How to quit using fossil fuels the Hawaiian way

Just three days after President Trump announced his June 3, 2017 decision to withdraw from the Paris Climate Accord, Hawaii Governor David Ige signed a bill committing his state to the goals of the international agreement. On signing the document, Governor Ige said:

“We are the testing grounds. As an island state, we are especially aware of the limits of our natural environment. Tides are getting higher, biodiversity is shrinking, coral is bleaching, coastlines are eroding, weather is becoming more extreme. We must acknowledge these realities at home. That is why Hawaii is united in its political leadership on tackling climate change.”

Hawaii Governor David Ige
Hawaii Governor David Ige. Image: – @GovDavidIge

A year later, Governor Ige signed another environmental bill, this time committing his state to achieving carbon neutrality by 2045. According to the new law, by that year, 100% of the state’s electricity must be produced from renewables — photovoltaics, wind, geothermal, biofuels — completely displacing fossil fuels in the process.

The following figure provides a measure of the task ahead. Prior to 2008, less than 4% of the state’s electricity was generated from renewables. By 2017, that had grown to about 26%. Today, the percentage is around 30%.

Figure from Rhodium Group, April 19, 2019 report
Image from Rhodium Group, April 19, 2018 report

Some might think that the environmental actions of a small, isolated state (pop 1.4 mil) is of little account in the grand scheme of things. They’d be wrong. The work involves more than simply replacing old technology with PV panels and wind mills. Hawaii has six power grids, one for each of its larger islands. The current mix of renewable energy sources includes at least 60 utility-scale plants and 150,000+ residential rooftop solar systems, all with outputs that fluctuate depending on time of day, weather conditions, and other factors. How to integrate such diverse systems in a way that maintains grid stability (no overloads, brownouts, shutdowns) — that’s the real challenge. And the project is being watched closely by other states keen on cutting  their dependence on fossil fuels.

The key to success will depend on energy storage — batteries that can store energy when the systems are producing an excess, and return it when they are not producing enough. Judging by the rapid pace of solar development now taking place in Hawaii, that should not be a problem.

A Jan 3, 2019 news release from the utility Hawaiian Electric, says it has submitted contract proposals to the state’s Public Utilities Commission for seven grid-scale, solar-plus-storage projects on three islands. “The projects – three on Oahu, two on Maui and two on Hawaii Island – will add approximately 262 megawatts (MW) of solar energy with 1,048 megawatt-hours (MWh) of storage. The energy storage can provide four hours of electricity that can further reduce fossil fuel use during peak demand in the evening or at other times when the sun isn’t shining.”

Solar array, Poipu, Hawaii
Solar array, Poipu, Hawaii. Photo from Scientific American. Credit: Getty Images

The National Renewable Energy Laboratory (NREL) has been helping the Hawaiian Electric Companies respond to their grid stability issues. Commenting on the work (NREL News, April 24, 2018) Martha Symko-Davies, program manager for NREL’s Energy Systems Integration Facility said, “We’ve helped Hawaii integrate not just solar, but also storage, electric vehicle infrastructure, and more. If this can be done in Hawaii, it can be replicated anywhere else—the question is not ‘if’ we can do it, it’s ‘how’ we can do it. How do we apply the solutions we’ve helped implement in Hawaii and translate those solutions into ones that can work in other, mainland states?”

Map of Hawaiian Islanda
Hawaiian Islands – Image: Google Maps