Sustainable urban energy planning: The case study of a tropical city Henrique César Sampaio a,⇑ , Rubens Alves Dias b,1 , José Antônio Perrella Balestieri b,2 a UNISAL, Centro Universitário Salesiano de São Paulo, Rua Dom Bosco, 284, 12.600.100 Lorena, SP, Brazil b UNESP, Univ Estadual Paulista, Av. Ariberto Pereira da Cunha, 333, 12.516.410 Guaratinguetá, SP, Brazil highlights " Sustainable energy planning of tropical cities with hybrid energy technologies competes on economic and environmentally issues. " We examine variations in the level of energy production. " The energy planning of cities involves the exportation of pollutants and/or importation of external energy. article info Article history: Received 3 November 2011 Received in revised form 4 December 2012 Accepted 6 December 2012 Available online 9 January 2013 Keywords: Energy policy Optimization modeling Integrated resources planning Cities abstract The urbanization of modern societies has imposed to the planners and decision-makers a more precise attention to facts not considered before. Several aspects, such as the energy availability and the delete- rious effect of pollution on the populations, must be considered in the policy decisions of cities urbani- zation. The current paradigm presents centralized power stations supplying a city, and a combination of technologies may compose the energy mix of a country, such as thermal power plants, hydroelectric plants, wind systems and solar-based systems, with their corresponding emission pattern. A goal pro- gramming multi-objective optimization model is presented for the electric expansion analysis of a trop- ical city, and also a case study for the city of Guaratinguetá, Brazil, considering a particular wind and solar radiation patterns established according to actual data and modeled via the time series analysis method. Scenarios are proposed and the results of single environmental objective, single economic objective and goal programming multi-objective modeling are discussed. The consequences of each dispatch decision, which considers pollutant emission exportation to the neighborhood or the need of supplementing elec- tricity by purchasing it from the public electric power grid, are discussed. The results revealed energetic dispatch for the alternatives studied and the optimum environmental and economic solution was obtained. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Since the 1970s, with the petroleum crisis, energy and environ- mental questions have become a key concerns for policymakers and societies across the globe. Those questions motivated individ- ual and collective behavior modification on the use of the energy in the next decades. As a consequence, themes such as natural re- sources use and environmental impacts of energy generation tech- nologies, the use of renewable energy and the disposal solid wastes and/or equipments after their lifetime are under discussion by the society. The sustainability of cities is a theme with high pertinence in the current world context; the technological, social, economic and environmental aspects of the urbanization process present important intersections. The division of spaces, the evolution of environments, the definition of green areas and sector areas for activities such as commerce, industrial poles, land-filling, among others, are the object of urban analysis [1]; associated with the geo-processing of images and with the help of mathematical opti- mization, the urban planning can conceive the best plans of streets and avenues, the location of services and public equipments, the definition of bus routes and surface trains [2,3], among others. From the environmental viewpoint, cities also demand urgent answers, for which mathematical methods of evaluation have been revealed favorable – vehicles emissions, appropriate disposition and elimination of solid wastes [4], meeting of crescent drinking water needs [5] and sewage collection and treatment are some of the points that deserve special attention. It is opportune to mention that the sustainability of public buildings has also been 0306-2619/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.apenergy.2012.12.022 ⇑ Corresponding author. Tel.: +55 12 3159 2033. E-mail addresses: henrique@lcp.inpe.br (H.C. Sampaio), rubdias@feg.unesp.br (R.A. Dias), perrella@feg.unesp.br (J.A.P. Balestieri). 1 Tel.: +55 12 3123 2832. 2 Tel.: +55 12 3123 2160. Applied Energy 104 (2013) 924–935 Contents lists available at SciVerse ScienceDirect Applied Energy journal homepage: www.elsevier.com/locate/apenergy