Return to CityLoops Data Hub
Sector-wide Circularity Assessment
for the biomass sector


The EU Horizon 2020 funded CityLoops project focuses on closing the material loops of two central sectors of any city in terms of material flows, societal needs and employment, namely the construction and biomass sectors. Due to their sizes, they represent a considerable opportunity for cities to transform their metabolism and economy towards a more circular state.

Within this project, seven European cities, amongst those also the City of Mikkeli are planning to implement demonstration actions to kickstart their circularity journey. To better understand what the current circularity status quo is, as well as the impact of these actions, and the efforts needed to transform their sector, a Sector-Wide Circularity Assessment method was developed. This method combines a circular city and circular sector definition, a material flow and stock accounting method, as well as circularity indicators. The sector itself was defined in terms of a number of representative materials that make up a large share of the sector and associated economic activities. The biomass sector is made up of 12 materials, depicted as icons here, which were studied along the entirety of their supply chains. Altogether, these elements help to set a solid knowledge and analytical foundation to develop future circularity roadmaps and action plans.

Dairy products
Fodder crops
Garden and park materials
Live animals
Oil-bearing crops
Roots, tubers
Sugar crops

The assessment was carried out by the cities themselves after receiving extensive training in the form of courses on data collection (construction and biomass) and data processing. Numerous additional insights can be found in the individual Data Hubs of each city.

This current Sector-Wide Circularity Assessment report provides contextual information on the city and the economic sector under study. It then illustrates how circular these sectors are through circularity indicators and a Sankey diagram. Finally, it analyses and interprets the results, presents the limitations from the data used and offers recommendations about how to make this sector more circular.

(* The italic texts in this report were written by Metabolism of Cities' Aristide Athanassiadis and Carolin Bellstedt. They provide relevant general information and serve as connecting elements of the single report parts.)

Urban context

To contextualise the results of the sector-wide circularity assessment, this section provides population and land use information data of the city. In addition, population and area of the city under study, as well as its corresponding NUTS3, NUTS2 and country were included. Data for these scales were added to better understand how relevant and important the approximations are when downscaling data from these scales to a city level.

3,229 km2
19,130 km2
Pohjois- ja Itä-Suomi
236,450 km2
390,908 km2

Population of Mikkeli

The population development in Mikkeli

In 2019, there were 53 130 inhabitants in the city of Mikkeli, of which 13.9% were aged 0-14, 60.2% were aged 15-64 and 25.7% were over 65 years old. The population of the city of Mikkeli has been slightly declining in the 21st century, but since 2016 the population change has clearly accelerated and the city lost almost 1 400 people between 2016 and 2019. The negative demographic development of the city of Mikkeli is largely the result of two components: natural demographic change has accelerated slightly, but especially outward migration (particularly emigration of young adults) has increased considerable in 2016-2019. In 2019, Statistics Finland published a new population forecast for the city of Mikkeli. The city’s population is predicted to decline by 11 % by 2040. (Kumpusalo 2020, Mikkeli Development Miksei Ltd)

In 2018, Mikkeli was the 18th largest city in Finland by population. (City of Mikkeli website)

Land use

  • Agricultural areas
  • Artificial surfaces
  • Forests
  • Roads
  • Water bodies
  • Wetlands

Data source

Living in Mikkeli

There are various living environments in Mikkeli. These include a growing downtown area, developing agglomerations and the quiet of the rural area. Living in Mikkeli is divided in two main area types: city/agglomerations and dispersed habitat/rural areas. There are 10558 summer cottages by the lake shores of the rural areas of Mikkeli. This makes the city the second most popular summer cottage areas in Finland. In Mikkeli, there are around 700 lakes and ponds and water covers 424.7 km2 of the city. In 2019 there was 12,747 ha of agricultural land in Mikkeli and 479 farms in total. (Riihelä et al. 2015)

Economic context of biomass sector

This section puts into perspective the economic context of the sector under study. It describes how many people are employed in this sector, as well as who the main actors involved (from all lifecycle stages for the sector’s materials) are.

GVA (monetary value, in €) Employees
Mikkeli 353,200,000 653
Etelä-Savo 784,800,000 3,724
Pohjois- ja Itä-Suomi 9A 9B
Finland 13,750,000,000 65,159

The biomass sector in Mikkeli

Mikkeli is rich in forest resources and water bodies, but its industrial production relies heavily on the forest cluster surrounding the city. The major industries in Mikkeli are in mechanical wood processing and engineering. According to Kumpusalo, important future trades in Mikkeli might be with the production of various bioproducts, expertise in bioenergy and environmental technology. (Kumpusalo 2020, Mikkeli Development Miksei Ltd)

The biomass sector is smaller in Mikkeli compared to the surrounding areas in South-Savo region. In South-Savo, forestry-, farming- and fishing industries are the fourth largest in employment (Etelä Savo Ennakoi 2021). In Mikkeli, these are only the twelfth largest industry sectors in employment. The most significant employment sectors in Mikkeli are in health- and social services, manufacturing and in wholesale- and retail trade. (Data of Statistics Finland on industries and employees in Mikkeli)

The actors of the biomass sector

Actors in waste collection and treatment

The main actors in waste collection and treatment in Mikkeli are seen in the map of actors. Metsäsairila Ltd. is the municipal waste company of Mikkeli. Metsäsairila has one main waste collection- and treatment area and three smaller waste stations in conurbations in Mikkeli. There are several other companies in the waste business such as RL Huolinta Ltd. which concentrates in the collection of waste. Mikkelin Romu Ltd. mainly recycles metal, wood, cars and CDW material. Lassila & Tikanoja Ltd. collects and recycles paper, glass, cardboard, metal and plastic. In addition to waste stations there are around 60 recycling points in Mikkeli where one can recycle paper, glass, cardboard, metal and plastic.

Actors in recycling

Mikkelin Toimintakeskus assoc. focuses on reuse by fixing and upcycling goods and materials. They collaborate with the waste companies and sell products in several stores in Mikkeli. ViaDia Mikkeli assoc. and Mikkelin Työttömät assoc. both collect food waste (expiring food) from grocery stores in order to distribute it as food aid.

![]( [Data source](

Actors in production of food

In Mikkeli area, there is some primary production of food, but only a little of further processing it. Cultivation of vegetables, berries, cereals and production of milk have had an important role both in South-Savo region and in Mikkeli. As it can be seen in the charts below, carrots, cabbages and lettuces are the main vegetables produced in Mikkeli. Strawberries, currants and raspberries are the main berry products cultivated in the area. For cereal products, farming oats is clearly favoured.

Milk production has been important in the South-Savo area, but for several years has been steadily declining. In Mikkeli there is less milk production than in the surrounding areas of the city, and farming is shifting towards the municipalities surrounding it. This is well expected, since to enhance production, the size of the farms and fields need to grow and there is simply more farming land available in the rural areas. The number of farms are also declining, since small farms either need to invest and grow in size or find other means to support their livelihood in the countryside.

![]( [Data source]( ![]( [Data source]( ![]( [Data source]( ![]( [Data source](

Actors in manufacturing of food

In further processing these farmed goods, the main actors in Mikkeli are Suur-Savon Leipomo Ltd. for bread and other baking products, HK Scan Mikkeli Ltd. which produces meat products, sausages and ready-meals. There are plenty of smaller producers in Mikkeli, which some can be found in this link.

Actors of biogas refineries and the production and distribution of heat, energy and gas

Etelä-Savon Energia Ltd. is a local energy company in Mikkeli that produces energy, heat and biogas. At the Pursiala power plant, Etelä-Savon Energia Ltd. (ESE) produces about 100 GWh of electricity, 400 GWh of district heat and 20 GWh of industrial steam annually. The plant is fueled by wood 80% and peat 20%. ESE owns part of the biorefinery Biohauki Ltd and distributes transport biogas through 4 of its biogas stations in Mikkeli and Kuortti. ESE also distributes the biogas produced from the new biogas refinery BioSairila Ltd.

Biohauki Ltd. is a small biogas refinery in the rural area of Haukivuori, designed to produce methane from the manure of livestock and hay from the surrounding areas. The by-products of this refinery is then transported back to the farms inorder to use as soil improvers for the cultivation of crops.

![]( [Data source](

BioSairila Ltd. began its biogas production in year 2021. Biosairila is owned by the municipal waste company Metsäsairila Ltd. (70%) and the energy company Etelä-Savon Energia Ltd. (30%). The biorefinery treats sewage sludge, biowaste and agricultural and industrial by-product streams generated in Mikkeli and the surrounding areas. The end products of biorefining is biomethane processed into transport fuel and fertilizer and soil improvement products. At full capacity, the plant will produce approximately 1.5 Mm3 (1,000 tons, 15 GWh) of transport biomethane, which corresponds to the annual consumption of approximately 2,000 passenger cars.


To monitor the progress of this economic sector towards circularity, a number of indicators were proposed and measured. Altogether, these indicators depict several facets of circularity of the sector. As such, they need to be considered in combination rather than in isolation when assessing circularity. In addition, these indicators can be compared to other cities or spatial scales (such as the country level). However, this has to be done with great care and use of the contextual elements in the previous sections of the report. Finally, the value measured from these indicators can be traced over time to track the sector’s progress towards circularity.

Indicator number Indicator Value Unit
34 Domestic material consumption (DMC) 906,983.00 Tonnes/year
41 Share of secondary materials in DMC 0.33 %
48 EU self-sufficiency for raw materials 1.04 %
53 Quantity of material for anaerobic digestion 0.00 Tonnes/year
56 Quantity of material for composting 7,469.00 Tonnes/year
57 Amount of sector specific waste that is produced 22,733.00 Tonnes/year
58 End of Life Processing Rate 40.17 %
59 Incineration rate 0.00 %
61 Landfilling rate 0.00 %

Indicators 34, 41, 48

  • Domestic material consumption (DMC)
  • Share of secondary materials in domestic material consumption
  • EU self-sufficiency for raw materials

In the strategy of the city of Mikkeli (strategy 2018-2021): Establishing new opportunities from the use of material flows in Mikkeli, the idea is to increase the utilisation of reused and recycled materials. This saves in extraction and use of virgin materials. In Mikkeli, biowaste has been recycled for years into soil products, but now the intention is to upcycle the biowaste material into biogas. From the by-products of the biogas process, the nutrients are developed into soil improvers and fertilisers. By producing and using biogas from biowaste, the city is able to reduce the usage of fossil fuels. The extraction of nutrients from the reject water of the biogas process, reduces the need to extract and use virgin fertiliser chemicals.

Materials such as wood and peat have been a stable source of energy and heating in Mikkeli. Now peat is being slowly abandoned because of the negative environmental effects. Locally produced peat for energy use, is coming to an end. New sustainable and local energy sources need to be developed.

Wood is still an abundant resource in Finland and Mikkeli, but cold winters set a challenge in self-sufficiency. It is not sustainable nor economical to use logs that can be further manufactured, for energy- and heating purposes. This is well respected throughout Finland, so instead wood chips and other by-products from the forest industry are used at district heating plants such as Etelä-Savon Energia´s Pursiala plant. During cold peaks in winter, there is occasionally shortage of local wood chips and by-product wood for heating purposes. This is then imported from other parts of the country or Russia. Mikkeli keeps on pursuing to be more sustainable in its energy- and heat production.

Concerning the indicator 41, the expected outcome of these actions in Mikkeli is 5% reduced consumption of virgin materials at city level, compared to the start of the CityLoops project.

The results of the Sector-Wide Circularity Assessment research for domestic material consumption in Mikkeli is 17 tonnes per capita. This is a slightly higher value when compared to the average in Europe of 13.4 tonnes per capita. The corresponding value in Finland is at 31.6, making the difference to Mikkeli at 14 tonnes per capita. This result is very interesting and seems that in this comparison the city of Mikkeli is doing quite well with using less resources in material consumption.

Indicators 53, 56, 57, 58, 59, 61

  • Quantity of material for anaerobic digestion
  • Quantity of material for composting
  • Amount of sector specific waste that is produced
  • End of Life Processing Rate
  • Incineration rate
  • Landfilling rate

In the city strategy of Mikkeli, the aim is to reduce traffic emissions and increase the use of biofuels for city transportations. In this aim, it is vital to be able to provide the city with enough biofuel made of local biowaste. Further promoting and adding the coverage of the biofuel distribution network, as well as growing the number of biofuel vehicles used in the city is needed. This would then set a good base for a more sustainable and self-sufficient production and use of fuels.

Previously, there has only been one biogas refinery in Mikkeli, Biohauki Ltd. This plant was designed to start its production in the year 2017, but because of having problems with its construction, began its production in the year 2020. Now even larger biogas refinery, BioSairila Ltd., has been recently taken to use in year 2021.

To be able to produce and distribute more biofuels in Mikkeli, more biowaste is needed to be collected in the city. The city strategy (2018-2021) has the aim of increasing the recycling of biowaste by improving sorting and collection (residential waste, waste recycling: Baseline 98.6% / Target 99%).

The study in Mikkeli (South-Eastern Finland University of Applied Sciences´ study of waste composition in Peitsari area) show that there is still much biowaste to be salvaged from the municipal solid waste going to incineration. This biowaste could be recycled if it were collected separately and placed in the proper biowaste collection bins by the citizens. The study showed that about 35% of the municipal solid waste is of recyclable biomaterial. This raw material could be used in upcycled products such as biofuel and soil products. Landfilling is not an issue in Finland or Mikkeli, since non-hazardous bio-waste has not been landfilled, but has mostly been composted into soil products.

The CityLoops project in Mikkeli has several expected outcomes for the collection, treatment and use of biomaterials. These are:

  • Increasing upcycled amount of CDW/soil and organic waste 50% by the end of project.
  • Increasing recycling/reuse rate of CDW/soil and organic matter: Increased recycling rate of bio-waste in the demonstration area (Peitsari) within the demo action.
  • Increasing recycling/reuse rate of organic matter within the city boundaries: increase of soil products made from bio-waste.
  • 10% reduction in the amount of organic waste landfilled or incinerated.

Data source

In the results of the Sector-Wide Circularity Assessment research, it should be noted, that some waste is exported to incineration. This waste includes the municipal solid waste (MSW) and the biowaste within MSW (not recycled by the citizens). Stump waste and other non hazardous wood waste are used mostly as raw material for the Pursiala power plant. These organic matters are substantial in weight when compared to the total amount of biowaste accompanied for. Also ash (from the Pursiala plant) and grease separation well sludge cannot all be recycled into upscaled products, so they are recycled in building the grounds of the landfill.

Benchmarking the different indicators need more insight in the particular matters that are studied for the comparison, in order to be just, and to be taken into account properly. It is possible, that wood materials, ash and grease are not accounted for in the compared numbers of the studied EU countries. Exporting some materials to incineration, might not give the right picture in the calculated indicators. Perhaps there should be developed a standard for various biowaste materials accounted for in waste management, in order to compare information between other EU countries. For more information about the different biowaste materials that are included in the study of biowaste in Mikkeli, please see the collected data in the graphic above.


Measuring circularity is a data heavy exercise. Numerous datasets were collected and visualised throughout the sector-wide circularity assessment process. To synthesise these findings, a Sankey diagram illustrates how material flows from the studied economic sector are circulating from one lifecycle stage to another. The height of each line is proportional to the weight of the flow. This diagram therefore helps to quickly have an overview of all the materials flows that compose the sector and their respective shares. The flows that are coloured in light blue in the Sankey diagram, are return flows. This means that they flow in the opposite direction of the lifecycle stages and are subjected to reuse, redistribution, or remanufacturing. Their size relative to the others is a good indication for the materials' circularity.