By Louise Hansen, Robert Spencer and Tony Barbagallo BioCycle February 2019, Vol. 60 No. 2, p. 20
In September 2018, a diverse group of 13 professionals from the U.S. biogas sector traveled to Denmark to learn about policies and innovations related to development and operation of biogas systems. The four-day trip (see sidebars for itinerary and U.S. participants) was organized by the Danish Trade Council, and included meetings with policy makers, and tours of biogas plants, associated gas treatment and odor control systems, and food waste preprocessing facilities.
Denmark is well known as a world leader in its endeavors to create a circular and green economy. The study tour demonstrated a significant national commitment to the development of biogas, as well as collaboration between private companies and universities. The state of biogas in Denmark has been driven by economies of scale, standardized designs, buy-in from farmers and, not least, strong, bipartisan policy support.
Waste Management Evolution
The oil crisis in the 1970s and 1980s made energy security a political priority for the Danish government. Denmark started to invest in oil and natural gas exploration in the North Sea, but due to limited natural resources, there was also a significant push for exploring alternative means of energy.
Denmark consists of several islands, with favorable winds making wind power a good investment. In 2017, 43.2 percent of Denmark’s power production was derived from wind. Its economy has remained robust during the past 38 years of investing in renewable energy, growing by more than 70 percent since 1980, while holding energy consumption at the 1980 level.
For over 100 years, Denmark has incinerated a large portion of its solid waste in municipally owned waste-to-energy (WTE), combined heat and power (CHP) plants. The Danish government considers WTE to be renewable biomass energy. Today, there are over 30 WTE CHP plants around the country that provide renewable energy in the form of district heating to the surrounding community, and power to the electrical grid. A large fraction of the waste combusted at these plants (over 375,000 tons in 2015) is imported from Western Europe due to decreases in domestic waste flowing into these plants, a result of successful waste reduction programs.
From a climate perspective, however, there remains a significant desire to find an alternative to WTE that provides the same heat and power benefits as incineration but also recirculates nutrients from urban areas back into agriculture.