Cities today are the heart of humanity, with over half the world population living in urban areas. More than 6 billion people are expected to be city dwellers worldwide by 2050. Cities are also responsible, both directly and indirectly, for over two-thirds of global energy consumption and associated carbon emissions, and play a decisive role in the future of the energy sector and the success of decarbonisation strategies.
Technology and the rapid digitisation underway in all areas of activity of the urban economy have enabled the development of solutions geared to a more rational use of the resources existing in our cities, enhancing citizens´ quality of life and rendering them more sustainable. In the coming decades we are going to witness the transformation of the urban ecosystem, whereby the energy system will be at the centre of these changes.
In relation to the production and management of energy, the decentralised solutions for the generation of solar and wind energy and potential storage using batteries or hydrogen, associated with peer-to-peer technology, with smart meters and the dynamic management of consumption, could give citizens the power to decide again, making them, ultimately, self-sustainable in an isolated manner or as part of micro-networks. In theory, these new solutions could also reduce the need to invest in the electrical grid, replacing part of the role undertaken today, for example, by producers through services consisting of the guarantee of power or voltage regulation. However, the decentralised model gives rise to additional challenges in relation to the public network, due to the need to interact with thousands of small producers-consumers and to the predictable reduction in traffic and consequent income, forcing us to think carefully about future models for financing our electrical networks.
With regard to mobility, we will need to reduce traffic congestion and its respective environmental impact. Aside from the variable role played by public transport, in accordance with the specific context of each city, the technological revolution underway in the automobile sector – perfectly defined by the acronym CASE (Connected, Autonomous, Shared and Electric), should result in a significant increase in the actual use of vehicles, a reduction in the amount of energy consumed and an improvement in the quality of the air, further supported by micro-mobility solutions such as bicycles and scooters. Underlying this revolution are the MaaS (Mobility as a Service) solutions, integrated mobility solutions that allow for the personalised optimisation of the time and space of the process, thereby enhancing the efficiency of the system.
Nevertheless, doubts remain with regard to the model for charging electric vehicles, which, on the widespread use of this alternative, will balance out users´ needs with the need to invest in the electrical grid in a more effective manner. Electric vehicles could also serve as an additional alternative for storage and stabilisation of the electrical grid in the event Vehicle to Grid technology materialises and car batteries are used to offset the supply and demand for electricity throughout the day.
In buildings, the ubiquity of sensors and electronic devices could also enable communication with control and optimisation systems and a permanent adaptation of spaces to the most appropriate conditions of use and comfort, at the same time as reducing energy costs. The possibility of generation and storage will require us to develop solutions that manage all the different energy flows. For example, in a residential complex equipped with solar panels, rules will need to be created to define the destination of the energy produced, which may depend on the price of grid energy at the time and on the capacity of the points of consumption to deal with peaks in production.
To sum up, energy systems in cities of the future are going to have busy information and data processing flows, bi-directional energy flows, in which producer and consumer figures are blurred, far greater needs for storage solutions, the active management of consumption and more decentralised networks, giving rise to a far more complex and dynamic reality.