Innovations
Technologies

Innovations
Technologies

Eolian

The word “eolian” derives from Aeolus, the Greek god of the wind, whose name “Aiolos” means “quick”.
Wind energy is the energy obtained by harnessing the power of the wind.
Wind represents, therefore, a source of renewable and clean energy.

This energy is harnessed through devices called wind turbines, which are essentially composed of a wind turbine placed at the top of a supporting tower and an electric generator. The operating principle is the same as that of old windmills:
the wind blades, turned by the wind, convert the kinetic energy produced by the wind into mechanical energy. Subsequently, a generator connected to the blades transforms the mechanical energy produced by the rotation of the blades into electrical energy.

The factors that influence the formation of winds are:

  • the uneven heating of the atmosphere by the sun
  • the irregularity of the Earth’s surface: the rougher the terrain, i.e., with forests, mountains, or steep variations in slope, the more obstacles the wind will encounter, reducing its speed
  • the rotation of the Earth

 

The Earth receives heat from the sun and then transfers it to the atmosphere, but the amount of heat transferred is not uniform in different areas of the Earth’s surface.

In areas where the Earth transfers less heat to the atmosphere, the pressure of atmospheric gases increases (high-pressure area), while in areas where it transfers more heat, the air warms up and the pressure of gases decreases (low-pressure area). The rotation of the Earth also influences the formation of high and low-pressure areas. These different air masses, coming into contact, move from areas of higher pressure to those of lower pressure, generating wind. The greater the pressure difference between the areas, the faster the air movement will be, and consequently, the stronger the wind.

In summary, wind is the movement of air between areas of different pressures, with varying force and direction.

Therefore, to determine the potentially usable wind energy in a specific area and assess the feasibility of installing a wind power plant, one must understand the terrain’s configuration and the wind direction and  speed over time.

In relation to direction, there are the winds: ‘Tramontana’ from the north, ‘Scirocco’ from the east, ‘Libeccio’ from the south, and ‘Maestrale’ from the west.

The wind’s force can be expressed:

  • in knots, a unit of measurement for its speed (1 knot = 1 nautical mile per hour = 1.85 kilometers per hour)
  • through the Beaufort Wind Scale, ranging from zero to twelve, increasing based on wind speed, wave height, and effects produced.

It is, firstly, a substantially inexhaustible source of energy with relatively low maintenance costs. A significant advantage is the reduction of CO2 emissions and pollutants in the atmosphere, as wind turbine operation does not involve combustion processes (unlike fossil fuel sources, for example).

Worldwide Wind Energy Production

Wind energy is continuously growing. According to data from the Global Wind Energy Council, the current global installed wind capacity is approximately 743 GW, leading to a reduction of 1.1 billion tons of CO2 emissions. Worldwide, China and the United States are the leading countries in the sector, accounting for 75% of all new wind installations in 2020 and producing half of the world’s wind energy output.

Wind Energy in Italy

Wind energy production in Italy is mainly concentrated in southern Italy, as confirmed by the 2020 Terna report. As seen on the map below, Basilicata ranks first with 1417 plants, followed by Puglia (1176 plants) and Sicilia (883 plants). The following positions are held by Campania, Sardegna, and Calabria, while in central-northern Italy, Tuscany is the most successful region in this field with 119 plants.

The factors that influence the formation of winds are:

  • the uneven heating of the atmosphere by the sun
  • the irregularity of the Earth’s surface: the rougher the terrain, i.e., with forests, mountains, or steep variations in slope, the more obstacles the wind will encounter, reducing its speed
  • the rotation of the Earth

 

The Earth receives heat from the sun and then transfers it to the atmosphere, but the amount of heat transferred is not uniform in different areas of the Earth’s surface.

In areas where the Earth transfers less heat to the atmosphere, the pressure of atmospheric gases increases (high-pressure area), while in areas where it transfers more heat, the air warms up and the pressure of gases decreases (low-pressure area). The rotation of the Earth also influences the formation of high and low-pressure areas. These different air masses, coming into contact, move from areas of higher pressure to those of lower pressure, generating wind. The greater the pressure difference between the areas, the faster the air movement will be, and consequently, the stronger the wind.

In summary, wind is the movement of air between areas of different pressures, with varying force and direction.

Therefore, to determine the potentially usable wind energy in a specific area and assess the feasibility of installing a wind power plant, one must understand the terrain’s configuration and the wind direction and  speed over time.

In relation to direction, there are the winds: ‘Tramontana’ from the north, ‘Scirocco’ from the east, ‘Libeccio’ from the south, and ‘Maestrale’ from the west.

The wind’s force can be expressed:

  • in knots, a unit of measurement for its speed (1 knot = 1 nautical mile per hour = 1.85 kilometers per hour)
  • through the Beaufort Wind Scale, ranging from zero to twelve, increasing based on wind speed, wave height, and effects produced.

It is, firstly, a substantially inexhaustible source of energy with relatively low maintenance costs. A significant advantage is the reduction of CO2 emissions and pollutants in the atmosphere, as wind turbine operation does not involve combustion processes (unlike fossil fuel sources, for example).

Worldwide Wind Energy Production

Wind energy is continuously growing. According to data from the Global Wind Energy Council, the current global installed wind capacity is approximately 743 GW, leading to a reduction of 1.1 billion tons of CO2 emissions. Worldwide, China and the United States are the leading countries in the sector, accounting for 75% of all new wind installations in 2020 and producing half of the world’s wind energy output.

Wind Energy in Italy

Wind energy production in Italy is mainly concentrated in southern Italy, as confirmed by the 2020 Terna report. As seen on the map below, Basilicata ranks first with 1417 plants, followed by Puglia (1176 plants) and Sicilia (883 plants). The following positions are held by Campania, Sardegna, and Calabria, while in central-northern Italy, Tuscany is the most successful region in this field with 119 plants.

Procedure to build a wind farm.

  1. Site Identification
    a) Perceived windiness
    b) Accessibility
    c) Land availability
    d) Proximity to inhabited areas
    e) Proximity to High-Voltage power lines
    f) Anemometer positioning
    f.1) Exposed location without obstacles
    f.2) Availability of land
    g) Local Authority availability
  2. The measurements should be taken for a minimum period of 12 months, foreseeing any potential issues such as ice formation that could affect the readings.
  3. For the measurements to be valid, they must be certified.
The validated data must be collected and entered into powerful calculation software that will process the collected data based on:
  • Meteorological data collected on-site.
  • DTM – Digital Terrain Model – are 3D digital maps for assessing the terrain with an extension of at least 20 km from the measurement point.
  • Orthophoto – for evaluating terrain roughness.
  • Surveys of large obstacles on the site.
This processing will provide:
  • the wind contour map of the location.
  • wind data correlations at the desired height.
  • wind statistics.
  • Site class (indicating the maximum intensity with a 50-year return period). This phase, summarized in Micrositing, outlines the energy potential of the site.

The next phase involves selecting a series of generators deemed suitable based on:

  1. Wind type, including intensity and prevailing direction. The wind distribution is determined by wind statistics, which will determine the wind resource exploitation technology.
  2. Wind class (from 1 very strong maximum wind to 4 weaker), the selected wind turbines must withstand the maximum winds at the chosen site.
  3. Transport constraints, as turbines are typically transported in pieces and assembled on-site; the most complex element to transport is often the blade, which presents the largest constraint on the size of installable wind turbines, as it is not detachable. While this element may not be the heaviest component, it is the longest. In some cases, transportation may require road modifications such as guardrail removal, adjustments to bends, tree cutting, etc. However, today transportation can be done using specialized hydraulic dollies that can lift the blades at angles up to 60°, allowing for quicker installation, minimizing costs, and reducing the need for infrastructure modifications. Additionally, a crane with a capacity of 800 tonnes (max 200 tonnes per axis) is required for mounting; hence, bridge overpasses need to be evaluated based on capacity, and any necessary interventions must be planned.


And subsequently, they must be located on the territory based on:

  1. Terrain geology:
    A geomorphological and geotechnical study will be conducted in the interested area to define the type of soil and any existing landslides. This information will serve both for blade placement and site organization. The study will initially provide a geomorphological map and subsequently, after positioning the towers on the map, the specific soil characteristics of the relevant areas.
    Palm-based data derived from specific surveys should provide the mechanical and stratigraphic characteristics of the site.

  1. Orography:
    The site’s orography is crucial for logistical and tower assembly phases, necessitating an analysis of the terrain to highlight physical constraints.

  1. Available properties:
    This is often the most challenging aspect as it may involve purchasing land or securing land rental agreements. Based on geological and physical constraints and wind contour maps, the most promising areas for project development must be acquired. Areas for the High-Voltage station to connect to the National Transmission Grid (RTN) should be acquired.

  1. Windier positions:
    After analyzing the physical and ownership constraints, the blades must be positioned in locations that guarantee more windiness throughout the year. This information is obtained from the previously conducted Micrositing.

  1. Interference effects between generators:
    Various technical and aesthetic aspects are essential for positioning. Technical aspects focus on turbulence between wind turbines, which should be minimized as it could impact energy production. Aesthetically, crucial for regulatory approval, entails harmonious turbine placement to avoid visual clutter.

  1. Field efficiency:
    This aspect requires input from the designer and investor and is obtained from field simulations that predict wind data intersections with selected generator characteristics. Field efficiency measures the energy loss of a wind turbine inserted into a field compared to the same wind turbine isolated and, therefore, without interference. Field efficiency is primarily influenced by the proximity of the blades, which also determines the number of installable generators on the same territory, leading to the equivalent operating hours expressed in kWh/kW – typically ranging from 1800 to 2300 kWh/kW for the site to be considered productive.

  1. Environmental impact:
    This includes several aspects:
  • Avifauna:
    Any migratory routes and local fauna must be analyzed.
  • Floristic surveys:
    Identification of local flora species; this can significantly impact blade positioning.
  • Visual impact:
    Crucial for the authorization process, analyzed through visibility maps up to 20 km (a human eye’s maximum range) and photorealistic inserts.
  • Land occupation and land use hydrological analysis:
    Usually, wind turbines and support structures occupy approximately 2-3% of the land necessary for plant construction (considering the distance of the machines equal to 3-10 times the blade’s diameter); the rest of the land is usable, e.g., for agricultural activities and pastoralism. The construction site must not contaminate water tables or alter the territory’s hydrological balance.
  • Electromagnetic fields:
    Power lines in medium-voltage connected to large wind farms transport energy with significant currents. Therefore, an analysis of the electromagnetic fields produced must be conducted, and containment measures should be studied, if necessary.
After choosing the model and finalizing agreements with the manufacturer, the design of the accessory works to the generators can commence. The design will not only focus on the turbine sizing but also on all the complementary works necessary for the installation and connection of the plant to the electrical grid. Once the aforementioned aspects have been defined, the design process will unfold across three main pillars:
    1. Transportation Design: The design will involve analyzing the route of the generator from the port of arrival to the site of interest. Attention will be given to the last kilometers, assessing any necessary road modifications such as lay-bys, widening, realignments, and other requirements. Typically, the transportation of the wind turbine is handled by the manufacturer up to a certain distance from the installation site. The project will also address the site’s internal roads, construction of roads, assembly platforms, and the number of necessary passages, including construction vehicles, to transport all the required materials for construction.
    2. Structural Design: This phase will be based on:
      • Geotechnical indications
      • Forces communicated by the manufacturer of the blades
      • Construction foundation schemes communicated by the generator’s manufacturer
    3. Electrical Design: This phase will be based on:
      • Manufacturer’s recommendations
      • Choice of system layout (radial with a central station, ring, etc.)
      • Road crossings
      • MT/AT connection station location
      • Enel’s (MT)/Terna’s (AT) indications and those of the network operator in general.
Through dedicated underground lines, the plant will be connected to the nearest suitable point as identified by the operator for connection. It is crucial to pay close attention to the connection to the Enel/Terna grid, which may be limited based on the line transport capacity and its position in the National Transmission Grid; Enel/Terna will provide the connection costs, design, build the distribution station, and address the network manager. The customer’s design process will initiate from the connection point made available. The customer should acquire the areas for the entire infrastructure and transfer them to Enel/Terna for their management part.
With the project, now at the Detailed stage, and the accompanying documentation, the necessary permits are requested. A conference of services is convened along with the Endo-Procedural Environmental Impact Assessment. The main involved authorities are:
  • Ministry of Environment and Energy Safety (for plants exceeding 30 MWp of installed power);
  • Region;
  • Province;
  • Municipality;
  • Superintendence for architectural and landscape heritage;
  • Entity managing protected natural areas, SCI, SPA;
  • Mountain Communities;
  • ENAC (National Civil Aviation Authority), ENAV (National Flight Assistance Authority), Italian Air Force.
Usually, the timing for implementation is as follows:
  • Site identification: 2/3 months.
  • Measurement campaign, including permits for the installation of the anemometric tower: 18 months.
  • Micrositing, wind turbine type, and placement: 1 month.
  • Design: 12 months.
  • Permits: 12 months.

Implementation timing and connection of the onshore plant varies from 24 +/- 6 months from the authorization release, depending on the project’s size.

Deca Service Ltd, through its wholly-owned subsidiary Windtek Ltd, has designed and submitted, for the authorization process, a project in the Province of Savona with an installable capacity of 43.4 Mwp, currently under review by the relevant authorities.

  1. Site Identification
    a) Perceived windiness
    b) Accessibility
    c) Land availability
    d) Proximity to inhabited areas
    e) Proximity to High-Voltage power lines
    f) Anemometer positioning
    f.1) Exposed location without obstacles
    f.2) Availability of land
    g) Local Authority availability
  2. The measurements should be taken for a minimum period of 12 months, foreseeing any potential issues such as ice formation that could affect the readings.
  3. For the measurements to be valid, they must be certified.
The validated data must be collected and entered into powerful calculation software that will process the collected data based on:
  • Meteorological data collected on-site.
  • DTM – Digital Terrain Model – are 3D digital maps for assessing the terrain with an extension of at least 20 km from the measurement point.
  • Orthophoto – for evaluating terrain roughness.
  • Surveys of large obstacles on the site.
This processing will provide:
  • the wind contour map of the location.
  • wind data correlations at the desired height.
  • wind statistics.
  • Site class (indicating the maximum intensity with a 50-year return period). This phase, summarized in Micrositing, outlines the energy potential of the site.

The next phase involves selecting a series of generators deemed suitable based on:

  1. Wind type, including intensity and prevailing direction. The wind distribution is determined by wind statistics, which will determine the wind resource exploitation technology.
  2. Wind class (from 1 very strong maximum wind to 4 weaker), the selected wind turbines must withstand the maximum winds at the chosen site.
  3. Transport constraints, as turbines are typically transported in pieces and assembled on-site; the most complex element to transport is often the blade, which presents the largest constraint on the size of installable wind turbines, as it is not detachable. While this element may not be the heaviest component, it is the longest. In some cases, transportation may require road modifications such as guardrail removal, adjustments to bends, tree cutting, etc. However, today transportation can be done using specialized hydraulic dollies that can lift the blades at angles up to 60°, allowing for quicker installation, minimizing costs, and reducing the need for infrastructure modifications. Additionally, a crane with a capacity of 800 tonnes (max 200 tonnes per axis) is required for mounting; hence, bridge overpasses need to be evaluated based on capacity, and any necessary interventions must be planned.


And subsequently, they must be located on the territory based on:

  1. Terrain geology:
    A geomorphological and geotechnical study will be conducted in the interested area to define the type of soil and any existing landslides. This information will serve both for blade placement and site organization. The study will initially provide a geomorphological map and subsequently, after positioning the towers on the map, the specific soil characteristics of the relevant areas.
    Palm-based data derived from specific surveys should provide the mechanical and stratigraphic characteristics of the site.

  1. Orography:
    The site’s orography is crucial for logistical and tower assembly phases, necessitating an analysis of the terrain to highlight physical constraints.

  1. Available properties:
    This is often the most challenging aspect as it may involve purchasing land or securing land rental agreements. Based on geological and physical constraints and wind contour maps, the most promising areas for project development must be acquired. Areas for the High-Voltage station to connect to the National Transmission Grid (RTN) should be acquired.

  1. Windier positions:
    After analyzing the physical and ownership constraints, the blades must be positioned in locations that guarantee more windiness throughout the year. This information is obtained from the previously conducted Micrositing.

  1. Interference effects between generators:
    Various technical and aesthetic aspects are essential for positioning. Technical aspects focus on turbulence between wind turbines, which should be minimized as it could impact energy production. Aesthetically, crucial for regulatory approval, entails harmonious turbine placement to avoid visual clutter.

  1. Field efficiency:
    This aspect requires input from the designer and investor and is obtained from field simulations that predict wind data intersections with selected generator characteristics. Field efficiency measures the energy loss of a wind turbine inserted into a field compared to the same wind turbine isolated and, therefore, without interference. Field efficiency is primarily influenced by the proximity of the blades, which also determines the number of installable generators on the same territory, leading to the equivalent operating hours expressed in kWh/kW – typically ranging from 1800 to 2300 kWh/kW for the site to be considered productive.

  1. Environmental impact:
    This includes several aspects:
  • Avifauna:
    Any migratory routes and local fauna must be analyzed.
  • Floristic surveys:
    Identification of local flora species; this can significantly impact blade positioning.
  • Visual impact:
    Crucial for the authorization process, analyzed through visibility maps up to 20 km (a human eye’s maximum range) and photorealistic inserts.
  • Land occupation and land use hydrological analysis:
    Usually, wind turbines and support structures occupy approximately 2-3% of the land necessary for plant construction (considering the distance of the machines equal to 3-10 times the blade’s diameter); the rest of the land is usable, e.g., for agricultural activities and pastoralism. The construction site must not contaminate water tables or alter the territory’s hydrological balance.
  • Electromagnetic fields:
    Power lines in medium-voltage connected to large wind farms transport energy with significant currents. Therefore, an analysis of the electromagnetic fields produced must be conducted, and containment measures should be studied, if necessary.

After choosing the model and finalizing agreements with the manufacturer, the design of the accessory works to the generators can commence. The design will not only focus on the turbine sizing but also on all the complementary works necessary for the installation and connection of the plant to the electrical grid.

Once the aforementioned aspects have been defined, the design process will unfold across three main pillars:

    1. Transportation Design:
      The design will involve analyzing the route of the generator from the port of arrival to the site of interest. Attention will be given to the last kilometers, assessing any necessary road modifications such as lay-bys, widening, realignments, and other requirements. Typically, the transportation of the wind turbine is handled by the manufacturer up to a certain distance from the installation site. The project will also address the site’s internal roads, construction of roads, assembly platforms, and the number of necessary passages, including construction vehicles, to transport all the required materials for construction.

    2. Structural Design:
      This phase will be based on:
      • Geotechnical indications
      • Forces communicated by the manufacturer of the blades
      • Construction foundation schemes communicated by the generator’s manufacturer

    3. Electrical Design:
      This phase will be based on:
      • Manufacturer’s recommendations
      • Choice of system layout (radial with a central station, ring, etc.)
      • Road crossings
      • MT/AT connection station location
      • Enel’s (MT)/Terna’s (AT) indications and those of the network operator in general.

Through dedicated underground lines, the plant will be connected to the nearest suitable point as identified by the operator for connection. It is crucial to pay close attention to the connection to the Enel/Terna grid, which may be limited based on the line transport capacity and its position in the National Transmission Grid; Enel/Terna will provide the connection costs, design, build the distribution station, and address the network manager. The customer’s design process will initiate from the connection point made available.


The customer should acquire the areas for the entire infrastructure and transfer them to Enel/Terna for their management part.

With the project, now at the Detailed stage, and the accompanying documentation, the necessary permits are requested. A conference of services is convened along with the Endo-Procedural Environmental Impact Assessment. The main involved authorities are:
  • Ministry of Environment and Energy Safety (for plants exceeding 30 MWp of installed power);
  • Region;
  • Province;
  • Municipality;
  • Superintendence for architectural and landscape heritage;
  • Entity managing protected natural areas, SCI, SPA;
  • Mountain Communities;
  • ENAC (National Civil Aviation Authority), ENAV (National Flight Assistance Authority), Italian Air Force.
Usually, the timing for implementation is as follows:
  • Site identification: 2/3 months.
  • Measurement campaign, including permits for the installation of the anemometric tower: 18 months.
  • Micrositing, wind turbine type, and placement: 1 month.
  • Design: 12 months.
  • Permits: 12 months.

Implementation timing and connection of the onshore plant varies from 24 +/- 6 months from the authorization release, depending on the project’s size.

Deca Service Ltd, through its wholly-owned subsidiary Windtek Ltd, has designed and submitted, for the authorization process, a project in the Province of Savona with an installable capacity of 43.4 Mwp, currently under review by the relevant authorities.

Innovations
Technologies

Innovations
Technologies