Assessing the path to sustainable energy : a focus on optimal power generation methods for heat and electricity in Lahti, Finland

Abstract

This study assesses the environmental sustainability and energy efficiency of Lahti’s Kymijärvi II (gasification) and Kymijärvi III (biothermal) power plants, with the goal of providing policy recommendations for sustainable power generation. Kymijärvi II, operational since 2012, converts 250,000 tons of waste annually into 50 MW of electricity and 90 MW of district heating, significantly reducing carbon dioxide emissions compared to coal-based power plants. Kymijärvi III, which started in 2020, uses certified biomass with a capacity of 190 MW for district heating, aiding the closure of a coal-based plant and further lowering carbon emissions.

The study's primary objective is to promote green energy power plants to reduce greenhouse gas emissions and enhance sustainable energy production. It includes a comprehensive Life Cycle Assessment (LCA) of these power plants to determine their environmental impact and energy efficiency, adhering to ISO 14040 standards. The LCA evaluates the efficiency of converting primary energy sources into usable heat and electricity. The research highlights the varied dependencies and challenges of renewable energy sources such as solar, wind, biomass, and geothermal. While solar and wind energy are globally available, they are intermittent and dependent on climatic conditions. Biomass and geothermal energy, though more stable, are geographically limited.

Despite these challenges, renewable energy technologies can displace more environmentally burdensome energy sources, indirectly benefiting the environment. Lahti’s innovative approach to waste management and renewable energy production serves as a model for other cities. Lahti Energia’s efforts have enabled the city to produce 90% of its electricity emission-free and generate 95% of its district heating from recycled or renewable fuels, showcasing the potential for other municipalities to adopt similar sustainable energy strategies. The research also emphasizes the critical role of policy in fostering the adoption of sustainable power generation methods. It provides evidence-based policy recommendations aimed at aligning regional, national, and global sustainability goals with practical strategies. These include promoting circular economy integration, regulatory compliance, and stakeholder engagement to enhance overall energy production sustainability.

In conclusion, this study underscores the importance of comprehensive evaluations like LCA in optimizing renewable energy technologies. The insights gained can help policymakers, plant managers, and decision-makers develop environmentally responsible strategies for waste and biofuel management, contributing to global efforts to mitigate climate change.