Where

Renewable Energy Sources in Latvia and Czechia

For more information please read https://vilniustech.lt/files/5102/255/12/3_0/-849.pdf

Borodiņecs, A., Skandalos, N., Ļebedeva, K., Odiņeca, T. On-Site and Nearby Electricity Production Potential in Latvia and Czechia. No: 12th International Conference “Environmental Engineering” (ICEE-2023): Conference Proceedings, Lietuva, Vilnius, 27.-30. augusts, 2023. Vilnius: VilniusTECH, 2023, 1.-8.lpp. e-ISBN 978-609-476-342-7. ISSN 2029-7092. e-ISSN 2029-7092. doi:10.3846/enviro.2023.849

For our project PV potential is one of the key statistics in terms of climate data, as it represents the potential level of solar energy utilization. According to Karásek et al, countries with annual PV performance exceeding 1000 kWh/kWp are suitable for the economic use of PV. Depicts the annual power output (kWh/kWp) of utility scale PV installation, considering mono-facial c-Si modules with optimal tilt angle, in Latvia and Czech Republic. A peak value of 1113 kWh/kWp, annually, is observed for the Western part of Latvia with an average of 1040 kWh/kWp for the whole country. PV potential is further increased for the case of Czech Republic, with peak and average values of 1175 kWh/kWp and 1113 kWh/kWp, respectively

• Karásek, J., Šebek, V., Kvasnica, J., Veleba, J., Anisimova, N., Pojar, J.: Energy Performance of Buildings in Danube Region. (2023).

Why

Energy prices

The energy costs are the main driving force for end-users to take a decision on investments in energy efficient measures including installation of renewable energy sources. The average nordpool price in 2021 was 0.09 Euro/kWh and in 2022 0.22 Euro/kWh.  While in 2020 – 0.03 Euro/kWh. This price doesn’t include trading services, distribution of electricity, connection provision and compulsory procurement component for renewable energy.   Pellets 0.03 Euro/kWh 2021 year and 0.1 Euro/kWh 2022 year with boiler efficiency 100 %.  Data form nordpool was used for in-depth analysis

https://www.nordpoolgroup.com/en/Market-data1/Dayahead/Area-Prices/ALL1/Hourly/?view=table

Who

End Users’ Electricity Usage Pattern

For this project, 31 apartments were selected for analysis. Each apartment is equipped with a smart electric meter that records hourly electricity consumption data. All collected data are anonymized, including only the number of inhabitants and limited information on major electric appliances.

As of now, data from the years 2020, 2021, and 2022 have been analyzed. A more comprehensive energy consumption analysis has been submitted to a peer-reviewed journal and is expected to be available by the end of this year.

Already done

Current situation with PV installation

Solar photovoltaic power installations have been the dominant force in the renewables industry for an extended period among all renewable technologies. While the installation of PV systems for single-family houses is a standardized and widely used technology, the integration of PV systems in multi-apartment buildings remains relatively rare.Integration of on-site energy production, such as rooftop PV, offers a promising solution for  decarbonization of a multiapartment buildings.

Number of of PV system installation in Latvia

The most popular residential buildings are five-story and nine-story multi-apartment buildings containing between 36 and 80 apartments. The developed two reference building models represents a typical ive and nine-story residential buildings comprising one-, two-, and three-room units. The number of inhabitants per apartment ranges from 1 to 5. The electricity consumption for each apartment type was based on the analysis of real measured data.

Results were presented at ASHRAE International Building Decarbonization Conference 2024 and will be publicly available by the and of 2004.

Project output Nr.2: Building scale

Optimization of Rooftop PV Systems

The analysis of modeled results indicates that it is optimal to install a rooftop PV system for the referenced building with a PV generator power (Case 1) of 16.56 kW and a PV generator area of 78.27 m². This is because installing the largest possible system (which greatly depends on the available roof space) would result in higher excess electricity, requiring storage. However, the generated energy would only be able to cover 33.28% of the total multi-apartment electricity demand. Of course, a larger system (Case 2) could cover 100% of the building’s electricity consumption for shared needs, but it significantly increases (almost twofold) the self-cost price and extends the payback period. The more detailed information could be found in https://www.frontiersin.org/articles/10.3389/fenrg.2023.1297297/full

Project output Nr.3: Building scale

Solution for rooftop PV system connection to the power grid

First simplified proposed solution – a rooftop PV system connected to the power grid. According to calculations, in this case, the average annual self-consumption rate of a 5-story building is approximately 40%. Maximizing economic results is closely related to self-consumption, which refers to the direct use of electricity produced by PV in the building. When PV production exceeds immediate demand, resulting in overproduction, this excess will be stored in the grid.

Project output Nr.4: Building scale

Connection schemes for integrating the building’s existing electrical network with the city’s electrical network

The distribution of solar PV panel energy within apartment buildings has earned significant research attention due to its potential to enhance sustainability and reduce electricity costs. Studies have investigated various technical solutions, with direct and indirect connections emerging as prominent strategies. Direct connection involves delivering solar power directly to consumers, optimizing energy utilization and potentially leading to cost savings. However, challenges such as securing consent from power distribution services, inverter regulation complexities, and control system uncertainties have been noted. In contrast, the indirect connection approach focuses on grid synchronization for power balancing and offers flexibility in battery integration. Challenges similar to direct connection are encountered.

The two technical solutions for distributing solar PV panel energy in an apartment building, direct and indirect connections, offer distinct advantages and disadvantages. In the direct connection approach, solar power is seamlessly delivered to consumers, potentially resulting in cost savings when the power distribution service (ST) grants consent for meter bypass. However, this method may encounter challenges in matching inverter power with varying consumption demands and navigating control complexities when the battery is depleted or generation falls short.

Project output Nr.5: Building scale

Implementation cost

Project output Nr.6: Building scale

Implementation Barriers

Decision-Making Process: For a typical multi-apartment building with 60 units, a decision requires the agreement of at least 51% of the apartment owners (i.e., 31 votes).

Ownership Structure: All apartments are privately owned, which can complicate collective decision-making and investment agreements.

Electrical Infrastructure: Many buildings are equipped with single-phase electrical systems and aluminum wiring, necessitating significant investments to upgrade the electrical installations.

Roof Condition and Obstacles: The roofs are not renovated and have numerous obstacles, including ventilation shafts, electrical fixtures, and TV and internet antennas, which complicate any potential renovations or installations.