Estudio técnico y económico del autoconsumo de un prosumidor con instalación fotovoltaica y vehículo eléctrico

Abstract

[EN] The project intends to assess the technical and economic performance of a Danish household characterized by several domestic (1-phase) appliances and a 5.4 kW (3-phase) photovoltaic (PV) plant. The PV installation consists in 18 solar panels (300W). Besides, there is a three-phase inverter (6kW) which produces in a balanced way over the three phases. The thesis quantified the amount of photovoltaic production and domestic consumption on each phase. To do that, an analysis of the amount that was self-consumed was developed, depending on the metering mode. One method consisted of measuring the 3 phases together, while the other measured them individually. With the second procedure energy imports and exports could occur simultaneously in two different phases, whereas with the 3-phase method imports and exports were mutually exclusive quantities. These two methods were applied monthly, considering the energy over: every second, every five minutes, every hour and every day. In the end, with the different results obtained, a quantification of the production and consumption depending on the scenario was conducted. Once the quantification over the months was done for the different periods, based on typical values of energy selling and purchasing, an economic study was conducted to determine in which months and scenarios the household obtained profits. In addition, a study in the voltage quality of the photovoltaic supply was done taking as reference the European Standard EN 50160. Furthermore, for the results obtained, it was assessed how much photovoltaic production could be used to charge an electric vehicle, instead of being injected to the grid, considering realistic driving patterns. The analysis was based on the fact that in maximum production hours (noon) the car cannot be charged as is being used (not at home) attending to the typical usage of a vehicle for a labour timetable. The data used in this study for both photovoltaic installation production and household consumption came from the energy supplier’s meter, the inverter’s meter and an additional smart meter. The supplier takes the measurements with a per second resolution whereas the other two use a 5- minutes resolution. The months subject to this study were from September 2019 until May 2020 and the tool selected to process all this data was MATLAB. Finally, the results obtained have shown the economic advantages of the 3-phase billing method for the owner, compared to the individual billing, as well as the benefits of having longer netting periods, like hourly or daily. In addition, the voltage analysis showed a correct performance of the photovoltaic installation meeting always the established standards. In the end, regarding the electric vehicle charging, it was discovered that it was only possible to actually produce spare energy to charge the car, during the decided charging window (18:00 to 20:00), in September, April and May. Moreover, not even in the best-case scenario it was achieved enough spare photovoltaic production to cover the whole charge needed.

[ES] El proyecto intenta evaluar el comportamiento técnico y económico de una casa danesa caracterizada por un cierto número de dispositivos domésticos (monofásicos) y una planta fotovoltaica de 5.4kW (trifásica). La instalación consiste en 18 paneles solares (300W). Además hay un inversor trifásico (6kW) que equilibra la producción de cada fase.

El trabajo consiste en cuantificar la producción fotovoltaica y el consumo doméstico de cada fase. Se desarrollará un doble análisis de la cantidad que es autoconsumida dependiendo del modo de medida. Un método consistirá en medir las tres fases juntas mientras que el otro medirá las fases individuales. Con el segundo procedimiento consumo y producción pueden darse simultáneamente en dos fases diferentes mientras que con el método de las tres fases el resultado será el balance entre las tres. Estos dos métodos serán aplicados cada mes, considerando la energía: cada 5 minutos, cada hora y cada día (24 horas). Al final, con los diferentes resultados obtenidos, se realizará una cuantificación de la producción/consumo dependiendo del escenario.

Los datos utilizados para este estudio tanto para la producción fotovoltaica como para el consumo se han obtenido con una resolución de 5 minutos empezando en Septiembre de 2019 y hasta el final del proyecto. La herramienta seleccionada para trabajar con todos estos datos será MATLAB.

Finalmente, para perfiles históricos dados, se evaluará cuánta producción puede ser destinada para cargar un vehículo eléctrico, en vez de ser inyectada a la red, considerando perfiles realistas de conducción. El análisis investigará en el hecho de que en las horas de máxima producción (mediodía) el vehículo no se puede cargar ya que está siendo usado (no está en casa) atendiendo al típico uso de un vehículo para un horario laboral.