The answer lies in decarbonisation and there is one company looking to geological formations to drive net-zero ambitions in a sector with a notoriously high carbon footprint…oil and gas.
To learn more about how bedrock can aid decarbonisation, PEi’s Pamela Largue spoke to John King, CEO and co-founder of Hyperlight, a systems engineering company over a decade old and originally focused on generating biofuels from algae.
The concept of Geological Thermal Energy Storage
Hyperlight’s system is based on Geological Thermal Energy Storage (GeoTES) technology, a hybrid geological solar power plant that uses existing oil drilling infrastructure to store carbon-free thermal energy underground in massive quantities.
King explained that clean energy is stored underground at oil well sites and can be extracted and converted to electricity whenever needed using traditional geothermal power generation technologies.
Geological thermal energy storage is currently being investigated to decarbonise the hard-to-abate oil and gas sector in California, but King states, “it can be deployed wherever you have sun and sedimentary formations with or without oil.”
California, explains King, is a perfect canvas to develop and deploy this technology due to its strong public policy framework and a market large enough to encourage deployment at scale.
Given California’s 100,000 enhanced oil recovery wells (EOR), Hyperlight estimates the statewide potential storage capacity of its technology to be the equivalent of one billion Tesla Powerwalls, with energy production potential over 100TWh annually, exceeding the output of all the natural gas power plants in California combined.
However, Hyperlight is looking to expand far beyond the borders of California.
The world is moving towards greener energy which makes storage more important than it has ever been, stated King, in light of the intermittent nature of renewables and the corresponding need for flexibility.
Said King: “In terms of ensuring grid reliability, when the sun isn’t shining, eight-hour batteries are great, but you still need weekly, monthly and seasonal storage”.
Taking advantage of existing infrastructure: Enhanced oil recovery sites
EOR involves steam being injected into the ground to produce oil. The oil and gas sector has spent billions optimising thermal efficiency techniques in the process, such as replacing natural gas fired burners with solar power to create steam for EOR operations.
According to King, this is a big part of the reason why Hyperlight has focused the last decade on maximising and monetising process heat.
A great deal of the thermal energy injected into the ground remains there for several months, creating a synthetic geothermal resource, said King.
“Coupled with CSP, you have a very predictable, reliable source of heat and you can stick a power generation cycle on the back end of this and generate power very efficiently.
“This provides an effective decarbonisation pathway for oil and gas. When the wells dry up, the heat is still there allowing power generation to go on indefinitely.”
Explaining the potential scale of this solution, King explains that there is a massive volume of bedrock. “In California alone, underneath the 100,000 wells that are producing, there’s six cubic miles of rock”.
Unlocking 6 months of energy storage with Tectonic Sun
King explained how Hyperlight, in collaboration with US-based National Renewable Energy Agency (NREL), has worked to maximise CSP coupled with geothermal resources.
Enter the platform called Tectonic Sun, which stores months’ worth of solar energy in the geological formations at EOR sites.
Said King: “Tectonic Sun transforms the wells into renewable energy resources that enable power generation which can be switched on at any time and generate for as long as needed.”
The development roadmap for this technology is called “Tectonic Sun Alpha” and will see Hyperlight pursue heat-only and power generation projects.
“The Tectonic Sun platform is an incremental improvement, where we are keeping the high-quality surface heat of 300 to 400 degrees centigrade. Then we split the heat, keeping some at the surface and sending most of it into the rock.
“When we bring that produced fluid back to the surface it’s at 120 C, and we recombine it with the high-quality heat we kept at the surface. This allows for super heating at the surface, ensuring higher efficiencies during power generation.
“You’re increasing the quality and efficiency of what you’re doing and getting more bang for your buck out of your power cycle investment.”
A startup with a few decades of experience
Hyperlight considers itself a hybrid between a startup and a scaleup. Said King: “We started out as an algae company, then we pivoted over to be a CSP company.
“We have had an opportunity to demonstrate our ingenuity and grit, to navigate a very challenging environment and still advanced the technology.
“We have done that and now have a transformative market application.”
The company is currently focused on project finance and securing an offtake agreement with a credit-worthy offtaker.
“Then the goal is to overcome the hurdles associated with a first-of-its kind technology, focusing on second iterations and scaling up projects,” added King.
For now Hyperlight plans to take its place in the global fight against climate change, making use of an enormous battery beneath our feet to provide clean electricity and aid decarbonisation as far afield as possible.
