What area is required to build a solar PV power plant?

Solar photovoltaic modules are increasingly used in Ukraine as a reliable source of “green” electricity. The current green tariff rates attract investment in the industry for the construction of commercial solar power plants of various capacities. One of the questions that inevitably arises before everyone who decides to invest in the construction of such an object often sounds like this: “What area will it take to install a solar power plant of a given capacity and what factors affect its final size?”

The size of the territory that is needed to build a solar power plant is one of the important parameters that is usually carefully analyzed at the initial stages of modeling and design of solar power plants. Obviously, this parameter is directly dependent on the future power of the solar station. For example, to build a solar station with a capacity of 10 kW, you can use 27 solar modules with a capacity of 375 watts, which will occupy an area of ​​about 50-60 square meters. But depending on the configuration of the solar power plant, you may have to add technological passages to this area, as well as maintain the necessary distance between the individual modules to prevent their mutual shading. Thus, in the calculations it is necessary to take into account several factors:

  • The geographic location of your property.
  • Mounting method for solar modules – stationary metal structures will be used or the project provides for the installation of dynamic systems (trackers).
  • The angle at which solar photomodules will be installed.
  • Spatial orientation of the working surface of the panels (south or east-west).

Roof Mounted Solar Power Plant

To begin with, consider the simplest case – placing solar panels on roof of a private house. Since the surface of the roof has its own angle, it makes sense to install the panel directly on it, of course, provided there are no external shading and at a suitable orientation of building. With this arrangement, the problem of mutual shading of the panels is also solved, and the area occupied by solar panels will be minimal. Depending on the size and efficiency of the solar panels used, a 10 kW solar power station located on a pitched roof covers an area of ​​up to 75 sq.m.

Solar Power Plant on Flat Roof

Placing solar equipment on a flat roof is an option that is most often used for larger structures such as warehouses, retail and office buildings, etc. To improve the mechanical stability of the structure when installing solar panels on a flat roof, an angle of inclination of about 10-15 degrees is chosen:

  • A small angle of inclination of the solar panels reduces windage (i.e. minimizes the wind load), which reduces the weight of the entire structure. As a result, the overall load on the supporting structures of the building is reduced and the investment is cheaper.
  • A small value of the angle of inclination allows avoiding mutual shading of the solar modules during their denser installation, thereby reducing the area occupied by the station, which is important, given the limited roof space.
  • According to calculations, the installation of a 10 kW solar power plant on a flat roof will require approximately 100-120 sq.m.

Ground Mounted Solar Power Station

If there is a sufficient amount of available space, the most rational way is to install solar panels at an angle close to optimal for this latitude. This method of installing modules allows us to increase the total electricity production and accelerate the payback period of capital investments. The ground-based installation of a solar power plant with the fixing of solar panels at optimal angles is an excellent option for both industrial plants and private power supply systems.

There are several approaches to choosing a fixed angle of inclination of solar panels for ground-based deployment of solar power plants:

  • Fixed angle – is selected in such a way as to ensure maximum volume of electricity generation throughout the whole year. This option is most often used in the construction of commercial solar power plants.
  • The angle of inclination, fixed in the position most effective for use during the winter season. This option is most demanded in cases where a photovoltaic power plant is installed as a backup power supply system to cover large peak electricity consumption in winter.
  • The angle of inclination, fixed in the position most effective for operation in the summer season. This installation option is best suited for facilities that need electricity only in the summer – cottages, pensions, holiday homes, etc.
  • Installation of panels, allowing you to change the position of the angle of inclination of the panels 2 times a year – in order to ensure maximum generation volumes, the angle is set depending on the season – winter or summer. This option is suitable for use in commercial solar power plants, if there are necessary resources for the periodic change of orientation of solar modules.
  • Installation of panels at different angles (east-west orientation) allows halving the occupied area and balancing the daily generation profile with the power consumption profile. Often used in agrovoltaics and for flat roofs.
  • Single-axis tracker system – by tracking the position of the sun, it allows you to increase generation by 20-30% (when tracking the movement of the sun during daylight hours) and 10% (when tracking the average annual movement) compared to installing solar modules on stationary metal structures.
  • Biaxial tracker system – such a dynamic system allows to increase electricity generation by 30-40%, if we compare the performance of solar power stations with solar panels on stationary metal structures.

Each of the above examples has its positive and negative sides. For example, the use of tracker systems can increase the generation of electricity, but much more space will be required to install a dynamic system. In addition, in addition to increasing the cost of building the station, the tracker system also requires more expensive future maintenance costs. On the other hand, the use of a fixed angle of inclination in solar plants on stationary structures allows minimizing both initial investments and the expenses for subsequent periodic maintenance.

Most often, the angle of inclination is fixed in the position that provides the greatest amount of power generation in year-round generation mode. In this case, in winter, the generation will be minimal. If the PV plants is used for backup (autonomous) energy supply of the facility, it is necessary to provide for the possibility of compensating for the missing amount of electricity in the winter. When installing modules on stationary structures at an optimal angle (for our latitudes, it ranges from 25 to 35 degrees), an area of ​​about 170-200 sq.m will be required to accommodate a 10 kW power plant.

If a ground-based solar power plant will be mounted using uniaxial trackers, then more space will be required to place solar panels with a total capacity of 10 kW. This is due to the fact that in the tracker system throughout the day the value of the angle of inclination varies depending on the movement of the sun. Therefore, in the morning and evening hours, when the sun is low, in order to achieve optimal illumination of the solar panel, the tilt angle can reach a value of 50-55 degrees. Accordingly, in order to avoid mutual shading of the panels, the distance between adjacent rows must be increased.

The use of biaxial rotary trackers allows you to change the angle of inclination of the plane of the solar panel in a wider range of values, but it will also require more area to accommodate the photovoltaic system – for this type of station the size of the area required for the installation of all equipment will be maximum. Approximately two times more than for stationary ground-based photovoltaic stations with a fixed angle.

To get more detailed information and instructions for selecting a site for a solar station, please, contact Avenston’s office. Our design engineers will choose the best option for installing solar modules.