Energy glossary
Environmental terminology
CO2 or carbon dioxide
So-called greenhouse gas, which accounts for about half of global warming. Carbon dioxide sources include fossil fuels, such as coal, oil and natural gas.
Fossil fuel
A fuel originating or converted from organic material over a long period of time, stored in the soil. For example, coal, oil and natural gas.
Acidification
Acidification is caused by sulphur oxide, nitrogen oxide and ammonia emissions, which, once entered the atmosphere, create sulphuric and nitric acid with the water vapour in the air. This so-called acid rain or acid deposition acidifies the soil and waterways. Sulphur dioxide and nitrogen oxides are created in connection with combustion.
Particles
Particles are usually divided into total suspended particles (TSP) and respirable particles (PM10). TSP consists of all airborne particles, PM10 means particles with a diameter of less than 10 micrometers. When inhaled, these can travel into the lungs and cause health hazards in sensitive population groups. Urban particles are mainly produced by vehicle traffic. In Helsinki, the share of energy production in the limit value of particles of the proportional concentration is less than 3%.
Bulk deposition
Consists of flue gas particles from power plants, ambient suspended particles (e.g. pollen and dust caused by traffic), handling and storage of coal, and the impact of humidity and rain. Rain has a significant impact on bulk deposition because, for example, rainfall of five millimetres within a short period of time removes about half of the suspended particles. The origin of bulk deposition cannot be established with the monitoring method in use.
Fly ash
A by-product generated in connection with coal combustion. Fly ash can be utilised in the earth construction industry and in mine filling.
NO and NO2 or nitrogen oxides
Nitrogen oxides are derived from the nitrogen contained in fuels and the combustion air itself. In the Helsinki region, the principal nitrogen oxide emission sources are traffic and energy production.
Specific emissions
The emission amount of a power plant in proportion to the amount of energy produced. Measured separately with respect to sulphur dioxide, nitrogen oxides, particles and carbon dioxide. The specific emission figure (mg/kWh) expresses how well an energy company has succeeded in limiting its emissions into the air.
Concentration
The relative amount of a particular substance in a compound.
Bottom ash
A by-product generated in connection with coal combustion. Bottom ash can utilised in the earth-moving industry.
Primary energy
Natural unrefined and unused energy, including hydropower, wind, solar radiation, and various fuels, such as oil, coal, wood, natural gas and peat.
Emissions trading
An activity where the emissions of a power plant have a monetary value and in which emission allowances or reductions are bought and sold.
Certification
For example, proving that the environmental management system is in compliance with the requirements set by standards.
By-products
In energy production, products generated in the cleaning of flue gases, such as fly ash, bottom ash and the end product of desulphurisation.
SF6 GAS
Sulphur hexafluoride SF6 is an inert gas used in the electricity sector as an insulating and cooling agent and as an arc-extinguishing agent especially in high-voltage equipment.
SO2 or sulphur dioxide
Sulphur dioxide is produced when sulphur contained in a fuel reacts with the oxygen in the combustion air. Sulphur dioxide is a water-soluble and colourless gas, which is oxidised further in outdoor air, for example, into sulphuric acid. In addition to nitrogen oxides and ammonia emissions, sulphur dioxide emissions cause acidification of soil and waterways.
Sulphate deposition
Is derived from sulphur dioxide produced by various fuels, sulphur trioxide bound to fly ash, and short or long-range transport of pollution. The impact of power plant flue gases on sulphate deposition can be assessed on the basis of correlations between power plant emissions and environmental sulphate depositions.
Renewable energy sources
Solar, wind, hydro and bioenergy, geothermal heat, and energy produced by waves and tidal movement.
EIA
Environmental impact assessment. A method for establishing any environmental impacts of a planned project and its alternatives before final decision-making.