Our city is located in a temperate coniferous-mixed forest zone with cold wet winters. The mean temperature of the warmest month is at least +10 °C and the coldest can reach -3, with moderate rain in all seasons. “Heating degree day” describes the demand of energy needed to heat the buildings. The “heating degree day” is calculated by adding up the differences of the daily indoor and outdoor temperatures, of the whole month (Fig. A1.).
Complete Green Shift in Local Energy Production of Lahti
Lahti Energy Ltd (part of the Lahti City Group) has invested in energy efficient and sustainable district heating. The network of district heating is extensive, with over 90% of the population and 99% of the municipal buildings using district heating.Over 95% of the district heating is produced energy efficiently in the combined heat and power plant of Kymijärvi I-II. The Kymijärvi II power plant (2012) is a unique gasification power plant that uses solid recovered fuel. The net efficacy of gasification is better, in comparison to combustion, which emphasizes that gasification represents the BAT of the much-argued energy-utilization of waste. However, the City of Lahti is currently undergoing a complete change in centralized energy production, by replacing the old Kymijärvi I power plant with the new Kymijärvi III plant, by 2020 (Fig. A2). When procuring biomass, Lahti Energy demands FSC or PEFC forestry certificates.
Our actions to improve energy efficiency and the partial change to renewable energies has dropped Lahti’s CO2 emissions per capita from 10.99 tons in 1990 to 6.9 tons of CO2e in 2015. The total emission has dropped from 1 023.9 kilotons of CO2e in 1990 to 717.1 kilotons of CO2e in 2015.
Increasing the share of renewable energy in district heating significantly increases the use of renewables in total (Fig. A2, A3, A4). In 2015, 42.65% of the district heating was generated with renewable sources.
Energy Efficiency of Municipal Premises
Lahti Premises’ energy consumption (electricity + heat) decreased from about 70 kWh/m2 to about 57 kWh/m2, between 2000 and 2014. The total energy consumption of municipal premises (without annual meteorological correction) decreased over 7% between 2005-2015 (Fig. B1). The City of Lahti signed a new Energy Efficiency Agreement for 2017-2025, targeting a further 7% energy saving by 2025 (from the 2017 level). This implements the EED-EC.
In 2015, Lahti Premises signed an ESCO contract with Siemens Ltd . The contract includes energy efficiency investments in ten large real estates owned by the city. The target is to save about 6 GWh (about 3%) of the total energy consumption. Part of the ESCO project includes building a solar power plant in the Lahti Winter Sport Arena.
Lahti Housing Ltd had managed to save 8 949 MWh of energy by the end of 2016, which was 34% greater than that targeted.
Improving Energy Performance
Integrated District System Solutions
In 2012, KymijärviII, which is an innovative combined heat and power waste gasification plant, was completed (investment 165 M€) (Fig. B3).
Eco-efficient Energy Solutions
In 2015-2016, the “Eco-efficient Energy Solutions” project ran. It included developing an e-service for property owners and residents. The service uses open data sources (e.g. age and energy efficiency of buildings) and maps (e.g. geothermal energy potential and solar radiation maps). The e-service assists in comparing sustainable energy solutions, suitable for each particular building, and acts as a contact channel to local businesses. Budget 190 000 €.
Continuing Master Planning Process
Urban planning has a major effect on long-term solutions for effectiveness of urban structure, and traffic and energy solutions. The City of Lahti has an innovative 4-year-cycle, which continues the master planning process, with lofty environmental aims. Environmental and climate impact assessments have been conducted for the latest Master Plan and extended to 2030. In 2015, 82.8% of residents will be living within a walking or intensive public transportation zone (Fig. B4). Urban planning aims to consolidate the urban structure, within these zones, while preserving green areas. Green areas are important, as storm water risks have been identified as one of the climate change risks in Lahti.
Energy Efficient Housing
In 2012, Lahti Housing Ltd constructed three low-energy houses (56 rental apartments). The houses use geothermal or solar energy, employ energy recovery ventilation and have an excellent energy class. Also, the electrical system is energy efficient. The buildings have 20 solar panels (area 43 m2).
In 2013, an almost zero-energy house was completed by a company providing housing for the elderly (part of the Lahti City Group). The building uses central heating and partially solar energy. The consumption of electricity and heating energy is 50% less, compared to similar traditional house. In 2016, low-energy house (energy class A) for elderly was completed, building uses district heating and solar energy (Fig. B5).
WWF Earth Hour City Challenge
In 2015, Lahti was awarded in the WWF Earth Hour City Challenge. Lahti was the Finnish winner that year, and among the 16 best in the world. The evaluators appreciated the energy investments and the concrete solutions that Lahti has made.
Actions and Investments
Towards 100% Renewable: Kymijärvi III
Lahti Energy Ltd is aiming for development of local energy production to become 100% renewable or emission free (Fig. A2). The biomass used in Kymijärvi III will largely come from nearby forests and will create around 75 new jobs. The energy efficiency of Kymijärvi III is created through the use of the latest technology, heat recovery and condensing water from combustion gases. Efficient purification of condensation water enables water to be released into the river, as well as enabling it to be used at the plant. Heat recovery will lower emissions (SO₂, NO/NOₓ, PM) significantly, which will affect the air quality. Resultant ash can be used as fertilizer in forests.
Sustainable Energy Action Plan (SEAP)
The Mayor of Lahti signed the Covenant of Mayors in 2012. The new CoM for Climate & Energy is currently under preparation. A SEAP was published in 2013, it includes energy actions and plans for the different sectors of the City, as well as from Lahti City Group organizations and companies. Lahti has promised to decrease its GHG emissions by 35%, from the 1990 level, by 2020. The SEAP was updated in 2015. Almost all of the 42 actions are in progress.
Continuous Master Planning
A new round of Master Plan development for 2017-2020 has been started. Targets will be found in close participation with residents, decision-makers, organizations and experts. Because Lahti is now bigger than ever, we have new challenges such as maintaining carbon storage in forests and livable villages.
Challenges and Actions
We have a strong focus on improving the energy efficiency of the traffic system. Traffic GHG emissions, in Lahti, grew by 17% between 1990-2015. However, traffic output simultaneously grew by 59.5%. This is a national challenge; although modern cars and buses have lower emissions, the total traffic increase has been so dramatic that it has overtaken the positive developments, in the traffic sector. A preliminary long-term decision has been reached by the City of Lahti for, public transport buses to be changed to electric buses (Fig. C2). In other logistics, the use of biogas cars will be enhanced.
Lahti will soon start a large innovative project, CitiCAP (2017-2020), that aims to build a holistic data platform for mobility and to build, pilot and implement a Cap-and-trade system for consumer mobility.
Heating will remain a significant part of energy use, in the future. New operational models are being developed, at Lahti Energy, to adapt district heating production and consumption, in order to save the environment.
Goal is to use public building space more efficiently. This has the greatest energy savings potential, but implementation is challenging. All new buildings, constructed by the Lahti City Concern will be low- or zero-energy houses. The same principle will apply in retrofitting, whenever possible. New funding schemes, as Munifin Green Bonds, will be used.
Consumption will be monitored even more efficiently.Remote reading of heat and electricity, and hourly measurements in most premises. An alarm function to indicate changes in values.
Lahti will continue with the Energy Efficiency Agreement in the next period of 2017-2025, with an aim to lower energy consumption by 7%.
Päijät-Häme Waste Management Ltd is planning to cover an old landfill with solar panels.
Finnish Sustainable Communities (FISU)
In 2016, Lahti joined the FISU Network. We will strive to be carbon neutral and waste-free, and to curb overconsumption by 2050. Many co-creation methods and participatory events and tools will be applied to further collect ideas for the implementation of these plans. The FISU roadmap will be integrated into the new Environmental Programme 2017-2030, including: comfortable, safe and diverse environment, energy production and use, mobility and city structure, consumption and circularity, food, and water.