Untapped Waste and Energy Surplus Plausible for District Heating

On various levels policies encourage use of renewable energy and reduced energy end-use in buildings laying large responsibility on end-users consumer. Comprehensive systems linking energy resources with the demand for energy such as district heating, in which the heat is distributed to a block or entire city through a pipe-network, is common in many European countries where space heating of buildings is required. However, more than a quarter of primary energy supply in Europe is wasted in terms of losses from electricity production in condensing plants. These losses are of the same order of magnitude as the total heat demand in Europe and could instead, at least partially, be utilized to cover heat demand by district heating.

District heating supply heat at moderate cost using low-cost energy sources such as waste and surplus heat to a diverse sort of buildings primarily multi-family and service premises enabling hot water and heating of space most commonly via a central borne heating system supplying the entire building. By using various energy sources, many times of local origin promoting local industry and business, district heating is a central element for forestry, power production, waste management systems and efficient energy use in industry. In Sweden district heating (DH) is parlayed extensively and contributes to half of the heat demand with more than 400 systems, one in every urban commune with more than 10 000 citizens. Half of Sweden’s DH systems are supplying heat to multi-family buildings and the other half mainly to premises such as schools and offices whilst the fraction of heat to industry and single-family hoses are growing. The fuel used today in Sweden are a mixture of a multitude of heat sources with two thirds being wood and waste fuels as apposed to being oil in the 1970’s. (Swedish Energy Agency, 2015) In comparison to other European countries, Sweden uses a significant amount of industrial energy surplus (a single pulp and paper mill could waste as much as 500 GWh per year) for its DH system, and heat pumps use heat from soil water and lakes. Carbone-dioxide emissions have been reduced significantly since the use of fossil fuels for DH is less than 15 % and in order to stress fossil fuel phase-out there is currently a carbon-dioxide tax of approximately €100 per ton which initially promoted the use of biomass. In order to further promote fossil phase-out green electrify certificates and higher electricity prices making biomass-fueled plants more economically viable were implemented in Sweden. A prohibition of disposal of combustible fuel has led to an increased market for Swedish companies collecting an incinerating waste for production of heat wherein many other parts of Europe waste is landfilled and not used as a resource. (Åberg & Henning, 2013)

Little of waste and energy surplus is used other than for district heating and it is therefore beneficial both environmentally and economically expanding existing district heating system rather than the current landfilling of waste and massive loss of energy surplus. Energy sources, such as heat from incineration waste, industrial surplus heat, heat from pulp and paper mills etc. that are difficult to use for individual buildings needs be wield for district heating in order to phase out conventional fossil fuels and minimize dependency of energy imports for heating. A huge amount of surplus heat is lost within the energy and industry sectors, bearing in mind that these same latter sector account for a third of the final energy consumption in connection to the fact that primary energy supply is dominated by fossil fuels. Utilizing surplus energy and waste should by any government be considered as an essential measure to obtain an overall sustainable energy system in a their region. In Sweden there seem be a political commitment to invest in infrastructure and reduce dependency on imported fossil fuels and thereby also an increase of district heating taking advantage of waste and energy surplus for heat production at a reasonably low cost for both producer and consumer. Other countries in Europe with a less developed district-heating infrastructure might see Sweden as a predecessor in order to converge goals of the 2030 agenda for sustainable development. Other measurements, a part from what Sweden has done already, could be developing of a regional heat market to encourage efficient usage of energy surplus in regions where district heating is well established and where the concentration of industries is high. Such a market could constitute to industries becoming a multiple of small producers of heat posing a significant role as heat suppliers in local or regional markets in the same way small producers of electricity has become more customary in terms of PV systems.

References
Energy in Sweden - facts and figures 2015, ET2015:46. Eskilstuna: Swedish Energy Agency; 2015. www.energimyndigheten.se (accessed Nov 2015)

Åberg M, Widén J, Henning D. Sensitivity of district heating system operation to heat demand reductions and electricity price variations: A Swedish example. Energy 2013 in press.