Why the US military is driving storage innovation

• ‍US Navy & Department of Defense recently announced $100m of storage investments
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• Department of Defence uses 80 per cent of US government’s energy supplies
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• ‍Military’s storage-powered microgrids being used to help US public utilities in crisis

The US military could become one of the main drivers of innovation in the energy storage industry in the coming years. In recent weeks, there were two announcements that have highlighted the US military’s increasing focus on harnessing the power of energy storage to reduce energy costs as well as improve energy security. Earlier this month, it was revealed that energy storage system manufacturer EnerSys had agreed a $91.8 million deal to supply its ‘thin plate pure lead’ batteries to the US Navy for use on nuclear submarines. Meanwhile, days prior to the EnerSys announcement, it emerged that the US Department of Defense's (DoD) Office of the Assistant Secretary of Defense for Industrial Base Policy had awarded $30 million to a three-year project to establish an energy storage systems campus at the University of Texas at Dallas. The new campus is part of DoD's Scaling Capacity and Accelerating Local Enterprises (SCALE) initiative which aims to stimulate commercial investment and build “sustainable markets” in technologies that are essential to national security. 

Military consumes huge proportion of US government's energy

It's unsurprising that the US military is taking steps to better manage the way it consumes energy. Research has shown that, between 2001 and 2018, the DoD has consistently consumed between 77 and 80 percent of all the energy used by the US government, according to the Watson Institute for International and Public Affairs at Brown University (see chart below).

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There are signs that the DoD has been successful in reducing its expenditure on energy – for example, in the 2017 financial year, the DoD spent $3.5 billion to heat, cool, and provide electricity to its facilities, which was a decrease on the previous year’s total of $3.7 billion. But the Department of Defense wants to go further, military spending takes up a massive part of the federal government’s budget – it spends more on defence that the next 10 biggest spending countries combined, so it is keen to pursue any avenues that could result in meaningful savings.

It is known that the US military is keen to make greater use of stationary energy storage to bolster the energy security of its bases and meet their energy independence requirements. The wider deployment of storage within the military would help keep critical infrastructure – such as communications, medical functions, refrigeration and vehicle charging – operational even in the event of outages.

To this end, the military is planning to make storage a key component of new microgrids that are being developed on its sites. In February last year, it was revealed that the US Army wants to build microgrids on each of its 130 bases worldwide by 2035 and the army reportedly has 24 microgrid projects scoped and planned up to the end of 2024. It’s also understood that the US army’s “climate plan” includes proposals to procure enough renewables and battery storage “to self-sustain its critical missions” on all army installations by 2040. Also last year, it emerged that the US Navy and Marine Corps plans to build cybersecure microgrids at critical military facilities. The move came after the US Navy entered into a partnership with renewable energy company Ameresco in 2021 which involved the signing of a $173 million contract for the construction of a 3MW battery system, 19MW combined heat and power plant, and a microgrid control system. Ameresco said the microgrid would provide the Norfolk Naval Shipyard in Portsmouth, Virginia with “long-term energy security while reducing the electricity imported from the grid by 68 per cent”. 

Military microgrids bailing out US utilities

The wider significance of the military’s investment in energy storage shouldn’t be underestimated as there have been occasions when the military’s storage facilities have been used to support US public power supplies provided by utility companies. For example, in August last year, Marine Corps Air Station Miramar and Naval Facilities Engineering Systems Command (NAVFAC) Southwest ran a military base microgrid power plant to help California utility San Diego Gas & Electric (SDG&E) avoid a power emergency. After receiving a request from the utility, NAVFAC Southwest operated the microgrid for five hours, which meant SDG&E could provide continuous power to 300,000 homes in the San Diego area during a time of high grid demand.

In this instance, MCAS Miramar and NAVFAC Southwest sprang into action in response to a state-wide ‘flex alert’, which was issued as part of the Miramar Summer Generation Incentive, an agreement the base and NAVFAC Southwest have entered into with California Public Utilities Commission and SDG&E to provide generation support. The agreement entered into force in the summer of 2021, but this was the first time it had been put into effect.

Other organisations set to follow US military's storage lead

Where the military leads, other sectors are expected to follow. With the introduction of the US Inflation Reduction Act last year – and, in particular, the associated investment tax credits for domestically sourced and manufactured standalone energy storage systems – a wide range of organisations, including businesses, city authorities, and universities have been offered a bigger incentive to invest in energy storage systems. Experts have advised such organisations to look to the US military for examples of how best to proceed in this respect.

So with the military viewed as having a pioneering approach to the utilisation of energy storage, what new trends should we look out for? In one of the most recent developments, it is understood that the US Army is now focussing on new liquefied gas (LiGas) electrolytes for high powered, non-flammable energy storage systems that can withstand high-pressure conditions in the field. This is because traditional lithium-ion batteries use a liquid electrolyte, which consists of a lithium salt dissolved by a solvent. Despite the presence of the solvent, it’s generally considered to pose little safety risk – however if a battery is defective or punctured, it can potentially become a fire hazard. This is a major concern for soldiers – and their equipment – in the field, which means the US Army has prioritised securing safer types of lithium-ion batteries. Consequently, LiGas electrolytes – which  use use non-toxic and non-corrosive gases that are liquefied under moderate pressures and can be contained in standard cylindrical cell cans are currently of interest to the army. To this end, the military is understood to be keeping a close eye on a project being undertaken by South 8 Technologies – and funded by a $3.125 million US Department of Energy grant - aimed at developing high-power, rapid-charge Li-ion battery cells using its ‘LiGas’ electrolyte.

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