Box 10J Energy balance in Helsinki

Cities can implement measures to control energy flows; increasing efficiency, and thus conserving energy sources and reducing environmental impacts. In Helsinki (Figure 10.14) the total net efficiency (excluding motor vehicles) provided by the Helsinki Energy Board in 1993 was 82 per cent. Including motor vehicles, it becomes lowered to 73 per cent, which shows the low energy efficiency of motor vehicles compared with heating and electricity supplies. Of the total process losses (4061 GWh per year), more than half (2016 GWh per year) are due to motor vehicles which account for a quarter of total energy used in traffic. The remaining losses are from electricity generation and heating production which totals 1630 GWh per year and accounts for only one sixth of total production.

Cogeneration of heat and electricity at an urban scale is economically advantageous and saves raw energy. By means of cogeneration Helsinki has been able to save 25 to 35 per cent of fuel compared with the earlier separate production of the same amount of heat and electricity (in condensing power plants and private boilers). An additional advantage is reduced dependence on oil. The fuel in thermal power plants in Helsinki is now mainly coal, in heat supply stations it is mainly heavy fuel oil, and in boilers for single houses it is light fuel oil. In the near future more natural gas will be used. The level of emitted carbon dioxide decreases considerably with combined energy production and with increased use of natural gas.

Source: Helsinki Energy Board, 1993


Figure 10.14 - Helsinki energy flow

Source: Helsinki Energy Board, 1993