This view shows the total carbon dioxide (CO2) emissions of the building from heating, hot water production, cooling and electricity used over the previously simulated period. The emissions are divided between different consumers and energy sources. It should be noted that at present, emissions from the manufacture or dismantling of the plant components or the building are not included in this balance, but only the plant operation is considered. In addition, any PV systems and the electricity produced by CHPs are shown as separate bars, since these emissions are partly prevented by these. The possible consumers shown are:

Heating & hot water

Here the emissions, which are emitted for the heating of the building and the warming of the drinking water, are shown broken down to the individual energy sources. For example, boilers and CHP units, which both burn natural gas, are combined. 

Cooling

This bar shows the emissions caused by cooling the building. These are also broken down by energy source.

Household electricity

This bar represents the emissions caused by household electricity. It is assumed that grid electricity with an average emission factor is used to cover the electricity demand. Possible savings through own consumption of self-produced PV or CHP electricity are shown separately to illustrate the savings.

CHP- Electricity

If there is a CHP in the plant, its fuel consumption for the production of electricity and heat is divided proportionally and the emissions for heat are added to the "Heating and hot water" bar. The emissions caused by the production of electricity are shown as a positive part of the CHP electricity bar. On the other hand, savings from own consumption or feeding into the grid are shown as negative emissions. 

PV system

Here the emissions avoided by feeding in and own consumption of the produced electricity are shown.

Total (total balance)

This bar represents the balance of carbon dioxide emitted over the year. If the total is positive, the column is red, if it is a net saving, it is green. 

Examples

Building with heat pump, gas boiler and large PV system

Here a system with heat pump, gas boiler and PV system was simulated. The heat requirement for heating and hot water is covered by the heat pump and the thermal bath with the help of electricity or gas. The resulting emissions are shown in the first column in blue (gas boiler) and yellow (heat pump). The second column represents the CO2 emissions by the household electricity, under the assumption that the household electricity is drawn completely from the grid. In the third column, the emissions saved by the PV system are now offset. A distinction is made between the electricity consumed by the PV system itself (shown in green) and the electricity fed into the grid (shown in yellow). The last column shows the total balance over the year, which is the sum of the other columns. Due to the large PV system, the total CO2 balance in this project is negative, i.e. net CO2 savings are achieved.

Gebäude mit BHKW und Gas Spitzenlastkessel

This building is heated with a natural gas-powered CHP and a natural gas-powered peak load boiler. The emissions of the CHP unit are proportionally credited to the production of heat and electricity. The share of emissions emitted by the heat generation is shown in the first column (here together with the emissions of the peak load boiler), those for the generation of electricity in the CHP electricity column. The emissions avoided by internal consumption as well as by feeding the electricity generated in this way into the grid are shown negatively in the CHP electricity column. In total, this building emits 0.67 tons of CO2 over the year, as shown in red in the right-hand bar.

Emission factors

For the calculation of CO2 emissions, the emission factors specified in the  Building Energy Act (Act on Energy Saving and the Use of Renewable Energies for Heating and Cooling in Buildings - draft) in Appendix 9 are used.

The emission factors for electricity in g CO2 equivalent per kWh are included: