Case Study: Nordic Solar, Largest Solar Park in Lithuania to Date

Project Overview

Nordic Solar A/S developed the largest solar park in Lithuania to date, boasting an impressive capacity of 100 MWp. This project involves the installation of more than 150,000 bifacial solar modules and 300 inverters across a challenging hilly terrain. Detra Solar played a crucial role in the project by providing effective design solutions that ensured the solar park’s maximum efficiency. Through meticulous optimization efforts, including a significant reduction in LV AC cable length and innovative design solutions to address the complex terrain and environmental limitations, Detra Solar successfully maintained the desired 100 MW DC power capacity, overcoming initial challenges that could have led to a significant power decrease.

Client

Danish-based solar energy developer Nordic Solar A/S

Project Location

Moletai Region, Lithuania

Key Deliverables

The project focused on delivering highly detailed and accurate supportive documents for construction, including:

1. General Plan: Overall layout optimizations of the slide-in fixed-tilt PV system within the provided boundary.
2. Fence Layout: Design and placement of fencing around the site.
3. CCTV (Camera) layout: Design, placement and coverage of security camera equipment on site.
4. Various Elevation Drawings: Detailed side views of the fence, road, mounting system (PV, inverter, sensors, weather stations), CCTV, string wiring, and other elements.
5. Stringing Layout: PV String design and labeling system on a string level.
6. String Cable Duct Layout: Distribution of string cable ducts on site.
7. DC/AC Cabling Layouts: LV cables distribution on site (string/inverter/MV station level).
8. Fiber Optic Cable Layout: Network and communication system design of fiber optic cables.
9. Earthing Layout: Design of earthing and lightning protection system.
10. Trench Design: Design of trenches for cabling and water management on site.
11. PVSyst Yield Analysis: Simulation and analysis of the PV system’s energy yield while accurately evaluating various shading on site.
12. Bill of Materials: Comprehensive list of equipment and quantities required for construction.
13. Ampacity calculations: Main power cables selection for the project.
14. Pilling information: Preparation of module structure coordinates, pile length lists with leading PV software – PVcase.

Unique Challenges

• Hilly Terrain: The project required a thorough cut-and-fill analysis to manage the complex topography of the Molėtai region, ensuring that 100 MW of solar panels could be mounted successfully.
• Cost-Effective Design: Ensuring the design was cost-effective while connecting 14 MV stations and 300 inverters across five different areas.
• Environmental Protection: Incorporating measures to preserve biodiversity and enhance local ecosystems.

Contributions and Solutions

• Piles Layout Consultation: We provided consultation on the piles layout using PVcase and offered assistance in determining appropriate pile lengths in challenging areas of the site, particularly in the most mountainous regions, prior to the construction work.
• Optimized Cabling and Stringing: We optimized the cabling and stringing configurations based on the client’s requirements in order to optimize costs.
• Customized Solutions: We implemented the most optimal solutions tailored to the specific information and needs provided by the client.
• Fixed-tilt System Integration: We thoroughly acquainted ourselves with the client’s Fixed-tilt system to ensure we provide the most efficient and effective solutions.
• Environmental Design Compliance: We designed the solar park to comply with Nordic Solar A/S’s environmental protection requirements, which include preserving land, enhancing biodiversity, incorporating native plants and microclimates, and collaborating with biologists to create ecological features.

Detra Solar Optimization Results:

• LV AC Cables Optimization: We conducted a thorough analysis and optimization of the LV AC cables (Al XLPE 3x240mm²), successfully reducing the required cable length from the initially calculated 60km down to 41km. This resulted in a significant 46% saving in cable length, which not only reduced material costs but also streamlined the installation process. By achieving this optimization, we ensured that the system maintained its high efficiency, delivering reliable performance while minimizing both resource use and project timelines.
• Terrain and Environmental Solutions: We developed design solutions to manage the complicated terrain with a +/- 20 degrees variation and strict environmental limitations (max 1m cut and max 1m fill). By working through multiple iterations, we identified suitable positions for the PV tables to maintain the 100 MW of DC power capacity. This was a significant achievement, as the initial analysis indicated a potential ~20% decrease in DC power due to tables being unable to be installed. 

Project Timeline and Schedule

• 1st scope (Mechanical package): July 2023 (Delivered on time)
• 2nd scope (Electrical package): September-November 2023 (Delivered on time)

Results

The project successfully delivered all required documents and designs on time and within budget. Detra Solar’s expertise ensured effective design solutions, even on challenging hilly terrain. The innovative engineering and environmental protection measures integrated into the project not only met but exceeded the biodiversity enhancement requirements, creating a significant positive impact on the local ecosystem. Our optimization efforts, including the substantial reduction in LV AC cable length and strategic solutions for terrain challenges, played a critical role in maintaining the solar park’s full 100 MW DC power capacity, resulting in a highly efficient and cost-effective installation.

The collaboration with Nordic Solar A/S resulted in a thoroughly planned and executed solar park that aligns with the highest standards of sustainability and efficiency. This successful execution underscores the potential for renewable energy projects to harmoniously coexist with environmental conservation efforts.

Nordic Solar A/S expressed high satisfaction with the quality and detail of the deliverables, enabling them to advance confidently to the construction phase. 

The project stands as a significant milestone in Lithuania’s renewable energy landscape, providing sustainable energy to approximately 28,000 households.