From ash to cash: the future of geothermal energy
Geothermal energy has traditionally lagged behind the supply generated from solar and wind technologies, but that could all change. Recent advances in exploration and drilling techniques, combined with the willingness of countries to explore the potential for renewables, are delivering exciting developments in the excavation of geothermal wells near tectonic plate boundaries and into the heart of simmering volcanoes.
The Earth’s geothermal resources are, in theory, more than capable of supplying global energy needs. Here’s the catch: only a fraction of these opportunities may be profitably exploited. This issue explains why geothermal energy produces less than 1% of the world’s electricity, according to the World Energy Council.
However, according to Professor Yan Lavallée, a volcanology and magma research chair at Liverpool University, the potential for geothermal energy to harness the power of volcanoes is enormous: “Even a small body of magma in the order of a fraction of a cubic kilometre could power a whole country the size of the UK.”
Currently, four countries hope to release that potential volcanic power.
If ambitions to deliver a significant percentage of its electricity supply from geothermal sources are to be achieved, it will represent a ‘phoenix from the ashes’ moment for the Caribbean island. A modern Pompeii, its capital Plymouth still remains buried in volcanic dust following a series of eruptions in 1995 which led to it being abandoned completely in 1997.
The UK’s Department for International Development (DFID) is at the helm of the continued geothermal development project on Montserrat, having invested just under $24mn. During summer 2017, drilling work began on a third and final test well which has not been without its problems, says DIFD rep Martin Dawson: “With the technical expertise from the specialists on site, we were able to make the decision to use bentonite slurry, a mud slurry, to secure the well. These efforts seem to have worked. The well is safe, but the slurry must now be cleaned out before we can go into the stimulation short term testing phase.”
With temperatures of 250°C already recorded at 1.7km depth there is potential for each well to deliver 1.5MW to make this the little island that could. The test phase of the project is due to end in December 2018.
It might sound outlandish but plans to harness geothermal energy from Iceland’s magma lakes to supply the UK and Europe are on the boil. Scientists working on the $100mn Krafla Magma Testbed project are set to drill over 2km below the Earth’s crust in northern Iceland, boring their way into a molten magma chamber. As part of an experiment due to commence in 2020, researchers will drill a primary borehole through which water can be pumped via reinforced U-shaped pipes. The resulting ‘supercritical steam’ could potentially be used to power turbines with the energy generated distributed across the North Atlantic via underwater cables.
Icelandic energy company Lansvirkjun discovered the magma chamber by chance while deep drilling on another project in 2009. “Utilising geothermal energy from the near magma environment is a very exciting next step for the geothermal industry. Understanding where the magma is, how to locate it and the properties of the fluid, is very relevant to developing the concept of near-magma geothermal energy in volcanic areas all over the world,” says Landsvirkjun’s project manager, Sigudur Markusson.
The project’s first phase is being coordinated by Iceland’s Geothermal Research Group and the British Geological Survey involving 38 other institutes and companies from 11 countries around the world. These include the Norwegian oil and gas giant Statoil, Canadian mining firm Falco Resources and US-based Sandia National Laboratories – a nuclear contractor to the US government on-hand to assess the processes for dealing with magma hitting temperatures of 900°C.
Plans to further harness the power of the island’s five active volcanoes (Loihi, Kilauea, Mauna Loa, Hualalai and Haleakala) are gathering a head of steam in a bid to create a 100% renewable-sourced electrical grid – something no other US state has yet managed to achieve. Governor David Ige signed a bill in 2014 pledging that Hawaii will become completely energy self-sustaining by 2045. It is a much-needed goal as Hawaiians currently pay two to three times more for their electricity than the national average and, according to the US Energy Information Administration, the state spends around $5bn per year importing enough oil to meet energy demands.
Hawaii’s geothermal Puna plant currently generates in excess of 38MW, tapping into the hot rocks in the eastern rift zone of the Kilauea to provide over 25% of the island’s electricity by directing steam from underground wells to a turbine generator. Research suggests planned expansion of the plant could help provide up to 50% of the island’s power.
Renewable energy companies are also keen to tap into the geothermal potential of Mauna Loa, a giant volcano at the island’s centre near several volcanic hot spots. However, construction of a new plant here has stalled, meeting with opposition from some locals who believe the mountain, which last erupted in 1984, is home to the deity Pele.
Dating back hundreds of years, the first use of geothermal energy in New Zealand was by the central North Island Māori for heating, cooking and therapeutic purposes. The Kiwi nation’s first geothermal plant, and the world’s second ever, was opened at Wairakei in New Zealand’s Taupo volcanic zone in 1958. The Taupo zone still produces most of the country’s geothermal electricity, contributing 750MW (13%) of the New Zealand’s supply.
The main operators here are listed company Contact Energy Ltd and Mighty River Power, a 51% state-owned enterprise. A significant factor in recent geothermal projects has been the high level of commercial participation by Māori-owned enterprises. The nation’s newest plant was delivered by Contact Energy at Te Mihi and went online in 2014.
Global positioning satellite and satellite radar interferometry measurements indicate the birth of a new magma chamber along the Taupo Volcanic Zone. Geophysicists noted geodetic measurements which highlighted widespread subsidence, suggesting the cooling and contraction of magma within the shallow crust. This large body of magma, found at depths of 6-10km below the Earth’s surface in the Taupo geothermal zone, could be further exploited via drilling at new plants to push the nation towards its increased target for renewable energy.
UK must stop blundering into high carbon choices warns CCC
The UK Government must end a year of climate contradictions and stop blundering on high carbon choices, according to the Climate Change Committee as it released 200 policy recommendations in a progress to Parliament update.
While the rigour of the Climate Change Act helped bring COP26 to the UK, it is not enough for Ministers to point to the Glasgow summit and hope that this will carry the day with the public, the Committee warns. Leadership is required, detail on the steps the UK will take in the coming years, clarity on tax changes and public spending commitments, as well as active engagement with people and businesses across the country.
"It it is hard to discern any comprehensive strategy in the climate plans we have seen in the last 12 months. There are gaps and ambiguities. Climate resilience remains a second-order issue, if it is considered at all. We continue to blunder into high-carbon choices. Our Planning system and other fundamental structures have not been recast to meet our legal and international climate commitments," the update states. "Our message to Government is simple: act quickly – be bold and decisive."
The UK’s record to date is strong in parts, but it has fallen behind on adapting to the changing climate and not yet provided a coherent plan to reduce emissions in the critical decade ahead, according to the Committee.
- Statutory framework for climate The UK has a strong climate framework under the Climate Change Act (2008), with legally-binding emissions targets, a process to integrate climate risks into policy, and a central role for independent evidence-based advice and monitoring. This model has inspired similarclimate legislation across the world.
- Emissions targets The UK has adopted ambitious territorial emissions targets aligned to the Paris Agreement: the Sixth Carbon Budget requires an emissions reduction of 63% from 2019 to 2035, on the way to Net Zero by 2050. These are comprehensive targets covering all greenhouse gases and all sectors, including international aviation and shipping.
- Emissions reduction The UK has a leading record in reducing its own emissions: down by 40% from 1990 to 2019, the largest reduction in the G20, while growing the economy (GDP increased by 78% from 1990 to 2019). The rate of reductions since 2012 (of around 20 MtCO2e annually) is comparable to that needed in the future.
- Climate Risk and Adaptation The UK has undertaken three comprehensive assessments of the climate risks it faces, and the Government has published plans for adapting to those risks. There have been some actions in response, notably in tackling flooding and water scarcity, but overall progress in planning and delivering adaptation is not keeping up with increasing risk. The UK is less prepared for the changing climate now than it was when the previous risk assessment was published five years ago.
- Climate finance The UK has been a strong contributor to international climate finance, having recently doubled its commitment to £11.6 billion in aggregate over 2021/22 to 2025/26. This spend is split between support for cutting emissions and support for adaptation, which is important given significant underfunding of adaptation globally. However, recent cuts to the UK’s overseas aid are undermining these commitments.
In a separate comment, it said the Prime Minister’s Ten-Point Plan was an important statement of ambition, but it has yet to be backed with firm policies.
Baroness Brown, Chair of the Adaptation Committee said: “The UK is leading in diagnosis but lagging in policy and action. This cannot be put off further. We cannot deliver Net Zero without serious action on adaptation. We need action now, followed by a National Adaptation Programme that must be more ambitious; more comprehensive; and better focussed on implementation than its predecessors, to improve national resilience to climate change.”
Priority recommendations for 2021 include setting out capacity and usage requirements for Energy from Waste consistent with plans to improve recycling and waste prevention, and issue guidance to align local authority waste contracts and planning policy to these targets; develop (with DIT) the option of applying either border carbon tariffs or minimum standards to imports of selected embedded-emission-intense industrial and agricultural products and fuels; and implement a public engagement programme about national adaptation objectives, acceptable levels of risk, desired resilience standards, how to address inequalities, and responsibilities across society.
Drax Group CEO Will Gardiner said the report is another reminder that if the UK is to meet its ambitious climate targets there is an urgent need to scale up bioenergy with carbon capture and storage (BECCS).
"As the world’s leading generator and supplier of sustainable bioenergy there is no better place to deliver BECCS at scale than at Drax in the UK. We are ready to invest in and deliver this world-leading green technology, which would support clean growth in the north of England, create tens of thousands of jobs and put the UK at the forefront of combatting climate change."
Drax Group is kickstarting the planning process to build a new underground pumped hydro storage power station – more than doubling the electricity generating capacity at its iconic Cruachan facility in Scotland. The 600MW power station will be located inside Ben Cruachan – Argyll’s highest mountain – and increase the site’s total capacity to 1.04GW (click here).
Lockdown measures led to a record decrease in UK emissions in 2020 of 13% from the previous year. The largest falls were in aviation (-60%), shipping (-24%) and surface transport (-18%). While some of this change could persist (e.g. business travellers accounted for 15-25% of UK air passengers before the pandemic), much is already rebounding with HGV and van travel back to pre-pandemic levels, while car use, which at one point was down by two-thirds, only 20% below pre-pandemic levels.