Researchers have developed a new energy map that traces the flow of global energy from the fuel sources to the final services provided. The study provides new insight into the potential of energy efficiency measures by focusing on technologies rather than economic sectors.
According to the International Energy Agency (IEA), improving energy efficiency remains the largest and least costly strategy for reducing carbon emissions.
The flow of global energy has been mapped for many years but this new map makes a number of unique contributions:
• It traces energy flow from the initial fuel source right through to final energy services, such as passenger transport and heating.
• Within each energy chain it focuses on technical components rather than economic sectors. For example, electric motors are not found in a single economic sector but used in transport, industry and buildings. The study therefore looks at electric motors rather than each sector.
• It distinguishes between conversion devices and passive systems in the flow of energy. Examples of conversion devices are engines, burners and heaters, which convert energy into a useful form. Passive systems are the final technical part of the energy chain and do not convert energy; instead they lose energy as low-grade heat. Examples of passive systems are vehicles, furnaces and household appliances.
• It identifies key areas where technical innovation is likely to deliver the greatest efficiency gains.
Using data mainly from the IEA, the research produced a map that traced the global flow of energy through society. This was divided into four columns: energy sources, conversion devices, passive energy systems and final services.
A copy of the map, adapted from the original study, is available to download from: http://ec.europa.eu/environment/integration/research/newsalert/pdf/energymap.pdf
From an analysis of the different columns it is clear that fossil fuels are still the main source of energy used in society. Low-carbon sources make up about 20 per cent of the energy supply and are dominated by nuclear, hydropower and biomass. Renewable energy from wind, solar, tide and geothermal accounts for less than 1 per cent of energy supply.
The map indicates that the best opportunities for efficiency gains from conversion devices would be in heaters, burners and engines rather than from lighting devices, electronics and aircraft engines.
For passive systems, improving the efficiency of heating space in buildings is a priority and appliances are also ranked highly in their energy use. Lastly, passenger and freight transport dominate final services when added together. Improvements can only be made here by reducing demand.
A further analysis of the map identifies alternative energy chains and potential energy savings. For example, switching all petrol engines to diesel engines would save approximately 4 x 1018 Joules worldwide. However, switching one component usually has a knock-on effect on other components.
Both the scale of energy flow and the efficiency of each device in the chain need to be assessed in order to make specific policy recommendations on alternative energy chains.
The current study has assessed only the energy flow and further research is needed to provide an estimate of the potential benefits of efficiency measures.
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