May 17, 2020

Renewable Geothermal Energy Pumps Up Heat's Power Potential

earth
Energy
Geothermal
heat
Admin
4 min
Geothermal power plant pumps up Earth's heat to generate energy
Written By: Brittany Johnson Human populations, for more than 10,000 years, have utilized geothermal resources. Geothermal energy continues to impact o...

Written By: Brittany Johnson

Human populations, for more than 10,000 years, have utilized geothermal resources. Geothermal energy continues to impact our lives, from the Paleo-Indian populations bathing in the warm water of hot springs to present-day geothermal energy harnessing the capability to generate sustainable electricity. The upper six miles of the earths crust, alone, harnesses 50,000 times more energy than all the oil and gas reserves combined. However, geothermal potential is far from being reached as advancements have slowly and sporadically progressed over the past century. These twentieth century advancements can be traced technologically in the form of the three main geothermal plants. The plant types: dry, flash, and binary have contributed to the accessibility and popularity of geothermal energy. Gaining knowledge of their progress and structure helps aid in the proliferation of sustainability.

Dry Steam
Dry plants were first invented in the Italian town of Lardarello in1904. Dry plants use a direct system of pumping the high-pressure steam straight from a geothermal reservoir in order to generate electricity. The steam travels up the production well, passes multiple rock-catchers to prevent congestion and blockage, and then enters directly into the steam turbine, resulting in units of electricity. The Dry Steam Plant’s close relationship to the underground reservoir obviates secondary steps such as boilers and boiler fuel, which is used by other steam-generated plants. Due to this requirement, however, Dry Plants are only in locations such as The Geysers in Northern California, where a direct geothermal connection can be made. While effective, the inhibited accessibility of Dry Plants makes it the least widespread of the three. Dry plants first succeeded in America in the 1960’s and are still in use today. Further advances in Geothermal Technology were not seen until the early 1980’s in the form of Binary technology.

Binary
Binary plants are distinct from the dry steam plants, because the geothermal water is not the only catalyst for electricity. Instead, a secondary fluid is used to ignite the generator and produce electricity. During the process, two separate cycles are taking place simultaneously to create a steady and efficient generation of electricity. These two processes are converted using the binary heat exchanger. At one end of the exchange is the geothermal water, which is used to heat the secondary fluid with a lower boiling point. The outcome is a vapor, which acts much like the dry steam, moving up the production well and into the turbine, resulting in the generation of electricity. The binary process also acts as a closed cycle, meaning after electricity is generated, much of the remains will condense back into a cooler liquid form, running down another well, and returning to the reservoir from which it came, where the process can be repeated. This full circle is the binary process that enables cooler reservoirs to generate electricity.

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Flash
Flash plants were implemented later in the 1980’s and as of 2010 have been the most common geothermal plants in operation. Flash plants operate on a pressure-based system where high-pressured water and super-heated fluid is sprayed into the reservoir. This injection causes a lower-pressured fluid to “flash” into a vapor, forcing it up through a series of high to low-pressure valves within the production well. When this stream reaches the turbine and goes through the generator, it produces electricity. The fluid left over, which is not turned into steam, flows back through a clarifying process and returned back down the production well.

Companies spearheading the geothermal energy industry include: Chevron; Calpine Corp., Ormat Technologies; Magma Energy Corp.; Raser Technologies; Nevada Geothermal; and Polaris Geothermal.

While geothermal technology continues to advance and spread, a hope for a cleaner future appears closer than ever before. Geothermal energy is clean, producing less than one-sixth of the carbon dioxide emissions of a clean natural-gas power plant. Geothermal energy is also abundant, steady, predictable, and available twenty-four hours a day. With further efforts from governmental and privatized sectors continuing the development of geothermal plants, the technology will become more affordable, more widely available and more efficient. While the technology has not yet reached its full potential, the gap is slowly closing and progress will continue to be made.

GEOTHERMAL STATISTICS
-First Geothermal Generator: Built by Prince Piero Ginori Conti in Lardarello, Italy
-Types of Geothermal Plants: Dry Steam, Binary, Flash
-Current Installed Power: 11,000 MW
-Potential Worldwide Power: 2000 GW
-Largest Producers: USA, Philippines, Indonesia

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Jun 25, 2021

UK must stop blundering into high carbon choices warns CCC

climatechange
Energy
Netzero
UK
Dominic Ellis
5 min
The UK must put an end to a year of climate contradictions and stop blundering on high carbon choices warns the Climate Change Committee

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.

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