The downward trend in Helsingin Energia’s emissions, which had continued for some years, stopped in 2006, mainly due to a 57% increase in coal consumption compared to 2005. The use of natural gas remained almost unchanged. The increase in demand for electricity was caused by the Nordic water situation, which reduced the supply of hydropower in the market.

Helsingin Energia’s 2006 carbon dioxide emissions increased from the exceptionally low emissions in 2005 by 30%. The specific carbon dioxide emissions of the energy sold increased by approx. 15% to 320 g CO2/kWh. In the 21st century, the specific emission has been 260–330 g CO2/kWh. In the international reference year 1990 Helsingin Energia’s carbon dioxide specific emission was 400 g CO2/kWh.

Measured in tonnes, acidifying emissions of sulphur dioxide and nitrogen oxides increased in 2006 from 2005, sulphur dioxide nearly twofold and nitrogen oxides by over a third. They remained clearly below the permit limits based on specific emissions, however, and the emissions expressed in tonnes did not exceed the level of the peak year 2003.

Helsingin Energia’s particle emissions in 2006 were 290 tonnes, the fluctuation range for these emissions in the 21st century being 270–720 tonnes per year. Microparticle emissions fell dramatically already at the beginning of the 1990s.

Environmental effects under close surveillance

As regards the effects of energy production, the expansion of district heating, introduction of technical means of restricting emissions and the wide introduction of natural gas resulted in good air quality, and the situation remained unchanged in Helsinki in 2006.

Due to district heating, thermal load on seawater has in the past decades been re­latively small, undiscoverable in mandatory monitoring of sea areas. Thermal load increased, but did not reach the level of the peak year 2003 (2,200 GWh). In 2006, thermal load on seawater was approx. 1,700 GWh. In 2005, the corresponding emission was 300 GWh.

At Vallila measurement station, the annual average of sulphur dioxide content which is a good indicator of the effects of energy production on air quality in Helsinki, was 3.9 µg/m3, i.e. on the same level as in the preceding year. At their present level, sulphur emission fluctuations have little effect on air quality in Helsinki. They were clearly below the limit value of 20 µg/m3 set to protect the ecosystem. Before the expansion of district heating, in the 1950s and 1960s, usual annual average sulphur dioxide contents in the centre of Helsinki were 10–20 times higher than they are now.

Although Helsinki is one of the cleanest capitals in Europe, the limit value levels or the guide values for air quality are exceeded from time to time, as regards particles and also nitrogen oxides. But in these ca­ses the affecting factors are traffic and long-range transport. The dustiest time is in the spring, when the snow melts. In 2006, smoke from fires in Russia polluted air for several weeks in the spring and late in the summer. On the average, two thirds of microparticle contents in Helsinki are caused by long-range transport.

Chemical safety ensured

Safety surveys required by the Dangerous Chemicals Act based on the Seveso II directive were conducted at the Salmisaari and Vuosaari power plants. The reports were delivered to the authorities and associated safety communications mailed to residents living in the vicinity of the power plants.

The periodic inspection performed by the Safety Technology Authority (Tukes) proved the technical condition of the Salmi­saari and Vuosaari power plants and the measures aimed at preventing accidents to be at such a high level that an official inspection can be omitted in 2007.

The Hanasaari area, which has been in industrial use for 100 years, is partly being converted for other use. During the year under review, comprehensive studies of the known pollution of the soil were launched in co-operation with the authorities and various offices of the city.

Combustion by-products

The coal combustion process produces bottom ash and fly ash, while the desulphurisation process generates a solid desulphurisation product. These materials can be utilised, e.g., in the concrete industry and earth construction. Due to the increase in coal consumption, the total quantities of combustion by-products increased from the previous year.

38% of the by-products were utilised, which is approximately the same amount as in the previous year. In respect of bottom ash, seasonal and annual fluctuations can be evened out with the aid of an intermediate storage located in Vuosaari.

Exceptional situations

In 2006, the usability of the desulphurisation plant was 95% in Hanasaari and 77% in Salmisaari. In air quality, no significant increases in concentrations resulting from repairs were observed.

District heating and district cooling work hampering traffic in the centre of Helsinki was widely discussed in the media at the beginning of the year. Additional construction of infrastructure and real estates in a city that has already been built is problematic. During the financial year 2006, earthwork site management was improved. Information about ongoing projects is also actively provided on web sites in co-operation with the Public Works Department of the city.

Systems for continuous improvement

The coverage of environmental management systems advanced at Helsingin Ener­gia. Energy is generated at power plants certified in accordance with the ISO 14001 standard. In addition to environmental protection, monitoring of emissions, chemical safety and safety surveys are managed within the same system.

The environmental management system of office buildings has been granted the Finnish WWF’s Green Office label. In addition to Helsingin Energia’s Main Building, it covers six offices. During the year under review, the environmental considerations included in the operating systems, drawn up for the different business units, were spe­cified at HelenDistrictHeat. The subsidiaries Helen Sähköverkko Oy and Mitox Oy already have environmental guides.