Uses of energy

Consumption of final energy worldwide is distributed as follows between the main sectors of activity (Figure 1.2):

- The residential (dwellings), tertiary (offices and service activities) and agricultural sectors represent 36% of the global energy demand.

Industry (and non-energy use)

Residential and tertiary

Transport

Figure 1.2 Distribution of the global energy demand (final energy consumption) (Source: IEA)

Transport

Figure 1.2 Distribution of the global energy demand (final energy consumption) (Source: IEA)

- Transport (road, air, rail, sea) accounts for a share of 28%.

- Industry consumes 36% of the final energy.

In the residential and tertiary sectors, energy is mainly consumed for heating and the supply of hot sanitary water, as well as for air-conditioning. Much of this demand is therefore seasonal. Fossil energies, which are easily stored, are ideal for this type of irregular demand. This is less true of the other forms of energy, apart from hydraulic. In particular, energies exploited directly as electricity are difficult to store. Solar contributions are intermittent and offset with respect to the demand, in particular as regards heating requirements.

Road and air transport poses a highly critical problem, considering the rocketing increase of the demand in these sectors and the limited possibilities of turning to substitute fuels.

Improved standards of living are accompanied throughout the world by a rapid rise in the number of vehicles and increasing use of air transport.

Simultaneously, goods transport by road has developed considerably at the expense of rail traffic. This trend is related to the undeniable advantages of road transport in terms of shipment flexibility and implementation of 'just in time' production lines, with minimisation of stocks. It has also been favoured by the state, which has paid for most of the road infrastructure costs and done little to encourage rail freight transport.

Between 2000 and 2050, road passenger traffic is expected to increase by 150% and goods traffic by 200%. Air traffic, for passengers and goods, is also increasing sharply, at an annual rate of about 5%. This trend will inevitably have an impact on oil demand.

In industry, energy is consumed mainly as heat, often at high temperatures, to convert raw materials (metallurgy, iron and steel, glass, cement, etc.) and as mechanical energy to drive machinery.

Electricity holds a special place amongst the various types of energy. It represents 16% of the final energy demand and about 37% of the primary energy consumption, the difference between these two figures being due to electricity production efficiency, which is taken into account when calculating the primary energy consumption.

Electricity production is rising steadily at an average rate of 3% per annum and its share in the total energy consumption is rising regularly throughout the world [3]. By 2030, according to the IEA reference scenario, this share is expected to change from 37% to 41% in the primary energy balance and from 16% to 21% in the final energy balance.

Electricity consumption is rising in particular in the residential and tertiary sectors, due to the growing number of devices (household appliances, media, etc.) and more intensive use of electricity for air-conditioning and heating.

Special vigilance is required in the transport and electricity production sectors, whose fossil energy consumption is rising at an alarming rate.

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