🔒UTRC aims to revolutionize grid-scale battery storage

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Like a number of other environmentally progressive states, Connecticut has set ambitious goals to dramatically reduce greenhouse gas emissions over the next three decades.

But achieving those goals, which amount to slashing current emissions roughly in half by 2050, is far from guaranteed. At a lab in East Hartford, a dozen scientists are trying to create a pathway to make it happen. Battery experts at the United Technologies Research Center (UTRC) — the R&D arm of Farmington's United Technologies Corp. — are using a $2.7 million cash infusion from the federal government to try to solve a crucial problem — making large-scale energy storage more affordable and commercially viable.

Storage is seen as a key component in transitioning to a grid that relies much more heavily on carbon-free wind and solar power — “intermittent” sources that produce electricity only when the wind blows or the sun shines. Being able to store that energy output in batteries for later use during calm and cloudy days could revolutionize the grid.

The problem is, despite technological advancements, large-scale storage efforts remain too expensive for most states and utilities, said Mike Perry, an electrochemical systems engineer at UTRC, whose team is working with Harvard University, the University of South Carolina and others to try to bring down the cost of grid-scale storage by experimenting with new battery chemistries and components.

“Renewables have really raised the bar and storage is kind of the missing link for what we do when the sun doesn't shine,” Perry said. “So you've got to have storage.”

UTRC bets on flow battery

Some utilities, particularly in California, are already using batteries. But installed capacity remains small across the country.

To fuel a surge in renewable power, batteries need to be able to store and discharge energy for longer durations, which is where UTRC's battery comes in.

UTRC's technology isn't the typical lead-acid or lithium-ion batteries you'd find in various consumer gadgets. It's a tractor-trailer-sized “flow battery,” which uses two large tanks of liquid solution containing dissolved metals to store electrical energy that can later be sent to the grid.

Perry's team has already had success in reducing the cost of its flow battery, which it licensed to Massachusetts-based Vionx Energy several years ago. Vionx, which has raised nearly $90 million from investors, has installed a flow battery at a military base and is working to further develop and commercialize the technology in partnership with a number of big companies, including Siemens, 3M and United Technologies, which is providing ongoing R&D support through UTRC.

Flow batteries are competing with lithium-ion batteries, which are more common today in utility-scale storage.

Lithium technology has seen steep price decreases akin to those experienced by solar panels in recent years, said Richard Fioravanti, a longtime energy storage expert and principal of Exponent Inc. in Washington, D.C. “We're seeing this very aggressive, steep cost decline on the lithium side, and that's a challenge to these [flow battery] manufacturers,” said Fioravanti, who several decades ago worked for UTC Aerospace predecessor Hamilton Standard.

But the race toward a potentially lucrative utility market is still on. Various companies are betting on flow batteries in the hopes they can drive down costs and improve performance, ultimately overtaking lithium's early lead in the grid-scale market.

“They're all going after this long duration market, but who's going to get there first is a question,” Fioravanti said. “Who's to say what a company like UTRC can do?”

With its latest round of federal money, from the U.S. Department of Energy, UTRC will test out different and potentially cheaper membranes — an expensive part of the battery that separates the liquid solution in the large tanks.

They will also experiment with the makeup of the solution itself. To date, UTRC has used an element called vanadium in the mixture, but Perry said the team will explore using iron, which is a cheaper element, as well as man-made molecules that are organic-metal hybrids.

Signs of change

Though still too expensive for most states to bother with, grid-scale storage has started to catch on in certain areas.

The biggest example is California, which in 2013 ordered its utilities to install 1.3 gigawatts of storage capacity by 2020.

Closer to home, Massachusetts announced early this year that it would set its own storage targets by July.

Connecticut has dabbled a bit. Several bids into a recent clean-energy procurement included storage proposals, but none were selected.

In addition, a 2015 state law required utilities Eversource and Avangrid to propose storage-demonstration projects. But utility regulators earlier this year deemed the proposals too expensive.

Both utilities are re-evaluating their proposals.

“We strongly believe there is a place for this technology and earlier this year filed with Massachusetts regulators a proposed $100 million energy-storage program there,” Eversource spokesman Mitch Gross said. “Energy storage will be another tool we can use to reduce the length of any outages. It will help provide our customers with a stronger, more reliable electricity delivery system. While there is currently limited use of these energy-storage systems nationally, we are seeing projections showing more of them coming online across the country in the next three to five years.”

Neither Eversource nor Avangrid has any battery storage installed in Connecticut. Absent a state mandate, that may remain the case for some time, unless battery prices fall far enough, said Fioravanti. After all, it's not like the grid is in shambles, Fioravanti said. “It's not in their charter to test new technologies for the heck of it,” he said.

Grid operator ISO-New England is preparing for the potential advent of storage. New England's grid had 16 megawatts of battery storage capacity as of late last year, and ISO-NE reported in January that an additional 77 megawatts of battery capacity are in the development pipeline. Battery operators were also recently granted permission to sell power into ISO-NE's wholesale energy markets.

”Storage technology is developing rapidly and is expected to have increased levels of participation in the markets in coming years as costs associated with storage continue to decline and levels of intermittent renewable resources in the markets continue to increase,” ISO-NE said.

However, ISO-NE and others have also noted that significant transmission upgrades will be needed to grow wind power.

RPS goals a challenge

Connecticut has been gradually ramping up the amount of clean power its utilities must buy each year.

But despite various state incentives, solar and wind represented just 3 percent of New England's power mix in 2016. Meanwhile, natural gas plants produced nearly half and nuclear plants — a carbon-free source — generated 31 percent.

There are different categories of what the state considers to be “renewable,” but the cleanest category — which includes true renewables like solar and wind as well as emissions-emitting technologies like fuel cells and landfill gas — is scheduled to reach 20 percent in 2020.

Lawmakers are currently weighing a bill that would double that requirement by 2040.

If that happens, at some point during the transition, there could be infrastructure problems, Fioravanti said.

The electric grid has been able to absorb the modest levels of renewable generation so far, but a significant ramp-up will lead to periods where output from intermittent renewables doesn't match up with demand.

“As you get to higher and higher penetrations [of renewables], these swings can become greater and create larger problems,” Fioravanti said. “Consensus is that this point is hit around 20 to 30 percent penetration levels. If a state has a mandate to hit 20, 30, 50 percent renewables, obviously they're going to need storage.”