Author: Richard Worthington - WWF South Africa
( Article Type: Sustainable Development )
Energy – the capacity to do work – is key to the success of any society or civilisation and fundamental to all life. The industrial revolution has been powered by unconstrained access to the concentrated energy of fossil fuels (coal, oil and gas), a geological store of energy taken up in organic material over many millions of years. This is a finite stock of energy, which we are using at an accelerating rate to support exponential economic growth, with accelerating and cumulative negative impacts upon our planet’s ecosystems. Dependence on traditional biomass fuel is generally considered a defining characteristic of poverty and global development objectives include extending access to modern energy services to about 1.5 billion people. However, sooner or later it will not be possible for our consumption of fossil fuels to continue to grow and many geologists believe that we are already reaching a peak in the availability of oil, i.e. that we have used up about half of the practically recoverable resources and, after a relatively short levelling off (plateau), global annual production will start to decline (see Topic ‘Peak Oil’). Others argue that technology developments, such as deep water drilling and extraction from tar sands, will enable oil consumption growth to continue for the foreseeable future.
Renewable energy resources are constantly replenished, but most are not continuously available in any one place. Solar and wind energy require extensive infrastructure to harvest (e.g. fields of heliostats or large diameter wind turbine blades) and biomass production requires a lot of land and water. Technology developments are increasing the efficiency and reducing the costs of the transformation of renewable resources into modern energy carriers, such as electricity. The cost of manufacturing photovoltaic panels, which directly convert solar radiation into electricity, has come down five-fold within a decade. There are high hopes for innovation in the production of biofuels, but also serious challenges regarding unsustainable agricultural practices and land use changes that currently are often involved. Technology developments in the extraction and use of fossil fuels can extend the amount of a resource practically available, as well as reduce the amount of pollution released, but both options invariably increase costs and involve diminishing returns on energy and materials invested. There is some speculation that some recently discovered ‘unconventional’ natural gas may be able to buck this trend (e.g. prospects of shale gas in the Karoo), but the extent of the reserves and practicality and impacts of extraction technologies ( see Topic ‘Fracking’) have yet to be established. There is also on-going research into underground gasification of coal that is too challenging to mine.
The pros and cons of nuclear power remain strongly contested, with industry proponents heralding a nuclear renaissance and a potential for technology breakthroughs, while opponents maintain that negative social and environment impacts and risks are unacceptable. The full extent of the costs of the nuclear industry and the share of costs attributable to power supply are also contested terrain. In the 21st Century the share of nuclear power in global energy supply has declined, while costs of nuclear power plants continue to increase in real terms. Unresolved issues include management of long-life toxic and radioactive waste, potential for nuclear weapons proliferation and associated security and regulatory costs. Currently China has the largest new nuclear build programme, with financial costs apparently about half of those in Europe and the USA.
Social and ecological consequences of energy supply and use, beyond the immediate benefits of the services supplied, are commonly referred to as ‘ externalities’ These ‘externalized’ costs are borne by local communities, other sectors or society as a whole but are not included and accounted for in conventional accounting and pricing of services. All energy technologies have some associated externalized costs, ranging from human health impacts of air pollution from combustion (and associated public health care costs) to the impact of wind turbines on bird or bat populations or on tourism – visual impacts often being regarded as negative, although some wind farms are also tourist destinations.
Quantifying externalised costs of energy supply and use can be considered in two categories:
1. The parameters of full cost accounting (How far upstream and downstream should a full life-cycle analysis extend?)
|2. The value attached to externalized factors (What is the value of the life of a coal miner, the integrity of a water catchment or wetland, or the time of a rural mother collecting biomass?).
Challenging questions include: How does one associate the impacts of exploration for minerals resources with the eventual extraction of resources identified as viable? To what extent does one attribute the impacts of mining to the nuclear fuel cycle when uranium is a by-product of gold mining? Should legacy issues such as acid mine drainage be valued in terms of the costs of effective remediation, on an assumption that there will be on-going pumping and treatment, or can costs of actual (unmitigated) impacts, such as pollution of agricultural land, be factored into assessments of energy development options? (These issues are considered in more detail in Energy Criteria Section below)
Energy resources and carriers Fossil fuels and biomass serve as both energy sources and carriers. Electricity and hydrogen, not readily available in nature, are just energy carriers, requiring extensive infrastructure to produce and transport, but have the advantages of being clean at the point of use and easier to move around than coal or wood. Liquid hydro-carbon fuels refined from crude oil (e.g. diesel and paraffin) are the most concentrated and convenient energy carriers available, as they have high energy density by weight and volume. Charcoal is still used extensively as an energy carrier because of its higher energy density than wood.
The most abundant energy resource is sunlight, which in terms of human needs is effectively an infinite resource, but of low energy density. Photosynthesis converts solar energy into biomass, from the food that fuels people, through the wood that fuelled the Roman Empire, to algae that modern technology can convert into liquid hydro-carbon fuels on a par with petroleum products.
Radioactive Uranium (U235) is a source of energy, but since the mining, processing and especially the enrichment of Uranium requires extensive energy input, in the form of electricity, to arrive at nuclear fuel, it is also to an extent an energy carrier. The ecological footprint of fuels are determined to some extent by the energy resources used to produce them. This is particularly so for nuclear fuel, with the required electricity in Canada coming mostly from hydropower (large dams), while in South Africa, when we produced nuclear fuel at Pelindaba, it required a dedicated coal-fired generation plant.
The Millennium Development Goals recognise energy poverty and the moral and practical imperatives for all people to have access to appropriate and affordable energy services. South Africa’s Constitution also implies a human right to basic energy services. Optimally, the choice of energy technologies and sources will match the specific nature of energy service needs (e.g. for cooking, mobility or productive activities) with locally and sustainably available resources. Equitable access to energy requires that everybody has access to some electricity, for communications and some lighting, which could come from localised generation and distribution systems (mini-grids) or solar home systems (photo-voltaic panels with batteries). Cooking heat could be supplied from concentrating solar power, fuel used in efficient stoves or gas could be supplied from a biomass digester using agricultural residues and animal waste.
There are various gender dimensions to energy supply and use, which are particularly pronounced in households depending on traditional biomass use, as activities such as collecting fuelwood are widely considered to be women’s (or girls’) work and cooking generally involves unhealthy exposure to smoke. The convenience of unlimited electricity at the flick of a switch, requiring secure participation in the cash economy, may suck wealth out of a community that might otherwise be retained as various energy service needs are met with the labour of its members. The development of energy infrastructure has historically been driven by commercial and industrial interests, but to be fair and sustainable, energy planning should consider all dimensions of meeting energy service needs, including inter-generational equity (not compromising the prospects of our children). Energy-intensive industries tend to secure the cheapest energy supplies through bulk and long-term procurement. Such contracts often serve as the primary revenue source for suppliers such as electricity utility companies. However, the infrastructure for such supply requires direct state investment or support, such as railways or roads for trucking coal and petrol, bulk electricity transmission or ensuring water supply for thermal power stations. Such subsidies provided to the fossil fuel industries in industrialised countries are estimated to be about US$ 700 billion annually, without taking into account externalised costs, such as resource depletion, land degradation or the impacts of greenhouse gas emissions. Labour, environment and social justice groupings are advocating for a just transition to sustainable energy supply, informed by full cost accounting ( i.e. including the previously ‘externalized’ costs) applied to entire lifecycles. This will require massive infrastructure development, international cooperation for financing and sharing of best available technologies and ‘patient capital’ – investments which are based not on short-term profit, with high returns for high risks, but on long-term returns and social benefits. Ensuring universal access to modern energy services into the future will also require profound improvements in efficiency in all areas of energy use, as well as supply. Studies indicate the potential for a fourfold increase in final output, through optimal utilisation throughout energy supply chains.
Energy supply and use in South Africa
South Africa’s economy is highly energy-intensive, requiring twice the energy input per unit of gross domestic product (GDP) as Spain. A 2010 index of the International Energy Agency (IEA) provides a figure in terms of toe (tonnes of oil or equivalent energy) per thousand US dollars, of 0.19 for the USA and China – also the world average – while South Africa is rated at 0.261. As economies develop and technologies improve, energy intensity naturally tends to decline. In South Africa the contraction of minerals and mining within the economy as a whole has supported such a trend, but in 2006 we ranked 11th in the world in terms of primary energy intensity. South Africans collectively also have a relatively high per capita energy intensity, despite about a quarter of the population lacking access to modern energy services. The South Africans economy is also highly carbon-intensive, having a high rate of greenhouse gas emissions per unit of gross domestic product. The IEA 2010 index, which accounts carbon dioxide (CO2) only, puts South Africa at 0.63; above China at 0.59 and a world average of 0.46. On a per capita basis our emissions are also relatively high, being on a par with the United Kingdom at a little over 10 tonnes CO2e per person per annum. About 80% of our total national greenhouse gas emissions result from energy supply and use.
Both energy and carbon intensity make the national economy vulnerable to international fuel price volatility and environmental governance initiatives, such as border tax adjustments that have been mooted to penalise high emissions rates. Up to 40% of South Africa’s greenhouse gas emissions are accountable to (or ‘embodied’ in) exports. South Africa is the world’s sixth largest producer (and fifth largest exporter) of coal, which currently accounts for about 70% of our primary energy supply, with the balance made up mostly by imported oil. Over 90% of our electricity supply is based on coal, with some nuclear and hydro-power which is also mostly imported. Somewhere in the region of 8% of our total national energy supply comes from renewable resources, almost entirely in the form of traditional biomass ( fuelwood), which is only truly renewable if it is sourced from sustainably managed land, which is not usually the case. In 2006, the total amount of energy supplied in South Africa is reported to have been 5 644 PetaJoules (PJ) whilst the total final energy consumption was only 2 705 PJ. The difference between the two is due to energy used or lost in transformation processes, e.g. about two thirds of the energy in coal is released as waste heat in existing coal-fired generation plants. A detailed breakdown of energy supply and use is provided in the Digest of South African Energy Statistics 2009, published in March 20102. Regarding liquid fuels it notes: “Approximately 30% is sourced from coal through Sasol and 100% of the natural gas production from PetroSA is converted into liquid fuels, supplying about 7% of liquid fuel requirements.”
South Africa’s electricity use per annum (which is less than 30% of total final energy supply) is upwards of 220 TWh – equivalent to 792 PetaJoules (PJ), or roughly 0.8 EJ. Total primary3 energy supply in South Africa was a little over 5.6 EJ in 2006. Total global energy supply is currently about 300 EJ . Total global energy supply is currently about 300 EJ4. Symbol Prefix Value k kilo 1000 or 103 M Mega 106 G Giga 109 T Tera 1012 P Peta 1015 E Exa 1018 Energy flow in the South African economy (Source DoE, 2010) The above graphic provides an overview of the entire national energy supply chain. Though it is not exactly to scale, it does visually suggest the losses in transformation. It does not portray the efficiency of end use conversion, at the point of consumption, e.g. the efficiency with which electricity or paraffin is converted into light or heat. (GTL is gas to liquids; CTL is coal to liquids.)
The consumption of energy in the South African economy is portrayed in the following graphic, on the left broken down by energy carrier (e.g. 26.9% of energy is delivered and directly used in the form of coal; while 7% is used in the form of ‘Combustibles and waste’ another name for traditional biomass). On the right consumption is shown per economic sector (industry accounts for 40% of total energy consumption). The figures attached on the left of the lines of input (in red) indicate the share of that carrier going to a sector, while the figures to the right (in blue) indicate the proportion of the sector’s energy use coming via a particular carrier. Thus 68% of direct coal use is by the Industry sector and this constitutes 47% of the sector’s total energy consumption.
End use efficiency is not reflected above. Thus, while 18% of total electricity despatched goes to the residential sector and this comprises 27% of total energy use in the residential sector, this does not reflect the value of the energy services derived from electricity. Such services will be far more extensive than those derived from the 36% of residential energy consumption inefficiently used in the form of ‘Combustibles and waste’.
Energy efficiency (EE) offers important opportunities to get more energy service or output per unit of energy input, to the extent that it has been called ‘the cheapest fuel’. This involves not only more efficient appliances, industrial boilers, vehicles, etc., but also modal shift. For example, gas used directly for cooking provides more heat per unit of primary energy input than an electric cooker, using electricity with coal the primary resource. Electric motors provide more mobility or transport service per unit of energy input than liquid fuels in internal combustion engines.
The use of energy that would otherwise not be utilised is generally referred to as energy conservation. This includes switching to solar water heating, whereby water is heated in panels directly exposed to sunlight, thus displacing electricity used in geysers. As electricity prices rise to more closely reflect the current costs of generation, several industries are making use of waste heat for electricity generation (see topic ‘Combined Heat and Power’). Intelligent building design and management can radically reduce energy required for light, heating and cooling. Demand side management (DSM) involves end-use efficiency and conservation, but is primarily concerned with more efficient use of infrastructure. For example, utilising electricity at times of low demand, particularly late at night, while large coal-fired plants need to be kept running anyway, can reduce the use of the inefficient generation capacity specifically designed to provide top-up power during short peaks in demand, using expensive liquid fuel. Integrated Energy Planning (which is required by the National Energy Act, 2008) takes the nationally required energy services as the point of departure, seeking to optimise all EE and DSM opportunities, rather than simply seeking to expand supply. Efficiency is also receiving attention in the broader, long term scheme of things, in terms of the over-all efficiency of technologies or entire energy systems. Some technology options can be considered in terms of the pay-back period required for a project or intervention, e.g. the time it will take for a photovoltaic (PV) panel to generate from sunlight, under typical operating conditions, the same amount of electricity as was required to produce and install the panel; or the time required for an up-grade to more efficient motors to save as much energy as was required to produce the motor. A question deserving urgent attention is whether a particular resource is worth developing, such as tar sands, which require extensive heat and chemical inputs simply to arrive at crude oil. Assessing the merits of resource and technology options is increasingly undertaken in terms of the energy return on energy invested (see EROEI below ).
Evaluation criteria for energy supply options
In the age of cheap and abundant oil little attention was given to linkages between the availability and pricing of energy and food, or their potential competition for water. However, with an increasing dependence of agriculture on synthetic inputs like fertilizers, mostly derived from oil, accumulating land and water degradation through fossil fuel extraction and use and increasing conversion of land use to the production of biomass for liquid fuels, these linkages are becoming more pronounced. Clear-cutting forests to make way for biofuel production, e.g. from palm oil, provides the most glaring example of how a switch away from traditional farming practices to fossil fuel production can result in depriving communities of food and livelihoods while actually increasing the carbon footprint – total greenhouse gas emissions – of transport.
South Africa is officially designated a water-scarce country and this provides the clearest link, or competition, between food and commercial energy supply. This is particularly pronounced in the prospects for our coal-to-liquids industry, the most water-intensive energy technology available. The development of new coal-fired power stations, even with dry cooling, is also constrained and dependent upon substantial inter-basin water transfers (i.e. piping in from different water catchment areas). Not only are the impacts of a highly centralised and minerals-oriented energy supply system increasingly apparent, but the trade-offs and compromises involved in resource and technology choices are increasingly challenging and significant to other sectors.
The following set of criteria has been proposed, through South Africa’s National Economic Development and Labour Council (Nedlac), for the evaluation of new grid-connected electricity supply options5. Additional criteria would be required for fully-fledged Integrated Energy Planning to take account of progress towards universal equitable access, gender dimensions, the benefits of off-grid electrification options, infrastructure requirements for possible increase in the supply of liquid hydro-carbon fuels and issues of imports, exports and regional integration.
Humanity now faces the prospect that fossil fuels will largely be used up within the first half of this century. Our grandchildren will probably consider the burning of fossil fuels, particularly oil, as a flagrant waste of hydrocarbon stocks required for agricultural chemicals and synthetic materials, from plastics to materials that can be used for harvesting renewable energy resources. Furthermore, if we release even one third of the carbon contained in currently known fossil fuel reserves, we are highly likely to cause runaway climate change with catastrophic consequences.
International studies indicate that the costs of a transformation to fully sustainable energy supply and optimal use would range between 1% and 2% of global GDP (additional to business as usual investment projections) over the coming two to three decades, by which time net savings would start to grow, principally from avoided fuel costs. However, failure to address the human contribution to accelerating climate change and variability would undermine development, at a cost of between 5% and 20% of global GDP. Such studies generally relate to average global warming (relative to the pre-industrial average) exceeding 2 degrees C; however, if feedback effects trigger runaway climate change, which many scientists consider highly likely at global warming of over 3 degrees, the impacts and costs will be beyond meaningful quantification.
Much can be achieved to address energy poverty through decentralised power generation, particularly in areas like Southern Africa, empowering communities to meet energy service needs by utilising local resources. However, optimal utilisation of renewable resources, including electricity from sources not constantly available, such as wind and solar, also requires end use applications that are responsive to fluctuations in supply and international cooperation and integration of networks for moving energy over long distances. The potential to increase the energy services available from a given amount of primary energy input are so great that one must question prevailing assumptions of an endless growth in primary energy supply