Braking Energy Heats Trams and Saves Electricity | Kaupunkiliikenne x Lumikko
Since 2013, Helsinki trams have been equipped with a braking energy recovery system developed and manufactured by Lumikko, resulting in significant energy savings for public transportation in the Helsinki metropolitan area. With this system, Kaupunkiliikenne Oy collects braking energy from trams and uses the recovered energy to heat the trams. This approach saves both electricity and costs.
Lumikko’s regenerative braking system supports Kaupunkiliikenne’s goals and provides significant energy savings.
When a tram brakes, the innovative system collects the energy generated from braking, stores it, and eventually converts it into heat, which is then directed to warm the passenger compartment during cold weather. Braking energy can cover up to 85 percent of the energy consumption required for heating the entire passenger compartment.
“This way, we can utilize energy that would otherwise be wasted and reduce the need for other energy sources. Obtaining heating energy largely ‘in-house’ also significantly reduces the heating costs of tram passenger compartments. Kaupunkiliikenne Oy aims to develop the entire infrastructure and transport service industry towards carbon neutrality through its choices. One way to do this is by using products like the braking energy recovery system,” says Maija Sarpo, Sustainability Manager at Kaupunkiliikenne Oy.
Thanks to the system, a total of 37.4 GWh of energy has been saved over 12 years. This is equivalent to the annual electricity consumption of approximately 1,870 large detached houses or 0.44 percent of the total electricity consumption of the Helsinki metropolitan area in 2023. Annually, a single tram saves about 74,000 kWh, which can be compared to the annual electricity consumption of four electrically heated detached houses.
Currently, the braking energy recovery system is used in 70 trams operating in the Helsinki metropolitan area, including Artic trams, articulated trams, and light rail trams. The system will also be installed in trams operating on Kruunusillat in the future. The system has been designed and manufactured by the Finnish company Lumikko Oy.
“Lumikko has over 30 years of experience in climate control and thermal management solutions for rail transportation. Our first systems were designed for diesel locomotives back in 1992, and today, Lumikko’s technology is present in all trams operating in Finland. Utilizing braking energy for passenger compartment heating is a concrete example of how our product development supports both energy efficiency and more sustainable urban transport. We are proud to contribute to reducing emissions and saving energy,” says Lauri Latvala, Lumikko’s Owner & CEO.
