top: howstuffworks.com / © iStockphoto.com/caracterdesignTo those interested in the world’s future power supply
Extracts from the media following the disaster in Japan:
- "With one massive lurch, planet Earth has put an end to the nuclear power "renaissance" that was gaining momentum around the world as a safe, clean energy source."
- "But in mere moments, Mother Nature showed the world how vulnerable nuclear power plants really are to the whims of the unexpected."
- "Once the Japanese think things over, I expect they will make the right decision, namely to shut down all 55 of their current reactors and cancel the 11 new reactors they have planned. And other countries will likely come to the same conclusion. The natural and human risks make the chance of a repeated nuclear reactor catastrophe extremely high . . . If the world then follows Japan's example, then energy costs will certainly rise, but so will the incentive to develop better alternatives."
- "The disaster has prompted a rethink of nuclear power around the world, just as the technology was starting to regain momentum as a tool to fight global warming."
- "Switzerland freezes plans to build more nuclear plants, Germany raises questions about its nuclear future, and opposition to atomic reactor construction mounts from Turkey to South Africa."
- "Will explosions and other worries at disaster-stricken Japanese nuclear plants halt what has come to be known as the nuclear renaissance?"
- "Fears about nuclear safety that took a generation to overcome after the accidents at Chernobyl and Three-Mile Island are resurfacing around the globe. They are casting new doubt on a controversial energy source that has seen resurgence in recent years amid worries about volatile oil prices and global warming."
As I see it.....
by L. Berney
by L. Berney
Nuclear Power: After Japan, what now?
The nuclear catastrophe at Fukushima in Japan
The nuclear catastrophe at Fukushima in JapanThere are 439 Nuclear Plants operating world-wide providing 6.3% of the world's energy.
Nuclear power is controversial; opponents believe that nuclear power poses serious threats to people and the environment -- an “accident waiting to happen”. Indeed, several serious nuclear and radiation accidents have occurred: Windscale, UK (1957); Chelyabinsk, Soviet Union (1957); Three Mile Island, USA (1979; Chernobyl, Ukraine(1986); and currently Fukushima, Japan (2011).
The current nuclear catastrophe in Japan threatens to contaminate an entire nation with radiation. Other countries are heeding the wake-up call from the worse nuclear disaster since Chernobyl. Germany has decided to temporarily shut down seven older nuclear plants while it studies a more rapid conversion to renewable energy. China is suspending new nuclear power plant approvals and expediting inspections at existing plants. Spain has ordered a review of its nation's nuclear plants. Israel is now seriously rethinking nuclear power. New Zealand has banned nuclear. Many other countries are “rethinking” their nuclear policies.
In recent years, Nuclear Power Plants have been seen by many governments as one of the solutions to their country’s future source of power. Now, in the light of the disaster in Japan, world public opinion will almost certainly prohibit the construction of new Nuclear Power Plants. In that event, what other possible solution to the World’s power problem is available?
This paper examines that problem and the possible solution.
First, a few facts.
HOW MUCH POWER DO WE USE?
A colossal amount! The power we use from all sources is equivalent to the power contained in 130,000,000 tons of oil a year!
About 2/3 of the power we use is in the form of electricity for lighting, heating, communications, and to drive many millions of electric motors to work just about everything. 1/3 of the power we use is in the form of portable fuel (diesel, gasoline, natural gas) for road vehicles, aircraft and shipping.
HOW MUCH POWER WILL WE NEED OVER THE NEXT DECADES?
Certainly much more than we consume now. Here are some of the reasons:
* The population of the world is set to increase from the 6.8 Billion that it is now, to 9.5 Billion by 2050.
* Of the world’s present population, about one third, over 2 Billion, live below the poverty line. We need to lift those 2 Billion people out of poverty. This will require large volumes of power.
* If, as scientists predict, in the coming decades we will experience climate change and sea-level rise, many millions of people will have to be re-located. This will require also require large amounts of additional power.
* The world is running out of both drinking and irrigation water. The shortage can be met by De-Salination Plants, but these consume large amounts of electricity
Over the last 50 years, the world’s power consumption has been increasing by around 2% each year. If it continues to increase at that rate, in 50 years’ time we will need nearly three times as much power as we use now.
WHERE DOES OUR POWER COME FROM?
Currently, 87% of the world’s power consumption is obtained from the three fossil fuels, coal, oil and natural gas. Nuclear contributes 6%, and another 6% comes from Hydroelectric Plants (dams). Only about 1% is generated from the ‘Renewables’, Solar, Wind, Biofuel and Geothermal (natural hot water).
Other possible sources not so far developed are Wave-power, Tidal Flow, and Geothermal (using the Earth’s subterranean heat).
THE PROBLEM WITH FOSSIL FUELS
As stated above, by far the largest source of our power comes from burning coal, oil and natural gas, the Fossil Fuels. Looking forward, the world is presented with a major problem:
* The reserves of coal, oil and natural gas are finite, not replaceable.
* We are using up these reserves at an ever increasing rate – thus the remaining reserves are being depleted at an ever increasing rate.
* Accessing those remaining reserves is becoming progressively more difficult.
* Because of the increasing difficulty, the price of power will progressively increase.
* Burning fossil fuels generates CO2 which many scientists believe is causing climate change and sea-level rise.
* Every country needs power, yet the major sources of that power, the three fossil fuels, are only found in some of the world’s countries. The increasing scarcity will inevitably cause international friction and even wars between the ‘have’ and ‘have not’ countries.
Over the coming decades we must phase out the generation of power by fossil fuels and replace it by phasing in an alternative source of power.
HOW COULD FOSSIL FUELS BE REPLACED?
Remembering that fossil fuels supply 87% of the power we consume, there is no possibility that this 87% can be replaced by solar, wind, biofuel, hydroelectric, tidal-flow or wave-power.
Nuclear Power could, in theory, replace fossil fuels. The number of plants required to replace the current consumption of fossil fuels would be up from the present 439 to a number in the order of 7,000 plants and, to keep pace with the World’s increasing needs over the coming decades, possibly up to three times that number. Nuclear plants on that scale would present vast problems in the disposal of radioactive nuclear waste and the supply of sufficient uranium.
However, logistical considerations apart, after the disaster in Japan public opinion will almost certainly prohibit the construction of any new nuclear plants in the foreseeable future.
So, where is our power to come from? How can we replace fossil fuels? Is there a solution?
Fortunately there is: the solution is Geothermal Energy.
WHAT IS GEOTHERMAL ENERGY?
Geothermal Energy is “Energy in the form of Heat emanating from within the Earth”.
At certain places on the Earth, subterranean reservoirs of hot water exist naturally. Natural hot springs were used in ancient times but it was not until the beginning of the 20th Century in Italy that natural hot water was used to generate electricity. Today Geothermal Power Plants using natural hot water exist in Iceland, USA, China, Sweden, New Zealand, Indonesia, and in several other countries.
The principle is simple. A well is drilled from the surface down to a natural reservoir of hot water. The water emerges as steam which is used to power a traditional steam turbine electricity generating plant. The spent steam is condensed back to water which is recycled back to the reservoir by means of another well – a closed loop system. The heat emanating from the centre of the earth reheats the reservoir.
A Geothermal Power Plant in Iceland (The white emission is surplus steam)Unfortunately, the planet holds relatively few such natural reservoirs of hot water. A few years ago, in Europe and in Australia, work was commenced on creating subterranean hot water reservoirs; the process is named an Enhanced Geothermal System (EGS). These pilot plants have proved the viability of the system.
The temperature of the Earth’s centre is some 6,000ºC. It is a fact that, just anywhere on the Earth’s surface, if you drill down, the deeper you go, the hotter it gets. For an EGS to operate, the temperature of the water being raised to the surface must be 200+ºC. Inevitably, the temperature of the subterranean rock will at some depth reach that critical temperature of 200+ºC. The actual depth varies from place to place but, on average, the critical 200+ºC temperature is reached at 3 to 5 miles (5 to 8 Km) below the Earth’s surface.
At an EGS plant, water is pumped at very high pressure down a well (the Injection Well) which fractures the rock surrounding the end of the bore hole – this process, “Hydraulic Fracturing”, has for many years been in general use in the oil and gas industry. The injected water percolates through the fractured rock and forms an artificial or engineered underground reservoir. A second well (a Production Well) is bored some distance from the Injection Well. The injected water, raised to a high temperature by its passage through the fractured hot rock, travels up the Production Well emerging at the surface as superheated steam. The steam powers the turbines of a standard Electrical Power plant. The spent steam is condensed back to water and is injected down the Injection Well to replenish the engineered reservoir. The method of drilling the wells is the same as used in the oil and gas industry.
Hot Dry Rock Power GenerationIn 2006 the Massachusetts Institute of Technology issued a report on “The Future of Geothermal Energy in the United States”. The findings include:
- We estimate the extractable portion of the geothermal resource to exceed 2,000 times the annual consumption in the United States in 2005. With technological improvements the economically extractable amount of useful energy could increase by a factor of 10 or more, thus making geothermal energy sustainable for centuries
- The advantages of EGS are many: A continuous, inexhaustible, renewable ‘base load’ power source; Security of supply -- every country generates its own power -- no imports and therefore avoidance of international conflict; Environmentally friendly -- low-rise plants with small land usage; Completely safe – no danger to surrounding population or site workers; No nuclear waste problem; 100% clean -- no CO2 or other emissions; Low electric unit cost; No storage or transport costs.
If the World were to adopt a programme of converting to Geothermal Energy, existing coal, oil, natural gas and nuclear electricity generating plants would be gradually replaced by EGS-powered generating plants. By or before 2050, the World would have discontinued the mining and use of coal, oil and gas; would be free of the harmful emissions that the burning of fossil fuels inevitably create; we would have eliminated the potential for conflict between the fossil fuel ‘have’ and ‘have not’ countries; we would have eliminated the danger of nuclear radioactive contamination; road vehicles, ships and aircraft would be emission-free, powered by electricity or electrically made hydrogen -- we would have eliminated city smog; and we would be well on the way to the elimination of poverty world-wide.
FURTHER READING ON ENHANCED GEOTHERMAL SYSTEM
L.Berney
March 2011
Note This paper includes many statements for which, in the interest of brevity, no source has been quoted. However, on request, I will supply corroboration for any and all of the statements made.
