Reduce propane in favour of thermal solar power
EARL de la Haute Brosse, Chemillé-en-Anjou (49) To heat his post-weaning building, Ludovic Posnic invested in a solar thermal power plant. The goal is to reduce propane use and reduce energy bills by at least 50%.
Ludovic Posnic raises 285 farrow-finish sows in the town of Chemillé-en-Anjou (49). In November 2022, he decided to install a 35 kW solar thermal power plant with the aim of reducing the heating bill for his 1,200-place post-weaning building. The installation took place in June 2023. “My building was heated mainly with very energy-intensive electric heaters,” confides Ludovic Posnic. “It is also equipped with underfloor heating powered by propane-heated water.” The energy savings expected with the new installation are of the order of 50-55% minimum but can, depending on the user's practices, reach 70-75%.
Facing south, 14 Fengtech units installed in series capture solar energy in evacuated tubes connected to a tank. Each unit has a power of 2.5 kW and a volume of 300 litres. The water circulates in a closed circuit between the external platform, the hot water tank and the post-weaning system.
Water heated to 100°C
Even in overcast weather, the technology is capable of capturing energy. The water temperature can vary between 25-30°C on a gray, cool day to 100°C on a warm, sunny day. In winter, the propane boiler acts as a relay. “The objective is that it triggers as little as possible,” says the farmer.
The electric radiators were dismantled and replaced with radiators suspended from the ceiling. The heated floor has been retained. “I have planned enough radiators so that they will be enough to heat the building on the day when the floor is obsolete or its tubes are too damaged,” explains the breeder. The solar installation cost €98,500, 60% subsidized by the Icare4Farms project. The return on investment time is approximately 8 years. “The suspended radiators cost me €20,000 more,” explains Ludovic Posnic.
Two water loops for two types of heating
In the technical room, the 1,000-litre buffer tank makes hot water immediately available if needed. This then serves two circuits. A loop for underfloor heating with water at 40°C and a loop for radiators with water at 65°C. During the summer, when heating needs are less or even zero, the water circulates in a loop in the system. “I’m still looking for a way to use it,” says Ludovic Posnic. “I'm perhaps thinking of connecting my employees' showers and/or my high-pressure cleaner.”
Self-consumption of electricity
The EARL de la Haute Brosse has also been equipped with a 40 kW solar tracker for 3 years. This covers the electricity needs of the fans, the light, the Paf or even the soup machine. “I calculated a 22% reduction on my electricity bill,” concludes the breeder.
Producing knowledge on solar thermal
The Icare4Farms project aims to stimulate the use of solar thermal energy on European farms. Four pilot sites are installed in 4 different countries: France, United Kingdom, Belgium and the Netherlands. The 4 farms use Fengtech technology. All data collected on these sites is collected and analyzed by the University of Lincoln in the United Kingdom and the University of Bretagne Sud in Lorient. “We measure, among other things, solar radiation, wind, precipitation or even the difference between the measured energy and the output of the system,” explains Liqun Feng, founder of Fengtech. “We seek to produce knowledge to communicate scientifically about our technology” A thesis has also been launched by the University of Bretagne Sud on Ludovic Posnic’s installation. It will begin in September 2023.
