District Heating CO2 Conversion Factor and primary Factor

[btysoe]

Does Anybody have experience of calculating the factors for district heating or can they point me in the direction of some useful documentation?

I have a District heating system cosisting of:
30% biomass CHP
60% NG CHP
10% NG Boiler

[Complex Potential]

District carbon factors can be a real pig to work out. If you are plugging into an existing energy centre then you can often go to whatever external party is responsible for it to provide the numbers.

However, if you are designing it then it normally takes some additional specialist software like EnergyPro to work out and it can be dependent upon a dizzyting number of variables.

I'm fortunate in that the company I work for have others who's job it is to look at site wide considerations like that which leaves me to get on with the building models.

[ColinR]

Hi, did you have any luck with soving this problem?

[Complex Potential]

In my experience there is little guidance on the calculation and justification of site carbon factors. My opinion is that you should go through the following steps:

1. Determine the dynamic site demands - since this is independent of the energy centre you can model up all of the buildings in a single IES (other other) model to get combined demand profiles for the year. This can be done using a compliance model but since we all know that compliance models are not meant for actual energy prediction, a bespoke thermal model might be better (although more time consuming).

2. Process the demands - take those demands and process them to determine the energy in/energy out ratios for the energy centre. This is the tough part and, for simple energy centres, it can often be done by setting up a big spreadsheet, assuming you understand the workings of the energy centre sufficiently. However, if the energy centre is highly complex you may need to utilise another piece of software such as TRNSYS to complete this step.

Another option could be to use a program like energyPRO which I think uses benchmark data rather than dynamic model inputs.

[btysoe]

The client was able to provide detailed meter readings for all the fuel used and energy delivered enabling a emission factor to be calculated using a spreadsheet.

[Complex Potential]

Real life data That's always welcome.