The Realities of Solutions to the Energy Question. Are Renewable and Sustainable Options Practical?
Dr. Mike Clarke, CPEng, FIEAust, MAusIMM, RPEQ
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The energy question that is considered in this paper is:
What will be the sources of energy for society and industry in the coming decades, and will renewable and sustainable sources be practical options for supplying the required energy?
A review of the terminology of renewable and sustainable energy sources is first presented. Following that review is a discussion of fossil and nuclear energy as sustainable energy resources in the light of presently recoverable resources and resources yet to be developed. The agreement by Australia to the 2% reduction in Greenhouse gas emissions, as stipulated in the Kyoto protocols, is discussed in terms of present and projected usage of renewable and sustainable energy resources. The ability of Australia to meet that agreed goal, and move beyond the 2% target to a significant usage of renewable and sustainable energy sources is referred to, along with a discussion of issues of Generational Equity* as it applies to energy provision.
Lastly the question of why Australia should meet the requirements of those protocols or move past them is questioned for reasons other than legal and political niceties.
Keywords: Energy, sustainable, renewable, fossil, nuclear
The energy question that is considered in this paper is:
What will be sources of energy for society and industry in the coming decades, and will renewable and sustainable sources be practical options for supplying the required energy?
Firstly some definitions:
From the NSW Sustainable Energy Development Authority (SEDA) web site , the following has been gleaned:
Renewable Energy: Energy which is naturally occurring and which is theoretically inexhaustible, such as energy from the sun or the wind, and which by definition excludes energy derived from fossil fuels or nuclear fuels. (Source: The Macquarie Concise Dictionary), and
Sustainable Energy: Renewable plus co-generated energy. An amorphous concept also supplied by SEDA. But is such a concept reasonable?
The better view of sustainable energy may be a combination of: renewable energy, recovered energy (co-generation), energy sourced from waste produced in fossil fuel mining and, energy derived from resources for which there is no reasonable middle term (foreseeable with accuracy) depletion date. The last inclusion will be a controversial inclusion to some people.
Sustainable energy would thus include an extended resource inventory of fossil fuels and nuclear energy, or in other words it is an energy resource that can be extended (sustained) by improved technology.
Figures 1 & 2 Views of Sustainable/Renewable Energy
2.0 FOSSIL FUEL AS A SUSTAINABLE ENERGY SOURCE.
Traditionally fossil fuel has included coal (black and brown), oil and more recently natural gas. In 2000, oil had a Reserves to Production (R/P) ratio of 40 (years), natural gas 61 (years) and coal 490 (years). Given the continuing discovery of oil and gas reserves and the size of the coal reserve, these ratios are not expected to dip significantly for a considerable time. Fossil fuel can also include oil-shale, carbonaceous shale and natural gas hydrates, as well as oil that is recovered by secondary and tertiary systems.
Given that only a small percentage of the contained energy values (say 4 - 8%) are present in traditional and readily recoverable reserves, then the prospect for a continuation of the fossil fuel age for the foreseeable future looks to be excellent, if non-traditional fossil energy resources are included. (eg. Oil shale is not usually counted in energy reserves, but is conservatively estimated to have a recoverable oil reserve of two and a half times the present liquid oil reserve ). Coal that is now sub-economic is more abundant than presently economically recoverable reserves.
3.0 NUCLEAR ENERGY AS A SUSTAINABLE ENERGY SOURCE.
Again traditionally nuclear fuel has included fissionable uranium, combined with non-fissionable uranium and bred plutonium. One estimate has indicated that the useful resource of nuclear fuel (based on U235 with some allowance for fissile plutonium) is around 50 years. Fast fission (breeder) reactors can extend that period by sixty times by burning most of the U238. Further a doubling of the uranium price will create about a tenfold increase in measured resources. Thus at the present rate of nuclear fuel burn-up, the reserves could approach a thousand years with current technologies.
But how about other nuclear fuels and advanced reactor systems that are now engineering realities or possibilities? Nuclear fuel can also include fissionable uranium converted from thorium, non-fissionable thorium and depleted uranium. If these 'other' nuclear fuels are included in the inventory, then the resource life is a minimum of many hundreds of years, if not thousands of years, for all scenarios of projected usage. (No account is taken of the promise of controlled nuclear fusion, for it will remain a dream in all probability.)
The question is now which of these sustainable energy resources should we concentrate upon. The answer will in part be dependent as to what credibility an individual or organisation gives to Global Warming and the Greenhouse Effect. If great credence is given to Greenhouse, then Nuclear Energy should be the choice of sustainable energy; if less credence is given to Greenhouse, a broader view should be taken of sourcing fossil energy.
4.0 ENERGY UTILISATION
How to utilise these sustainable fuels is the question that must be addressed, so that their sustainability becomes a reality. The answer will be in use of technology to access those energy resources and gain the maximum conversion efficiencies, and in the application of Demand Side Management to stabilise demand (and possibly even to reduce demand).
Some practical examples.
1. The insitu gasification of coal and volatiles in associated strata .
The use of traditional mining methods in coal extraction, leads to the sterilisation of much of the resource. The sterilisation is caused by the disruption of strata that prevents further economic mining/extraction. Further, in a coal sequence the gradual progression from mineable coal to sub-economic coal to carbonaceous shale is often evident, with the majority of the 'thermal' value of the sequence being held in 'non-economic' material.
In considering the gasification of a coal sequence, parts of the central Queensland coalfields would be (are being) considered as ideal candidates. Coal that is too gassy, deep or with awkward geological structures can be 'tapped' using in-situ gasification techniques.
The opportunity exists for the utilisation of all the recognised and non-recognised coal (carbonaceous shale) plies by the application of Insitu Gasification Techniques (IGT). The ability of IGT to efficiently access the fuel values is still being proven, but work on the IGT looks very promising.
IGT has the potential of providing 'BIG' energy, from a resource that is now often wasted.
2. Energy Co-production Schemes.
The Hunter Valley coal situation is used as an example. Such seams as the Vaux, Ravensworth and Bayswater can be found in descending order. Included in the series are plies of carbonaceous shale and minor coal.
The coal that is mined from the sequence is, the Vaux (when thick enough), part of the Ravensworth (for steaming and coking usage) and the Bayswater (where a demand exists for low quality steaming coal). In most extraction scenarios, probably less than 20% of the energy value is recovered from the total contained energy in the strata that is being mined.
In the example above, where it is desired to mine the coal sequence, for specific seams and plies, co-production energy should be considered. Here coal and carbonaceous shale that is not wanted for export or traditional power generation, will be directed to gasification plants. The product of these gasification plants, will be synthesis gas (CO and H2), that can be either used for power generation or for liquid fuels synthesis.
4.1 Energy Conservation and Pricing
The use of Sustainable Resources of nuclear and fossil fuel will come at a price. The price will be reflected in higher energy bills. These bills will reflect both the increased cost of energy sourcing and conversion, and the cost of environmental management associated with energy.
The incentive will be strong to maximise energy conservation, and manage demand. A fifty percent increase in the price of energy delivered to point of use, would see the cost of many manufactures increase by ten to twenty percent. The increased cost of domestic energy as supplied by the grid (electrical or gas) may make some household renewable energy schemes economically viable, on a real cost basis.
5.0 FUTURE OPPORTUNITIES FOR SUSTAINABLE ENERGY RESOURCES
5.1 The use of depleted uranium and high level wastes in Accelerator Driven Systems.
By bombarding depleted uranium, natural thorium and high level wastes with protons created in an accelerator, useful energy can be obtained. The advantages of such a system is that the system can be turned-off by stopping the externally produced proton beam, and that the waste produced in the ADS and conventional nuclear systems will be largely 'burnt-up'.
5.2 The insitu gasification of residual oil in depleted oil-fields.
In traditional oil recovery methods, the percentage of oil recovery in primary extraction can range from 5 - 30% depending on the geological conditions. Secondary and tertiary recovery techniques can recover another 10 to 15%. Insitu gasification (quaternary recovery) may see the total recovery in some fields top 70%. This energy reserve is huge, is convenient to many areas of human activity and is waiting to be tapped.
5.3 The recovery of methane hydrates from the deep ocean. Methane hydrates, a physio-chemical combination of water and methane exist in abundance in the oceanic abysses. A challenge for technology will be mining these hydrates, but the rewards will be great.
6.0 THE GREENHOUSE SCENARIO, AND THE APPLICATION OF THE PRECAUTIONARY PRINCIPLE OUTSIDE THE STRICT ENVIRONMENTAL CONTEXT.
The continued and probable increased use of fossil fuels into the distant future will certainly test the Greenhouse Theory. Do we have conclusive or even strong evidence for the Greenhouse Effect: NO! What we do have is the application of the Precautionary Principle.
The Precautionary Principle is defined by Sydney Water  as: "To reduce the chance of serious or long-term environmental problems even if we are not sure that these problems will occur ". Does this mean, 'If unsure, do nothing'?
Since the Greenhouse effect is not proven, and in fact there is some indication that we are moving towards an ice-age, great caution in our response to calls for changes in our energy usage should be exercised. Given such doubts, to move beyond the 2% Kyoto target is irresponsible and under the Precautionary Principle, as applied to our greater existence, should not be attempted.
Note: Recent reports [9, 10] have indicated that the Antarctic ice-sheet is thickening, and that temperatures are falling in parts of that continent. Further, models that match greenhouse gas production and warming are also inconclusive[11,12], and evidence is now suggesting that Global warming or cooling is strongly effected by Global Water Cycle.
Further if we apply the same Principle to the triple bottom line; health, the environment and our economic well-being. The choice of the DO NOTHING OPTION because of an excessive view of just one aspect of the triple bottom line, ie the environment, could easily lead to great human harm .
The move towards a renewable energy economy could be the source of such harm. The question is should we risk damaging our economic base for what may be no more than Piltdown Man Science or providing a soapbox for those preaching a new version of the Phlogiston Theory.
By excessively increasing the cost (price) of energy for the sake of an uncertain phenomena (The Greenhouse Effect), serious dislocations in human activities will occur. These dislocations will lead to health and economic problems. The better application of the Precautionary Principle at this stage would be to ignore the Greenhouse Effect, till some less contradictory evidence is available (if ever).
6.1 The way to Human Generational Equity in energy resource use.
The use of a significant portion of a resource by a generation, or by a cluster of generations, is frowned upon as an act of Generational Greed. Part of the move towards demand-side energy management and the reduction in the use of fossil fuels have been because of the fear that these generations are using more than their fair share of the oil, gas and coal resource. These fears have been based on very pessimistic views of the size of the total fossil fuel resource.
If a wider view is taken of the total fossil fuel resource, and the technologies that are available to convert one form of fossil fuel into another, then those fears are really nonsense. To ensure Generational Equity in fossil fuels the following should be put in place:
· On-going support for developing technology for the conversion of solid fossil fuels into gaseous and liquid fuels,
· The development of technology to significantly increase the percentage recovery of fossil fuel extraction,
· The emplacement of sensible regulation to ensure that reserves are used in an orderly way and are not sterilised by poor recovery technology, management practices and corporate greed and
· The development of energy supply and usage scenarios, that will see the development of 'best-mix' supply and usage practice. The 'best-mix' supply and usage practice will include continued development of demand side management practice, and the appropriate mixing of energy from renewable and sustainable resources.
Regarding Generational Equity, it should also be remembered that the past and present generations are now doing the R&D that will provide for future energy provision from new and innovative sources. The past and present generations have also provided infrastructure that in many cases will be still viable in four or more generations time.
The emplacement of regulation for managing fossil fuel energy reserves will be vital. Coal (and coal seam methane) is the energy resource most liable to unsustainable exploitation. Honey-potting (high-grading) will need to be curtailed. The extraction of coal (and associated methane) will need to be policed, so as to avoid the unnecessary sterilisation of significant parts of the resource.
As part of this regulation/management package, the provision of the means of utilising coal that is low of quality, will need to be made at pit-head power stations and other heat generation facilities.
6.2 The structure of this regulatory/policing body
The Joint Coal Board (NSW - Commonwealth) , as originally established under the Coal Industry Act (1946) provided a good example of how regulation can assist in better utilising a resource. The Board had the role of advising coal producers of what coal should be taken and in what manner and sequence. (The Coal Industry Cried: WHAT, INTERFERENCE IN COMMERCE!)
Interference Yes: The Board had its own mining and geological experts who were able to determine fair extraction scenarios for the NSW coal resource. Those experts in co-operation with colleagues from industry helped establish and maintain an orderly and wise extraction regime for coal mined in that state. We need such public/government participation in the management of all fossil fuel resources, since they belong to all of us.
The role of industry is important. In the case of oil, industry may require less governance, since market forces may be best at determining when secondary, tertiary and quaternary methods of recovery are appropriate. However oil may need government regulation/ incentive for developing new fields, and for maintaining plant on fields that are sub-economic, during periods of low oil price.
An example of where such government/industry co-operation should be regulated, would be in the in-situ gasification of coal and/or carbonaceous shale. Here the resource could be categorised as being suitable for, traditional extraction only, traditional extraction followed by gasification, or straight gasification
Energy extraction comes at some environmental cost. Therefore the regulators and policing bodies that are involved in resource management, should be involved in environmental management. The old Joint Coal Board had such powers.
7.0 THE ROLE OF RENEWABLE ENERGY
There is a role for renewable energy. It can be used as a topping supply or augmenting supply, and in some cases as a primary supply, eg in remote regions. Some good news developments on the renewable energy front are the following:
1. Low Temperature Geothermal Energy (LTGE) - Appendix 1,
2. Hot-Rock Geothermal - Appendix 2,
3. Wind generation and
4. The slow but steady improvement in Photovoltaic and the complementary battery storage systems.
Remote areas with small to moderate power demand that are well away from energy grids, and are lucky enough to be close to:
· a hot-rock mass,
· a hot artesian water source,
· be in a wind-blown region or
· receive strong sunlight for a significant part of the year, will be candidates for renewable energy as a primary energy source. In these cases the provision of traditional fossil fuel based energy may well be a great waste of infrastructure, and be an un-reliable energy source.
Due to the intermittent nature of many forms of renewable energy, energy storage systems will need to be created for evening out supply. For large amounts of energy, large amounts of storage will be required. The only system that we presently have available is pumped storage. This form of storage suffers from many of the disadvantages of hydro and is capital intensive.
Where renewable energy (say wind or tidal) and be matched with an existing hydro project, then big and competitive renewable energy is possible.
Renewable energy is not a feasible alternative for supplying human energy needs for the foreseeable future. Meeting the 2% Kyoto target for renewable energy can and will be achieved; but will it have been worth the bother? Meeting a 10% target is surely not worth the bother.
Sustainable energy, with all its vague definitions is a very feasible option. Tapping energy sources such as the in-situ gasification of coal (or carbonaceous shale) or the distillation of oil-shale are both feasible and desirable.
By extending the fossil fuel resource through innovative recovery techniques of presently sub-economic resources, our fossil fuel reserves can be stretched into the distant future. Likewise, nuclear energy can provide base load electricity also for an indeterminate period. The balance between nuclear and fossil fuel will be determined by economics, the development of alternate transport fuels and the ownership of energy resources.
The price of energy is going to increase. The increased prices will reflect the cost of 'Primary energy' sourcing, and the use of more complex energy conversion and supply systems. Those systems will incorporate additional environmental safeguards as well as increased levels of power supply guarantee. The prices for sustainable energy will be significant, but affordable. For 'pure' renewable energy the prices will often be very high and unacceptable.
The management of energy resources needs to be vested in groups or bodies that are accountable to the public. The trend towards privatisation has been strong in the later quarter of the twentieth century. Due to failures or doubts in energy supply in such places as California, Victoria and New South Wales Wales, privatisation and/or deregulation are being critically re-examined.
If the Greenhouse Effect is 'proven' then the sustainable energy option will be increasingly limited to nuclear power. The challenge will then be to create transport fuels from nuclear energy that are economical and safe. Perhaps then the Vanadium-Redox Battery  will then become a practical reality.
Renewable Energy is practical in some situations, so long as fairly strict parameters are placed on those situations. Sustainable energy as defined in this paper is practical for the future as far as humans can reasonably foresee and thus can provide Generational Equity in terms of energy availability.
1. Projections of Price of Renewable Energy Certificates
to Meet the 2% Renewable Energy Target. Report to the Australian Greenhouse Office, November 1999.
2. Qld. EPA - Sustainable Web Site: www.env.qld.gov.au/sustainable_energy/
3. A statistical view of world energy, June 2001. BP www.bp.com/centres/energy/
4. Oil Shale. Dyni J. R. Oil Shale Committee Chairman U.S. Geological Survey
5. Nuclear Electricity, 6th edition. Uranium Information Centre. Australia. 2000
6. Thorium as a nuclear fuel resource. Clarke M. C. Chemical Engineering in Australia, Vol. 12, No. 3, 1987
7. Underground Coal Gasification: A Clean Coal Technology Ready for Development. Walker L.
The Australian Coal Review October 1999
8. Towards Sustainability 2001. A report to Sydney Water. www.sydneywater.com.au/html/tsr/understanding
9. "Positive mass balance of the Ross Ice Streams .."
Joughin I. & Tulaczyk S. Science, Vol 295, Issue 5554, P 476-480, Jan 2002
10. "Antarctic climate cooling and terrestrial ecosystem response". Doran R. et al. Nature 415, 517 - 520 (Jan. 13 2002)
11. Accurate "Thermometers" in Space, Arnold J. E. NASA
12. Globally-Averaged Atmospheric Temperatures Spencer R. NASA www.ghcc.msfc.nasa.gov/MSU/hl_temp_glbave.html
13. Understanding the Global Water Cycle. Arnold J.E.
14. Coal Industry Act (NSW- Commonwealth) 1946
15. "Recent Progress with the Vanadium Redox Battery", Skyllas-Kazacos, M. UNSW 2000
* Generational Equity. From Sydney Water: 'Intergenerational and Intragenerational Equity. To reduce the effects of activities on the environment that the community, now and in the future, relies on to meet its needs and expectations'.
Appendix 1. Low Temperature Geothermal Energy (LTGE)
BIRDSVILLE GEOTHERMAL POWER STATION (added October 2000)
'The Birdsville 150kW electric Geothermal Power Station is the first commercial geothermal-electric power station in Australia.'
'In November 1999, QSEIF provided funding to Enreco Pty Ltd to upgrade the Birdsville Geothermal Power Station. The upgrade was completed in August 2000 and the plant is now capable of producing 120kW of renewable power for the Birdsville electricity supply grid.' It uses primary energy contained in artesian water.
Appendix 2. Hot Dry Rock Energy (HDRE)
Rock Energy for Australia's Future
Australian National University (HDR) Group http://hotrock.anu.edu.au/
'The Australian National University's Department of Geology and Pacific Power have jointly been offered a grant of $790,000 to complete the first element of the exploration of the Hot Dry Rock (HDR) resource in the Hunter Valley geothermal anomaly. By the end of 2000, the project team will determine the a real extent, temperatures, rock properties and stress conditions at a depth of around 2km in the core of this anomaly.'
Hot Dry Rock geothermal energy is a vast, environmentally benign, economically appealing energy source. HDR is a conceptually simple technology, that looks to the tapping of heat contained in granite and similar rock masses. That heat being derived from the decay of uranium and thorium contained in the rock.
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Author: Michael C Clarke
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