Islands of energy storage

Island energy storage projects offer a test bed for the systems and technologies that might proliferate on the mainland on a much larger scale. Photo credit: El Hierro renewable energy project, ABB energy storage systems

Island energy storage projects offer a test bed for the systems and technologies that might proliferate on the mainland on a much larger scale. Photo credit: El Hierro renewable energy project, ABB energy storage systems

Energy storage for island communities has been in the news a lot recently. Hawaii has been seeking out up to 200MW of storage, while El Hierro in the Canaries is set to become the first island to rely entirely on wind and pumped hydro power next month.

Meanwhile, the millionaire’s playground of Necker Island in the Caribbean and several more are looking to invest in various technologies that store energy. The reasons are hardly surprising.

Islands are usually isolated from large mainland grids and shipping or in some cases even flying in diesel to generate energy is expensive. As a result, island-dwellers, such as those in Hawaii and the Caribbean, suffer high energy bills.

Energy autonomy

Generating your own energy from renewables such as wind and solar seems like a sensible option and, of course, the usual issues such as intermittency and lack of grid stability quickly follow, requiring some sort of energy storage.

Indeed, the current requirement from Hawaii for additional storage capacity stems from the risk of rooftop solar power from the noonday sun threatening to swamp the grid.

There is a more far-reaching motive for some islands to seek renewable energy plus storage, however.

Their vulnerability to rising sea levels and the extreme weather inherent in climate change means island communities have a vested interest in throttling carbon emissions.

Petri dishes for energy storage

Island communities are also ideally placed to act as laboratories for the systems and technologies that might one day proliferate on the mainland on a much larger scale.

To quote Amory Lovins, co-founder and chief scientist of the Rocky Mountain Institute: “Islands are a microcosm of larger energy systems around the world and offer an excellent test bed to demonstrate and scale innovative clean energy solutions.”

Some of those microcosms are currently, or will soon be, demonstrating the value of renewables, microgrids and energy storage to the wider world.

Hawaii’s grids feel the heat of solar

In the Hawaiian island of Oahu, for example, the Hawaiian Electric Company (HECO) has recently called for proposals for one or more large-scale energy storage systems able to store 60 to 200MW for as much as half an hour on the grid.

Proposals are to include everything from engineering, procurement and construction, to testing, commissioning, start-up and performance verification.

The seemingly unstoppable march of rooftop solar has created problems for the existing grid, which already carries 11% renewable energy. HECO’s goal is to add whatever energy storage project is chosen by the beginning of 2017.

And in March, the Kaua’i Island Utility Cooperative (KIUC), also in Hawaii, issued a request for proposals for an energy storage system that could help its grid cope with the increasing penetration of solar energy.

This is currently supplying 5% of the island’s needs and expected to double in the next few years.

Windpower and pumped hydro

Whilst additional energy storage is being demanded to deal with growing solar, there are plenty of existing projects in the state, mostly soaking up excess energy generated through wind power.

Xtreme Power leads the supplier pack with its advanced lead-acid battery technology being used at a number of wind farms, including Kahuku and Kaheawa.

Altairnano’s ALTI-ESS lithium-ion titanate and A123 Systems’ lithium-ion technologies also make a contribution, with a project featuring a ZBB zinc-bromide flow battery currently under construction.

Beyond batteries, back in 2009 the now-defunct concentrated solar power developer Sopogy supplied thermal energy storage for a parabolic trough solar array at Keahole Point.

And one Hawaiian island that plans to add pumped hydro to the energy storage mix is Lana’i, a resort popular with the super-rich and owned by billionaire Larry Ellison.

Island initiatives for renewables

Billionaires seem to be a re-occurring theme in island-based renewable energy.

Richard Branson, owner of Necker Island in the Virgin archipelago, is one of the backers of the Ten Island Renewable Challenge, which was launched in 2012 with a mission to reduce dependency of islands on fossil fuels.

Six islands have joined up so far, with an open-ended objective of replacing diesel generation with 100% renewable energy.

The scheme is also reported to have attracted USD$300m to support renewable energy and energy-efficiency projects for hotels, hospitals, schools and utilities.

The UK’s Isle of Wight signed up to a similar commitment with the EcoIsland Partnership, although its stated aim to make the Isle energy self-sufficient and carbon-neutral by 2020 was not such a success story.

Its high ideals ended in liquidation, charges of fraud and the suicide of its founder.

100% renewable plus energy storage this year

One island that looks like it will soon come good on its pledge of 100% renewable energy is El Hierro.

The smallest of the Spanish-owned Canary islands, it has a population of 11,000 who currently consume around 40,000 barrels of oil to generate their annual electrical needs.

By the end of this year its hoped that this figure will be reduced to zero, thanks to a combination of five turbines and an 11.3MW pumped hydro storage plant, whose upper reservoir is the crater of an extinct volcano.

The EUR€80m project will be owned 60% by local authorities of the island, 30% by electricity generator Endesa and 10% by the Technological Institute of the Canary Islands.

A lengthening list of projects

These are far from the only island-based energy storage projects, however. Others include:

  • The Faroe Islands, a North Atlantic archipelago, where Danish utility Dong Energy has an island showcase for its Power Hub technology, which balances an increasing amount of wind power with pumped hydro storage.

Written by Mike Stone

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