Photovoltaic solar energy
Photovoltaic solar energy is a technology that converts solar energy directly into electricity without mechanical parts or pollutants.
Photovoltaic cells, based on the photovoltaic effect discovered in 1839, use semiconductor materials to convert sunlight into electric current. Our region of Quercy Blanc has an above-average level of sunshine, regularly exceeding 2,000 hours per year.
The large-scale development of photovoltaics is considered essential for achieving carbon neutrality by 2050. It has also become competitive with conventional energy sources and is expected to see sustained growth.
Our photovoltaic project is designed with a perspective of global ecological quality, prioritizing proximity and short distribution loops. It supports the development of our energy autonomy on the estate. While we initially installed panels on our machine storage barn, a more ambitious project will soon be implemented on the equestrian buildings.
We have great confidence in this sustainable energy, which will allow the estate to become completely self-sufficient and independent.
Solar thermal energy
Since 2010, during sunny days, our domestic hot water has been heated entirely by vacuum solar thermal panels, the most efficient technology available. 1,000 liters of water are continuously heated to 60°C.
This water supplies all the buildings (swimming pool, guest rooms, restaurant) without the use of gas, wood, or electricity, relying only on sunlight—which is plentiful in Quercy Blanc.
Domaine de Saint-Géry is thus taking a further step towards environmental responsibility, significantly reducing CO2 emissions.
Naturally, wood-fired heating takes over automatically when there is insufficient sunlight.
Wood-fired heating
The 20 hectares of woodland on the estate provide the fuel for our wood-fired boiler, which generates approximately 70% of the domestic hot water and heating for the buildings.
We carry out selective felling in our forests during the winter; the wood is extracted by horse, seasoned for one to two years depending on its moisture content, and finally cut into one-meter logs to fuel the boiler that heats the house throughout the winter.
Young green branches are shredded to produce RCW (Ramial Chipped Wood). This innovative agronomic technique creates a soil similar to a natural forest floor by shredding the tips of green tree branches.
Tree branches with a diameter of less than 7 centimeters store 80% of the tree's nutrients. By shredding them and spreading them on the ground, earthworms feed on the cellulose while fungi break down the lignin, creating a significant amount of humus and accelerating the formation of forest soil.
Ramial Chipped Wood (RCW) is used to create a natural soil amendment and provides nitrogen for the kitchen garden, green spaces, and truffle orchards.
The Provencal well
The principle involves circulating air underground through glazed stoneware pipes. During this passage, thermal exchange occurs between the air and the earth via the tubes. Since the temperature of the subsoil is little affected by ambient air variations, the air is cooled in summer and warmed in winter.
The Romans already used underground air circulation systems in their villas. Similar systems also exist in warm climates.
In reality, the temperature of the earth varies between winter and summer, with an amplitude that depends on the depth:
At a depth of 1 meter, the temperature of the earth varies from 5°C to 25°C.
At 3 meters, the variation is from 19°C to 9°C.
At a depth of 5 meters, the variation is from 19°C in summer to 12°C in winter.
One must reach a depth of 8 meters for temperature variations to disappear. These figures are subject to change depending on the nature of the soil.
Here, our pipes are buried 6 meters underground.
The Provençal well is also an excellent way to ensure a constant supply of fresh air in all living areas to:
provide oxygen for people and combustion appliances;
exhaust odors and accumulated pollutants;
- eliminate excess humidity that causes aesthetic and structural damage to the buildings, as well as molds that produce allergens, contributing to asthma and respiratory allergies.
Phyto-purification of wastewater
To treat wastewater, phyto-purification relies on the action of macrophyte plants, or more precisely, the bacteria that grow on their root systems (roots or rhizomes). These bacteria break down organic molecules from the wastewater into components that can be absorbed by the plants.
Phyto-purification utilizes the bacteria found in the plants' root systems.
Compared to traditional independent sanitation systems (septic tanks), it offers undeniable advantages. It treats phosphates and nitrates, produces no sludge, and allows for easy monitoring of discharge, unlike buried systems.
On the estate, reeds and nettles work actively to purify wastewater. This water then infiltrates the soil, which acts as the final filter for a completely ecological phyto-purification process.
