Passive Energy Sources. Geothermal Energy
This essay examines the geothermal passive energy systems of the Earth.
It does not cover renewable sources of energy since these are variables within the maximum and minimum external and internal energy constraints and have been covered in other essays as shown in references at the end of this article.
Earth Surface Area
The surface area of the Earth = 510.1 trillion m²
Source: https://www.google.co.uk/?gws_rd=ssl#safe=strict&q=surface+area+of+earth+in+m2&spf=1499337611726
Geothermal Energy Potential
‘The Earth has an internal heat content of 1e31 joules (2,777,777,777,777,777.5 terawatts) approximately 100 billion times current (2010) worldwide annual energy consumption.’
This is caused by Radioactive Isotope decay.
Source: https://en.wikipedia.org/wiki/Geothermal_energy#Types
Geothermal Energy Gradient.
The average geothermal gradient in the UK is 26˚C per km of depth.
Therefore; at suitable locations; the deeper a borehole is put into the Earth the larger potential the of geothermal energy that can be tapped.
Source: https://en.wikipedia.org/wiki/Geothermal_power_in_the_United_Kingdom
Geothermal Passive Energy Flow
‘The Earth's internal thermal energy flows to the surface by conduction at a rate of 44.2 terawatts (TW), and is replenished by radioactive decay of minerals at a rate of 30 TW.’
Source: https://en.wikipedia.org/wiki/Geothermal_energy#Types
There is a net energy decay rate of 14.2 TW.
Geothermal Passive Energy Extraction from Surface Absorption
‘The top layer of the (Earths) surface to a depth of 10 meters (33 ft) is heated by solar energy during the summer, and releases that energy and cools during the winter.’
Source: https://en.wikipedia.org/wiki/Geothermal_energy#Types
This allows heat to be extracted from the ground; by heat pumps, heat pumps and coils and artificial solar energy absorbers; and used to heat buildings.
Incoming shortwave solar energy = 341.3 w/ m²
Absorbed in atmosphere = 78 w/ m²
Absorbed by surface = 161 w/ m²
= 78 + 161 w/ m² = 239 w/ m²
= 70% of solar energy hitting earth is absorbed.
This amount of energy is allowed for in the calculations for the net absorbed energy.
In the UK this amounts to a 9–13 °C ground temperature which is approximately the mean annual air temperature.
Source: https://en.wikipedia.org/wiki/Geothermal_power_in_the_United_Kingdom
Source: Earth's Energy Explained UCAR Connect https://www.youtube.com/watch?v=t9B8gGQtJzo National Center for
Atmospheric Research Kevin Trenberth Nasa, Goddard Nasa Langley
Source: https://en.wikipedia.org/wiki/Solar_energy
Source: Diagram_ About half the incoming solar energy reaches the Earth's surface.
Source: https://en.wikipedia.org/wiki/Solar_energy
Source: http://climate.ncsu.edu/edu/k12/.eeb
Source: https://en.wikipedia.org/wiki/Earth%27s_energy_budget#Energy_budget
Source: https://science-edu.larc.nasa.gov/energy_budget/
Source: Diagram_showing_the_Earth's_energy_budget,_which_includes_the_greenhouse_effect_(NASA)
Source: GEOG3890: Earth's Energy Budget https://www.youtube.com/watch?v=lxxEE_phcMk
Geothermal Passive Energy Extraction from Aquifer-based locations
Certain locations in the UK have groundwater in Permo-Triassic sandstones at a depth of 1 to 3 km that; due to their depth and local geology can be tapped for geothermal energy.
Geothermal Passive Energy Extraction from Hot Rock locations.
There is no deep geothermal power generation in the UK.
Source: https://en.wikipedia.org/wiki/Geothermal_power_in_the_United_Kingdom
This type of geothermal energy extraction technology is under review.
Initial Cost.
Domestic Installations costs vary. They are approximately between £13,000 to £29,000.
Source: http://www.energysavingtrust.org.uk/renewable-energy/heat/ground-source-heat-pumps
Source:http://www.which.co.uk/reviews/ground-and-air-source-heat-pumps/article/ground-source-
heat-pumps-explained/ground-source-heat-pump-costs-and-savings
Non-Domestic. Power Plants costs vary. The electricity plant and drilling can cost about £2,000,000 to £5,000,000 per megawatt.
Source: https://en.wikipedia.org/wiki/Geothermal_energy#Economics
Environmental Effects.
‘Fluids drawn from the deep earth carry a mixture of gases, notably carbon dioxide, hydrogen sulfide, methane and ammonia. These pollutants contribute to global warming, acid rain, and noxious smells if released.’
Source: https://en.wikipedia.org/wiki/Geothermal_energy#Types
There are also reports of geothermal drilling being linked to Earthquakes.
Current Geothermal Energy Production
World energy production in 2013 was: 21.33 trillion kWh (2010 est.)
Source: CIA World Factbook 2013
‘Worldwide, 11,700 mw, (11,700,000 kw) of geothermal power is online in 2013.’
Source: https://en.wikipedia.org/wiki/Geothermal_energy
Geothermal Energy currently accounts for considerably less than 1% of the total global energy production.
Conclusions
Therefore whilst geothermal energy has a long term potential to produce energy for humans it tends to be limited in use currently due to its geological location issues, high initial cost, environmental destruction and pollution potential.
Ian K Whittaker
Websites:
https://sites.google.com/site/architecturearticles
Email: iankwhittaker@gmail.com
07/07/2017
14/10/2020
750 words over 3 pages
Additional references.
Towards an Architecture without manufacturing web site.
Source: https://sites.google.com/site/architecturearticles/home
Source: https://sites.google.com/site/architecturearticles/home/article-027---human manufacturing related to global warming
Source: https://sites.google.com/site/architecturearticles/home/article-028---the cost of solar energy
Source: https://sites.google.com/site/architecturearticles/home/article-031---the problem with wind energy
Source: https://sites.google.com/site/architecturearticles/home/article-047--- The Potential Energy of the Earth
Source: https://sites.google.com/site/architecturearticles/home/article-049--- The Role of Human Beings in relation to the Bio-Sphere of the Earth
Source: https://sites.google.com/site/architecturearticles/home/article-051--- Human Passive Energy Systems – Breathing
Source: https://sites.google.com/site/architecturearticles/home/article-052--- Human Passive Energy Systems – Temperature Control
Source: https://sites.google.com/site/architecturearticles/home/article-053--- Human Passive Energy Systems – Light
Source: https://sites.google.com/site/architecturearticles/home/article-054--- Human Passive Energy Systems – Oxidation
Source: https://sites.google.com/site/architecturearticles/home/article-056--- Human Passive Energy Systems Photosynthesis to Leaf Fall
Source: https://sites.google.com/site/architecturearticles/home/article-121---human-potential-energy-gain-and-energy-output
Source: https://sites.google.com/site/architecturearticles/home/article-133---the-inefficient-sun