Solar greenhouse for crops
Scientists in Canada have created a greenhouse that is exclusively heated by solar panels. The rooftop PV system is not connected to the grid, but is linked to four batteries with a total capacity of 5.56 kWh.
A research team at Canada’s Université de Sherbrooke has designed a greenhouse for fruits and vegetables that is heated and powered entirely by solar energy.
The VG360 greenhouse prototype has internal dimensions of 3 meters by 6 meters. The scientists claim that a family of three to four people could use it to grow their own produce throughout the year.
The energy generated by the small solar arrays can be used to heat the greenhouse during cold periods, while also powering its various systems. In addition, intelligent ventilation systems and irrigation solutions can be automated to handle specific cultivation-related activities within the greenhouse.
“We wanted to limit heat loss from the building envelope, as well as on thermal battery systems that accumulate excess heat during periods of overheating, to redistribute them in the greenhouse during cool periods,” researcher Raphael Boisjoly told pv magazine.
The VG360 project was developed at a cost of roughly CAD 25,000 (US$19,560). This included all of the materials needed for construction, as well as various mechanical and electrical components needed for its operation.
The PV system was built with six panels, with power outputs of 165 W. The researchers also used four 6V batteries, totaling 235 amp-hours.
“The PV system is capable of producing 2.02 kWh in July and storing all this energy in its batteries with a capacity of 5.56 kWh,” the researchers explained. “By way of comparison, a house in Quebec consumes an average of 50 kWh per day and a car battery has a capacity of approximately 0.5 kWh.”
They added that this level of consumption is far from that of a residential client, as the mechanical systems were chosen to consume the least amount of energy possible.
The researchers sized the PV system to enable the operation of all greenhouse equipment for three days during periods of cloudy weather. The greenhouse’s cultivation surface is on the ground, but also on the interior faces of the northern and western walls to maximize the use of space.
The scientists are currently testing the greenhouse at a farm run by Ferme Berthe-Rousseau, a nonprofit organization that manages a 20-hectare plot of land in Durham-Sud, in the Canadian province of Quebec.
From: https://www.pv-magazine.com/2020/12/08/solar-greenhouse-for-crops/
