• Energy Research
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• 11. Sustainability close

Although family-run micro and small businesses largely form the crux of the locally based tourism sector, either as part of a community organization or as independent units of private enterprise, in El Castillo (Nicaragua) can be found an example of how, even in the absence of a community organization to provide a structural framework, the development of local tourism has sustained practically all businesses set up and run by households, organized largely through family relationships. This structure is pivotal in stoking resilience, not only with regard to private businesses, but also to the system of tourism (specific) and, by extension, to the whole of local society and the surrounding socio-ecosystem, or socio-ecological system (SES) (general). The case study presented here, developed on the basis of long-term ethnographic fieldwork, highlights the role of the family structure within Locally-Based Tourism (LBT) in general and also in specific cases, such as the one studied here, in which it takes on a particularly central role. The confirmation of the importance of families and family relationships as key elements in the robust development of tourism in El Castillo, and of the specific characteristics that its local society presents for this, must be taken into account in order to support Community-Based Tourism projects by institutions and organizations interested in promoting sustainable local development. Indeed, once further case studies are conducted, with a view to providing comparative evidence of these findings, it might even be proven advantageous to create a distinctive subcategory within LBT: Family-Based Tourism.

Greater penetrations of variable renewable generation on some electric grids have resulted in increased levels of curtailment in recent years. Studies of renewable energy grid integration have found that curtailment levels may grow as the penetration of wind and solar energy generation increases. This paper reviews international experience with curtailment of wind and solar energy on bulk power systems in recent years, with a focus on eleven countries in Europe, North America, and Asia. It examines levels of curtailment, the causes of curtailment, curtailment methods and use of market-based dispatch, as well as operational, institutional, and other changes that are being made to reduce renewable energy curtailment.

This paper presents a three-year pilot experience of a new municipal waste management system developed in Navarre, Spain that integrates composting and hens. The aim of this new system is to motivate the general public to participate more in waste prevention programs. The Composter-Henhouse (CH) is a compact facility comprised of a henhouse and three composters. This is shared by 30 families who provide the organic part of their kitchen waste to feed the hens. Hens help speed up the composting process by depositing their droppings and turning the organic residue into compost. This study assesses the CH in terms of treatment capacity, the technical adequacy of the composting process, the quality and safety of the compost obtained and some social aspects. Over three years, the CH has managed nearly 16.5 tons of organic waste and produced approximately 5600 kg of compost and more than 6000 high-quality fresh eggs. No problems or nuisances have been reported and the level of animal welfare has been very high. The follow up of the composting process (temperature, volume reduction and compost maturity) and a physicochemical and microbiological analysis of the compost have ensured the proper management of the process. The level of involvement and user satisfaction has been outstanding and the project has presented clear social benefits.

The paper analyses how between 1956 and 2009 the agrarian metabolism of the Barcelona Metropolitan Region (BMR) has become less functional, losing circularity in biomass flows and in relationship to its landscape. We do so by adopting a Multi-Energy Return on Investment (EROI) and flow-fund (MuSIASEM) analyses and the nexus with landscape functional structure. The study of agricultural flows of Final Produce, Biomass Reused and External Inputs is integrated with that of land use, livestock, power capacity, and population changes between 1956 (at the beginning of agrarian industrialization) and 2009 (fully industrialized agriculture). A multi-scale analysis is conducted at the landscape scale (seven counties within the Barcelona metropolitan region) as well as for the functions deployed, within an agroecosystem, by the mutual interactions between its funds (landscape, land-uses, livestock, and farming population). A complex nexus between land, livestock, dietary patterns, and energy needs is shown; we conclude that, from the perspective of the circular bioeconomy the agrarian sector has gone worse hand in hand with the landscape functional structure. Therefore, a novel perspective in landscape agroecology is opened.

The long-run relationship between carbon dioxide emissions from energy use and economic activity level is estimated for Uruguay between 1882 and 2010. We apply cointegration techniques and estimate a Vector Error Correction Model (VECM) for testing whether these variables are endogenous over the long-rung while also considering the short-run dynamics. The economic productive structure, the degree of openness, and the share of clean sources on total energy supply are also considered as explanatory variables. The results show that there exists a linear relationship between carbon dioxide emissions and per capita economic activity level. Moreover, emissions increase jointly with the industrial sector participation in total output, as a consequence of the intensity of this activity in the consumption of energy from fossil fuels sources. The degree of openness is inversely related with carbon dioxide emissions. This is so because the periods of major opening were based on primary inputs exports, lower in energy intensity than industrial products. The changes in carbon dioxide emission are inversely related to the variation in the share of clean sources on total energy supply. Finally, all the variables included in the cointegration vector are endogenous, adjusting together to the deviations from the long-run relationship. As a consequence of the above, economic growth appears to be not enough for diminishing Uruguayan emissions in the long-run. Changes in the energy matrix should be encouraged, and emissions reduction should come not by energy constraints but by the development of clean sources or energy use efficiency improvements, given the impact of energy on economic activity level.

The long-run relationship between carbon dioxide emissions from energy use and economic activity level is estimated for Uruguay between 1882 and 2010. We apply cointegration techniques and estimate a Vector Error Correction Model (VECM) for testing whether these variables are endogenous over the long-rung while also considering the short-run dynamics. The economic productive structure, the degree of openness, and the share of clean sources on total energy supply are also considered as explanatory variables. The results show that there exists a linear relationship between carbon dioxide emissions and per capita economic activity level. Moreover, emissions increase jointly with the industrial sector participation in total output, as a consequence of the intensity of this activity in the consumption of energy from fossil fuels sources. The degree of openness is inversely related with carbon dioxide emissions. This is so because the periods of major opening were based on primary inputs exports, lower in energy intensity than industrial products. The changes in carbon dioxide emission are inversely related to the variation in the share of clean sources on total energy supply. Finally, all the variables included in the cointegration vector are endogenous, adjusting together to the deviations from the long-run relationship. As a consequence of the above, economic growth appears to be not enough for diminishing Uruguayan emissions in the long-run. Changes in the energy matrix should be encouraged, and emissions reduction should come not by energy constraints but by the development of clean sources or energy use efficiency improvements, given the impact of energy on economic activity level

The aim of this study was to evaluate the settling velocity distribution of microalgal biomass with and without flocculant (Tanfloc SG). Microalgal biomass was obtained from two experimental wastewater treatment high rate algal ponds (HRAPs) operated with 4 and 8 days of hydraulic retention time. Two sets of dynamic sedimentation tests were carried out using a water elutriation apparatus. In the first set, most of the biomass of the 8 days-HRAP (63%) had settling velocities between 16.5 and 4 m/h, while most of the biomass of the 4 days-HRAP (65%) had settling velocities between 16.5 and 1 m/h. In the second set, most of the biomass from both HRAPs (60% from the 8 days-HRAP and 80% from the 4 days-HRAP) had settling velocities between 6.5 and 0.4 m/h. In this second set, settling velocities of 6.5 m/h, compared to 10% and 14% of microalgal biomass without flocculant for the 8 days- and 4 days-HRAPs, respectively. With flocculant, a very small amount of biomass (3% for the 4 days-HRAP and 8% for the 8 days-HRAP) had settling velocities of 105 microalgae individuals/ mL). According to our results, a settler designed with a critical settling velocity of 1 m/h would reach biomass recoveries as high as 90-94% with flocculant compared to 77-88% without flocculant.