How Much Does It Cost to Go Off-Grid with Renewables? A Case Study of a Polygeneration System for a Neighbourhood in Hermosillo, Mexico

Abstract

As governments and companies struggle to meet their own objectives for the energy transition, more innovative social and technological measures are needed to reduce Greenhouse Gas (GHG) emissions. For this purpose an assessment of an off-grid polygeneration system, which can serve the electric and cooling demand of a neighbourhood in Hermosillo, Mexico, has been conducted. Energy computations have been done, the energy demand of one dwelling has been measured to ascertain the correctness of the computations, and a demand model for the entire neighbourhood has been created. Based on the model, an off-grid polygeneration system has been designed, which uses a biodiesel engine, PV panels, and an absorption chiller. The system has been optimized for its economic performance and is compared to the currently used system. The results show that the polygeneration system with higher energy efficiency could reduce GHG emissions down to 14%. However, electricity in Hermosillo is heavily subsidised making it harder for innovative systems to compete. Moreover, even without the state subsidies to the end-user, the polygeneration system has still a nearly 30% higher Net Present Cost (NPC) than the conventional system over its project lifetime of 20 years. Nonetheless, with precise political incentives and further advances in the applied technologies, small-scale renewable polygeneration systems could become cost-efficient alternatives in the near future.

Low-Cost Architectural Strategies to Reduce Heat Stress in Social Housing for Hot Desert Climates

“…In a hot desert climate, solar radiation is the main source of heat gains in buildings, making it a key parameter to consider in achieving indoor thermal comfort [12]. The study is carried in a dispersed and low-density city with a hot desert climate, characterized by almost exclusively single-family houses with a high air conditioning demand during the hot season [13].…”

Sistemas de poligeneración en el ámbito urbano: ventajas e inconvenientes en la actualidad

“…Al contrario, en el caso urbano los costes aumentan casi en un 50% al compararlo con el caso de referencia, indicando que varios factores complican la viabilidad económica. (Wegener, Isalgué, et al, 2019;Wegener, López-Ordóñez, et al, 2019;Wegener, Zhang, et al, 2018) Hay que recordar que, en ambos casos los sistemas propuestos son considerablemente más complicados en su diseño, su instalación y su funcionamiento con respecto a los sistemas convencionales debido a un conjunto de tecnologías avanzadas y menos conocidas. Por ello, también la educación y formación de técnicos para operar y mantener los sistemas sería necesario.…”

“…En áreas urbanas con acceso estable a la red eléctrica dichos sistemas aún no pueden competir económicamente con sistemas convencionales, pero podrían aumentar la resiliencia del sistema eléctrico y disminuir las emisiones de gases contaminante (Wegener, López-Ordóñez, Isalgue, Malmquist, & Martin, 2019).…”