RECOMMENDATIONS FOR PLANNING
6.3.2 Home Heating

An important factor for the reduction of emissions on behalf of air pollution control and climate protection is the type of energy supply and of the selected fuels.

Table 6/4 gives a summary of the specific pollutant emissions of various heating systems used in the field of domestic heating and small businesses. Natural gas turns out to be the "cleanest" fuel with regard to conventional pollutants. In the climate protection sector, it is only topped in what is carbon dioxide emissions by wood heating systems, which, however, are characterised by high pollutant emissions. A good alternative by the current state of scientific knowledge are natural gas mini-CHPs. Thanks to the conversion/modernisation of heating systems, air quality in German towns and cities, especially in the new Länder, could be fundamentally improved through the decrease of the sulphur dioxide, carbon monoxide and dust particle concentrations. Carbon dioxide emissions must now be significantly reduced through the maximisation of energy efficiency and the use of renewable energy sources.

Pollutants	CO2 g/kWh	SO2 g/kWh	NOx g/kWh	CO g/kWh	Staub g/kWh
Heating system
Fuel oil - Low temperature boiler	371	750	266	215	34
Natural gas - Low temperature boiler	295	179	234	166	10
Natural gas - Condensing boiler	252	154	200	145	9
Electric heating, 100 % coal-based electricity	1075	1056	525	246	26
Electric heating, 85 % coal-based electricity	968	980	494	232	27
Electronic heat pump Air, 100 % coal	342	347	178	115	12
Electronic heat pump Ground, 100 % coal	288	294	152	104	11
Electronic heat pump Water, 100 % coal	270	277	144	101	11
Natural gas CHP, small	-97	-82	400	383	12
Biogas CHP, small	-411	855	1365	1183	166
Wood pellet firings	83	847	1020	2709	317
Solar panels + wood heating system	30	469	269	15901	196
Wood heating, firewood	15	401	272	14120	276
Stove, firewood	24	335	142	12130	298

 

Table 6/4: Emission factors of different heating systems (according to GEMIS, Global Emission Model for Integrated Systems, Öko Institute, Freiburg ), wood furnaces, Source: LUBW in cooperation with Institute for Process Engineering and Power Plant Technology, (IVD)


However, the use of wood as renewable energy source, which is advocated by current climate protection efforts, must be critically examined in urban agglomerations from the point of air quality. The combustion of wood requires at least modern firing systems where the best available techniques control the wood loading, burnout behaviour, flue gas treatment and flue conducting. In financial terms, this often only pays for larger, i.e. generally commercial, installations.

The combustion of logs in private homes creates the risk that inadequate, insufficiently dried or processed wood is used and this sometimes even the wrong way. Especially lower chimneys then lead to complaints by neighbours – and insufficiently considered roof superstructures or higher neighbouring buildings (hillsides!) also obstruct the stack effect in the discharge of flue gases. The investigation of neighbour complaints shows that private fireplaces sometimes mislead the owners to illegal waste combustion.


Legal Bases

Emissions reduction

§ 9 (1) 23. BauGB offers a regulatory option for direct emissions reduction in site plans: Areas can be established in a site plan in which the use of defined air-polluting substances can be limited or forbidden in order to protect against harmful environmental effects in the sense of the BImSchG.

This regulation, known as a "burning prohibition" for fossil fuels (especially coal), requires a reasoned urban development interest in the securing of spatial usage qualities at less-than-dangerous pollution limits. For example, the limiting or elimination of light heating oil may not result from its sulfur content. It must also be shown that the forbidden or restricted fuels substantially contaminate the air.

The establishment of a burning prohibition presupposes, as does every other regulation, its own necessity in the sense of planning law. Incidentally, climatic and topographic characteristics (e.g. the existence of fresh-air corridors) can provide a sufficient reason for a burning prohibition.

In view of the possible limitation on the use of air-polluting fuels, the air-hygienic equal weighting of natural gas and heating oil can be created by a corresponding textual regulation in a site plan. This can establish values for limiting the emission of pollutants that, if necessary, can also be reached via measures for reducing heating energy needs (modern heating systems or strengthened insulation for outer walls). These regulations in their entirety thus define the "limited use."

Energy efficiency ( production , use, and construction ) and renewable energy

After the revision through the Act on the Promotion of Climate Protection ( Gesetz zur Förderung des Klimaschutzes , see Chapter 1), § 9 (1) no. 23 b) of the Federal Building Code provides the opportunity to designate areas in which, at the installation of buildings or other construction works, particular building or other technical measures are obligatory as for the production, use or storage of electricity, heat or cold from renewable energy sources or combined heat and power systems. As to the options provided by the Renewable Energy Heat Act ( Erneuerbare-Energien-Wärmegesetz , EEWärmeG 2008), the question arises whether it would be justified in urban development terms to designate a particular form of renewable energies. In individual cases, there certainly exist justified reasons to do so, especially as the Climate Protection amendment disconfirms the previous practice justifying designations only with regard to locally confined features.

The urban development contract as a legal instrument according to § 11 of the Federal Building Code also provides extended regulation options with regard to energetic issues, in analogy to the designation options. Besides technical regulations on the decentral and central production, distribution, use and storage of electricity, heat or cold from renewable energy sources or combined heat and power systems, it is thus possible to formulate requirements (even beyond the Energy Saving Ordinance from 2009) on the energetic quality of buildings. As before, the designation of areas required for supply facilities and lines is carried out on the basis of § 9 (1) nos. 12 and 13 of the Federal Building Code.


Renewable Heat Law in Baden-Wuerttemberg

After the new law in Baden-Wuerttemberg, (in vigor 1.1.2008) must the heat supply with new buildings (starting from 1 April 2008) to at least 20 percent over renewable energies such as solar power, terrestrial heat and heat pumps or biomass be generated. This can be mostly already achieved by means of a solarthermal plant on the roof.
For existing buildings starting from 2010 a portion of regenerativ energies of ten percent is prescribed, which must be fulfilled whenever it comes for the change of the heating system. As a substitute the obligation can be fulfilled by an improved energetic insulation. The goal is to reduce the output from greenhouse gases. Also other ways like Power-heat-coupling to reduce greenhouse gases are accredited.