Process Heat
The industrial and commercial sectors consume around 220 PJ or 43% of the country's energy use. Of this energy there is estimated to be 44 PJ of bioenergy produced heat consumed each year. The overall technical efficiency of energy use averages 25%.
A survey on heat plant (boiler) use in New Zealand industry was undertaken in 2006 on behalf of the Bioenergy Association of New Zealand (BANZ).
The survey includes industries such as:
- Wood Processing
- Dairy Processing
- Education
- Food and Beverage Processing
- Hospitals
- Metal Processing
- Other Manufacturing
The survey is limited to sites or heating plant greater than one megawatt thermal capacity. If a survey respondent has a boiler less than 1MW thermal, it is not recorded. However, where a respondent has boilers of size less than 1MW, but site capacity is assessed to be greater than or equal to 1MW, this is recorded within the database.
The database is maintained by East Harbour Management Services on behalf of the Bioenergy Association of New Zealand (BANZ), in conjunction with Energy Efficiency and Conservation Authority (EECA).
Survey Results
Nearly 4100 MW thermal of heating plant is included in the database. Just over one third of this is plant smaller than 10 MWth. Wood processing with 39% of the total installed MWth capacity has the largest amount of heating plant followed by the dairy processing sector with 34% of the total. The remainder is spread over the other sectors as shown in Figures 2 and 3. Gas is the predominant fuel followed by coal and woodwaste.
Figure 1: Heating Plant Size Distribution
It can be seen from Figure 1 above that there are a significant number of small plant plus a few very large ones. The median heating plant size is 2.3 MWth.
Figure 2: Installed Heating Plant
Figure 3: Installed Heating Plant by Sector and Fuel
Estimates of annual fuel consumption based on responses given in the survey are shown in Table 1 and Figures 4 and 5.
Table 1: Sector Energy Use
| Sector |
PJ |
| Dairy Processing |
26.5 |
| Education |
0.4 |
| Food Processing |
3.5 |
| Hospitals |
3.0 |
| Meat Processing |
4.3 |
| Other Manufacturing |
2.9 |
| Wood Processing |
47.2 |
| Total |
87.9 |
Figure 4: Heating Plant Energy Use by Sector
Figure 5: Sector Heating Plant Energy Use
More details of fuel type used in each of the sectors are given in the following figures:
The full report on Heat Plants in New Zealand is available from the Bioenergy Association of New Zealand (BANZ) website.
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