The “Talk series – Porto Towards Carbon Neutrality by 2030” is an initiative organized by the Porto City Council, which includes 10 clarification and debate sessions related to the theme of sustainability and decarbonization. The first session took place last Thursday, May 4, at the Porto Innovation Hub and its theme was “Decentralized and Clean Energy”.

The opening of the event was led by Filipe Araújo, Deputy Mayor of Porto, who began by saying that “Porto is leading by example”. “The logic of moving towards neutrality fills us all and has been greatly driven by cities, cities have been leading this theme”, he said.

The deputy mayor added that it was in this sense that the Porto Climate Pact was created. It is “a commitment from everyone” and, proof of that, was that it “quickly had hundreds of subscribers, including institutions, who wanted to contribute”.

This first session also included four interventions – one from Rui Pimenta, manager of the Porto Energy Agency; another from Jorge Sousa, director of the Service of Installations and Equipment of the São João University Hospital Center; another by João Peças Lopes, full professor at FEUP; and yet another by Carlos Sampaio, CEO of Elergone Energia. At the end of each person’s reflections, there was room for a debate among all, moderated by Rui Pimenta, followed by a clarification session to the public present.

Solar Energy Projects in Porto

“Portugal has 2300 to 3000 hours of sunshine per year. Germany has 1700 hours, but even so, it is the country with the highest European index of photovoltaic energy. We are clearly behind and we have to continue to push this issue”, said Rui Pimenta.

Still, despite this national delay, the manager of the Porto Energy Agency pointed out that the city of Porto has already made notable advances in the implementation of renewable energies, especially solar photovoltaic energy which, according to him, “is the most suitable for our territory”.

Porto Solar was one of the projects referred to by the manager: “Porto Solar is a project that is in its final phase and covers 25 schools”. It is an initiative that installed solar panels in various municipal buildings, among which are 25 schools, in order to make them self-sufficient.

In addition to this project, there are other initiatives under development, such as the installation of 6MW of photovoltaic panels in social housing buildings in Porto, as well as the creation of the first renewable energy community in the Agra do Amial social housing neighborhood, “which is in the conclusion of the licensing process”.

The support for this purpose was another point addressed by Rui Pimenta, who highlighted the incentive of the Porto municipality on IMI for those who bet on the installation of renewables, as well as an advice counter framed with the Porto Energy Hub, which provides support to any citizen who needs information or clarifications regarding the process of photovoltaic production installation or aiming to increase the energy efficiency of their home or company.

Consumers become energy producers

The goal of decarbonization is at the base of all these projects and initiatives that want to be sustainable and João Peças Lopes added that for this, “consumers will also become energy producers”. “This is the scenario that will consolidate in the coming years”, he said.

However, according to the FEUP professor, for this scenario to consolidate it is extremely necessary to have energy efficiency: “It is important that consumption is shifted, to coincide with times when renewable energy is stronger. For this, it is necessary to implement devices that communicate with appliances, such as washing machines or dishwashers, heating systems, etc., in order to shift consumption to coincide with the period of greatest source of renewable energy. This translates into an efficient use of energy and a reduction in the electricity bill”.

Despite the advantages associated with this system, João Peças Lopes reinforced the idea that there are things that need to be changed and improved for this implementation to be possible and effective. “Of course all of this has implications. The whole paradigm of the electrical system changes, investments need to be made in hardware, in storage systems, in system sensing and in new management tools”, he said.

The energy reality of São João Hospital

Within the energy consumption of a city, hospitals have a considerable weight and, this session of the Conversation Cycle being related to the theme of energy in the municipality of Porto, talking about the São João Hospital would be inevitable, even given the huge area it occupies and its high energy consumption.

“São João has 200,000 m2 and consumes more than 5 MW by the end of the morning”, revealed Jorge Sousa. Even so, the manager assured that “all outpatient activity has a zero footprint”.

However, the director of the Service of Installations and Equipment of the São João University Hospital Center warned that “a hospital is constantly mutating, this because any hospital, after 10 years, consumes more energy because it is always putting new equipment inside”. That is, this leads to the fact that even if its energy efficiency can be improved, it has to be constantly updated, since it is the equipment that consumes the most in the hospital.

For this reason, and with a view to implementing effective solutions, São João hospital began by making changes in the building structure itself. First it changed the asbestos-cement roofs for sandwich panels, which, according to the manager, brought a noticeable difference to the hospital temperature, even without heating or air conditioning devices, and then it insulated all the glazing.

Later, the hospital also built a trigeneration plant, used to this day: “In 2009/2010, the hospital had naphtha boilers that, when connected, released black smoke visible for kilometers. In 2011, we replaced and set up a trigeneration plant. This plant allowed a set of distribution lines that feed, including, the faculty”.

And the food retail? How does it become more sustainable?

After the energy performance in business, housing, and health buildings, there is also another fundamental aspect for human life: food. And how can the food retail sector become more sustainable and contribute to the decarbonization of municipalities and the country?

According to Carlos Sampaio, the three challenges are in the “energy consumption of buildings, transport, and refrigerant gas.” In the particular case of Sonae MC, a roadmap has been set up that can contribute to the objectives of the Paris Agreement to ensure that the Planet does not warm more than 1.5ºC by 2030, and the requirement of SONAE is that the operation of SONAE MC is neutral by 2040. The person in charge affirmed that, at least until 2030, these changes will still be made with fossil fuels, as they still can’t put their fleet on hydrogen because it is still “very unknown.”

“The idea is to optimize the fleets, have state-of-the-art trucks, set up photovoltaic power stations, optimize the use of equipment, have flexible schedules and teleworking, promote eco-driving, as well as the use of bicycles and also have a fleet of electric vehicles and a charging network,” he affirmed.

Within the initiatives promoted in the stores, the person in charge highlighted two – the Plug and Charge and the Happy Hour. The first is a service for charging electric cars, which allows customers to leave their cars charging in the supermarket parking lot while they do their shopping, while the second is still an idea to be realized, but which aims to create a “Happy Hour” of charging with the surplus energy generated by stores that have a photovoltaic power station.

What is the future?

In the conclusion of the first session of the “Conversation Cycle”, some challenges that may happen with the massification of distributed renewable energy production, but also the solutions for them, were addressed.

João Peças Lopes began by pointing out the issue of under-voltages, which are more likely to occur with the use of photovoltaic energy, since the hours of greatest light are concentrated in a certain period of the day, which “can lead to quality issues in the service and congestion.”

In turn, Jorge Sousa warned that with this option, there are more chances of energy cuts, since there is not a constancy in the arrival of energy. Therefore, the person in charge of the São João hospital highlighted the need to continue using natural gas to ensure that these cuts do not influence the good functioning of the hospital and also added that “the paradigm shift to stop using natural gas must come from above”, i.e., from the government.

Carlos Sampaio did not hesitate to affirm that he has no doubts that the world has to go through this energy transition, however, he is also of the opinion that “there has to be the correct stimulus for this to happen.”

The solution, according to João Peças Lopes, “begins in production, which should be limited through converters so as not to reach under-voltages, and goes through the flexibility of demand and storage.” “At this moment, the network is still not prepared for this massive production, but there are solutions and they have to come from all those who are involved in the process,” he concluded.