# Making Optimal Location-Sizing Decisions for Deploying Hybrid Renewable Energy at B&Bs
## 2 Literature Review  
There is limited research investigating the feasibility of using RE in accommodation businesses [40]. Among those papers, design system optimization, that is, identifying a reliable and affordable system configuration, has been the main focus. Due to highly complicated dynamics between the major factors (costs, system performance, and energy demand/supply management), designing such an RE system is challenging. Therefore, a cost-effective energy solution requires an appropriate combination of RE systems [41]. Generally speaking, simulation-based optimization is arguably the most popular tool for solving this kind of problem [42]. Hybrid optimization of multiple energy resources (HOMER) [43] is one of the most well-known software developed for such purposes, with cost minimization as the primary objective. At a high level, HOMER works by simulating various system configurations based on user inputs [44]. Limited by its optimization technique, HOMER does not always produce an optimal solution. To be precise, when there are a large number of system configurations, HOMER often identifies only a suboptimal solution. Some researchers [45; 46] also use mathematical optimization models, and the results are more cost-effective than HOMER. Despite these issues, several tourism-related papers have used HOMER to evaluate the usage of RE at accommodation facilities. [PERSON] et al. [47] conducted a cost study and evaluated the allocation of various configurations, including solar or wind energy (i.e., stand-alone RE), diesel-only, and diesel-RE. Using HOMER, these simulations revealed the feasibility of using renewables to meet all energy needs in an Australian resort. Another finding was that diesel-RE would cost 30% less than the other configurations. Furthermore, [PERSON] et al. [48] extended the research to investigate the current and future feasibility of a stand-alone hybrid solar-wind system using three tourist hotels as case studies. [PERSON] et al. [49] used HOMER to determine the optimal size of RE technologies, including solar panels, wind turbines, batteries, and converters, for an uninterrupted power supply for a Turkish hotel. Since the hotel had a surplus RE (that is, RE neither consumedby the hotel nor saved in the battery) in certain time periods, it would be able to open up new revenue streams for the hotel. [PERSON] et al. [50] investigated the environmental benefits of deploying an RE system at an Iranian hotel with HOMER. When emission costs were considered, the most effective configuration changed from a diesel-only to a diesel-wind system. Using HOMER, [PERSON] et al. [51] analyzed the performance of a stand-alone diesel-wind system to power an eco-lodge in the highlands of Malaysia. In addition to the applicability of the RE system for supplying remote areas, this study also proves that the optimal allocation of renewables requires accurate weather data. [PERSON] et al. [52] explored the competitiveness of various hybrid systems with HOMER for supplying energy in an island resort. A diesel-solar-wind-hydro system had the highest RE penetration compared to others. However, this configuration is not feasible since only a certain amount of land is available for solar panel installation. Finally, [PERSON] et al. [53] demonstrated that a hybrid energy system consisting of two or more RE sources used together (e.g., diesel-solar-wind system) is more viable than energy systems with only one type of energy source. Another finding was that energy demand may vary greatly depending on the season due to occupancy rates, which was also studied by [PERSON] et al. [54]. Another simulation-based tool called transient system simulation program (TRNSYS) [55] has also been used to study energy problems for tourism facilities. This software offers flexibility by allowing users to modify their models [56] or adjust the component library when necessary [57]. [PERSON] et al. [58] used TRNSYS to simulate a geothermal-solar energy system at an Italian resort.