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Spanish researchers have studied the potential of using photovoltaic (PV) or photovoltaic-thermal (PT) systems in microbreweries and have discovered that PT systems can cover more energy demand, but have a longer payback period.
Researchers from the Andalusian Association for Industrial Research and Cooperation (AICIA) have studied the potential use of photovoltaic thermal energy (PVT) in beer production. Specifically, they have studied the use of photovoltaic systems in microbreweries, defined as those with an annual production of less than 5,000 hectolitres (hl).
“A FVT system has the potential to preheat brewing water and generate electricity,” the researchers explain. “Since the brewing process requires low-temperature heating and cooling, a solar-assisted multi-generation system is ideal.” Microbreweries typically lack steam boilers, so they often rely on gas burners or electric resistors for heat supply. In addition, small vapour compression chillers are common for cold production.”
For his research, the researcher built computer simulations using TRNSYS software, using real heat and cold load profiles from a Spanish microbrewery located in Jerez de la Frontera, southern Spain. The brewery is supposed to be able to produce 650 l of beer in batches three times a week, totalling an annual production of about 1,000 hl.
“The main energy-related components of the brewery include thermal resistors (2 x 10 kW); a 7.5 kW air-water chiller, a 1.3 m3 chilled water tank; and an air-conditioning-heat pump (ACHP), 3.5/3.2 kW (heat/cool),” the scientists specify.
To cope with the electrical and thermal loads, several scenarios were created. First, the simulation was carried out with different panels. Either 350 W PV modules, 390 W unglazed PVT panels or 260 W glazed PVT modules were used. For each of them, three system sizes were considered: 3.9 kW, 10 kW and 15 kW. They were tested under the climatic conditions of Malaga and Madrid (Spain) and Stuttgart (Germany), together with the relevant economic parameters.
“In addition, two configurations of PVT-plus-thermal storage were analyzed,” the academics added. “The first one considers that the storage tank has an internal coil through which the fluid circulates to/from the solar field. The working fluid in the storage tank is treated water, since it is an ingredient of beer, at grid temperature. The second configuration considers that the working fluid in the tank is the same as that of the solar circuit (water), and through the internal coil flows the treated water that is subsequently used in the process.”
The simulation showed that the PV-only system could cover between 6.9% and 28.2% of the electricity production at the 4 kW plant in Stuttgart and 28.2% at the 15 kW microbrewery in Malaga. With the PV systems, the range was 12.4% to 27.1% in Malaga, 10.4% to 23.9% in Madrid and 5.8% to 16.9% in Stuttgart.
“If we only consider the thermal contribution of FVT systems to the pre-boiling heat demand, it can cover between 12% and 47.6% in Malaga, between 11.3% and 42.4% in Madrid, and between 4.9% and 27.6% in Stuttgart,” the scientists add.
“The payback period for all PV systems, regardless of their location, is around 4-6 years,” they concluded. “In this study, despite Spain having higher solar radiation, the cost of conventional energy is lower than in Germany, which compensates for the economic analysis. The payback period for PV systems ranges from 13 to more than 25 years.”
Their findings were presented in “ PVT potential for a small-scale brewing process: A case study,” published in Thermal Science and Engineering Progress . Scientists from the Association for Industrial Research and Cooperation of Andalusia (AICIA) and the University of Seville led the research.
The same research group recently studied the use of solar energy to improve energy efficiency in two microbreweries in Andalusia, Spain. Their techno-economic analysis showed that solar energy could help reduce the levelized cost of heating and cooling (LCOH) of a microbrewery in Spain by up to 29.7%, ranging from €0.285 (or $0.31)/kWh to €0.332 (or $0.36)/kWh. |
