Renewell Energy’s Gravity Batteries: Repurposing Abandoned Oil and Gas Wells for Clean Energy Storage

US startup Renewell Energy seeks to extract an untapped climate solution from the myriad of abandoned oil and gas wells across the United States.

Although there are few supporters of exploiting those inactive wells, Renewell Energy President Kemp Gregory is enthusiastic about moving forward with his plan to harness gravitational energy and eliminate methane emissions, according to information monitored by the specialist energy platform.

To illustrate why, Kemp Gregory is standing beside a 1,219.2-meter-deep well on the outskirts of Bakersfield, California. A 1,360.77-kilogram block is suspended from a bundle of wire deep below the surface of the well.

At the push of a button, Gregory starts a small motor, pulling the block up from the wellhead until it reaches a predetermined height, the block’s weight increases, and it becomes a source of potential energy.

Gregory presses another button, and the mass begins to descend, releasing that energy in the form of electricity that can be transmitted to the power grid. bloomberg (Bloomberg) May 5.

“The system is designed to store approximately 2 kilowatt-hours of electricity, which is barely enough to run a household dryer,” said Gregory, who co-founded start-up Renewell Energy in 2020.

Company ambitions

US startup Renewell Energy aspires to build systems larger than 30% of the millions of abandoned oil and gas wells across the United States.

In doing so, Renewell Energy wants to transform the infrastructure responsible for polluting the planet into a solution that addresses one of the biggest challenges of the energy transition, storing electricity in an economical and sustainable manner.

To keep global warming below 1.5°C, about 90% of the world’s electricity must be generated from solar panels, wind turbines and other non-fossil fuel sources by mid-century, up from about 30% now, according to estimates by the International Energy Agency.

In turn, adding more renewable energy to the mix will require solutions to store excess electricity generated on particularly windy days, or distribute stored electricity when clouds reduce solar electricity generation, according to a report seen by the specialized energy platform.

Rechargeable batteries help fill this need, although the metals needed to produce lithium-ion batteries are currently scarce and expensive to mine.

And despite the continued decline in the price of lithium-ion batteries, it could still cost $100 to store 1 kilowatt-hour of electricity this way in 2026, according to Bloomberg New Energy Finance research platform.

Kemp Gregory, co-founder and CEO of US start-up Renewable Energy, predicts that the company’s gravity storage solution — which relies largely on cheap steel pipe recycled from oilfields and off-the-shelf components — could cost as little as $5 per kilowatt-hour. By 2028.

“Converting abandoned oil and gas wells into gravity batteries can revive a large number of these non-productive wells,” said Daewoo Akindibi, an expert at the National Renewable Energy Laboratory (NREL), a US government research institution.

Renewell Energy estimates that the United States alone has spent nearly $4 trillion drilling and building those wells. bloomberg (Bloomberg) May 5.

In an effort to repurpose wasted infrastructure and turn a source of methane pollution, the US Department of Energy provided $2.7 million in grants to Renewell Energy in partnership with the National Renewable Energy Laboratory to test and improve gravitational energy storage technology.

climate gains

US start-up Renewell Energy’s plan has potential climate dividends, as oil and gas companies have relatively few incentives to clean up their operations, and many non-producing wells are abandoned without properly shutting down.

The latest estimate available from the US Environmental Protection Agency shows that the country had at least 1 million abandoned wells in 2019, and together they emitted as much planet-warming methane as roughly the emissions of nearly 450,000 cows.

Renewell Energy’s solution will include plugging abandoned oil and gas wells, reducing the risk of fugitive methane emissions, which are 80 times more potent than carbon dioxide.

How to benefit from abandoned oil and gas wells

If the US startup Renewell Energy can overcome its technical challenges, the company is ready to change the energy landscape, according to co-founder and CEO Kemp Gregory.

The company’s initial plan is to sell Renewell’s technology to power the oil and gas fields that are home to unproductive wells, allowing depleted wells to store excess renewable energy for when prices and demand fall.

Although Renewell’s gravity batteries are intended to facilitate a broader transition to renewable energy, this means that its first phase will provide affordable electricity to power oil and gas operations. Gregory believes the company’s technology can help remove carbon.

“The impact of our growth will be in cleaning more oil and gas wells faster than anything else, and a successful way to store electricity to help wind and solar energy gain market share,” he said.

And given the depletion of other wells, it is likely that the startup company will lease them and then equip them with its technology to increase storage capacity, rather than abandon them, according to what was seen by the specialized energy platform.

This approach, in turn, may allow Renewable Energy to take advantage of a new customer; And it is the grid network operators who need help balancing electricity demand with supply.

Renewell Energy believes that the depth and size of each well are among the main determinants of the amount of electricity that can be stored.

The company expects that the regular well, in which it will deploy its technology, can store 150 kilowatt-hours of electricity, which is enough to supply 5 average American homes with electricity for one day.

For wells deeper than 3,657.6 meters, Renewell Energy hopes to deploy a larger system that can store 300 kilowatt-hours of electricity. bloomberg (Bloomberg) May 5.

Visiting researcher specializing in energy storage at Imperial College London, Oliver Schmidt, praises Renoil’s ambition to repurpose abandoned oil and gas wells, but remains skeptical about its ability to scale up the technology.

In his view, the time, money and manpower required to adjust the capacity of these wells can be prohibitive. Renewell’s first prototype cost about $600,000 to build and install, according to the company.

The most pressing problem may come from the regulatory side. Abandoned oil and gas wells are required by law to decommission them, a process that usually involves removing equipment, concrete-filling and capping the well. But US lawmakers have not yet recognized gravity wells as an alternative.

That doesn’t worry Gregory, who has been talking to policymakers in California and Colorado about deploying Renewell’s technology.

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