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With the UK’s commitment to net zero emissions by 2050, geothermal energy generation has taken a high priority. 

Research has shown that commercial geothermal solutions can reduce household energy bills by over 50%, while reducing carbon emissions by as much as 80%, Interesting Engineering reports.

A new geothermal plant at the Eden Project in Cornwall was activated recently, the first deep geothermal project to launch in the UK for 37 years. 

The new project was partly funded by the European Regional Development Fund and Cornwall County Council. “The well cost about £24m to build and the current system will produce around 1.4MW of energy,” the Financial Times reported. 

Despite its high cost, the project aims to bolster geothermal energy from Earth’s core and reduce the Eden Project's energy bills by about 40%.

The plant taps five kilometres below the Earth’s surface through the geothermal well at the Eden Project, unlike previous shallow geothermal projects in the country.

Plant objectives

Executive director of Durham Energy Institute Professor Jon Gluyas said “this will have a lot of eyes on it, and rightly so. It will demonstrate that deep geothermal can generate low-carbon heat for customers around the region”.

The objective is to harness hot water with temperatures of up to 200C and function as a crucial source of heating for the nearby greenhouses and enclosed rainforest biomes, says the Financial Times. 

Additionally, the media reports that the geothermal power generated through the new system is reliable for around-the-clock energy, and has very low emissions. The hot water from below ground can be used to heat and generate electricity.

The UK government will announce policy recommendations after assessing the plant’s potential. In the coming weeks, it will publish a white paper on deep geothermal energy according to the Financial Times. 

Costly but effective

Costs have proven to be an impediment to launching this project and other similar deep geothermal projects.

The UK faces challenges in drilling wells with extended depth as the country’s location is away from tectonic plate boundaries, unlike Iceland. It implies that heat is further away from the Earth’s surface and thus, drilling deep towards the Earth’s core is the only solution to reach energy goals.

Chief executive of Eden Geothermal Gus Grand said that the Eden Project's artificial rainforest is an expensive thing to heat. 

Drilling through granite is extremely hard and pursuing the task during the pandemic proved to be very expensive. “It is a demonstration – it is a research project. If you were doing a commercial project, you wouldn’t do it like this.” 

Such initiatives are also time-consuming especially due to the lack of power lines – gridlock, he added. “We would love to turn it into electricity but it’s a nightmare – my grid connection is for December 2036.” 

A drilling rig unveiled by researchers at the University of Oklahoma could dramatically change how the world sources its energy. The research team at the University's Mewbourne School of Petroleum and Geological Engineering plans to use the rig to tap into geothermal vents below the Earth's surface for an unlimited energy supply, a local media report said.

With countries worldwide looking for ways to address their energy needs without emitting carbon, wind, solar, and even nuclear power are getting a boost. However, these sources are plagued by their constraints, such as intermittency or radioactive waste.

Geothermal energy, on the other hand, has neither of these issues and is a reliable source of power without any carbon emissions. The hurdle, however, is to tap into the source far below the depths we have dug into before. 

A drilling rig for geothermal vents

Orkhan Khankishiyev, a master's student at the university, conceptualised a rig that is 17ft (5.18m) tall which could be used to reach the depths necessary to tap into geothermal energy.

For comparison, oil and gas exploration technologies currently dig up to a depth of 10,000ft (3,048m), but for tapping into geothermal heat, one needs to dig to twice this depth to about 20,000ft (6,096m). The increased temperatures at this depth, which could range between 600-700 degrees Fahrenheit (315-371 degrees Celsius), further complicate the task. 

The digging will also need to be done in pairs, one for the upcoming vent and another for water. Once dug, one of the vents will be used to send in water, while the heat of the Earth will turn it into steam and send it up the other vent. The steam can then be used to power a turbine and generate electricity. 

Human dug vents will be much smaller in diameter and power thousands of homes. Image: Mlenny/iStock

The researchers predict that a single pair of vents can produce enough energy to power 2,000 homes per day. Since the circumference of the vent is not wider than nine inches (~23 cm), multiple vents can be dug at the same site, which could theoretically even be in an individual's backyard and generate power.

The team has moved from concept to prototype quite quickly but needs to extensively test its performance, which could take a few years. However, the potential of technology in the energy sector is tremendous.

The researchers compare it to fracking, which went from an unknown concept to one that everybody was using in just a decade. Geothermal energy could be the next big thing in the power sector if the drilling rig works out.