energy resources and security of supply
The issue of security of supply is at the top of the energy policy agenda. Concern is focused both on price security and the security of physical supply for countries with none if their own resources. At present around 80% of global energy demand is met by fossil fuels. The world is currently experiencing an unrelenting increase in energy demand in the face of the finite nature of these resources. At the same time, the global distribution of oil and gas resources does not match the distribution of demand. Some countries have to rely almost entirely on fossil fuel imports.
Table 8.1 shows estimated deposits and current use of fossil energy sources. There is no shortage of fossil fuels; there might a shortage of conventional oil and gas. Reducing global fossil fuel consumption for reasons of resource scarcity alone is not mandatory, even though there may be substantial price fluctuations and regional or structural shortages as we have seen in the past.
The presently known coal resources and reserves alone probably amount to around 3,000 times the amount currently mined in a year. Thus, in terms of resource potential, current-level demand could be met for many hundreds of years to come. Coal is also relatively evenly spread across the globe; each continent holds considerable deposits. However, the supply horizon is clearly much lower for conventional mineral oil and gas reserves at 40–50 years. If some resources or deposits currently still classified as ‘unconventional’ are included, the resource potentials exceed the current consumption rate by far more than one hundred years. However, serious ecological damage is frequently associated with fossil energy mining, particularly of unconventional deposits in oil sands and oil shale.
Over the past few years, new commercial processes have been developed in the natural gas extraction sector, allowing more affordable access to gas deposits previously considered ‘unconventional’, many of which are more frequently found and evenly distributed globally than traditional gas fields. However, tight gas and shale gas extraction can potentially be accompanied by seismic activities and the pollution of groundwater basins and inshore waters. It therefore needs special regulations. It is expected that an effective gas market will develop using the existing global distribution network for liquid gas via tankers and loading terminals. With greater competitiveness regards price fixing, it is expected that the oil and gas prices will no longer be linked. Having more liquid gas in the energy mix (currently around 10% of overall gas consumption) significantly increases supply security, e.g. reducing the risks of supply interruptions associated with international pipeline networks.
Gas hydrates are another type of gas deposit found in the form of methane aggregates both in the deep sea and underground in permafrost. They are solid under high pressure and low temperatures. While there is the possibility of continued greenhouse gas emissions from such deposits as a consequence of arctic permafrost soil thaw or a thawing of the relatively flat Siberian continental shelf, there is also potential for extraction of this energy source. Many states, including the USA, Japan, India, China and South Korea have launched relevant research programmes. Estimates of global deposits vary greatly; however, all are in the zettajoule range, for example 70,000–700,000 EJ (Krey et al., 2009). The Global Energy Assessment report estimates the theoretical potential to be 2,650–2,450,000 EJ (GEA, 2011), i.e. possibly more than a thousand times greater than the current annual total energy consumption. Approximately a tenth (1,200–245,600 EJ) is rated as potentially extractable. The WBGU advised against applied research for methane hydrate extraction, as mining bears considerable risks and methane hydrates do not represent a sustainable energy source (‘The Future Oceans’, WBGU, 2006).