Wind farm on the bocage plateau of Clussais-la-Pommeraie

Chaire Paysage et énergie (ENSP), 2022

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Changes in the agricultural landscape of the plateau: bocage and open field

Clussais-la-Pommeraie is a commune in the Pays Mellois, in the south of the Deux-Sèvres department. The region’s landscape atlas places it in the landscape entity known as « Les terres rouges, secteur bocager ». A wide variety of landscape scenes make up this entity. Its singularity is linked to the presence of a red earth, also called « chestnut land ». The presence of hedges has historically been a recurrent motif in the landscape. In 1950, the area was covered by one of the densest bocages in France, with an average of one hectare per plot. Since then, the percentage of hedgerows has been reduced and the plots of land have been enlarged, following successive land consolidation and the advent of mechanised agriculture. Today, there are relict hedgerows that may even be isolated trees.

Historically, the Clussais-la-Pommeraie area was cultivated for mixed farming and livestock. The quality of the soil is fairly deep and healthy, which allows for rapid growth, particularly of trees. These qualities can be explained by a soil profile of flinty clay on a permeable limestone geological base.

1 - The hedge and the relief: landscape layers in horizontal sheets

Although less present today, the hedge is still one of the main markers of the landscape. It creates real successive planes. It gives rhythm to the views which overlook a mosaic of agricultural plots. The slightly marked relief does not disturb this spatial organisation and makes this entity a landscape of intermediate scale where it is very rare to see the horizon bare. A network of small grouped settlements of light-coloured stone, linked to each other by a network of secondary roads, punctuates the crossing of this territory.

2 - A wind farm site located at a high point: vegetation and wind strata

The wind farm project is located on the edge of the Lezay plateau. The relief is not very marked. The agricultural plots are wider. The wind farm is therefore located in the heart of a site composed of medium-sized cereal crops. It is located on a high point, with a view over a large part of the territory. A ring of hedges delimits the plots and creates a physical link with the roads and nearby habitats.

3 - Wind power in the Deux-Sèvres

In 1923, the rural communes decided to pool their human, technical and financial resources in order to accelerate the provision of electricity to the countryside, which had not yet been electrified. They thus created Intercommunal Electricity Syndicates (SIE). This structure continues in the Deux-Sèvres. In 2001, the SIEDS set up the first experimental 30 m wind tower. In 2009, a first wind farm of 4 wind turbines of 2 MW each was installed. In 2010, 178 masts were installed, representing 393 MW. The SIEDS now owns 17% of the wind turbines in the department. It aims to achieve 30% of the production of energy needs in renewable energy. The department is thus densely productive. Although there are now protests, development continues on many wind farms.

Earth and wind: developing a joint project

1 - Education on wind energy: communication and consultation

The Clussais project was particularly interesting in terms of consultation. The developer WPD proposed a different strategy: public meetings were stopped, as anti-wind turbine associations, often from outside the project area, had willingly confiscated the debates during previous projects. Instead, public meetings were proposed. They were set up in the town hall and allowed meetings between citizens, local actors and developers. Posters and articles were published in the local newspaper to inform of the presence of these meetings. An agenda was proposed for each meeting with specific themes (acoustics, impacts on biodiversity, etc.).

2 - A common sense for the project: the citizen steering committee

A citizen steering committee (COPIL) was set up. Its aim was to bring a civil society vision to the project. It enabled a series of questions and fears to be raised and ideas to emerge « from below ». About ten people met every two months. The mayor, farmers, local residents and members of local associations were all involved in the wind farm project. The COPIL brought together citizens both for and against the project, in order to find a set of compromises and solutions to the various issues. The presence of the COPIL from the beginning of the project allowed the establishment of a dialogue, with the will to be proactive. Thus, the meetings were particularly dynamic.

3 - Taking hold of the ERC sequence: the Conservatoire d’espaces naturels to support the process

The mission of the Regional Conservatory of Natural Spaces of Poitou-Charentes (now CEN Nouvelle-Aquitaine) is to ensure the long-term preservation of natural spaces by taking into consideration ecological and landscape issues. It proposes to wind farm project owners to implement compensatory or accompanying measures under conditions that guarantee their efficiency. These measures involve land acquisition, so that they can be implemented over the long term.

« The CEN organised a mosaic of plots favourable to lowland avifauna. The dialogue with the developer was very constructive, and we were able to build the project with WPD. They have a strong concern with expectations of efficiency. Sabrina Maiano, CEN

A player such as CEN makes it possible to go further than the ERC doctrine (a sequence that accompanies projects to avoid, reduce and compensate for impacts on the natural environment) by having a project owner who ensures the implementation, management and monitoring of the project. The quality of the compensatory measures can be described in a specification from the beginning of the wind farm project to propose quality actors such as CEN.

In this case, CEN has pooled the compensatory measures of three wind projects and two different developers. This mutualisation has enabled the development of a sustainable action through the acquisition of plots. The developer activated its network to purchase relevant plots. The choice of plots was made in strategic locations for lowland avifauna, where specific management was put in place: late mowing of the meadows to allow nesting, a ban on tilling the soil, a choice of seeds from local harvests carried out by the CEN, etc. A young farmer wishing to set up in this area has been able to develop his activity. An agreement links the CEN to the farmer, allowing for strict specifications to be met in order to ensure ecological additionality, efficiency and the sustainability of the project. This approach makes it possible to give meaning to an environmentally friendly agricultural activity.

« It should be taken very early on in the wind power project so that the budget is sufficient for quality implementation, management and monitoring. Sabrina Maiano, CEN

4 - The wind turbine and the hedgerow, a common implementation: the Prom’haies association

The developer had previously worked with the Prom’haies association on a first neighbouring wind turbine project. The locally recognised association provides project management with strict specifications. In working with the developer, two scenarios are envisaged. Either the hedge installation areas are defined beforehand by the developer, or the survey is carried out by Prom’haies. In both cases, the association acts as technical designer and project manager. The association enters into negotiations with local actors to adapt the planting to the particularities of the site (management, choice of species, height, etc.). The planting is carried out by a company (ETS). An agreement is signed with the farmer for the duration of the wind farm project. The plantations must be carried out in two rows to avoid being cut back during maintenance. Three quarters of the species used in this project are from the local plant label. Three layers of plants are planted: trees, shrubs and bushes. Consideration is also being given to the choice of species, in this case fruit trees: grafted chestnut, pear and plum trees, but also species better adapted to drought in response to climate change. One of the hedge plantings was carried out by children from the Clussais la Pomeraie school. This action allowed the children to become aware of the role of the hedge and the wind turbine. This mission was supported by the COPIL. Management upstream of the wind farm project allows for the establishment of strategic hedges. The ideal is to draw up a layout plan at the beginning of the project, so that it can be taken into account in the negotiations with the owners. The installation of wind turbines and the planting of hedges are then inseparable. A follow-up mission of the plantations is also important in order to perpetuate the implantation of the plants.

The wind turbine as a new vertical motif in the mosaic of agricultural landscapes

On the Mellois plateau there is a network of wind farms, often in covisibility, grouped in small numbers, and which punctuate the routes. They become a recurring motif which, depending on the viewpoints and the farms, either takes the lead or participates in a more measured way by integrating into the mosaic patterns of the existing landscapes. This landscape is relatively well suited to hosting small wind farms, given the scale of the plots, the fairly gentle valleys which offer an intermediate dimension between the large plains and the landscapes of small reliefs. In this context, the installation of the five wind turbines of Clussais is successful because in the close perimeter of the wind farm, the object is not systematically visible. It is part of a succession of planes and vertical motifs punctuating the local landscape of agricultural mosaic: hedges, hamlets,…

1 - A pathway that assumes the primary role of the park

On the outskirts of the park, a 7 km path allows you to walk around the wind turbines. It highlights the wind turbine park, but also the surrounding paths and hedgerows. It is punctuated with explanatory panels. The themes of the trail have been thought out and validated by the COPIL. The aim is for people to take ownership of the park. It is promoted as a local walk.

2 - Hedgerows around the trail’s perimeter distance it from the park

Within the perimeter of the trail, the wind turbines take centre stage, dominating the cereal and sunflower fields and constituting a real event. Their scale, shape and the sound of the spinning blades are impressive. The wind turbines create a vertical dynamic that breaks with the relative flatness of the crops. There are very few hedges, only a few trees. As you move away from the park, the hedge network becomes more prominent and creates superimposed planes. The wind turbines are placed at a distance, in the second and third planes. From the surrounding roads, a gradient of visibility, between no visibility and the entire wind turbine over a short period of time, allows the park to be integrated into a wider area. This distance guarantees that the wind farm is well integrated into the landscape. The further away one gets, the more the hedge contributes to the harmonious presence of the park in a semi-bocage landscape.

3 - The case of Les Houmeaux

This hamlet near the park has received special attention. Some inhabitants have joined the COPIL and have been able to follow and give their opinions. This resulted in changes of opinion, but also in important accompanying measures: planting hedges, burying lines, installing solar lights.

A conscientious developer, public skills to be acquired

1 - Making the ERC sequence sustainable to accompany the project over time

The choice of actors in the ERC sequence ensures the quality and sustainability of the project. In this case, the acquisition of the land with the CEN, and the planting by Prom’haies allow the development of a landscape project with competent actors. To encourage the continuity of the project over time, a budget for monitoring should have been provided for upstream of the project and included in the specifications. 2 - A public-private partnership to be supported In the absence of public networks structuring the transition, it is difficult for small municipalities to benefit from strong competences in terms of energy transition. The Mellois en Poitou community of municipalities itself does not have a PCAET. Only the PADD of the SCOT sets out the following guidelines:

• Continue efforts to achieve energy sobriety in the region and in particular in its built environment.

• Diversify local energy production from renewable resources that have little impact in terms of greenhouse gas emissions

• Develop and make better use of local wood resources

• Orient the wood-energy sector towards the use of related products and hedge maintenance residues in a logic of short circuits and protection of the biodiversity linked to wooded areas

• Promote the production of electricity from solar energy, particularly on the roofs of public or private buildings and on land that has already been built on or polluted

• Develop methanisation from local biomass, to make use of waste from agriculture and the food industry

• Supervise the emergence of wind farms in the area, taking into account the cumulative effect of the various wind farms on the landscape SCoT du Mellois en Poitou, PADD

In the case of Clussais-la-Pommeraie, it is the conscientious wind energy developer who has supported the commune, in a virtuous private-public partnership that deserves to be promoted.

3 - The wind landscape of the Lezay plateau

The Clussais-la-Pommeraie wind project has been well thought out. Its scale, location and compensatory measures are of high quality and add value to the area. The Lezay plateau on which it is located is already heavily bordered by wind farms. Other wind farms are being developed around the site. It would be a pity to distort the qualitative work of the Clussais park by saturating the surrounding landscape. A landscape project must therefore be defined over a long period of time, expressing the principles to be respected, offering its share of flexibility to evolve, and highlighting the memory of the decisions and actions which shape the living environment.

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