By Paul Hlawatsch, USAG Bavaria Directorate of Public Works
HOHENFELS, Germany — When President Obama signed Executive Order 13693 “Planning for the Sustainability in the Next Decade” Mar. 19, 2015, Hohenfels military community — part of USAG Bavaria — was already one step ahead.
EO 13693 calls for reducing greenhouse gas emissions, promoting energy conservation and efficiency, increasing renewable energy and increasing alternative energy sources by various new technologies.
In 2011, four years prior to the signing of EO 13693, Paul Hlawatsch, the energy manager for Hohenfels military community, submitted a $3.5 million project to approve and fund a combined heat and power plant, or CHP, and soon received the funds.
A CHP, also known as a cogeneration unit, serves two purposes. It simultaneously produces electric power and thermal heat and utilizes both of them in an efficient manner. Heat that is normally wasted in a conventional electrical plant is harnessed as useful energy. CHP captures the heat by-product and feeds it into a local heating network, providing heat for buildings. This is more efficient than generating heat and electricity from separate sources.
“Due to the integration of both power and thermal generation, CHP systems are more efficient than separate generating systems and provide environmental, economic, and energy system infrastructure benefits,” according to the American Council for an Energy-Efficient Economy,
The conventional electric power plant has an efficiency rate around 25 to 38 percent. Since the generated electric and heat power are harvested and used close to the point of generation, the overall efficiency rate of a CHP is up to 90 percent.
Dietmar Wittman from the United States Army Corps of Engineers worked together with project manager Harald Mueller and Architect/Engineer Ulrich Dickert from the State Construction Agency to design and construct the state of the art system.
In April 2016, the CHP was installed in Camp Nainhof and began operation, providing energy to 110 buildings in the Camp Nainhof and Linderberg sections of the Hohenfels military installation. The plant is designed to produce 1.8 megawatts of power per year, generating roughly 50 percent of thermal energy (894 kilowatts) and 50 percent electrical energy (889 kilowatts).
The CHP generates around 30 percent of the yearly heat and electricity demand of the entire installation, achieving partial off-post power grid independency.
A CHP is considered optimally used if it runs at full capacity at least 5,000 – 7,000 hours per year. The unit in Hohenfels, however, runs more than 8,000 hours per year. It is shut down for only three weeks in the summer when heat demand is low to check the engines and perform maintenance. During those three weeks, a 16,000 gallon buffer tank is used to store and distribute any heat energy that is needed.
Hohenfels CHP reduces greenhouse gas emissions by 1,323 tons per year, greatly reducing the installation’s carbon footprint. In addition to the positive environmental impacts, energy costs are reduced by $900,000 per year. While the project was a costly investment, the four-year return on investment shows that the CHP is economically viable.
A second CHP of the same capacity is currently being built in another part of the Hohenfels military community and will start operation in spring of 2017.
In honor of USAG Bavaria Hohenfels dedication to energy reduction and sustainability, Paul Hlawatsch received the Secretary of the Army Energy and Water Management Individual Award for Energy Efficiency/Energy Management in August 2015 for his work on previous projects and initiatives.