Saltwater batteries and the emerging blue energy economy

  • Scientific breakthroughs are making saltwater battery storage more viable.
  • Many emerging markets are ideally positioned to harness saltwater battery technologies.
  • This new technology could decrease global dependence on lithium.
  • A sustainable blue energy economy is steadily developing in emerging markets.

As emerging markets seek to accelerate their energy transitions by increasing solar and wind power capacity, recent technological advancements that harness the sodium from saltwater could provide a crucial breakthrough in battery storage.

In recent months start-ups and researchers have debuted saltwater battery technologies that promise cheaper capacity to store variable solar and wind power at scale, a development that could help to reduce global dependence on lithium.

In January US-based tech start-up Salgenx unveiled a saltwater flow battery that can be used for standalone storage of renewable energy, as well as for powering agriculture irrigation pumps, greenhouse irrigation or lighting, oil well pumps and telecoms towers.

The technology operates with two separate tanks of fluid electrolytes, one of which is saltwater and the other its proprietary electrolyte. The circulation of the two fluids allows the battery to regulate the input and output of electricity.

Meanwhile, in December 2022 researchers at the University of Sydney in Australia announced that they had also developed a sodium-sulphur battery with four times the storage capacity of lithium-ion batteries.

By altering electrodes to improve the reactivity of sulphur, scientists in Australia and the US are developing solutions to meet the power needs of emerging markets while also helping to create a marketplace for competing technologies that has the potential help consumers around the world.

The global seawater battery market stood at $4m in 2021 but is expected to experience a compound annual growth rate of 37.1% and reach $36m by 2028, according to market research firm Business Research Insights.

Benefits for emerging markets

Whereas previous energy transitions replaced one dominant energy source with another – for example, wood was replaced by coal in the 19th century, and coal by oil in the 20th century – today’s multi-source, multi-technology transition offers different clean energy options for different geographies.

In this case, the harnessing of saltwater technologies will have positive effects for the many emerging markets that have ample access to coastal waters – and particularly for developing island nations, which are among the most vulnerable to climate change.

For these reasons, it is perhaps unsurprising that a Colombian start-up, E-Dina, forged the first breakthrough in the technology. In 2021 E-Dina debuted WaterLight, a cordless lamp that can generate 45 days of continuous light from 500 ml of saltwater – or even urine – by sparking a reaction with the magnesium in the device that emits hydrogen gas.

With the number of people around the world living without electricity rising by nearly 20m in 2022, according to the International Energy Agency, such a device could go a long way towards tackling energy poverty, especially in Africa.

The most recent breakthroughs in saltwater battery technologies, however, offer an opportunity for off-grid communities to develop large-scale renewable battery storage capacity by tapping into the reactivity of sulphur.

The Salgenx design is scalable, with the company offering 250-KW, 3-MWh, 6-MWh, 12-MWh and 18-MWh configurations. Most importantly, there is no membrane – the case in most redox flow batteries – which drives down its upfront and maintenance costs.

Another vital benefit of saltwater batteries for energy-importing markets is overcoming reliance on increasingly complex lithium supply chains.

Over the past year lithium-ion battery manufacturers have been zeroing in on Latin America’s so-called lithium triangle of Argentina, Bolivia and Chile, which holds 53% of global lithium reserves. This has prompted a wave of commercial diplomacy backed by public-private partnerships to position Latin America as the centre of global lithium supply for the coming decades.

However, with the threat of supply chain disruptions and China accounting for 60% of global lithium refining and processing, traditional lithium-ion batteries present supply insecurities much like hydrocarbons, with importing countries ultimately dependent on exporters and refiners.

The blue energy economy

Just as clean energy technologies have tapped into two of the planet’s most powerful natural forces – sun and wind – the embrace of the oceans and their valuable sodium creates another avenue for emerging markets to build sustainable domestic solutions to energy and climate challenges.

Saltwater batteries are the latest in a wave of new developments forging a so-called blue energy economy, which seeks to use ocean resources sustainably to drive growth, create jobs and protect vital marine ecosystems.

US clean energy company Tesla Energy is using Powerwall batteries and solar panels to transform saltwater into drinking water in coastal communities in Kenya.

Meanwhile, the Seychelles is currently building the world’s largest saltwater floating solar power plant, which is expected to be completed by the end of this year. The plant will be capable of contributing 5.8 MW of capacity to the grid and is part of the country’s commitment to reaching its climate goals.

The Seychelles pioneered the use of blue bonds globally in 2018, raising $15m to support the sustainable development of ocean resources, and other Southern and East African nations are seeking to use blue bonds to build the so-called Great Blue Wall to protect their ocean ecosystems.

Another area to monitor is the emerging technology to produce hydrogen from seawater, which is currently in the testing phase. In December 2022 scientists in China announced a similar breakthrough in testing a dual desalination-electrolysis device that produces hydrogen gas from saltwater.

In September 2022 French climate tech start-up Sweetch Energy was awarded €6m from French industrial partners EDF Hydro and CNR, as well as venture capital firms Go Capital, Demeter Investment Managers and Future Positive Capital, to produce electricity from saltwater.

Author: Oxford Business Group

This article was first published by the Oxford Business Group and is republished with permission.

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