## 3 Results and Discussion
### Potential for Energy Exploitation
At present, the cost of the extraction of this material is being assumed by hotels and the Mexican government and it is being disposed of as garbage. Moreover, it is essential to remove the _Sargassum_ spp. from the beaches of the Mexican Caribbean because the economic effects  
Figure 8: (**a**) Potential for exploitable bioenergy from coastal municipalities of Quintana Roo with reference to the _Sargassum_ spp. removed in August 2015 ([PERSON] et al. [19]); (**b**) economic-energy analysis of diverse fuels. and socioeconomic-environmental damage it causes are increasing steadily. This means that added value can be generated for _Sargassum_ spp., first, as a solid biofuel with promising properties that would contribute to the production of sustainable fuels. In 2018, the volume of _Sargassum_ spp. (mixed with sand, seagrasses, and, sometimes, other algae) removed from beaches by nine hotels between Cancun and Playa del Carmen, with a total beachfront of 8.01 km, was 290,626 m\({}^{3}\). The volume removed from those same sites in 2019 was 224,721 m\({}^{3}\). Averaged across sites, the monthly volume of _Sargassum_ spp. collected for removal by those hotels in 2018 was \(3.2\times 10^{3}\) m\({}^{3}\) km\({}^{-1}\) (95% CI: 2.3-4.1; range: \(1.0\)-\(5.4\times 10^{3}\) m\({}^{3}\) km\({}^{-1}\)), while the figures for 2019 were \(1.7\times 10^{3}\) m\({}^{3}\) km\({}^{-1}\) (95% CI: 1.2-2.3; range: \(0.01\)-\(5.7\times 10^{3}\) m\({}^{3}\) km\({}^{-1}\)) ([PERSON] et al., in prep.) (see Figure 9,b). In both years, the peak month was May and high spatial variability in the _Sargassum_ spp. depositions occurred among beaches throughout the year. The bioenergetic potential of _Sargassum_ spp. can be appreciated in Figure 9c. In 2018, the bioenergy potential was 0.61 TJ/km/month, while in 2019 it was 0.47 TJ/km/month. An extrapolation of this analysis can reveals that for an 80-km of coastline from Cancun to Playa de Carmen, 43.20 TJ/month could be used. On average (2018-2019) the bioenergetic potential was 0.651 TJ/km/month. The data reported by hotels include _Sargassum_ spp. mixed with sand, seagrasses, and sometimes other types of algae. The relative abundance of each component varied along the coast depending on  
Figure 9: Analysis of exploitable energy of _Sargassum_ spp. (**a**,**b**) spatial location of the hotels that provided data on the volume of beachcast material removed in 2018 and 2019; (**c**) potential exploitable bioenergy. the extension of the seagrass beds, their condition, and the characteristics and use of the machinery and management protocols used by different hotels. Data on the volume of _Sargassum_ spp. for the summer months might be underestimated as on some days the hotels lacked sufficient capacity to remove all the material that accumulated on their beaches. The volume:weight ratio can vary due to several factors: the condition of the alga (e.g., dry, fresh, decomposing); the amount of water retained (e.g., collected upon arrival or several hours later); and the amount of sand mixed in. The prospective energy analysis shown in Figure 9c considers the same assumptions mentioned above; that is, an estimate of only 11.1% of exploitable energy content. However, even this scenario reveals a favorable panorama for the use of these algae as a solid biofuel. Moreover, derived from the thermogravimetric analysis, we identified its potential for exploitation as a secondary biofuel that can produce methane and hydrogen, two fuels with high added value in energy, economic, and ecological terms.