Organic material, including wood, organic waste from kitchens and gardens and manure, serves as the raw material for the production of 100% green electricity. Biomass is the collective name for these materials.
Twence expressly makes use of organic waste materials for the production of bioenergy. We therefore do not make use of biomass specially cultivated for this purpose and that thus competes with agricultural land for the food chain. Material that was waste is thus put to good use.
Organic waste from kitchens and gardens
This includes vegetables, fruit and garden waste. It can be peels and residue from vegetables, fruit and potatoes, residue from cooked food, meat and fish residue, nutshells, eggshells, vegetable oil, solidified fat, weeds, small pruning waste, mown grass and leaves. Organic waste from kitchens and gardens is collected separately in the ‘green waste bin’. At Twence, we use anaerobic digestion to recover energy from this material, after which the remaining material is composted. That means we use the material twice in a row to get the most from it.
Material past its use-by-date
Production waste or rejected material from the foods industry, but also products past their use-by-date from the supermarket, supply a lot of extra energy through anaerobic digestion.
This involves residue of food which is not suitable (any more) for human consumption.
Waste wood, mainly painted and treated waste wood, woody non-compostable elements from our composting plant and large elements from green waste serve as fuel for our biomass power plant. For an optimum process, this wood should not be too large, so we mill it into pieces measuring between 10 and 50 centimetres. That allows us to achieve maximum efficiency.
The manure surplus from Dutch farmers can serve very well as the raw material for anaerobic digestion, so that this material delivers heat and electricity.
Manure contains phosphate, nitrogen and potassium; raw materials that are essential to everything that grows and flourishes. Also to food crops. The surplus of manure in the Netherlands has resulted in excessive amounts of phosphate in the soil. It leaches into the groundwater and can cause the undesirable growth of algae and plant species.
Large-scale processing will enable a maximum of energy and nutrients to be recovered. The plant we want to build at our Elhorst-Vloedbelt site in Zenderen converts one hundred percent waste into green electricity and one hundred percent valuable renewable materials.
Click here for the file on manure valorisation.
The sun is the most direct source of energy we know.
Solar energy means the energy which humans generate with technology directly from sunlight. The method most used for this purpose is solar panels with photovoltaic cells. ‘Harvesting’ the solar energy in an economically profitable way requires relatively large areas of solar panels.
Twence is building solar parks to put the energy from the sun to use. The first solar park is situated at our Boeldershoek site in Hengelo. This park supplies energy from May 2017.
Read more about solar energy here.
Municipal solid waste is a collective name for the waste which arises from the normal operation of a household. Households are stimulated to already separate the reusable part of their waste at the source, for example glass, old paper and cardboard and plastic.
A similar waste stream can arise at businesses. This waste, from which the reusable part has already been removed, is an excellent source of energy.
Combustible waste from the UK
More and more waste streams can be reused and no longer need to be incinerated. This has created an overcapacity of waste incineration in the Netherlands. In order to operate the plant at full capacity and guarantee the production of energy, we import combustible waste from the United Kingdom.
All reusable (raw) materials are already removed from the waste in the United Kingdom; only the so-called Refuse Derived Fuel, which has no other use, is used for the production of energy. Approximately one third of the waste processed in Twence in the energy from waste plant comes from the United Kingdom.
Research firm CE Delft investigated the transport of Refuse Derived Fuel from England to produce steam, heat and electricity at Twence. This study showed that processing the waste at Twence is better for the environment than dumping it in local landfills, which is still the practice in the United Kingdom. After all, the necessity to reduce CO2 emissions does not stop at national borders.
CE Delft’s calculations were based on transport by road. All the relevant environmental effects were evaluated in the study, including avoiding CO2, reduced use of fossil fuels, emissions of acidic chemicals and particulates. The environmental benefits are affected strongly by the high energy efficiency of Twence’s plants, which have the so-called R1 status. Transporting the waste by ship, as is now done between the United Kingdom and Twence, results in an even more positive balance. The Twente container terminal is literally just around the corner from Twence.
Recent British research by the firm Eunomia confirms CE Delft’s conclusions. The alternative of incineration in the United Kingdom (at a low level of energy efficiency) was also examined. In that case too, thermal processing in a European high efficiency plant is a better option for the environment.