How to Design and Plan a Solar Power Plant Project? A Guide to Site Selection, Engineering, Simulation, and Implementation Phases.
Ground-mounted solar power plant (GPP) projects are large-scale strategic projects in terms of high-capacity energy production and return on investment. However, the success of these systems is not solely dependent on the procurement of panels and inverters. True success is achieved through correct site selection, feasibility analysis, engineering design, simulation verifications, legal permits, and proper financial planning. In this article, we will examine the design processes of ground-mounted GPP projects step-by-step from a technical perspective.
1- Site Selection and Analysis
In ground-mounted solar power projects, the correct site selection directly affects the annual energy production. This stage is fundamental to the design. Analyses to be performed during site selection include:
Irradiation Data: Annual sunshine duration, GHI (Global Horizontal Irradiation), and DNI (Direct Normal Irradiation) values are examined according to meteorological data.
Terrain Structure: Flat, unshaded, wide, and homogeneous terrain is preferred.
Infrastructure Suitability: Criteria such as distance to the grid, road access, proximity to transformer substations, and access to water are evaluated. Note: These analyses are generally performed using databases such as PVGIS, SolarGIS, and Meteonorm.
2- Power Detection
Physical Space Analysis (Panel Accommodation): The total area of panels that can be installed is determined. A rough power estimate can be made by considering the surface area and installed power (e.g., 550 Wp) of each panel.
Formula:
Installed Power (kWp) ≈ Total Area (m²) × Panel Placement Efficiency × Panel Power (Wp) ÷ 1000
For ground-mounted solar power, approximately 12,000–13,000 m² is required for ~1 MWp.
For rooftop solar power, the usable area of the roof is reduced according to the static load.
Consumption-Oriented Power Determination (in Self-Consumption Solar Power Plants) is also performed in projects. It is used for systems that will only meet their own consumption without selling to the grid.
Formula:
Annual Consumption (kWh) ÷ Annual Production Coefficient by Region (kWh/kWp)
In Turkey, this coefficient is generally in the range of 1350–1650 kWh/kWp/year.
According to legal limits, power determination for rooftop solar power plants, within the scope of EPDK and TEDAŞ regulations, cannot exceed the contracted power of the subscriber they are connected to (e.g., for a 160 kVA subscriber, the maximum is 160 kWp solar power plant). For ground-mounted solar power plants, in permitted areas such as non-agricultural land, industrial plots, or energy fields, it is limited according to EPDK’s unlicensed installation limits (e.g., 5 MW, 10 MW, etc.).
3- Technical Feasibility Studies
After site selection, the technical and economic feasibility of the system is analyzed. This analysis involves the following steps:
A list of equipment such as solar panels, inverters, transformers, cables, and switchboards is created.
The placement plan and orientation of the panels, and the string distribution per inverter are determined.
Annual production estimates are calculated using PR (Performance Ratio) values. System losses (cabling, temperature, inverter efficiency, etc.) are modeled.
4- Engineering Design
At this stage, the electrical and mechanical design of the solar power plant is carried out based on field data.
The electrical design includes the following processes:
String inverter or central inverter configuration
DC cabling, AC cabling, grounding plan
Transformer power, medium voltage cells, grid connection
LV and MV single-line diagrams, selection of protection devices
SCADA systems and remote monitoring infrastructure
The mechanical design includes the following processes:
Selection of panel support system (aluminum construction)
Wind load, snow load, soil bearing capacity
Foundation type (driven piles, concrete blocks, screw systems)
Panel mounting angle and inter-row shadow analysis
5- Solar Power Plant Simulations: Which Software is Used?
Various simulation programs are used to test the technical accuracy of projects. The most common tools are:
PVsyst: The most widely used simulation software in the industry for production analysis, system losses, and PR calculations.
Helioscope: Used for panel placement, shadow analysis, and site optimization.
AutoCAD, SketchUp: Preferred for planning and site drawings.
ETAP or DIgSILENT PowerFactory: Used at the MV level for electrical grid integration calculations.
These simulations verify the predicted production of the system and evaluate the suitability of the design.
6- İzin ve Onay Süreçleri
The solar power plant to be established must comply with regulations and obtain permits from official authorities. Generally, the required documents are as follows. Since these may vary from region to region, the relevant institution may request different documents.
Environmental Impact Assessment (EIA) report or exemption letter
Connection opinion and call letter (Electricity Distribution Company)
Project approval file (single-line diagrams, loading reports, etc., in accordance with TEDAŞ regulations)
Zoning permit, title deeds, and land use permits
7- Cost and Financing Planning
The investment cost of solar power projects depends on many factors, such as the quality of the equipment to be used, the difficulty of installation, and the connection distance. Financial planning should include the following elements:
Design and planning costs
Costs of panels, inverters, transformers, switchboards, and medium-voltage equipment
Installation and labor costs
Commissioning and testing fees
Annual maintenance/operating expense estimates
Financing sources such as loans, grants, Renewable Energy Support Mechanism (YEKDEM) incentives, and leasing
Considerations in Solar Power Plant (SPP) Project Design
Compliance with Legal Regulations: The project must be designed and implemented in accordance with EPDK (Energy Market Regulatory Authority) and relevant regulations.
Correct Product & Technology Selection: Panel type (monocrystalline, bifacial), inverter (on-grid, central), and battery technologies should be determined according to the regional climate and investment objectives.
Engineering Supervision: All processes must be supervised by experienced electrical and civil engineers.
Maintenance and Operation Planning: A regular maintenance program should be established after the system is commissioned, and a production monitoring infrastructure should be set up.
What is needed for a successful ground-mounted solar power plant?
A successful ground-mounted solar power plant project is possible with the right site selection, well-designed engineering, verified simulation data, and appropriate financing. Working with expert teams at every stage of this process optimizes not only energy production efficiency but also the return on investment.
A successful ground-mounted solar power plant project is possible with the right site selection, well-designed engineering, verified simulation data, and appropriate financing. Working with expert teams at every stage of this process optimizes not only energy production efficiency but also the return on investment.