Plans to build five large-scale battery energy storage systems (BESS) across the islands of Hawaii will come up for public input via web links and community TV channels, as utility Hawaiian Electric (HECO) takes the process into the ‘virtual’ space.

A clear leader among US states for solar PV installations per capita, Hawaii has also been installing increasing amounts of energy storage in the form of batteries (and some other technologies including flywheels) in order to integrate that renewable capacity. This includes multiple megawatt-scale dispatchable solar plants, built to provide energy at much lower cost than from the imported fossil fuels on which the island state has long relied.

This time last year, six large-scale projects were approved by state regulator Hawaii Public Utilities Commission comprising 240MW of solar and 988MWh of four-hour duration battery storage that HECO said would will help to protect customers from the “volatile prices of fossil fuels”. The state also has the goal of reaching 100% renewables by 2045 as well as a 2030 interim target of 40%.

Subsequently, in August 2019, Energy-Storage.news reported main utility Hawaiian Electric’s plan to tender for 900MW of solar PV, along with grid services. The plan announced then was to select winning projects by May of this year, for them to be completed and online between 2022 and 2025. Under the request for proposal (RFP) issued by HECO, PV plants can range from 4MW to 119MW capacity.

Hawaiian Electric proposed to “self-build” five energy storage projects that go along with that renewables procurement and has decided to push ahead with the necessary community meetings to seek public input on those proposals. The islands of Maui and Hawaii will see their community meetings hosted on a local tv channel, with HECO accepting emailed public input. Plans for Oahu will be hosted via Webex.

Lithium-ion batteries offer high energy density in a small space. That makes them highly suitable for stationary electrical energy storage systems, which, in the wake of the energy transition, are being installed in more and more buildings and infrastructures. However, these positive characteristics have unique fire risks. This challenge can be addressed effectively by means of an application-specific fire protection concept for stationary lithium-ion battery energy storage systems, such as the one developed by Siemens through extensive testing. It is the first of its kind to receive VdS approval.

Each lithium-ion battery cell consists of two electrodes: a negative anode and a positive cathode. They are kept apart by a separator. Another essential component is the ion-conducting electrolyte.

However, this functional principle, while successful and generally safe, has designrelated risks. The battery cells are characterized by the presence of a large amount of chemical energy in a small space and a very small distance between the electrodes (separator layer typically ≈ 30 µm). At the same time, the electrolytes used are typically combustible or highly flammable.

For this reason, a battery management system (BMS) not only controls and monitors the state of charge at the cell and system level but also manages the temperature during charging and discharging. This ensures that the cells are kept within the operating range defined as safe.

Thermal runaway as a hazard scenario
Exceeding the safe temperature range can result in what is called “thermal runaway.” When this occurs, the energy stored in the battery is suddenly released, and within milliseconds the temperature rises to many hundred degrees. As a result, the electrolyte ignites or electrolytic gas explodes.

During a thermal runaway event, the electrolyte successively evaporates as the temperature climbs. This causes the pressure inside the cell to increase until the electrolyte vapors are released through a relief valve or a bursting cell wall. Without countermeasures, this results in an explosive gas-air mixture. All it then takes is an ignition source to cause an explosive combustion. In addition, a thermal runaway event in a battery system can spread from cell to cell, leading to a major fire.

One site, one interconnection, multiple megawatts of clean energy from solar and wind systems, smoothed out and rendered grid-friendly with the addition of a co-located energy storage system. Such is the promise of hybrid renewable energy systems, which, as outlined on the previous pages, are seemingly poised to become an exciting new frontier in the decarbonisation of the global energy system.

The current interest in hybrids is perhaps unsurprising. Wind and solar have traditionally been thought of as having limitations related to their inherent intermittence. But side by side, those negatives are largely cancelled out, and coupled with storage offer the promise of reliable, dispatchable power traditionally thought of as the preserve of fossil fuel generation.

“Wind is typically strongest at night, solar production during the day, so if you put the two of them together you have a higher capacity factor,” says Navigant senior analyst Alex Eller. “And if you add in storage, theoretically you could have round-the- clock output.”

More surprising, perhaps, than the apparent interest in hybrids is the question of why it’s taken this long for them to come to mainstream attention. Individually solar and wind have an enviable track record of rising deployment and falling costs, and the notion of putting them together to overcome their respective weaknesses is not a particularly new one.

Storage is certainly a newer kid on the block, but as we hear elsewhere in this edition of PV Tech Power, in certain markets such as the US and Canada, the large-scale solar-plus-storage nut appears well on the way to being truly cracked (‘See also ‘A developer’s eye view on North America’).

The reality, of course, is that what looks on paper like a seductively simple idea masks a number of interconnected complexities relating to cost, technology and market drivers that together make the hybridisation of the three technologies (and possibly others too) far from a simple prospect.

New York is well on its way to meeting the state’s goal of having 1,500 MW of energy storage by 2025 and 3,000 MW by the end of the decade, and the ‘value of distributed energy resources,’ or VDER, mechanism gets part of the credit, according to a report released by state utility regulators.

The state had deployed or contracted for 706 MW of storage by the end of last year, equaling about 47% of the 2025 target and 24% of the 2030 target, the New York Public Service Commission said in a report released April 2.

The New York Independent System Operator (NYISO) has about 9,780 MW of storage projects in its interconnection queue, the commission said, noting that not all projects will be built.

“Due to the technology’s declining costs and the ability to pair with solar photovoltaic (PV) and capture additional revenue streams, energy storage is increasingly being used to augment the existing pipeline of utility-connected solar PV projects being developed in the state,” the commission said in its first annual report documenting how New York is doing in reaching its storage goals.

Partly, the strong energy storage development is being spurred by the state’s VDER payment mechanism, which makes it easier to obtain project financing, the commission said.

VDER preferred by solar developers
The VDER mechanism pays distributed resources based on how they benefit the grid and reduce customer costs. The value stack is based on a utility’s avoided costs plus other benefits a distributed resource may bring like demand reduction and environmental values. The commission approved the methodology in 2017 and updated it a year ago.

VDER is the most common payment mechanism chosen by storage developers, and coupling energy storage with renewable generation allows developers to maximize their payments in many cases, according to the commission

Increasingly, developers of larger solar projects have been splitting them into smaller parts to qualify for VDER compensation, which is capped at 5 MW, instead of interconnecting to the grid at the bulk system level and receiving payments in NYISO’s wholesale markets, the commission said.

Energy storage installed costs remain relatively high, but are falling, according to the report.

In the early months of the coronavirus outbreak, the energy storage industry saw production delays in China and South Korea, but as manufacturing restarts there, social distancing and work restrictions in the United States have prompted delays of their own. And industry officials and experts warn that if those disruptions persist over the next few months, storage project deployment and climate change efforts could take a hit in the coming years.

According to internal industry polling from the U.S. Energy Storage Association, 2 in 3 major energy storage companies have experienced delays in project deployment as a result of the coronavirus pandemic. These delays range from pauses of under one month to indefinite suspensions.

The survey of 173 ESA members and nonmembers was conducted March 11-20, as social distancing measures began to take full force in the United States.

Andy Klump, chief executive officer of the China-based and North American-owned Clean Energy Associates, said present supply chain dynamics are “quite a stark contrast to where utilization stood in late January or early February, when factories were shut down post-Chinese New Year.”

“Now we see factories back up and running and fully utilized within China, but then we’re also seeing certain end markets like Germany or the U.S., which are being impacted by the spread of the virus,” Klump said.

According to Kelly Speakes-Backman, CEO of ESA, the spread of the virus has caused evolving disruptions for the industry.

At first, project delays were due to disruptions in the manufacturing of batteries and other infrastructure in China and South Korea. But now, as China revives its production facilities, Speakes-Backman said concern has “shifted to the domestic impacts of social distancing and work restrictions on the permitting, installation and commissioning of facilities here in the U.S., which has had an immediate impact on projects currently under construction or planned to commence construction soon.”

Rarely has such a crucial enterprise for the future of human civilization led to such little commercial success.

Long-duration energy storage holds great potential for a world in which wind and solar power dominate new power plant additions and gradually overtake other sources of electricity. Wind and solar only produce at certain times, so they need a complementary technology to help fill the gaps. And the lithium-ion batteries that supply 99 percent of new storage capacity today get very expensive if you try to stretch them out over many hours.

The problem is, no clear winner has emerged to play that long-duration role. Here at Greentech Media, we’ve spent years covering the contenders, which range from quixotic defiers of the laws of physics to understated, scientifically minded strivers. The makeup of this roster has fluctuated to the rhythm of bankruptcies and new investments.

Plenty of options technically “work.” The question is, do they work with an acceptable price point and development cycle, and can the businesses providing them stay afloat long enough to actually prove that? That last step has been hard for companies to fulfill, insofar as in previous years there were practically no places to actually sell this stuff.

That’s finally starting to change, thanks to two connected trends. First, wind and solar are now competing very effectively for capacity additions in the U.S. and other developed countries. The proliferation of these resources creates its own push for long-duration storage in places with high concentrations of wind and solar farms. A particularly appealing early market is in remote or island grids, where renewables-plus-storage already outcompete imported diesel fuel on price.

Second, spurred by this success, many utility companies, states and nations are upping their targets for clean energy. Once a jurisdiction officially commits to 100 percent carbon-free power, it has to start thinking in earnest about how to replace the gas plants that currently provide the flexible counterpart to renewables’ ups and downs. These policies typically give prime billing to the clean energy sources, but they just as well could be considered market-creation tools for the long-duration storage asset class.

Sustainable energy storage is in great demand. Researchers at Uppsala University have therefore developed an all-organic proton battery that can be charged in a matter of seconds. The battery can be charged and discharged over 500 times without any significant loss of capacity. Their work has been published in the scientific journal Angewandte Chemie.

The researchers have been able to demonstrate that their battery can be easily charged using a solar cell. Charging can also be accomplished without the aid of the advanced electronics that, for example, lithium batteries require. Another advantage of the battery is that it is unaffected by ambient temperature.

“I’m sure that many people are aware that the performance of standard batteries declines at low temperatures. We have demonstrated that this organic proton battery retains properties such as capacity down to as low as -24°C,” says Christian Strietzel of Uppsala University’s Department of Materials Science and Engineering.

A great many of the batteries manufactured today have a major environmental impact, not least due to the mining of the metals used in them.

“The point of departure for our research has therefore been to develop a battery built from elements commonly found in nature and that can be used to create organic battery materials,” explains Christian Strietzel.

For this reason, the research team has chosen quinones as the active material in their battery. These organic carbon compounds are plentiful in nature, among other things occurring in photosynthesis. The characteristic of quinones that researchers have utilised is their ability to absorb or emit hydrogen ions, which of course only contain protons, during charging and discharging.

An acidic aqueous solution has been used as an electrolyte, the vital component that transports ions inside the battery. As well as being environmentally friendly, this also provides a safe battery free from the hazard of explosion or fire.

“There remains a great deal of further development to be done on the battery before it becomes a household item; however, the proton battery we have developed is a large stride towards being able to manufacture sustainable organic batteries in future,” says Christian Strietzel.

When three scientists won the Nobel Peace Prize last year for their work on lithium-ion batteries, The New York Times was one of many outlets that drew the connection between improved energy storage and the fate of our planet: “By storing electricity generated when sunlight and wind are at their peak, lithium-ion batteries can reduce dependence on fossil fuel energy sources and help lessen the impact of climate change.”

This perfectly articulates the gauntlet we face today. How can we transition to using solar and wind to power the world when the sun isn’t shining and the air is still? The answer is to improve energy storage technology, which requires time, careful research, and expert engineering that goes beyond the scope of most other challenges we face today. Because of this, the path to meeting this objective cannot rely on uncertain venture capital raises or traditional fundraising models. As public awareness around the challenge of energy storage grows, we need public funding and support to help this sector of the energy industry rise with it.

The State of Green Energy
Today, many individuals, homes, and businesses benefit from wind and solar energy, and innovations and improvements in these fields are promising. Furthermore, interest in climate change has grown in the past several years, and I’m not just talking about Greta Thunberg’s voyage across the Atlantic. Research by Pew found that concerns about climate change have broadly increased since 2013.

In this rapidly evolving environment, it’s hard not to feel like we’re on the brink of making a huge breakthrough, if only we can innovate and execute fast enough. According to the U.S. Energy Information Administration’s July 2019 report, “Operating utility-scale battery storage power capacity has more than quadrupled from the end of 2014 (214 MW) through March 2019 (899 MW). Assuming currently planned additions are completed and no current operating capacity is retired, utility-scale battery storage power capacity could exceed 2,500 MW by 2023.”

These numbers herald major developments in the energy storage industry, and much of this is driven by the need to get better batteries into consumers’ hands faster. But that doesn’t mean the pace of research has changed. Consumer products from AirPods to pacemakers have set a new high bar for wireless charging and electric battery life. And that is where we find our current limit.

Electric Vehicles Have Gone Mainstream
One of the most exciting changes in the past decade is the arrival of affordable electric vehicles (EVs) in the consumer market. Prius drivers and early Tesla adopters have ushered in a new age in which cities and towns have to think about their charging infrastructure for EVs.

In 2018 alone, EV sales exceeded two million units globally—an increase of 63% year-over-year—but there are still significant barriers to EV adoption. On the road, EVs remain limited by the energy they can store and where the next available charging station is located. And this significantly hurts their appeal to drivers who are used to traveling with the assurance that there will be a gas station waiting for them at the next exit. As major corporations such as Amazon work with EV manufacturers including Rivian to develop new fleets of electric delivery vehicles, it’s reasonable to hope that these fleets will bring increased incentives for public investment in charging infrastructure for EVs across the country.