DHC Benefits

Each national DHC benefit has been estimated at three different time situations:Outcome for 2007, based on the 2007 district heat demand level with the actual 2007 heat supply mix according to available reliable statistics.Improved systems 2007, based on the 2007 district heat demand level with the projected 2030 improved heat supply mix. This intermediate time situation is provided in order to identify the benefits with the improved heat supply mix only. Projected expansion 2030, based on the projected heat demand level for 2030 with the projected improved heat supply mix.

The three situation model was chosen in order to illustrate that the current European DHC systems can improve both by enhanced heat supply mix and by increased heat sales.

The DHC benefits have been estimated by comparing primary energy supplies, energy imports and carbon dioxide emissions with a reference situation without any DHC and CHP at all. In that reference situation, all corresponding electricity is generated in coal condensing power stations and all corresponding heat is generated by a mixture of fuel oil and natural gas boilers.

The 2007 district heat sales have been corrected according to the bar diagram in Figure 3. This correction is needed since the IEA energy balances concerning district heat sales are not correct for some countries. The IEA energy balances were chosen as the basic statistical provider for the benefit analysis, since this database is more time efficient and contains fewer heat statistic errors compared to the corresponding Eurostat database. The 2030 district heat sales have been chosen as the future heat sales estimated in the 2006 Ecoheatcool WP4 report (available at www.ecoheatcool.org).

View the National DHC Benifts sheet below or download the pdf version.

Benefits with District Heating (DH) and Combined Heat and Power (CHP)







Country: Denmark










The fundamental idea of district heating is based on the use of recycled heat and/or the use of renewables.
These energy supplies are complemented by some traditional fossil fuels for peak and reserve capacity.





Heat can be recycled from electricity generation from fuels (combined heat and power),
from waste incineration in Waste-to-Energy plants, and from industrial processes.







Renewables used in European district heating systems are: Bioenergy (biomass, biogas etc),
geothermal heat, and solar energy through solar collectors.








The use of heat recycling provides:



* Higher energy efficiency, since the energy system heat losses are lower compared to

the combination of alternative heat supply and alternative electricity generation
* Lower primary energy supply, from the higher energy efficiency

* Lower energy import, from the lower primary energy supply, giving a higher domestic share
* Lower carbon dioxide emissions, since alternative primary energy supply are based on fossil fuels





The use of renewable energy supply provides:


* Lower energy import, since renewables used are domestic resources
* Lower carbon dioxide emissions, since fossil fuels are substituted from both heat supply and

 electricity generation










The combined benefits from heat recycling and renewables have been estimated for three situations:
* Outcome for 2007, based on statistics concerning heat sales and heat supply mix
* Improved systems 2007, based on the 2007 heat sales and future (2030) heat supply mix
* Projected expansion 2030, based on future heat sales and future heat supply mix







These combined benefits have been estimated for Denmark as:




Outcome for 2007 Improved systems 2007 Projected expansion 2030
Carbon dioxide emissions, Mton



Emissions with DH+CHP 9.0 2.9 3.3
Alternative emissions, heat 7.5 7.5 8.6
Alternative emissions, electricity 10.7 8.2 9.4
Change with DH+CHP -9.2 -12.9 -14.7
Reduction for DH+CHP -50% -82% -82%
Primary energy supply, PJ



With DH + CHP
192 166 190
Without DH + CHP
234 207 237
Change with DH+CHP -43 -41 -47
Reduction for DH+CHP -18% -20% -20%







Denmark
Outcome for 2007 Improved systems 2007 Projected expansion 2030
National primary energy supply, PJ



With DH + CHP
823 824 818
Without DH + CHP (2007) 865 865 865
Change with DH+CHP -43 -41 -47
Total national reduction -5.1% -4.9% -5.7%
National energy import, PJ



With DH + CHP
-309 -366 -391
Without DH + CHP (2007) -198 -198 -198
Change with DH+CHP -112 -168 -193
Higher energy export 56% 85% 98%
since this country is net exporter of energy


Renewable share for DH+CHP 36% 77% 77%







The estimations above are based on the following conditions:









Heat supply to the district heating systems, PJ:


Coal and Coal Products 32.9 9.8 11.2
Peat





Petroleum Products
4.7 2.4 2.8
Natural Gas
34.6 9.8 11.2
Nuclear





Geothermal
0.3 2.4 2.8
Solar

0.0 4.9 5.6
Combustible renewables 21.2 48.8 55.9
Waste

24.9 28.0 32.2
Electricity
0.1 12.2 14.0
Other heat recycled
3.2 3.7 4.2
Total heat generated
121.9 121.9 139.8
Distribution losses
24.2 24.2 27.8
Heat sold and own use 97.7 97.7 112.1







with the corresponding shares of CHP



Coal and Coal Products 100% 100% 100%
Peat





Petroleum Products
92% 77% 77%
Natural Gas
92% 75% 75%
Nuclear





Geothermal




Combustible renewables 71% 75% 75%
Waste

86% 100% 100%







Alternative electricity generation has been estimated with coal condensing plants, being the major marginal
power plants in the interconnected European power system.









Alternative heat generation has been estimated by natural gas to 63% and heating gas oil to 37%,
having annual conversion efficiencies of 85% and 78%, respectively.








The net climate change benefit of waste incineration has not been included, but allocated to the waste sector
according to the IPCC methodology.