Regional Operational Programme for the Pomorskie Voivodeship 2014-2020
Project Title: “Utilization of waste heat from biogas cogeneration in the district heating system of the city of Słupsk”
The project is an element of a broader concept of the Słupsk Bioenergy Cluster (SKB), within which local enterprises and energy communities should shift as extensively as possible from the position of an “industrial energy consumer” to that of an “industrial auto-producer” or business prosumer. The combined production of heat and electricity can serve as an element stimulating the development of local energy production and increasing the efficiency of generation and distribution. The existing local system requires significant capital expenditure in order to adapt to new legal standards and to increase system reliability. This creates an opportunity to combine the SKB initiative with the needs of shifting local infrastructure and energy transfer between two system operators: heat distribution and electricity distribution. The utilization of waste heat from biogas cogeneration will increase the energy efficiency of the district heating system of the city of Słupsk, reduce the emission intensity of energy production, and beneficially impact the costs of municipal services in the region. The dispersion of generation sources will improve heat transmission efficiency, introduce an element of competitiveness, and ensure better utilization of energy potential.
The project is implemented by “Wodociągi Słupsk” Sp. z o.o. as the Beneficiary.
- Date of signing the co-financing agreement: 17.08.2020
- Date of signing Amendment No. 1 to the project co-financing agreement: 18.12.2020
- Date of signing Amendment No. 2 to the project co-financing agreement: 21.12.2021
- Total project value: PLN 11,010,886.19
- Total value of eligible expenditures: PLN 8,045,740.54
- Co-financing value from the European Regional Development Fund: PLN 4,480,190.47
- Final project implementation period: February 2020 – June 2022
Project Objectives
The primary specific objective of the project is:
To increase the operating efficiency of the municipal energy infrastructure, restore the strong position of district heating, and create an attractive and competitive offer for network heat.
The implementation of the project will support the activities conducted by the City of Słupsk under the Low-Emission Economy Plan, as well as the district heating company Engie EC Słupsk, the operator and producer of system heat. It will reduce the costs of adapting system heat by providing a significant volume of waste heat derived from RES. It beneficially impacts the labor market and the attractiveness of the local economy, creates competition in the electricity market, and provides an opportunity for the further development of local energy production based on its own renewable generation sources.
Another objective of the project is:
To reduce GHG emissions in the local energy sector by utilizing the energy potential of biological waste and wastewater sludge in the RES installation and high-efficiency gas cogeneration.
The project aligns with the principles of the circular economy and significantly reduces emissions for electricity and heat production needs in the local market. The high calorific value of bio-waste produced by local industry and residents can be transformed into thermal and electrical energy in the digestion and cogeneration installations of the wastewater treatment plant and supplied back to the local economy. This will reduce production emission intensity, enable local producers of goods and services to obtain guarantees of origin for energy, and consequently allow the City of Słupsk and the region to achieve climate neutrality.
A complementary objective of the project is:
To create a business model that will beneficially and permanently reduce the pressure on municipal service prices caused by rising energy prices.
Project Scope
District heating in Słupsk is entirely based on coal generation sources, whereas waste heat is generated at the Słupsk wastewater treatment plant through biogas-based cogeneration. The concept of the project is to create technical and formal capabilities for its utilization in the municipal district heating system. In the combined heat and power (CHP) generation model using biogas and, supplementarily, GZ-50 gas, a significant amount of heat is generated, exceeding the consumption capacity for the wastewater treatment plant’s own needs. Consequently, waste heat is produced, which is lost through the radiators of the cogeneration units.
The initiatives undertaken to establish the Słupsk Bioenergy Cluster allowed for an effective solution. By connecting the wastewater treatment plant with the municipal district heating network at the heating substation of the “Trzy Fale” Water Park—which has substantial low-parameter heat energy requirements for heating pool water—it creates the potential to utilize waste heat from the treatment plant, while ensuring an alternative heat source from the network of the municipal district heating enterprise.
It is also vital to increase the production potential and reliability of heat supplies from the treatment plant, which is possible due to the growth in biogas production and the capability to utilize GZ-50 gas in high-efficiency cogeneration.
The investment option selected by the Company is optimal in terms of meeting the demand from the users identified in the project’s indirect beneficiary group, primarily by increasing the energy efficiency of the Company’s facilities and effectively eliminating health hazards associated with pollutant emissions (CO2).
The venture consists of expanding the cogeneration system at the wastewater treatment plant along with the expansion of the municipal district heating network system connecting the plant with the “Trzy Fale” Water Park facility in Słupsk. This task was divided into the following two stages:
- STAGE I – Expansion of the CHP unit (cogeneration system) at the wastewater treatment plant in Słupsk,
- STAGE II – Expansion of the municipal district heating system through the construction of a heating network from the wastewater treatment plant to the “Trzy Fale” Water Park, along with heating substations in these facilities.
Planned Project Effects
Taking into account all current emissions, including energy consumption from grid sources intended to be powered by the wastewater treatment plant’s CHP (Wodociągi Base, “Trzy Fale” Water Park), the expansion of the cogeneration system, the increase in its availability and efficiency, and the management of heat that is currently dissipated through emergency radiators will result in a CO2 reduction exceeding 30% compared to the baseline. The assumed reduction level stands at 3,486 tonnes of CO2/year. Furthermore, under the Stage II works, a district heating network with a length of approx. 1.55 km will be constructed.
Benefits of Implementation
The implementation of the project will reduce the costs of adapting system heat by providing a significant volume of waste heat derived from a renewable energy source. It will contribute to stimulating the development of municipal cogeneration systems and combined heat and power generation, and will beneficially impact the development of local energy production in a distributed model. The expansion of the cogeneration system at the treatment plant and the expansion of the municipal district heating network to the “Trzy Fale” Water Park will allow for competition in the energy market. The venture will enable the utilization of heat currently dissipated by emergency radiators and will bring about a significant CO2 reduction well above 30% compared to the baseline.
The project will have a positive impact on pricing, as it will be possible to distribute the operating costs associated with the functioning of the treatment plant’s energy infrastructure not only among sewerage service recipients but also among heat and electricity consumers distributed outside the Company’s installations.
With an appropriate scale of the venture, this will enable a decrease in the unit cost of energy generation and transmission using own infrastructure to a level that is competitive with the commercial energy market. The project leverages the potential of possessed resources to improve the security of energy supplies, rationalizes energy consumption, and reduces environmental impacts associated with its production through investments focusing on energy efficiency, renewable energy sources, and emission reduction.
Combined heat and power production will improve the energy balance and create opportunities for developing new competences and business models based on local renewable generation sources and the local labor market.