Carbon Pollution Reduction
It is evident that global warming is the result of the increasing emission of greenhouse gases, principally carbon dioxide, which results from the increasing consumption of fossil fuels by the world population. We can combat the problem by adopting three basic measures, namely (1) reduce energy demand by improving our efficiency in the consumption of energy (2) increase the proportion of energy which is produced by non-polluting methods and (3) remove greenhouse gases from the atmosphere.
(While methane gas is also a significant cause of global warming, it is not the result of burning fossil fuels. Current research aims to reduce the amount of the principal source of atmospheric methane, i.e. the digestion of food by ruminants.)
1. Reducing Energy Demand
(a) A significant proportion (around 30%) of our national energy production is consumed in houses, schools, shops and commercial buildings. This load could be substantially reduced by following the example of the U.K. Government, that is by expanding our existing programme of improving the insulation of walls and roofs. The saving in energy for heating and cooling could assist significantly in meeting targets for reduced greenhouse gas emission. The undesirable outcomes of the "Pink Batts" scheme were entirely the result of by-passing the normal processes of planning approval, workplace safety regulation, and inspection of completed work.
Perhaps we should tax excessive use of non-renewable energy by householders. Of course, any reduction in energy consumption by individual consumers will result in individual cost savings. These cost savings will encourage and justify improved energy efficiency.
(b) Ban the use of mains-powered electrically- or gas-powered hot water storage systems. Instead, install roof-mounted solar water heaters, or photovoltaic solar panels, and thermally-insulated storage tanks. Where it is necessary to distribute hot water in a building, use thermally insulated plastic piping, with low specific heat, rather than copper piping.
For most purposes, the water temperature in a well-designed solar water heating system is quite adequate. If hotter water is required, for example in a kitchen, then use a single-point gas- or electrically-powered instantaneous water heater, to boost the temperature.
(c) Fit water-cooled condensers to refrigerators, freezers and air conditioners, returning the waste heat to the hot water system. This will prevent the release of heat into the building, reduce the amount of energy consumed for water heating, and increase the efficiency of refrigerative appliances.
Consider the installation of passive airconditioners, utilising phase-change thermal accumulators.
(d) Replace all incandescent lighting with more efficient LED light sources. These use considerably less energy than incandescent lights, and have extended life of the order of 50,000 hours. They do not pose the toxic waste disposal problems of mercury-vapour fluorescent lights, or the carcinogenic potential of the PCB oil-filled power factor correction capacitors which are installed in most fluorescent light fittings.
(e) A large proportion of our greenhouse gas emissions result from the use of motor transport. Get really serious about producing more efficient vehicles. Use hybrid technology, diesel or lpg fuel in the short term, and electric power in the forseeable future. The currently achievable range of a small electric passenger vehicle is of the order of 120 - 200 kms, which is adequate for almost all commuter vehicles. Hybrid technology should be available as an upgrade option, required only by those users who need to travel longer distances.
Consider the upgrading of parking meters, to include electrical power outlets with credit-card readers, so that electric vehicles may be recharged while the users travel on by train, to work or to shop. Battery recharging facilities would be most useful in the parking areas at transport hubs, such as as rail or bus stations, or at all-day parking stations in city business precincts.
(f) Road freight transport is approximately ten times more expensive than rail, and very hard to make emissions-free. Concentrate upon the development of our rail network and transfer as much as possible of our long-distance freight transport to containerised rail. Where practicable, electrify the rail network. Where electrification is not practicable, equip existing i.c. engine locomotives with liquid fuel, lpg or lng tanker rolling stock, possibly to be replaced in the future by hydrogen gas tankers and fuel cells.
2. Increase Non-Polluting Energy Production
Again, we're part way along the path to meeting long-term objectives.
(a) Roof-mounted solar photo-voltaic power generation is best used for local demand, such as houses, schools, shops and commercial buildings. There is no energy loss in the distribution network. However, power is generated only during daylight hours.
While there are apparent benefits in grid-connection of solar power systems, there is usually a loss of function during emergencies. It is probably better to make the system independent of grid connection, by storing energy for night-time or periods of no-sun in 10 year life, deep cycle, lead acid batteries.
The additional cost of batteries is partially offset by a saving in the complexity and cost of the electrical control system. An advantage of installing a battery-backed system is that no UPS equipment is necessary for emergency lighting, essential medical equipment, telecommunications equipment, or computer equipment. During cloudy periods, when solar power may be reduced, any necessary battery charging may be provided by mains power, at night-time, at off-peak price rates.
I have presented a more detailed paper upon competitive domestic solar power systems in "Off the Grid"
(b) Large solar thermal or solar photovoltaic power generators are non-polluting and can contribute substantially to daytime generating capacity, when it is most needed. At least one such power station is under construction in Australia. Several are in service overseas, e.g. in Spain.
However, unless they incorporate mechanical solar tracking systems, they are inefficient and have an unacceptably-large "footprint". The need to incorporate tracking mechanisms decreases system reliability and increases maintenance costs. They may prove to be uneconomic for many projects.
(c) Wind farms have proved to be worthwhile in Australia. South Australia particularly now generates a significant proportion of the state's energy consumption by wind power.
Development by Isis Innovation at Oxford University, UK, has produced more efficient, gearless wind turbines which operate effectively and more quietly at lower wind speeds.
If individual turbines are interconnected by a local DC power grid, then there will be no technical synchronising problems in connecting together the output of a number of machines, and average generated power could be maximised. Unlike solar power, which is available only during daylight hours, wind energy is available at any time. If a sufficient number of wind farms at diverse locations were connected to the national power distribution system, then wind power could contribute to base load generation.
(d) Hot rock energy sources are widely available throughout Australia, and seemed to offer great promise as an enduring heat source for power generation. A trial facility now supplies the modest power requirements of the small settlement of Innamincka. Several other sites have been selected to develop geothermal power in Australia and it was estimated that around 8% of the nation's power could be provided from this source, with zero carbon emissions, by 2030.
The machinery and technology which are required to drill the deep wells has proved to be very expensive. Since as many as 7 bores are required for each site, the project costs may be uneconomical. The steam temperature, as low as 250C, does not support efficient or conventional large scale power generation, so that smaller Rankine-cycle machines are necessary. Several overseas "hot rocks" projects have been abandoned because of fear of seismic disturbance. Environmentalists claim that there there may be a danger of contamination of underground acquifers by aromatic hydrocarbons.
(e) Several methods of wave power generation have been under development and seemed likely to become viable. However, it has proved to be difficult to design the mechanical equipment which is needed to harness wave power.
This method of power generation is non-polluting and, by absorbing wave energy, may even assist in reducing coastal erosion.
(f) Since introduction of the first commercial nuclear power station in 1957, the industry has invested heavily in research, to improve the technology. Now, with the development of 4th Generation reactors, the operational safety is far superior to that of conventional fossil-fuelled power stations and the output of long-life toxic waste has been very substantially reduced. The environmental impact of a nuclear power station is considerably less than that of a comparable fossil-fuelled plant.
Radioactive material from earlier-design reactors or from outdated nuclear weapons may be utilised as fuel and rendered harmless. Reactors may be designed and operated to produce no weapons-grade material. The level of background radiation from a modern nuclear power station is less than that produced by a fossil-fuelled power station of similar capacity.
For more information, see the page Nuclear Power on this web-site.
As our fossil-fuelled power stations reach end-of-life, replace them by non-polluting nuclear power generating installations. Meanwhile, convert coal-burning power stations to use diesel oil, natural gas, or coal seam gas. These fuels are claimed to produce a lesser amount of greenhouse gas per MWhr than coal. We should not build any more fossil-fuelled power stations.
3. Emissions Reduction
(a) The Emissions Trading Scheme PRETENDS to achieve carbon emissions reduction but actually, like the story of the King's New Clothes, wouldn't fool any kid fresh out of kindergarten. While it may be important to introduce legislation to comply with international protocols, it will not result in a single tonne of reduced emissions. Of course, it may result in reduced energy consumption, simply by crippling our economy.
(b) If viable, develop the underground storage of carbon dioxide. At least two pilot schemes were commissioned in 2009, but nobody has yet achieved commercial success. Nobody has collected Richard Branson's prize for a successful full-scale demonstration. And yet, the construction of a new brown-coal fuelled power station at Yallourn was approved in anticipation of successful underground storage of CO2. You can be sure that nobody included the cost of CO2 sequestration when they did a cost/benefit analysis for the project.
(c) A potentially more viable method of CO2 sequestration for power stations is the recent development of more effective algal digesters of carbon dioxide. However, while this is a promising method of using solar energy to produce hydrocarbons from CO2, the product is invariably used as a fuel source and the CO2 is eventually released back into the atmosphere. As our need for fossil fuels diminishes, hydrocarbons should be converted into petrochemicals with more permanent uses, so that the carbon will be locked-up.
(d) Encourage the production of Bio-Char, using agricultural trash to produce methane gas and charcoal. The charcoal is used as a mulch. It is permanently stored, improves soil structure and fertility, and improves water utilisation and retention. The methane gas, if used as a fuel, produces CO2 but in reduced amount.
(e) Encourage forestry projects. Where possible, use durable plantation products such as plywood, flakeboard, particleboard, MDF, OSB and wooden poles in construction projects in lieu of energy-consuming products, such as brick, steel and concrete. Even the necessary annual disposal of banana plants can produce valuable veneer and plywood. The tropical rubber tree has an economic life of 25 years, after which it is a useful source of timber for the manufacture of furniture.
Discourage the logging of old-growth forests for low-value purposes, such as paper pulp production, which can instead utilise 100% plantation timbers. The old-growth forests should be preserved for their environmental benefits, erosion control and carbon dioxide sequestration. The timber which is milled from old-growth forests is more valuable for high-grade joinery applications and, except for sawmill waste, should not be converted into wood chips.
(f) Discourage the use of food crops to produce "bio-fuels". With a growing world population, there is a very real danger of food shortages. Bio-fuels only sequester CO2 until they are burned.
(g) Coal is a valuable feed-stock for our chemical industries. Use our coal resources economically, minimising CO2 release, for the production of petrochemicals and carbon fibre for durable applications. It should be remembered that, if coal is used to produce fuel such as gas, diesel oil, or petroleum, the carbon will be released into the atmosphere as CO2 and will contribute to global warming.