Rational Use of Energy
The aim of this section is to examine the way in which the UK uses energy. The data presented is intended to encourage us to examine our use of energy and to assist us in examining the relevance of different uses of energy. As energy is a core component in everything we do, the assessment of energy use in every activity is an enormous task and thus this paper shows only a sample of relevant data selected by the author. Existing patterns of energy use as well as historical and predictive data are used.
The cornerstone in this examination will be the individual. In using energy in order to achieve objectives, every sector aims to fulfil the desires and needs of individuals. Whereas in some aspects of our lives the energy implications (eg transport, use of energy directly in the home for heating) are fairly straightforward, other aspects (eg consumerism) may not be.
Use of energy in the United Kingdom
The energy for which the United Kingdom may be considered responsible is not the same as the energy used in the United Kingdom. The UK is an integral part of the worlds economy and trade and thus decisions made by consumers (both individual and institutional) within the UK, have energy implications not only for the UK, but also for the rest of the world.
Table 1: Energy Use (delivered) by sector of the economy, 1996, UK Mtoe (Million tonnes of oil equivalent) .
In Table 1 figures given are for fuel delivered to these end users. These do not total the gross inland consumption of primary fuels and equivalents as losses occur due to:
Cradle to Grave Analysis
Note that the overall efficiency for the above was 69% . When losses and energy expenditure connected with the initial 'winning' (and for some fuels: transportation to the UK) of the primary fuels are considered, the overall efficiencies will be lower. The overall efficiency of the energy delivery system in each of the sectors will of course be a combination of the efficiencies of delivery to each location representing a destination within that sector. However, these efficiencies represent only part of the efficiencies of each application. Further energy losses will be created by the efficiency of the equipment which is used in each application together with any overheads associated with the production of the product. Where this end product is not received by an individual 'consumer' then further losses will be involved in any further stages between the different processes and the end consumer.
What must also be included in such an analysis is the rate at which the consumer needs to replace the product or requires the service. Once the product has fulfilled its purpose it becomes or is converted into waste products. If these are then reused either to produce replacements to this product or other products then the efficiency of the system may increase.
Apportioning Energy Use
Whilst it is convenient to divide energy use into different sectors of the economy, all these sectors are interrelated and the boundaries may be defined differently, depending on the perspective. For example, whilst transport represents the single largest use of energy in the UK, it may be represented as a service to each of the other sectors (and is responsible for the movement of employees from the domestic sector to one of the work related sectors). Thus a different way of looking at energy use could involve apportioning all transport use to each of these sectors.
Another way of representing energy use is to divide it up into categories describing the end processes, as illustrated in table 2.
Table 2: Delivered Energy Consumption by End Use, UK, 1996