Development and performance evaluation of a solar assisted bakery unit for value addition

A large quantity of heat energy are consumed for preparation and heating of food. Firewood and fossil fuel are used for the generation of heat which causes deforestation and pollution. Severe energy crises and increased energy demand nationwide leads us towards alternate energy resources to minimize the load from the fossil fuels. Pakistan has a considerable potential of solar energy generation using photovoltaic (PV) and thermal technologies. The use of solar bakery can reduce the consumption of unsustainable firewood and fossil fuels, avoiding hazardous carbon emissions that cause global warming. The main objective of study was to develop the Solar Assisted bakery unit. In the first phase of research, the solar bakery unit was developed and installed at Department of Farm Machinery & power in University of Agriculture, Faisalabad. Solar Assisted Bakery Unit comprised of 10m-2 primary reflector made up of mirrors having dimensions of 226mm* 152mm, secondary reflector, Glass window of 400mm diameter, zig-zag receiver, pebble bed storage for storing of thermal energy for 1-2 hours, solar fan, DC motor of 80 watt, solar panel of 150 watt, baking chamber of 60cm x 60cm x 60cm, 2 baking trays, 5-6 kg of insulation and 2 Electric heater of 3000 watt. In the second phase of research, experiments were conducted for evaluating the performance of solar bakery unit by using continues data logging and quality analysis of baking products. The baking temperature was measured that varies from 160 to 240 degree C for baking of different products. As the Scheffler reflector works at 30 to 40% efficiency so the overall heat losses were calculated for different parts of Solar Assisted Bakery Unit and 60% energy was available to bake the different products. According to quality and economic analysis the Solar Assisted Bakery Unit is better than conventional baking. So the use of Solar Assisted Bakery Unit is best solution for on farm baking to reduce the consumption of unsustainable firewood and fossil fuels, avoiding hazardous carbon emissions that cause global warming. It was concluded that Baking requires a total of 2 kg of tola bushes for every kilo of bread; every family can save up to 30 kg of firewood each week. As the oven is available for more than 6 hours each day, up to 60 kg of bread can be baked each day.