Bolzano bets on hydrogen-fueled cogeneration to reduce polluting emissions

Bolzano thermal storage facility. Credits: IDM Südtirol


To spend a warm and comfortable winter, Bolzano citizens are currently relying on their local Combined Heat and Power plant (CHP) using natural gas engines for the supply of heat and electricity and operated by Alperia Ecoplus, partner of the Sinfonia project in Bolzano. While electricity is fed directly into the grid, heat produced in winter is used to back up the district heating network. As in any other combustion process, the operation of a CHP plant produces polluting emissions, such as unburned methane, which is 22 times more polluting than CO2 as a greenhouse gas.


In view of reducing these emissions, experts from Alperia’s Engineering & Consulting decided to test innovative gas blends of hydrogen and natural gas for the combustion process at one of the two engines of Bolzano cogeneration plant. Within that experience, Sinfonia partners managed to replace up to 30% of the natural gas with green hydrogen produced with renewable hydroelectricity. As a result, experts measured significant reductions in polluting emissions such as nitrogen oxides (NOx), unburned methane released in the atmosphere (CH4) and carbon dioxids (CO2) in the exhaust gas. On top of that, the special burning characteristics of hydrogen have enhanced the combustion process within the engine.


At the occasion of the site visit organised on 27 November 2017 in Bolzano, Stephan Hasse, senior engineer at Alperia, presented the first draft results of these tests to the European Commission and Sinfonia partners. These results, detailed in the figure below, will be analysed and evaluated in detail in the coming months.


Comparison of emissions without / with hydrogen blend in Bolzano CHP plant:


“As a local and renewable energy source, green hydrogen could represent a significant part of European energy production in the future”, says Daniele Vettorato, research group coordinator at EURAC Research, partner of the Sinfonia project in Bolzano, “Thanks to this new smart co-firing system tested in Bolzano, the city will be able to make substantial progress towards the achievement of its greenhouse gases emissions reduction targets.”


As of 2018, the Medium Combustion Plants directive from the European Union [(EU) 2015/2193] will impose stricter limits for the emissions of combustion plants with a thermal input between 1 and 50 MW. In that framework, Bolzano “smart cogeneration project” shows that the use of hydrogen in combustion processes can be an effective measure to reduce emissions. In the future, this system could help making the air of the alpine city even cleaner and improve the quality of life of all citizens.