Energy Efficiency & Energy Audits
- Investigation and evaluation of your production plant or waste treatment plant with regard to its current energy efficiency
- Presentation of the potential for energy savings and cost reductions
- Ecological and economic consideration of the possible improvement measures
- Implementation of the project under the lead of a certified European Energy Manager and Energy Auditor (EUREM)
In general, the energy efficiency is understood to be the ratio between the benefit and the effort of the process or operating state, respectively. The benefit refers to the energy generated, e.g. electricity production, steam generation, district heating production. The effort is the energy flows supplied to the system at the system boundaries.
The calculation of energy efficiency is generally carried out in the form:
If a system generates electricity and heat at the same time (combined heat and power, CHP; or cogeneration), the overall efficiency or fuel utilization rate is used as a key figure.
Depending on the balance limit of the system under consideration, energy efficiencies can be considered for the entire system (plant efficiency) or just for parts of a system (e.g. boiler efficiency).
Each of these indicators can be determined in the form of a gross efficiency and a net efficiency. The gross efficiency is based on the total amount of energy produced, i.e. the sum of the energy that can be made available to consumers and the system’s own consumption (e.g. for the purposes of preheating air or as an energy supply for fans and pumps). In contrast, the net efficiency only takes into account the energy that is made available to consumers, i.e. gross production minus the system’s own consumption.
First, a comprehensive analysis of current energy consumption levels is necessary in order to identify weak points of the system. The use of modern technologies, especially energy-efficient machines and systems, can significantly reduce energy consumption. Furthermore, regular maintenance and inspections, the implementation of energy management systems and ongoing training for employees help to increase energy efficiency in plant operation.
BAT 19. In order to increase the resource efficiency of the incineration plant, BAT is to use a heat recovery boiler.
Description: The energy contained in the flue-gas is recovered in a heat recovery boiler producing hot water and/or steam, which may be exported, used internally, and/or used to produce electricity
BAT 20. In order to increase the energy efficiency of the incineration plant, BAT is to use an appropriate combination of the techniques given below:
- Drying of sewage sludge
- Reduction of the flue-gas flow
- Minimsation of heat losses
- Optimisation of the boiler design
- Low-temperature flue-gas heat exchangers
- High steam conditions
- Cogeneration
- Flue gas condenser
- Dry bottom ash handling
(Source: BAT Conclusions on Waste Incineration (2019))
Waste co-incineration plants are by definition recovery plants, since the “main purpose of generating energy (or production of material products)” is decisive for their classification as a co-incineration plant (see Waste-to-Energy).
In contrast to co-incineration, however, the incineration of waste can be either a disposal process (D10 “incineration on land”) or a recovery process (R1 “main use as fuel or as another means of generating energy”), depending on whether and to what extent the energy released during waste incineration is utilized.
The R1 criterion can be found as a footnote in Annex II of the Waste Framework Directive.
It is used to distinguish between the D10 and R1 processes in waste incineration plants.
The R1 energy efficiency criterion is not an efficiency in the technical or scientific sense, but a parameter defined in the context mentioned, which can also reach values ≥ 1. The formula for calculation is:
Waste incineration plants are only considered recovery plants (R1 process) if their R1 value reaches at least the following values:
- 0.60 for plants in operation that are approved under current Community law before 1 January 2009
- 0.65 for plants that are approved after 31 December 2008.
It is therefore crucial for the fuel utilization rate whether heat consumers – such as industrial plants with process heat demand or the possibility of supplying district heating and/or district cooling to nearby consumers – are available at the site of a waste incineration plant.
