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Ludhiana: PAU introduces solar innovations to transform culinary landscape
Innovative solar cooking vessels, priced between ₹6000 and 80,000, are catalyzing a culinary shift. It can cater needs of families, hostels, army messes, midday meals, and langar preparation in gurudwara
In a bit to promote solar powered innovations, Punjab Agricultural University (PAU) is making waves with its introduction of solar cooking technology that has the potential to save up to four LPG cylinders annually. A series of solar cooking vessels, designed to cater to both domestic and commercial consumers, has been developed by the university.
Types
The flagship innovation in this series is a world-first: an ingeniously designed, optimally inclined rectangular box solar cooker equipped with two cooking pots. Unlike its horizontally positioned counterparts, this unique design outperforms during winter months. The addition of a parallelepiped-shaped cooking vessel further amplifies the efficiency of this remarkable system.
Highlighting the distinctive features of this vessel, vice chancellor Satbir Singh Gosal emphasised, “The elongated south-facing inclined wall and the top lid cavity facilitate rapid heat transfer to the food. Tilting the cooker at a 45° angle during Punjab’s winter months captures 25-30% more solar radiation intensity at noon compared to horizontal placement. This innovation results in a remarkable 15-18°C increase in the cooker’s stagnation temperature. With heightened solar radiation capture and an efficient cooking vessel, cooking times for foods like rice are reduced by 20-22%, a significant advantage during months with low solar radiation.”
The driving force behind these revolutionary developments is the team from the Department of Mechanical Engineering. Headed by VP Sethi, the team has also extended its innovation to community-scale cooking solutions with the introduction of the twin-chamber community solar (TCCS) cooker. This design, achieved by partitioning a single cooking chamber into two, not only enhances cooking performance but also minimises heat loss. The TCCS cooker’s impressive capacity, capable of cooking around 5 kg each of rice and pulses in its 18 vessels (9 in each chamber), for approximately 260 sunny days a year, makes it suitable for various community-level applications, from gurudwaras and temples to army messes and field operations.
The third innovative offering in the series is a multi-functional design that combines an inclined solar cooker with a dryer, boasting a cooker capacity of 750gms. Known as the multi-shelf side-loading inclined solar cooker-cum-dryer (ISCCD), this design employs a single reflector North Facing Booster Mirror (NFBM) to optimise both cooking and drying processes, particularly during the colder months. The incorporation of an elongated south-facing wall in the innovative parallelepiped-shaped vessel (PSV) enhances cooking performance.
The ISCCD can cook three times the food compared to conventional horizontal solar cookers, with its optimised volume-to-aperture area ratio and PSV size. Notably, the ISCCD maintains its effectiveness even in harsh winter conditions, outperforming traditional cookers and dryers.
Usage and Pricing
The benefits of these solar innovations are not limited to energy savings alone. VP Sethi pointed out that the TCCS cooker, installed five years ago in PAU’s Hostel No. 10, has been effectively preparing daily meals and treats like kheer for students, reducing LPG consumption and promoting eco-friendly energy sources. With the ability to cook 280 days a year, the TCCS cooker is adaptable for mass cooking in various settings.
Furthermore, the economic viability of these innovations is underscored by a comprehensive thermal model. The TCCS cooker, with an NPV of ₹83,253 and payback periods ranging from 25 to 72 months, emerges as a sustainable alternative with significant CO2 emissions reduction.
In terms of practicality, the solar dryer and cooker, costing around ₹8,000, are suitable for a household of up to ten individuals. The dryer can be utilised for preparing pickles, candies, and dry spices, while the cooker can handle a variety of dishes except for chapati. A techno-economic analysis demonstrates that the system can prepare a daily meal for a family of ten, recovering its cost within 65 months and contributing to a substantial reduction in CO2 emissions.
Perks and limitations
Maintenance of the solar cooking vessels is nearly effortless, primarily requiring careful handling of the glass and mirrors. Cooking times vary, with one-time meal preparation taking between one and a half to two hours and extending to four hours during extreme weather conditions.
While these solar innovations promise affordability, low maintenance, eco-friendliness, and sustainability, there are limitations, particularly in terms of the quantity of food that can be cooked at once. Additionally, the longer cooking times compared to LPG alternatives and the dependency on weather conditions introduce a degree of instability into the process.
