When asked how to best plan for battery storage in a future power mix, utilities, resource planning consultants, and researchers had the same answer: It depends.

The key variables are the system’s current and projected renewables and storage penetrations. But drilling into the complexities of planning for the right amount of battery storage in a least-cost future resource mix dominated by renewables revealed critical insights about how to properly value storage for the reliability it provides.

Planners have made “substantial progress” in “capturing the complex value of battery storage for reliability,” National Renewable Energy Laboratory (NREL) Senior Researcher and Group Manager Daniel Steinberg said during a California Energy Storage Association (CESA) May 22 webinar. Ways to value shorter duration storage in planning are “actively being improved,” but long-duration storage methods are only “developing.”

Arizona Public Service (APS), the first investor-owned utility to choose solar-plus-storage over a natural gas peaker unit, uses “multiple future scenarios” to plan for its storage needs, APS VP for Resource Management Brad Albert told Utility Dive. “There is no perfect scenario. We could not have predicted a pandemic in 2020. Strategic planning requires judgments.”

There are conditions in which overbuilding renewables is more cost-effective than deploying storage. And the value of battery storage for reliability changes significantly as costs fall and penetrations of variable renewables and storage rise on the system. Precise analytics, like the Effective Load Carrying Capability (ELCC) calculation, could simplify planning decisions, some stakeholders said. But others said no calculation substitutes for judgment.

From bidding to planning

Though utilities have long recognized the value of pumped hydro, compressed air, and concentrating solar’s thermal storage, those technologies have not proved cost-effective and scalable for storing energy. Two recent solicitations turned planners’ attention to batteries.

FlexGen, an energy storage system integrator that counts GE and Caterpillar among its backers, said this week that a lithium-ion battery storage system it was supplied was used by an Indiana utility to black start a 77MW natural gas plant.

Thermal power plants that go offline require black starting and the application is considered an essential service for the grid. While the theory of using batteries to perform this application, akin to “jump starting” a vehicle, was sound, grid-scale battery energy storage systems did not start actively doing so until around 2016, when Energy-Storage.news reported on projects in Germany and later in California that successfully proved the case in real-world settings.

Black start is still done using diesel generators in many places, including at FlexGen’s unnamed “leading Indiana utility” customer. FlexGen deployed a 12MW / 5.4MWh short duration lithium-ion battery storage system which has successfully black started one of two 77MW gas turbines.

As well as being zero emissions resources, FlexGen claims that batteries can perform the application at half the cost of diesel generators, coming online when there is a blackout to repower turbines. FlexGen said its proprietary software, called HybridOS can enable the functionality at any commercially available turbine. While energy storage systems have been used to black start power plants already, FlexGen claims its Indiana system black started a 112MVA generation set-up transformer (GSU), making it the largest black start of its kind of a transformer in the US to date.

“FlexGen provides integral capabilities like black start for utility clients’ existing power plant sites through cost-competitive battery storage assets. We look forward to helping Indiana further integrate carbon-free technologies that increase the reliability of the electric system,” FlexGen chief operating officer Alan Grosse said.

The European Parliament has called on the EU Commission and member states to remove regulatory barriers to boost the development of energy storage technologies.

The Industry, Research and Energy Committee proposed in a new report to abolish double taxation or shortcomings in EU network codes, which it said have hampered the development of hydrogen energy storage projects.

MEPs have also outlined the role green hydrogen and home batteries can play in stepping up renewable energy storage solutions.
The possibility of retrofitting gas infrastructure to transport hydrogen should also be looked into, they recommend.

Battery production outside Europe should be reduced, with recycled materials sourced within the continent. Mechanical and thermal storage solutions should also be developed further.

The MEPs also recommend revising the Trans-European energy networks to improve the eligibility criteria to develop energy storage facilities.

Lead MEP Claudia Gamon said: “Energy storage will be essential for the transition to a decarbonised economy based on renewable energy sources.

“As electricity generated by wind or solar energy will not always be available in the quantities needed, we will need to store energy.

“Apart from storage technologies that we already know work well like pumped hydro storage, a number of technologies will play a crucial role in the future, such as new battery technologies, thermal storage or green hydrogen.

“These must be given market access to ensure a constant energy supply for European citizen.”

Siemens Energy and EnergyNest have entered into a long-term partnership to develop thermal energy storage solutions for industrial customers. The two companies are exploring the use of excess renewable electricity to charge a thermal battery, which would in turn release steam when needed to provide power — lowering the plant’s natural gas demand, while increasing flexibility.

Life as niche tech

Thermal storage has long been considered vital to decarbonization, yet the market for the technology has remained niche and expensive. This is a reality recognized by Siemens and EnergyNest, with the two companies laying out their intent to create modularized and standardized thermal storage systems — improving both the efficiency and economics of the technology into a scalable model.

Thermal storage is currently a $4.35 billion market, small potatoes in the energy world. And while the technology is currently held back by limited efficiency and even more limited project economics, proponents of the technology hold to the idea that thermal storage can offer higher power capacity, improved cycle life and better overall system reliability, in comparison to lithium-ion batteries.

Siemens and EnergyNest aren’t the only companies operating in the thermal storage sector, so what other innovations are being made to guide this niche technology into the mainstream?

Development stage

It’s not just private companies looking to expand the scope of thermal storage. The National Renewable Energy Laboratory (NREL) has launched a project aimed at increasing the efficiency of thermal storage to then use the energy to drive a turbine-generator set. Specifically, NREL is looking to develop a system that uses electricity to power a high-performance heat exchanger, which will heat inexpensive solid particles to over 1100°C. The particles will be stored in insulated silos for up to several days. When electricity is desired, the hot particles will be fed through a fluidized bed heat exchanger, heating a working fluid to drive a Brayton combined-cycle turbine attached to a generator.

Speaking of Brayton Energy, the company is currently developing what it calls a “key component” to integrate turbomachinery into a cost-competitive thermal energy storage system. In English, that means that Brayton is looking to create a system in which each turbomachinery stage is designed to act as both a compressor and turbine, alternating between charging and discharging cycles. This system simplification and consolidation of parts is expected to increase efficiency and reduce capital costs.

Mitsubishi Corporation said today that it is partnering with major Japanese telecoms provider NTT to “study cooperation” in renewables, energy management using electric vehicles and battery energy storage, while according to reports, NTT is investing around US$1 billion a year in renewable energy up to 2030.

Newspaper Nikkei said yesterday that it had learned Nippon Telegraph and Telephone (NTT) will invest ¥1 trillion (US$9 billion) between now and 2030 in renewable energy generation and entering the electricity transmission and distribution (T&D) business.

Japan’s T&D network is dominated by 10 regional utility companies, but the sector has been gradually undergoing deregulation since 2016. NTT Group, which has more than 300,000 employees, could have the scale to “disrupt the dominance” of those electric companies and potentially help lower energy costs, the Nikkei report said.

NTT launched its own energy business, NTT Anode Energy, in mid-2019, with the parent company saying it would pursue business opportunities in “smart energy” and setting a target of increasing energy business sales by the Group as a whole to around ¥600 billion by the 2025 fiscal year. NTT said then that NTT Anode Energy would complement the existing businesses of three subsidiaries in the energy space through power generation, transmission, distribution and energy storage as well as electric retail and wholesaling.

The electric retail space in Japan has also been deregulated, leading to hundreds of participants registering to join a market that still remains in its infancy but is hope could lead to wider adoption of renewable energy. The country has a target of sourcing between 22% and 24% of its energy from renewable sources by 2030. One of the incumbent electric utilities, Tokyo Electric Power, recently announced a partnership with manufacturer Itochu to integrate its solar-based electricity retail subsidiary’s offerings with batteries.

This week’s clean energy investment roundup sees capital moving into long-duration energy storage and software for solar, wind and utilities.

An alternative to traditional pumped hydro

Quidnet Energy, a startup developing a long-duration energy storage technology, closed on a $10 million series B financing round. The firm also landed a contract with NYSERDA for a 2 MW/20 MWh demo project of its geomechanical pumped storage technology.

That’s ten hours of storage versus the four hours typical of the predominant lithium-ion battery technology. Quidnet aims to deploy a cost-effective alternative to traditional pumped hydro using “excess” renewable energy to store pressurized-water under ground at dry oil and gas wells.

“Quidnet’s GPS technology is a novel form of hydroelectric energy storage. It uses time-tested well-drilling and construction technologies to pump water under pressure into subsurface geological reservoirs to store energy. When variable renewable energy is not available, this water is released to drive hydroelectric turbines to power the electric grid,” said Quidnet CEO Joe Zhou.

Existing investors Breakthrough Energy Ventures (founded by Bill Gates in 2015) and Evok Innovations participated in the round, along with new investors Trafigura and The Jeremy and Hannelore Grantham Environmental Trust.

The CEO adds, “The 2-MW project will be funded by NYSERDA with $2.5 million — we’ll contribute the other half.” The startup suggests that “even at this modular scale, per-kilowatt installed costs are expected to be less than 50% of traditional pumped storage due to simpler civil construction scope.”

“Integrating renewables and replacing retiring thermal generation require cost-effective long- duration electricity storage at an immense scale,” said the CEO.

An alternative to lithium-ion batteries

Eos Energy Storage is a private zinc battery developer with the chance to go public via a merger with a special purpose acquisition company. The proposed merger would provide Eos with $225 million of new equity financing, including up to $50 million of proceeds from a backstopped PIPE by B. Riley Financial. The proposed transaction is expected to be completed in the fourth quarter of 2020, subject to a long list of terms and approvals.

Eos claims its zinc technology, twelve years in development, is a safe, scalable, and recyclable alternative to lithium ion.

Mines worldwide extract more than 11.9 million metric tons of zinc annually. There are zinc mines in over 50 countries around the world, and while the metal plays a key role in the steel industry, few people understand its transformative role in the energy storage sector. When most people think of the metals that power today’s energy storage systems, vanadium and lithium are at front of mind.

However, one of the challenges to growing an energy storage industry is the dependency on a supply chain of hardware components, metals and chemicals many of which come from outside of North America. Metals such as lithium, vanadium, rare earths and cobalt used today in many energy storage batteries, are impacted by price volatility, security of supply and duration restrictions. On the other hand, those same risks do not apply to zinc energy flow batteries.

Best known for its industrial use in galvanising steel, Zinc is abundant and inexpensive, and without any geopolitical complications as we have a significant North American supply. Zinc utilizes the only battery chemistry that uses earth-abundant, recyclable materials with chemistry that is robust and safe. Unlike lithium-ion technology, which requires new stacks in order to scale, zinc batteries are able to decouple the linkage between energy and power. This means that scaling the zinc battery technology can be accomplished by simply increasing the size of the energy storage tank and quantity of the recharged zinc particles.

Zinc-air batteries use oxygen from the atmosphere to extract power from zinc, making zinc-air battery production costs the lowest of all rechargeable batteries. Zinc-air batteries are non-flammable and non-toxic with a longer lifetime as compared to other batteries.

The zinc-air cell doesn’t require expensive and hard-to-find materials and can be manufactured locally which contributes to our North American economy. When combined with PV panels, zinc-air storage delivers a renewable, reliable, and affordable source of power.

Rethink Energy Research has released a new report exploring the pace at which global energy markets are deploying energy storage projects and the factors driving them to do so.

According to the report, USA Flying start triggers rush for Energy Storage Leadership, actions by utilities in the US to expand their energy storage capacity more than any other utilities in the early 2020s is triggering a global rush to leadership.

Global utilities, led by those in the US, have in the past weeks commissioned projects that will enable the energy storage market to double in 2020 and 2021, despite the COVID-19 pandemic.

The capacity commissioned will allow the storage market to have a ten-year annual growth rate in excess of 44.8%.

By 2029, the global battery storage capacity is expected to hit 1,462GWh up from 6.9GW today.

The US is expected to lead through 2024 by installing 27.7GW of new capacity. However, China its expected to take the leadership role by 2029.

The rest of the Asia Pacific, led by South Korea, India and Japan, as well as Europe, led by Germany and the UK, but also augmented by Italy, Spain and even the Netherlands and Belgium, will end this forecast period neck and neck with the USA, all chasing second place behind China. Latin America, Middle East and Africa will be far smaller markets.

By 2030 the situation will look like this:
China 107 GW
USA 77.6 GW
Europe 77.3 GW
Asia Pacific 76.5 GW

The activity in and around the 4-hour battery power storage using lithium-ion market is accelerating in the US so fast that by 2024, it will have overhauled the 100-year-old lead that pumped storage has in the storage market and installed more GW.

By 2030 it will have installed close to 4 times the amount that pumped storage ever reached at 77.6 GW of capacity, able to output solidly for 4 hours, in total some 310.4 GWh of battery cells.