Regenerative Energies

Today, renewable energies already make an important contribution to the energy supply in Germany, which will increase considerably in the future energy mix.

Their significance has continued to grow as a consequence of national and international legislative frameworks in recent years. A series of measures was initiated which direct or indirectly brought about an intensified use of renewable energies.

In addition, a new challenge for the use of regenerative energies in rural areas arises due to the amended Renewable Energy Sources Act and the Renewable Energy Incentive Programme. Stipulation of the compensation for electricity fed into the grid generated from biomass also safeguards investments in the liberalised electricity market, making electricity generation in this area economically interesting. Great expectations are placed in the use of biomass, in addition to solar thermal energy generation, photovoltaic electricity generation, wind energy, hydropower and geothermal energy.

Electricity generated from Renewable Energies in Germany

In addition to specially cultivated energy crops, production residues, by-products and organic waste will also make an equally large contribution. Based on the political and economic objectives, it is our central task to develop new methods for the use of biomass as a regenerative energy source in research and study projects, right through to their practical and marketable feasibility. The focus here lies on anaerobic fermentation (biogas production) from solid and fluid residues, as well as thermal use of solid production waste. Particular attention is devoted to specialty crops in the agricultural sector and processing industries. Residues from fruit and vegetable production and production residues from viticulture (pomace, turbidity), the brewing and distillery industry (brewer's grains, distiller's wash) have a high organic potential for which there are currently no practice-oriented utilisation strategies within the meaning of closed-loop recycling management.

Dried Pommace for Pelleting

To this end, we have an anaerobic pilot plant station and another testing plant in accordance with DIN 38414-S8 at our disposal for investigations to analyse the potential, quality, composition and reaction kinetics of biogas from all residues. In a research project funded by the Federal Office for Agriculture and Food, these testing facilities have already been used to develop a process to purify and reuse waste water and production residues from wine-making on individual vineyards. The thermal use of solid residues was investigated on the basis of a patented invention. Here, a method was developed that enables fuel pellets to be produced from pressing residues from wine-making, also called pomace. In Germany alone, approximately 330,000 t/a of grape pomace are potentially available, constituting an interesting and, above all, previously unused source for the supply of energy. Due to the grape seed oil released during processing, which acts as a binding agent, the pressed pellets are highly solid, fulfilling all of the relevant quality demands. Thanks to the energy-rich grape seed oils, the determination of calorific values revealed higher energy contents than wood pellets.