Abstract:
Nowadays, the production of craft beer in microbreweries has become very popular all over the world.
However, recent studies have demonstrated that the craft beer production process in microbreweries can
be considered as energy intensive due to the fact that more to 8% of the production cost is allocated to
thermal processes such as heating and cooling. Therefore, most microbreweries have been applying
some Energy Efficiency actions to their production processes to decrease the amount of energy
consumed and maximize the profits.
In cases where the amount of energy consumed cannot be reduced using Energy Efficiency actions,
Demand Response measures are implemented to reduce the cost of energy needed to supply the
different processes involved. From the available literature, most of the studies based on Demand
Response in the microbrewery sector have focused on the use of heating resources for the onsite energy
generation to directly support the thermal processes. Very few published studies looked at the onsite
“electricity” generation with small scale renewable energy sources and onsite energy storage to assist
with energy cost reduction strategies.
Therefore, this paper develops an optimal energy management model to minimize the energy cost of a
microbrewery, under demand response, supplied with a grid-connected photovoltaic system with battery
storage system. As a case study, a microbrewery in South Africa has been selected for simulation
purposes. The detailed brewing process’s load profile, the solar resource, the system components’
specifications as well as the Time of Use energy cost structure has been used as input to the developed
model with the aim of assessing and analyzing the technical and economic performance of the proposed
system under the given operation conditions and constraints. The simulation results have shown that, as
compared to supplying the microbrewery exclusively by the grid, the break-even point of the proposed
supply option happens after 9.5 years of operation, corresponding to ZAR 398583.18 (USD 22592,09)
cumulatively spent. For the considered 20 years’ operation lifetime, the projected savings on the lifecycle
cost is ZAR 603490.49 (USD 34206,44) or 40.8%. The result of the discounted payback period analysis
indicated that the total investment cost may be recovered in 13.8 years.
The microbrewery is selected as a case study just to highlight the fact that some processes are critical
and cannot be shifted without compromising the quality of the final product. Therefore, the proposed
hybrid system, the developed model and the optimization methodology can be applied to any load in
different demand sectors (residential, commercial and industrial) implementing demand response
measures in order to reduce their operation energy costs.
