Agriculture and technology facilitate sustainable business

tec.news: Mr Harting, as a “green entrepreneur” you laid the foundation for sustainable business from a very early stage. What was the initial idea behind the founding of ZEA Green Energy?

D. Harting: My passion for agriculture was something that I discovered at an early age. When the Renewable Energy Act (EEG) was passed by the red-green government under the chancellorship of Gerhard Schröder in March 2000, we viewed this as our green light: We started out with a pigsty and the construction of a 0.5-megawatt biogas plant, which we used to generate electricity. Any additional heat generated was fed to the farm via pipes. A little later, we came up with the idea of ​​producing biomethane, which was completely new territory for us. In Uchte, Lower Saxony, we acquired a site with a directly adjacent gas pipeline – for all intents and purposes a basic requirement. And in 2011, we built a biomethane plant here followed by a gas treatment facility. The biogas plant has an electrical output of 3 megawatts and corn is the biological raw material used. This is because the soil conditions in the Uchte region are ideal for growing corn: the soil is waterlogged in the winter and very light in the summer months.

G. Sudholz: As mentioned above, our 3-megawatt plant has also allowed us to move into the area of gas treatment; the treated biomethane is supplied directly to local gas pipelines as natural gas. Two important aspects come into play here: agriculture and technology – in the sense of production and treatment technology. We cultivate approximately 1,200 hectares of land for the entire plant and we use a process involving pressure water scrubbing for the gas treatment. In this treatment process, cold water is used under increased pressure to clean the raw biogas. The biogas is fed through a treatment column in counterflow to the water. Within the column, the CO 2 from the biogas is bound to the water and thereby “washed out”. The process produces biomethane and CO 2 in the form of exhaust gas.

All our products here come with a Nawaro label, which means that only renewable raw materials are used in production.

D. Harting: The facility´s power supply is guaranteed by means of a combined heat and power plant at the Uchte site. The waste heat generated at the site is used for pressure water scrubbing via an adsorption refrigeration system. Furthermore, some of the heat is supplied via pipes to municipal facilities in the municipality of Uchte. For instance, we supply the multi-purpose sports hall, the primary school and the secondary school, the kindergarten and the outdoor swimming pool.

tec.news: Mr. Sudholz, how exactly is the biogas plant integrated into the energy supply of the
HARTING Technology Group? Are there any other consumers?

G. Sudholz: We have two energy centres in Espelkamp, which we use to generate heat and electricity. These are operated with the biomethane produced and they supply electricity and heat to the HARTING production plants and the Espelkamp municipal utilities. The electricity generated is sold on the electricity exchange and the heat is used as local heat. We also supply HARTING directly with biomethane. The energy centres in Espelkamp are managed based on the amount of heat required and have a large heat storage facility.

tec.news: How do you source the corn you need for energy?

G. Sudholz: We grow and cultivate 90% of our requirements. This consists of 60% corn, 20% mixed culture from wild plants, corn-beans and 10% cereal based whole-crop silage. With this mixture, we reduce monocultures in the area. A further 10% of the biomass we require is purchased from third parties and is based on cultivation contracts. The biomass used is fermented by the bacterial colonies within the fermenter and converted into biogas. The resulting fermentation residues – approx. 65% of the feed quantity – come from the biogas plant in solid and liquid form and are fine use in fertilising our own areas, thereby completing the nutrient cycle. We can produce certified biomethane for our own areas by way of these and other measures. In addition, we are playing our part in contributing to biodiversity by cultivating annual and perennial flower strips and patches and wild grazing areas on 60 hectares of land.

tec.news: Are there plans to further expand ZEA Green Energy?

D. Harting: We plan to build a wind farm in 2024: three wind turbines, each generating 4.2 megawatts of wind energy. The predicted annual yield stands at 27 million kWh. We would also like to focus on the area of photovoltaics. We plan to build an outdoor PV system on an area of ​​14.5 hectares over the next three years. The predicted annual yield here totals some 14.5 million kWh. By combining PV and wind power, electricity production can be maintained at a constant level throughout the year and the yield curves can be compared: the highest wind yield occurs from autumn to spring, and in summer PV electricity takes over due to the high solar radiation. We are therefore expecting a constant production of renewable energy, with hydrogen production also being a topic we intend to examine in greater detail in the future.

tec.news: What kind of opportunities does this open up for HARTING in terms of its energy
supply?

D. Harting: “Green energy” strengthens the self-sufficiency of the HARTING Technology Group on a sustainable basis – our expansion plans are enabling us to further expand our position and to better utilise a constant volume of electricity. This means that we can continue to pursue our goal of setting the pace and direction for sustainable production in Germany.