Estonian utility Eesti Energia plans to tap into deep geothermal resources using 'closed-loop' technology from Canadian start-up Eavor, with heat stored in rocks kilometres deep harnessed to provide warmth for homes that previously relied on fossil fuels.
Eesti has signed an agreement with Geothermal Baltic, a company owned by Estonian investors representing Eavor’s technology in Baltic countries, to start the construction of a test borehole in the eastern Estonian city of Narva on the border with Russia.
“The heat stored in the Earth's crust is a similar source of renewable energy as wind and solar, the use of which will help us reach carbon-neutral energy production," said Eesti Energia board member Margus Vals.
"We will start testing in Narva whether the use of geothermal energy on a larger scale is possible in Estonia."
Narva has Estonia’s second-largest district heating network, supplying heat to nearly 60,000 inhabitants. Enefit Power’s existing heat and power plant there has been producing energy at a price of €39.83 ($43.53)/MWh, and Vals added that if the pilot project were to be successful, his company will be able to offer residents there carbon-free district heating “at a reasonable price”.
The company didn’t reveal how much exactly reasonable means, but a company press official told Recharge that the current price was set by Estonian competition authorities and has not been updated for more than a year.
"We must also take into account that currently the heating is produced mainly from fossil fuel (oil shale), which, due to its high carbon emissions, in time becomes more and more expensive."
Estonia is sitting on vast oil shale deposits, which it uses for electricity generation and heating, but the fossil fuel is highly polluting, so the country plans to phase out its use.
The Baltic state simultaneously after Russia’s war on Ukraine has been racing to wean itself off Russian energy imports. Narva is right at the border with Russia, half-way between the Estonian capital of Tallinn and Russia’s second largest city, St. Petersburg.
Estonia last year stopped importing fossil gas from Russia, and from this year on has banned such imports, making it dependent on imports of liquefied natural gas (LNG) from other countries.
The Baltic State is also trying to cut use of shale oils to help meet its climate ambitions.
'Self-powering cycle'
Eavor, which has secured backing from the likes of BP and Chevron, in 2020 presented its technology based on a closed loop in which cold water — or a similarly behaving working fluid — travels down a 3-5km pipe, then underground horizontally for a few kilometres, up another pipe and along the surface back to the start.
The company claimed the closed loop would essentially power itself due to thermodynamics, and be able to produce dispatchable renewable energy anywhere in the world for less than $50/MWh by the end of the decade.
Eavor CEO John Redfern told Recharge previously: “The advantage of this [technology] is that’s it’s distributable and benign enough that you can co-locate it close to centres of demand. The energy market is not just about LCOE [levelised cost of energy], it’s also things like the surface footprint.”
The start-up already has a plant operating with the technology in Alberta, Canada.
"Depending on the results of the pilot project, we can design a borehole for heat production with a capacity of at least 15MW," said Kaido Kõrm, head of Geothermal Baltic.
"The price of geothermal heating will be very competitive even in Narva where it is one of the lowest in Estonia. In addition, geothermal energy is stable and its price does not depend on the sudden price increases of other types of energy."
UPDATED with detail on pricing, Estonia's shale oil
