MICROGRIDS, A SUSTAINABLE SOLUTION FOR AN INTEGRAL ENERGY SUPPLY TO ECO-CITIES

Abstract

This paper refers to a case in which the reader can have an idea of a feasibility study of a microgrid implemented in urban districts or eco-cities. It wants to demonstrate the economical and technical feasibility of this concept as well as its sustainability. The exposed results have been obtained thanks to an application developed by Labein-Tecnalia, called CEEM-U, Cálculo Energético y Económico de Micro-redes Urbanas (Energetic and Economic Calculation of Urban Microgrids). In a first step, the application estimates the electric and thermal (heat-ing, cooling and water heating) demands in the studied area. This estimation is done considering the urban elements involved in the district like the residential and commercial buildings or premises, industrial facilities, common equipment (elevators, lighting, pumps). It also takes into account the characteristics of the buildings: average height, surface of the housing, rate of walls against windows, rate of exterior walls, thermal transmittance coefficient of walls, windows, ceilings and number of air renovations per hour. Climatic and use conditions, like the exterior temperature, objective temperature and heating and cooling hours are also considered depending on the month. Afterwards, taking into account other considerations like the installation, operation and maintenance costs of the generation (electric and thermal) and storage infrastructures, as well as local climatic conditions, the application allows to calculate which is the most profitable option (generation and storage technologies selection and power rates, including operation countersigns for a whole year) for the electricity and heat supply. At the end, alter calculating the generation profiles suitable with the most profitable option and knowing the gas emission taxes of the different technologies, the application calculates the global emission rate of the microgrid.