Climate change, energy and emissions

Takaisin raportteihin


1. Climate change, energy and emissions

muoviaImproving energy efficiency for properties

Among the City of Lahti properties in regular use, the specific heat consumption for public premises was approx. 40.3 kWh/m³ and the specific electricity consumption approx. 16.3 kWh/m³ in 2017. For the Lahti and Hollola properties, no considerable changes in electricity and heat consumption were recorded.

In 2017, Hollola continued to take precautions in case of disruptions to electricity distribution. Hollola has implemented geothermal heat, and the Kalliola School is practically self-sufficient in terms of heat and electricity in case of a power failure. Koivukoto and the Hollola fire station have also implemented stationary emergency power equipment. Additionally, the municipality has a mobile emergency power equipment.

The new Southern Lahti catering center has focused on energy efficiency. The catering center can prepare 10,000 meals daily for the schools and kindergartens in the Southern Lahti area. Heat energy for the catering center is provided by a hybrid heat pump and district heating. The hybrid heat pump generates heat energy from the building’s refrigerating machines and cooling equipment. The cooling energy is also provided by a hybrid heat pump. The catering center has mechanical incoming and exhaust air ventilation with an effective heat recovery system. The roof boasts a 100 square metre solar panel system, which in 2017 produced 12.7 MWh/a of usable electricity for the property.

Towards sustainable power and heat production

The main environmental objective for Lahti Energy is decreasing CO2 emissions. This started to become a reality in 2017, when construction for the Kymijärvi III biothermal power plant began. Alongside the already operative BioPolttimo, the bioenergy production at Koskisen Ltd was also acquired through a merger. Vääksy is also ready to start energy production using biomass. With the investments made and those to come, CO2 emissions will decrease considerably.

Renewable sources of energy accounted for 40.53% of district heat production for the energy network. In terms of electricity sales, renewable energy sources accounted for 37.83% of sales based on the energy source distribution for 2016 (fossil fuels 26.01%, nuclear power 35.16%). The national energy source distribution for 2017 will not be published until Summer 2018.

Lahti Energy has replaced the oil containers and outlets for four of its heating plants in order to comply with the new legislation, while the oil storage capacity in the groundwater area has been reduced. These renewals are a continuation to changes already made in the past years.

2017 was a good year for the recovery and reuse of ash. The volume of ash produced was smaller than that collected for reuse. Previously piled ash was delivered for use at earth work sites, and the first steps in the use of ash in fertilizer production were taken with the ashes from BioPolttimo.

Lahti Energy has considerably increased the proportion of wind power in its acquisition of energy through cooperative energy producers. Lahti Energy has installed three charging points –each point can charge two cars– in Lahti. E-cars can be charged at Kauppakatu 31, at Sibelius Hall and at Lahti Sports Center. Additionally, Lahti Energy has developed other services for e-cars, including a service providing properties with charging infrastructure. The service development has particularly focused on the development and piloting of new energy management solutions and energy efficiency services. With the new solutions, properties can manage their energy consumption in a smart way.

In 2017, the Kujala Waste management area was looking into new energy solutions, including the use of solar energy and the recovery of heat produced as a byproduct of waste processing. All key operators in the Kujala area participated in the project. In Fall 2017, two solar power plants were constructed in the area of the waste sorting facility, producing over 80 MWh of electricity every year. In addition to energy production, the objective is to test different types of solar panels in an environment such as the Kujala waste sorting facility. The solar panel project is continued and developed further in cooperation with Lahti Energy. The objective is also to repurpose the closed landfill area. With a potential new power plant, the waste sorting facility’s energy self-sufficiency would go up from the 5% to approximately 15%.

Municipal total electricity consumption increased considerably due to the consolidation of municipalities.

Electricity consumption (kWh per resident per year)



Electricity consumption data for 2017 not available in Spring 2018

The municipalities of Nastola and Lahti were consolidated in 2016, as were the municipalities of Hollola and Hämeenkoski.

Specific electricity consumption in municipal premises (kWh per cubic meter)



Heat consumption in municipal premises (kWh per cubic meter)



The municipalities of Nastola and Lahti were consolidated in 2016, as were the
municipalities of Hollola and Hämeenkoski. The figures for Hollola are not weather-normalized, those for Lahti are.

Carbon dioxide emissions from power plants and industries, Lahti (tonnes)




The circular economy of ash in Päijät-Häme region. 

The circular economy

As in the past years, nearly all waste received by Päijät-Häme Waste Management Ltd (PHJ) was utilized as materials or energy. PHJ aims to enhance their use of renewable sources of energy in their own operations, too. Fuel was made from separately collected energy waste for use at Lahti Energy’s Kymijärvi II power plant and other power plants. Mixed waste was also delivered for use in energy production. Biowaste was processed at LABIO Ltd digestion and composting plant, where it was converted into biogas and compost.

The utilization rate of municipal waste received by PHJ amounted to 95% in 2017. Of the waste, 32% was utilized as material and 63% for energy. A total of 5% of municipal waste was used as landfill, amounting to 26 kg per resident.

Amount of mixed (previous landfill) waste produced by Lahti municipal departments (tonnes)


The mechanical sorting plant LATE built at the Kujala waste sorting facility in 2016 utilizes various screening and separation techniques and was implemented in 2017. The plant should raise the recycling rate of municipal waste up to the objective of 50%. The processing of waste was impeded by a fire at the Murre crushing facility's magnetic station in May of 2017, which resulted in damages of over one million euros but did not impact the rate of waste recovery and reuse.

Amount of municipal waste to be disposed by landfilling in PHJ area (kg per capita)

Päijät-Häme Waste Management area23448402120351526


The reuse rate of municipal waste received by PHJ (incl. energy use) (%)

Päijät-Häme Waste Management area5187.990.695.095929695


The recycling rate of municipal waste received by PHJ (reuse as materials) (%)

Päijät-Häme Waste Management area3231312932

Lahti Aqua Ltd has an important role in environmental protection, as they treat wastewaters for 140,000 residents and for the businesses operating in the region. Lahti Aqua’s Kariniemi, Ali-Juhakkala and Nastola wastewater treatment plants treated a total of 13 million cubic metres in 2017, and the treatment results fulfilled all permit conditions at an annual level. The plants are biological-chemical wastewater treatment plants where solids and sand are removed from wastewater mechanically, organic matter and nitrogen biologically and phosphorus chemically. The treated wastewater is made hygienic using UV light before being discharged into water systems. Thanks to the efficient UV light treatment, nearly 100% of fecal microbes are eliminated. The UV treatment considerably improves the hygienic quality of the River Porvoonjoki.

100% of the biogas generated in the treatment of sludge at the Kariniemi and Ali-Juhakkala wastewater treatment plants is utilized as heating energy. Of the total 15,182 MWh of energy produced, 51% was used for heating the wastewater treatment plants and the rest was sold to Lahti Energy for use in the district heating network. The heating energy input to the district heating network was equivalent to the annual heating energy consumption of approximately 500 detached houses. After the digestion and utilization of gas, 14,650 tonnes of dried sludge was delivered to LABIO, where the sludge is composted. LABIO produces soil conditioners through composting and biogas at their biogas plant for Gasum Ltd, who then refine the crude gas further into vehicle fuels.


Loading of wastewater from Lahti and Hollola on the River Porvoonjoki (tonnes)

Nitrogen (NH₄)2629.331.414.4164.711


Loading of wastewater from Nastola (tonnes)

Nitrogen (NH₄)0,30,50,10,20,60,71,1


Future plans and challenges:
• Continuing climate change mitigation, while preparing for the changes already under way.
• Hollola will continue to implement back-up power solutions for public facilities. • Lahti Aqua has launched a development project with the goal of finding an energy-efficient way to control wastewater processes.
• The PHJ energy infrastructure development project will continue. Development of plant functionality.
• Increasing the number of vehicles running on biogas and electricity.



© Lahden kaupunki. Kaikki oikeudet pidätetään.