Solar energy, including photovoltaics, will contribute to Hawaiʻi’s goals for renewable. (photo credit: John Cole, HNEI)

Many wonder whether the state can reach the lofty goals set out by new laws requiring the University of Hawaiʻi to become net-zero by 2035 and for Hawaiʻi to achieve 100 percent renewable electricity by 2045.

A new report from the Hawaiʻi Natural Energy Institute (HNEI) at the University of Hawaiʻi at Mānoa identifies various scenarios that would allow the islands of Oʻahu and Maui to surpass the 2020 goal of 30 percent renewable energy while lowering electricity costs.

“This study provides a valuable tool to assess potential pathways to meet the aggressive 100 percent goal while also maintaining a reliable system,” said John Cole, HNEI project leader.

Modeling a renewable grid

The study, conducted by GE Energy Consulting, in partnership with and sponsored by HNEI, modeled the islands of Oʻahu and Maui, simulating electric power system operations with varying amounts of utility-scale wind and solar, and increasing amounts of distributed rooftop solar photovoltaics.

“This modeling provides an independent look at the utility system and how changes to it and its operations can affect its costs and ability to accept additional renewables,” said Richard Rocheleau, HNEI director. “The report and additional analyses that build upon it will provide regulators and other stakeholders with valuable information as we continue reducing our dependence on fossil fuels.”

Utility system upgrades recommended

To maintain grid reliability with high levels of intermittent renewable energy generation and minimal curtailment, the study recommends utility system upgrades, modified operating procedures and additional ancillary services. A balanced growth of wind and utility-scale and distributed solar was shown to help reduce the aggregate variability and intermittency, rather than relying on one source of renewable energy.

Future scenarios are continuing to be assessed

HNEI and GE are continuing this work including analysis of frequency stability at both the system and distribution levels with high penetrations of wind and solar; a more detailed evaluation of the value (cost/benefit) of mitigation measures including advanced grid technologies such as storage, demand response and other ancillary services; an assessment of the impact of advanced transportation systems such as electric and fuel-cell electric vehicles; and the risk of fuel price volatility.

Funding for the RPS Study was provided by the U.S. Department of Energy and the State of Hawaiʻi via the Energy Systems Development Special Fund (aka, “barrel tax”).

Read the Hawaiʻi Natural Energy Institute news release for more.

By Rachel Orange, Hawaiʻi Natural Energy Institute