Hafslund Varme’s emissions mainly stem from the generation of district heating in Oslo and Gardermoen. The base load comes from the incineration of residual waste (including pre-treated commercial waste), biomass (wood chippings) and heat pumps, which all produce extremely low levels of greenhouse gas emissions. Incinerating and exploiting residual waste, which consists of whatever is left after recovery and recycling, allows a resource to be exploited that would otherwise be lost. The incineration of waste is also preferable to landfilling as not only are greenhouse gas emissions significantly lower, but because waste energy replaces fossil energy carriers. Only in larger district heating plants and industry is it possible to exploit residual waste in a cost-effective and environmentally friendly way.
Greenhouse gas emissions derive largely from peak demand during cold weather (electricity, oil and gas). As in 2010 significant parts of the peak load were covered by bio-oil. Some emissions also result from support fuel used in the waste-to-energy plants (oil and propane).
Other emissions of greenhouse gases stem from leakages of refrigerants in heat pumps (R134a [tetrafluorane]). The gas is not poisonous, but has a powerful greenhouse effect if it leaks out. In 2011 there was one accident involving a valve at the plant, where emissions were higher than normal.
In 2011 Hafslund Varme’s total emissions of greenhouse gases amounted to around 159,000 tonnes of CO2. The graphs below show emissions of CO2 per kWh delivered to customers in Hafslund’s two main district heating areas. The figures are not climate-adjusted and show that in cold periods, such as in 2010, emissions increase due to use of fossil peak loads.
In the absence of Hafslund’s district heating operations, heating requirements would have to be met by other, generally far less environmentally friendly, solutions. The alternative for many smaller and older plants would be to burn fuel oil, increasing the environmental impact both with respect to greenhouse gas emissions and local pollution (primarily particle emissions and NOx). On the assumption that 80 percent of current district heating production has replaced heat previously generated from oil boilers, the annual emissions reduction equates to around 270,000 tonnes, and thus significantly more than the total emissions made by Hafslund Varme in 2011. This illustrates the continuing effectiveness of district heating as a climate initiative.
Hafslund has a long-term target of replacing as much as possible of the fossil peak load with renewable energy sources such as pellets and bio-oil. In 2011 consumption of bio-oil amounted to 112 GWh, which is very high compared to Norway as a whole. Hafslund Varme strives to use bio-oil that has already been used or processed. It is also a requirement that the oil is not intended for human consumption. Types of bio-oil used in 2011 were as follows:
- Fish oil, processed residual products, fine and course residue from various suppliers, and from abattoir waste
- Animal oil from abattoir waste and slaughtering
- Return oil from for example fast food outlets
- Bio diesel generated from return oils
- Bio diesel specifically intended for incineration generated from return oils
- Vegetable oils as processed residual products
- Vegetable oils not intended for human consumption
Hafslund Varme’s two waste-to-energy plants in Østfold deliver steam for both industrial purposes and district heating, along with a small amount of electricity production. In 2011 both plants produced the lowest emissions of greenhouse gases per sold kWh to date, see graphs. The emissions are primarily attributable to the use of support fuels such as fuel oil and propane.
Hafslund’s incineration plants are also responsible for emissions of a more local and regional nature, such as particles, NOx and SO2. Emissions from the three waste-to-energy plants are treated in state-of-the-art processing plants, which are also subject to stringent emission requirements, which the company endeavours to comply with at all times. Occasionally emission levels from the Group’s incineration plants may briefly exceed maximum permitted levels. These situations are dealt with immediately and the local authorities are informed as a matter of routine. In 2011 no excess emissions occurred that were regarded as having significant environmental consequences.
Most of the waste from Hafslund’s core business activities consists of ash from its incineration plants. The disposal and use of this ash is strictly regulated. All ash that cannot be disposed of at regular waste facilities is sent to NOAH’s facility for non-organic hazardous waste at Langøya near Holmestrand. The ash is used to neutralise other hazardous waste, such as acids, thus increasing processing efficiency at Langøya and reducing the use of other raw materials and input factors. A total of 29,317 tonnes of bottom ash and 15,763 tonnes of fly ash were removed from the incineration facilities during 2011.
Hafslund Varme 2012 - 2032
Hafslund Varme has set a target of phasing out fossil energy sources used in district heating production in a normal year by the end of 2016. This requires the establishment of a well-functioning market for bio-oils. To this end, the company is currently making significant investments in large plants for the production of renewable heat, including through the establishment of Norway’s largest pellets boiler at Haraldrud heating centre. The graph shows historical and estimated energy sources for district heating network in Oslo.
Society rightly expects a high security of supply from the grid. At the same time local opposition will be encountered to both new and existing power lines, and to work required to create sufficient clearance for power lines. Storm “Dagmar” showed how important the latter is in critical situations. As Norway’s largest grid company, Hafslund Nett regularly finds itself in situations where various stakeholders have differing opinions. Hafslund endeavours to balance different viewpoints, while always complying with the authorities’ regulations.
Loss of energy in the transmission grid represents a cost to society, and thus makes it important to secure efficient power transmission with the lowest possible energy losses. In 2011 the net loss in Hafslund Nett was 1,019 GWh, compared with 1,228 GWh in 2010. Around two-thirds of this occurred in the distribution grid, and the rest in the regional grid. Hafslund Nett is one of the grid companies in Norway with the lowest percentage of grid losses and fewest outages. Nonetheless, the size of the grid loss highlights the importance of keeping this figure as low as possible . The observed reduction since 2010 is attributable to a number of factors including a reduction in the transferred volume.
In order to reduce the losses it is important to establish a maintenance and investment level that guarantees efficient use of public funds. Hafslund continually works to reduce grid losses, and stringent requirements are made of components and equipment with a view to minimising losses. For example, the current upgrading of the grid in central Oslo to 132 kV will on its own reduce such losses by more than 30 GWh per annum.
Direct greenhouse gas emissions from Hafslund Nett’s activities primarily relate to non-planned emissions of sulphur hexafluoride (SF6). Sulphur hexafluoride is used as an insulating and circuit-breaking medium in switchgear installations. The gas, which is regulated by the Kyoto Agreement, is an extremely powerful greenhouse gas, with 23,900 times more impact than carbon dioxide. The gas is used in high voltage facilities because it allows the installations to be far more compact, something that is often essential in view of the space available. This is especially important because Hafslund Nett is currently increasing the voltage in the regional grid in Oslo. Sulphur hexafluoride is not normally consumed in the facilities, but is encapsulated in order to maintain the installations’ technical performance. In 2011 Hafslund’s installations contained around 20,000 kg of sulphur hexafluoride. Emissions totalled around 41 kg, compared to 49 kg in 2010. This includes emissions from plants that Statnett took over in 2011, but which Hafslund continues to operate.
Hafslund Nett still has some high voltage cables that use oil as an insulating medium. If cables of this type are damaged, oil may leak into the ground. The oil used in the cables is not considered directly toxic. It decomposes chemically in the ground in the course of about 30 days, but may still harm the environment if large concentrations are discharged into vulnerable environments, e.g. sources of drinking water and popular fishing rivers. The total of leaked cable oil in 2011 amounted to 7,120 litres, an increase of three percent against 2010.
Over a period of around ten years oil-filled cables will be replaced by plastic-insulated cables that do not harm the environment if they are damaged.
The company’s power production (3,140 GWh) is exclusively based on run-of-river hydropower plants that generate no emissions to air and that otherwise have very little impact on the environment. An important factor in this context is exploiting the Glomma watercourse in the best way possible to avoid wasting water that could potentially be used for power generation. This requires well planned maintenance and efficient management of water resources and generating facilities. In 2011 uptime at Hafslund’s Glomma generating plants amounted to 99.6 percent.
No discharges of hydraulic fluid into the river system were reported from electricity production in 2011. In addition, some of the oil is now being replaced with a type of oil which decomposes much more quickly.
The plant is still in its run-in phase and has only undergone limited trial operation for brief periods. Small amounts of electricity and propane were used during the trial operation.
The licence terms require that operations do not contribute extra noise exceeding 45 dB(A) and 50dB(A) in the evenings and at the weekends respectively. Noise emitted from the plant during the start-up phase has been within +/- 10 dB(A) of these values. In 2011 the company employed significant resources to restrict noise levels. The plant will start operation in February 2012, after which any noise issues are expected to abate.
BioWood stores wood chippings outdoors. The licence terms stipulate that chippings should be stored on impervious surfaces which collect percolating water. BioWood’s facilities do not have impervious surfaces, and percolating water is thus not collected. The licensing authority has issued instructions to comply with the storage conditions. BioWood has submitted an application to amend the emissions permit, in part based on an environmental survey which did not demonstrate any environmental effect on the lake or PH values from organic material in percolating water. The application assumes that the chippings will continue to be stored as they are today with continual monitoring in accordance with the agreed monitoring plan.
In all other respects BioWood complies with all environmental requirements.