’s energy transformation to facilitate clear-headed policy decisions surrounding renewable energy.  


Join us at our weekly Seminar in Energy and Environmental Policy


Latest Working Papers

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.

Working Paper


Making an Optimal Plan for 100% Renewable Power in Hawaii

The State of Hawaii has adopted the unprecedented goal of building a 100 percent renewable power system by 2045. This report identifies some of the central challenges in achieving this goal and uses the SWITCH power system planning model to identify solutions to these challenges. A 100% renewable power system must balance electricity supply and demand on two main time scales: diurnal (providing enough power each hour of the day) and seasonal (providing enough total energy on each day of the year). The diurnal balance could be achieved by installing large amounts of primarily solar production capacity, then using batteries, demand response, biofuels or hydrogen production to shift power production and/or consumption between day and night. The seasonal balance may be more challenging. Energy demand during days or weeks with low sunlight could be met by building extra solar and wind capacity, using biofuels, or using hydrogen produced during sunny months. Demand response will likely be less expensive than the other options for day-night energy balancing, and customer-sited solar may be competitive with utility-scale solar; consequently electric utilities may need to become energy integrators and market managers, rather than bulk power providers.It is unclear how much biofuel the State could use without compromising other environmental and energy independence objectives; consequently hydrogen energy storage merits serious consideration. SWITCH or similar models can be used to identify optimal long-term plans; however, a new incentive system is needed to encourage the State's utilities to develop and implement such plans, regardless of who will own the generating equipment.

white paper

Efficient Design of Net Metering Agreements in Hawaii and Beyond

In Hawaii, like most U.S. states, households installing rooftop solar photovoltaic (PV) systems receive special pricing under net-metering agreements. These agreements allow households with rooftop solar to buy and sell electricity at the retail rate, effectively using the larger grid to store surplus generation from their panels during sunny times and return it when the sun isn’t shining. If a household generates more electricity than it consumes over the course of a month, it obtains a credit that rolls over for use in future months. Net generation supplied to the grid in excess of that consumed over the course of a full year is forfeited to the utility. 

Project Report

Balancing Opportunities and Costs in Hawaii's Increasingly Green Grid

Hawaii’s tourism-dependent economy and oil-fired power plants make it the most oil dependent state in the United States. It also has the nation’s highest electricity prices, often between 3 and 4 times the national average over the last decade. These high prices, the state’s sunny and windy climate that make it amenable to increasingly economical renewable energy, plus a relatively progressive political culture have pushed the state to adopt an ambitious goal of being 100 percent renewable by 2045. Focusing mainly on the state’s largest grid on Oahu, where most people live, we discuss the cost structure of the current electricity system, the potential benefits and challenges of growing the share of renewable energy, and make a few policy suggestions. In particular, we argue that all homes and businesses should be given an opportunity to buy and sell electricity at the marginal cost of generation. Variable pricing could greatly reduce the cost of renewable energy, and perhaps seed development of Hawaii as a technology center focused on batteries and smart machines that can help shift electricity demand to align with the variable supply of solar and wind energy.

Working Paper

Factors Affecting EV Adoption: A Literature Review and EV Forecast for Hawaii

Electric Vehicles (EVs) reduce or negate gasoline or diesel use in vehicles through integration with the electric grid. Both plug-in hybrid electric vehicles (PHEVs)—which can draw from a battery as well as liquid fuel—and battery electric vehicles (BEVs)—solely powered through electricity—provide the opportunity for power-sharing with the electric grid and can potentially ease the integration of sources of intermittent renewable energy. This is a potentially important technology to help reduce greenhouse gas (GHG) emissions, local air pollution, and vehicular noise.

In this paper, we review studies informing the factors that affect EV adoption. We also review and harmonize studies that develop forecasts of EV adoption over time. We select a set of forecasts that represent low, reference, and high EV adoption and apply them to Hawaii-specific EV and car sales data to provide a preliminary forecast of potential EV adoption in Hawaii.

Read the full report on the Hawaii Natural Energy Institute website

Can Energy Efficiency Standards Reduce Prices and Improve Quality? Evidence from the US Clothes Washer Market

We examine the effect of energy efficiency standards on the clothes washers market using a constant-quality price index constructed from same-model price changes for a significant majority of clothes washer models sold in the United States between 2001 and 2011. We find constant-quality prices fell over time, while quality increased, particularly around times energy standards changed. We estimate total welfare changes by assuming the difference between average price and constant-quality price indicates average quality. Further examination shows product entry and exit are associated with changes federal standard for energy efficiency. With policy changes implicitly coordinating entry and exit, average vintage sharply falls when standards change. Controlling for individual model and time effects, we find that lower average vintage is associated with more rapidly falling prices, an effect we attribute to increased competition. We also find a strong relationship between clothes washer prices and average vintage of the same manufacturer, which indicates cannibalism explains much of the declining price of clothes washers over time. We apply the same methodology to other appliances (clothes dryer, room air conditioners and refrigerators) which did not experience simultaneous efficiency standard changes between 2001 and 2011. We see the same cannibalism in the market for clothes dryers, but not for room air conditioners or refrigerators. We also find notable improvements both in the characteristics of clothes washers that directly improve energy efficiency and those that promote convenience and space-saving. Energy efficiency standards appear to facilitate more rapid innovation and price declines.

working Paper


View all working papers