The Rosanese village photovoltaic power plants

Chaire Paysage et énergie (ENSP), 2022

To download : emer_13_article_historique_centrales_villageoises.pdf (1.3 MiB)

The Rosanais basin: geological, agricultural and village mosaics benefiting from a rather sunny climate

1 - The great valley of the Rosanais, a diversity of soils for an adapted habitat

The Centrales Villageoises Rosanaises photovoltaic installations are located in the heart of the Rosanais basin landscape unit. The complex geomorphology of the area has created a large Rosanais valley with irregular slopes. It offers slopes with varied sun exposure. The soils are contrasting, wet or dry depending on the emerging geological strata. The villages are located precisely in the landscape, on hillocks that are conducive to warmth in winter and on lines of water resurgence that are favourable to crops, particularly in summer when the climate can be arid. All these characteristics give the landscapes features specific to the Midi on the one hand, and the Alps on the other.

2 - Multiple motifs, recent and ancient, forming colourful microlandscapes

The Rosanais basin is made up of several landscape patterns, which form a balanced assemblage. Small to medium-sized plots of land with varied orientations develop in the green valley bottoms where numerous hedgerows and riverbanks cut through the agricultural assemblages. The main agricultural activity is livestock farming. On the slopes, orchards are sometimes planted. The slopes tend to be covered in scrub or planted with coniferous production forests. There are still open spaces where broom, thyme, lavender and rosemary grow. The outcropping blue marl creates badlands (erosion landscape, sculpted in soft rock [clay, marl, gypsum] gullied by run-off water into a multitude of small valleys), which contribute to the personality of the Rosanais basin landscapes.

3 - Stratification of sunny sloping villages

The villages of the Rosanais have developed by favouring exposure to the sun. Some are located on a slope, on a balcony on a hillock, natural defences often facing south. The houses are positioned along one or more contour lines, benefiting from the sun for a large part of the day. The modest extension of the urban morphology for recent constructions is generally in line with these principles. The new houses are built according to the sunshine, and make the most of it, as many roofs of individual houses are fitted with solar and photovoltaic panels. It is in this sunny context, in the heart of a preserved and slowly evolving rural area, with small village structures, that the Centrales Villageoises project in Rosans was born.

Solar experiments and landscape approaches, energy projects for the community

1 - Auvergne-Rhône-Alpes Énergie Environnement and the Regional Nature Parks: citizen energy and local landscapes

The Village Power Plants (CV) experiment was initially supported by European (ENERSCAPES project) and regional (former Rhône-Alpes region) funding. Rhônalpénergie-Environnement (RAEE), financed by the European Union, brings together five regional nature parks in the Rhône-Alpes region: the PNR des Baronnies provençales, the PNR du Pilat, the PNR des Monts d’Ardèche, the PNR des Bauges and the PNR du Vercors. Each of them participates in the programme in its own territory and in its own way.

The approach is initially experimental, to test a new type of energy and economic model. It quickly spread to the regions and today constitutes the network of village power plants led by the national association.

The actors of AURA-EE and the NRP start from the observation that photovoltaic energy production is essentially practised by private actors, who are often not very respectful of the local social, heritage and landscape framework. For energy projects located in NRP, this state of affairs is in contradiction with the spirit and vocation of the parks. In general, it is also in contradiction with a sustainable development anchored in the territory. The Centrales Villageoises propose an approach based on the landscape of the sites. They are managed by private companies (SAS or SCIC) which can bring together citizens, companies, associations and local authorities. Their management is cooperative, i.e. one member is one vote. The approach has been developed for groups of which local authorities can be part.

« A village photovoltaic power plant is always linked to a catchment area. This is defined by geography, but above all by the contacts between people who wish to work on a common project. Dominique Farhi, architect at Arch’Eco, a bioclimatic architecture agency in the Baronnies

The CVs are first and foremost companies with citizen governance: citizens have a predominant place in the shareholding, in the management and decision-making bodies. The support of local authorities is an important prerequisite for the start-up of projects. The link must necessarily be made with the objectives set by the communities in terms of renewable energy development, but also with their landscape charter, urban planning documents, etc. when they exist. They can support the projects in various ways and can be members or not. Finally, local companies can also be associated in local companies and contribute to the definition and financing of projects.

Within the framework of this experiment, the NRP associated with AURA-EE are developing the first village power plants. They meet with local elected officials and promote this new model in order to find the first host territories. Several elected officials were very quickly interested and facilitated the organisation of various public meetings to bring together groups of citizens around these projects. After the implementation of these test projects, a reversal of roles occurred: the initiatives were no longer necessarily launched by the NRP but came from the territories. The citizens’ collectives that are created call on the support of the NRP, if their territory of action is in one of them.

2 - The PNR des Baronnies provençales and its landscapes, the Rosans experience

The five NRPs of the former Rhône-Alpes region are divided into different study modalities for the implementation of a new energy model, in order to test them in depth. This makes it possible to export a model that is composed with different integrated themes for each project. Eight pilot projects are proposed, all of which have been subject to a landscape and architectural approach. Studies at several scales have been carried out. They integrate the notion of life basin and link it to landscape issues. The PNR des Baronnies provençales is a test territory for integrating an in-depth questioning of the landscape.

The landscape and architectural studies are divided into three phases, which complement each other.

1- Landscapes on the scale of the catchment area, a study to show the richness and possibilities of the future

For the creation of the pilot site of the Rosanese village power plants, a landscape study on the scale of the « Rosanais basin » was carried out internally by a landscape architect from the PNR des Baronnies provençales. This study will provide guidelines for the development of favourable areas with a view to drafting the specifications for the following phases. This document serves as a framework document, pointing out the issues and possible risks, and serving as a decision-making aid for the elected representatives and other technicians involved in the project.

The NRP chose to work on a landscape characteristic of the park’s territory. The choice of the Rosanais basin corresponds to these issues, as it is at the heart of the Baronnies massif and the Park project. The village of Rosans was then chosen for a more detailed part of the study, as it corresponds to several major characteristics of the Rosanais villages. The tools used for this study are traditional landscape tools that could be found in a landscape atlas for the definition of a landscape unit. They are used here to serve the energy project, integrating the landscape approach as a prerequisite.

The issues set out in this study are in line with the general direction of the Park’s charter, in order to move towards a coherent energy project for the territory.

• Various recommendations and actions are to be noted:

• Spare as much agricultural land as possible

• Locate production as close as possible to existing networks, therefore close to inhabited areas

• Locate production as close as possible to the places of consumption

• Avoiding losses by grouping photovoltaic panels

• Develop a collective project, with community management

• Experiment as much as possible with ways of integrating photovoltaic systems into the landscape and respecting the heritage, the challenge being the transferability of the method to other areas in France and Europe (the programme comes from the European Union)

• To develop a common project that is economically viable

• Play an educational role and open up the debate on urban planning, housing and energy

2-Architecture, urban planning and solar panels

The second study, carried out by the Coloco landscape agency, highlights the development possibilities according to the strong features of the proposed site, which is the village of Rosans. This study includes the advice of an Architecte des Bâtiments de France. The Sarrazine tower in the centre of Rosans village is a listed building, which generally means that any development project, including energy installations, must be within a 500m radius. For all these projects located within a 500m perimeter, the approval of the ABF is required. In this case, the architect recommends not to install panels in the heart of the historic centre, but makes it possible just before the 500m limit, on more recent buildings with no particular architectural character. This second phase proposes installation scenarios at the village level. It takes up the elements of the landscape study to specify the possibilities of implantation in terms of village organisation and the possibilities of implantation in architectural terms.

3 - Types of panel installation and land

Subsequently, the architect Dominique Farhi of the Arch’ Eco agency, in conjunction with the Enersun agency specialising in photovoltaic energy, was commissioned by the NRP to carry out a third, more precise study concerning the technical implementation and architectural integration of the panels. The agency has been specialising in eco-construction for some twenty years, and has already worked in Rosans on an eco-hamlet project. This phase makes it possible to design the layout of the panels in relation to the owners’ agreement to occupy the roofs. Eight photovoltaic installations were carried out on communal land: former holiday cottages, a former police station and a technical room. The types of panel installation have been determined. Whenever possible, the panels occupy an entire roof section. They cover surfaces of about 60 m² and produce 9kWC (kilowatt peak) per installation. The panels are installed in relation to the landscape, which is marked by horizontal lines corresponding to the level lines. The overall effect produced by the installation of the panels provides architectural unity for buildings with eclectic styles. The profile is of the same colour as the rest of the panel, an essential detail for good landscape integration. The installation is integrated into the roofs, i.e. the panel serves as a waterproofing for the roof, like a tile. This is not done anymore, for technical and financial reasons, with the end of the feed-in tariff. The electricity fed into the grid is sold on. The inverter boxes are attached to the buildings. They are built with local wood, by a carpenter from Rosan. The panels have a lifespan of 25, 30 years and more. The contract with EDF (obligation d’achat) is signed for 20 years (i.e. EDF’s commitment to buy the electricity at a regulated rate). The panels will continue to function after this period and will continue to produce electricity, although their yield will be somewhat lower. The leases provide for several possibilities at the end of the contract: Free disposal of the installations to the owner of the roof Continued operation of the installations by SAS Dismantling.

The role of the NRP in the development of citizen projects and in landscape and energy issues

1- The three village power plants in the Baronnies provençales NRP

Following the Rosanais project, two other village power plants were created within the PNR des Baronnies provençales: the Sud Baronnies village power plants and the Lance village power plants. They have taken on board the lessons learnt from the Rosans installations and the 7 other experimental territories, which led to the definition, with AURA-EE, of an approach and reproducible « turnkey » tools. In particular, they reused the principles of panel installation in relation to architectural and landscape issues. For the other two village power plants, a reversal of roles is taking place. The citizens were aware of the first projects and asked the NRP to support them. Private owners are interested in the new projects and offer their roofs. Photovoltaic installations are therefore easier to carry out, with a variety of land.

2- New types of insertion

Today, the development of village power plants in the NRP is mainly done on large roofs, for example sheds, because the feed-in tariff for electricity is more interesting on these surfaces where the costs of the installations have decreased. The architect Dominique Farhi won a call for tenders proposed by the NRP to think about replacing asbestos roofs with photovoltaic panels, particularly on agricultural sheds and large craft areas. The stakes are huge in terms of the environment and public health. But removing asbestos is very expensive. Replacing them with photovoltaic panels would make part of the asbestos removal work profitable. The landscape improvement is linked to the replacement of low-quality roofs by steel panels with photovoltaic panels. Currently, the development of village power plants and in general of renewable energy in the PNR des Baronnies provençales is slowed down, because the local electricity distribution network is saturated.

3- The NRP and territorial transition projects

Today, the PNR des Baronnies provençales is working on accompanying the VCs and defining a roadmap to prioritise the actions of the Charter over the next 3 years in the light of climate change and global change.

4- From experiment to model: networking village power plants on a national scale

Since the first experiments with village power plants in Auvergne-Rhône-Alpes, the national association of village power plants has been created, and today there are 54 village photovoltaic power plants in France. Thus, when a local group wants to create its village power plant (RE project in general), it applies to the National Association of Village Power Plants. The commitment committee is made up of volunteers from the Village Power Plant companies as well as NRP project managers. The committee ensures that the collective’s project is in line with the transversal issues that make up a Village Power Plant project and the charter (local economic development, coherent living area, landscape, environment). It provides technical and legal support. The project managers of the NRP or of any other voluntary local authority can support new projects. The national association now has an employee. From now on, the Centrale Villageoise model can be deployed in any type of territory, NRP or not. Thus, the PNRs can go from initiators to accompaniers, as the PNR des Baronnies provençales has done. They can answer experimental technical questions, for example on the problems of removing asbestos from roofs, an important subject at present. The main interest of the groups creating new village power plants seems to be today the production on a larger scale with the necessary capitalisation, and also self-consumption.

Sources

To go further