This work evaluates the techno-economic prefeasibility of waste to energy projects in Colombia using four different conversion technologies of incineration, gasification, anaerobic digestion and landfill gas. Three study cases were selected to represent typical urban centers in Colombia, which were namely Guayatá, Andes and Pasto. After feasible technologies were identified for each case, their energy recovery potential was calculated based on the mathematical models and publicly available information about the composition of the wastes produced in these three municipalities. A subsequent economic analysis was conducted by applying the incentives established in Law 1715 for projects involving non-conventional renewable energy sources. The cash flows produced by each technology in the three scenarios were evaluated to obtain the Internal Rate of Return (IRR), which was found to be influenced by the benefits of this legislation. However, the economic benefits were not significant in the small municipality of Guayatá. In turn, in Andes, a high electricity price (100 USD/MWh) would entail a positive IRR of 2.6%. In Pasto, which is the biggest city of the three, the maximum IRR of landfill gas and anaerobic digestion reached 13.59% and 14.27%, respectively. The results show that these types of projects can have positive economic results if tax and government incentives are taken into account.

This work evaluates the prefeasibility of energy from waste projects in Colombia under the guidelines of Law 1715. That piece of legislation proposes tax incentives for non-conventional energy initiatives, such as deductions of up to 50% on the investment through income tax, VAT exemption, tariff exemption, and accelerated depreciation of assets. Pasto, Colombia, was selected as the case study. Subsequently, incineration, gasification, anaerobic digestion, and landfill gas technologies were evaluated. The potential of electric power generation from municipal solid waste (MSW) of each conversion technology was estimated with mathematical models. Additionally, the economic evaluation considered five cases that combine loan options, accelerated depreciation, and income deductions. Finally, the prefeasibility analysis of each case and technology was based on the internal rate of return (IRR) and levelized cost of electricity (LCOE). The results reveal that only anaerobic digestion and landfill gas technologies constitute viable projects in case of traditional investment with and without loans, because they present IRRs greater than the discount rate, of 6.8%. However, by including the incentives in Law 1715 in the economic evaluation, IRRs of 11.18%, 7.96%, 14.27%, and 13.59% were obtained for incineration, gasification, anaerobic digestion, and landfill gas, respectively. These results make all four technologies feasible in this context.

Hepatitis E virus (HEV) is one of the main causes of acute viral hepatitis of enteric transmission. HEV has been detected in environmental samples in several countries from Europe and Asia, constituting a risk factor for waterborne infection. In Colombia, HEV has been identified in samples obtained from patients as well as from swine, but no environmental studies have been carried out. To determine if HEV is present in environmental waters, samples from the main source of drinking water plant and of wastewater system of eight municipalities and two villages of Antioquia state (North West Colombia), were collected between December 2012 and April 2014. The HEV genome was detected by RT-PCR in 23.3% (7/30) of the samples from the main source of drinking water plants and in 16.7% (5/30) from sewage. Viral concentrates obtained from three positive sewage samples were used to inoculate HepG2 cell cultures that were followed for one month; however, the viral genome was not detected in any cell culture. This study demonstrates the circulation of HEV in both source of drinking water plants and wastewater in Antioquia state, Colombia. The presence of HEV in environmental waters could be a risk for waterborne transmission in this population. The findings of the present study, together with the evidence of HEV circulation in human and swine in Colombia, should be consider by public health authorities for the development of surveillance programs and the inclusion of HEV infection diagnosis in the guidelines of viral hepatitis in the country. This is the first report of HEV in environmental samples in Colombia and the second one in Latin America.

Solar energy is one of the most strategic energy sources for the world’s economic development. This has caused the number of solar photovoltaic plants to increase around the world; consequently, they are installed in places where their access and manual inspection are arduous and risky tasks. Recently, the inspection of photovoltaic plants has been conducted with the use of unmanned aerial vehicles (UAV). Although the inspection with UAVs can be completed with a drone operator, where the UAV flight path is purely manual or utilizes a previously generated flight path through a ground control station (GCS). However, the path generated in the GCS has many restrictions that the operator must supply. Due to these restrictions, we present a novel way to develop a flight path automatically with coverage path planning (CPP) methods. Using a DL server to segment the region of interest (RoI) within each of the predefined PV plant images, three CPP methods were also considered and their performances were assessed with metrics. The UAV energy consumption performance in each of the CPP methods was assessed using two different UAVs and standard metrics. Six experiments were performed by varying the CPP width, and the consumption metrics were recorded in each experiment. According to the results, the most effective and efficient methods are the exact cellular decomposition boustrophedon and grid-based wavefront coverage, depending on the CPP width and the area of the PV plant. Finally, a relationship was established between the size of the photovoltaic plant area and the best UAV to perform the inspection with the appropriate CPP width. This could be an important result for low-cost inspection with UAVs, without high-resolution cameras on the UAV board, and in small plants.