At 11.30 today, at the Holy See Press Office, Via della Conciliazione 54, a press conference was held to present the environmental and energy sustainability project of the Papal Basilica of Saint Peter in the Vatican, conducted by the Fabric of Saint Peter, ten years after Laudato si’.
The speakers were: His Eminence Cardinal Mauro Gambetti, O.F.M. Conv., archpriest of the Papal Basilica of Saint Peter in the Vatican, vicar general of His Holiness for Vatican City and president of the Fabric of Saint Peter; Dr. Walter Ganapini, coordinator of the Scientific Committee of the project; Professor Niccolò Aste, lecturer at the Polytechnic of Milan – Department of Architecture, Construction Engineering and the Built Environment; Dr. Mario Jorizzo, Department of Sustainability, Circularity and Adaptation to climate change of the Productive and Territorial Systems of ENEA – National Agency for new technologies, energy and sustainable development; and Professor Gianluigi De Gennaro, lecturer in environmental chemistry at the Department of Biosciences, Biotechnologies and Environment of the University of Bari “Aldo Moro”.
The following are their interventions:
Intervention of His Eminence Cardinal Mauro Gambetti, O.F.M. Conv.
In this press conference, I would like to share the first achievements of a project of the Fabric of Saint Peter, aiming to make the Vatican Basilica, with the communities that inspire it and with the millions of pilgrims and tourists who visit it every year, a zero impact “house” that welcomes everyone and encourages everyone to grow in humanity.
In a world occupied by other crises – wars, economic instability, artificial intelligence – the environmental crisis may appear retro. In reality, climate change and sustainability have now become part of the educational, political and industrial agendas of western nations. Today it is spoken of less, perhaps not only due to the other dramatic emergencies that mark our days and our thoughts, but also because environmental themes are no longer “novelties” and have become part of the structural issues that relate to development or the decline of civilizations, linked as they are to the economy (ESG, green jobs, energy transition), public health (pollution, food, lifestyle), social justice (who pays the price of climate change?) and technology (renewable energy, smart cities, electric mobility).
I see in this change in the posture of world public opinion - note that climate marches, Fridays for Future and youth protests in general have become rarefied or dissolved - a “green light” signal for all “activists” like us, who are more proactive than oppositional. Without forgetting that there are strong resistances, cultural, political, corporate (polemics of some categories against environmental regulations, cuts to the Green Deal or climate spending in the name of economic growth), which might call for forms of protest - because the more the environmental crisis is normalized and passively accepted, the more dangerous and urgent it is to deal with -, I believe it is time to show the goodness and foresight of official climate plans.
In this regard, Vatican City State has been engaged for many years in promoting sustainable development through ecological policies to safeguard the environment and provide energy saving strategies, in the spirit of the principles of the Encyclical Laudati si’, the Apostolic Exhortation Laudate Deum, and the Encyclical Fratelli tutti. I refer, for example, to the text of the November 2023 press release in which the sustainable development programme Ecological Conversion 2030 was presented: “The Governorate is committed to reaching climate neutrality through the responsible use of natural resources, the implementation of projects aimed at energy efficiency, and the updating of our technological assets, sustainable mobility, diversification and the sourcing of cleaner or alternative energy products for transport, waste disposal and the development of concrete future reforestation projects”.
If we add to this programme the prayer and study initiatives promoted by various Vatican bodies, as well as the recent inauguration in Castel Gandolfo of Borgo Laudato si'- a laboratory of integral ecology and circular economy -, we can understand what form of activism I was referring to: a concrete and exemplary commitment to ecological and social transition according to the social doctrine of the Church.
The sustainability project regarding the monumental complex of Saint Peter’s Basilica, put into effect by the Fabric, is located in this sphere of spirituality, thought and action. The monumental architecture is complex, the field of intervention is complex, for its constraints, volumes and numbers, and the operation to achieve it is complex.
In this regard, I warmly thank Professor Walter Ganapini for the competence, generosity and humble fidelity with which he leads the Scientific Committee, supported by the Fabric’s technicians and workers. To face the complexity of the operation, we needed a high-profile Committee, constituted ad hoc, multidisciplinary, that counts among its members people who reflect the same values as Professor Walter. To them too I express our profound gratitude, which I extend to the various bodies and companies involved in the project, as well as to the Governorate of Vatican City State for the support it offers us.
Intervention of Dr. Walter Ganapini
In 2022, the Fabric of Saint Peter initiated a project based on the best methodologies and technologies available to bring Saint Peter’s Basilica and associated buildings – the Palazzo della Canonica, Santa Marta, and the Mosaics Studio, to “net zero emissions”, applying science-based approaches starting with the gathering of input/output data regarding the flows of material and energy in the “Project Perimeter” in order to reduce the environmental footprint and to plan priority structural and management actions.
A science-based approach is understood as the census of data on greenhouse gas generating sources: direct emissions (“Scope 1”), indirect from electricity input generation, heating, cooling (“Scope 2”), and other indirect supply chain sources (“Scope 3”).
From these systemic analyses of material and energy flows there emerges the “Baseline” for the analysis and modelling of the interventions, complete with economic, financial, legal and Life Cycle Assessment, and “Good Practices” to be disseminated also to the Jubilee Year Pilgrims to promote sustainable behaviour and lifestyles, care and custody of Creation.
The Project's “Scientific Committee”, which has validated methodologies and projects in the energy and environmental fields, monitors, reports and certifies the results of the actions, then contributing, with information and training tools consistent with the United Nations 2030 Agenda, also to interreligious dialogue.
Adhering to the “One Health” approach, given the pandemic crisis and the expected access to Saint Peter's Basilica of tens of millions of pilgrims, the project's “Scientific Committee” has promoted the creation of an intelligent advanced sensor system to reduce the risks of aggression by pollutants in closed environments, measuring CO2, Volatile Organic Compounds TVOC, fine dust PM10, PM2.5, temperature, relative humidity, and Radon.
Health risks from exposure to the measured pollutants are thus prevented, promptly alerting, in the event of critical situations, security systems and regulation of access flows, and at the same time activating room ventilation automatisms, which are also useful for managing thermal variations relevant to the conservation of frescoes, mosaics, stuccoes, and marble works.
Intervention of Professor Niccolò Aste
The Polytechnic of Milan has been involved in the Environmental and Energetic Sustainability Project of Saint Peter’s Basilica and has made available to the Holy See its competences in the energetic-environmental and global decarbonization fields.
The study carried out aimed to outline the possible intervention scenarios, aimed at the reduction of CO2 emissions in the atmosphere of Palazzo della Canonica, the Mosaics Studio and Saint Peter’s Basilica. In particular, the energy consumption of the buildings in question was analyzed, efficiency enhancement interventions were hypothesized (quantifying the benefits in energy, environmental and economic terms), and lastly, an offsetting strategy for residual emissions was drawn up.
In order to obtain the most realistic estimate possible of the energy performance achievable through the hypothesized intervention scenarios, the entire study was based on a model of calculation for the energetic simulation of the buildings in a dynamic regime, custom-created, calibrated and validated.
More specifically, only improvement measures were taken into consideration from a plant engineering and bioclimatic point of view, excluding a priori efficiency measures regarding the exterior, considered impracticable considering the historical-artistic context.
In particular, with regard to Saint Peter’s Basilica, solutions were studied to improve the efficiency of the lighting system of the aisles by means of LED lamps, and a natural ventilation system was developed for the renewal of internal air and summer cooling (night ventilation).
With regard to improving the efficiency of Palazzo della Canonica, it was assumed that all the existing hydronic terminals (radiators and fan coils) would be replaced with waterloop type terminals, consisting of delocalized water-to-air heat pumps connected to the same hydronic network currently present in the building. Using these terminals, it is possible to provide heating, cooling and dehumidification in all rooms in a totally autonomous manner. It was then planned to decommission the current natural gas boilers and install reversible vapour compression heat pumps, according to two possible scenarios: 1) air-cooled heat pumps, therefore with direct exchange with the air taken from the environment; 2) water-cooled heat pumps by means of heat exchange with groundwater.
From the energy point of view, it was estimated that this intervention would reduce current air-conditioning consumption by 48% (Scenario 1) and 57% (Scenario 2) respectively. The reduction in energy consumption would also have a significant impact on the associated CO2 emissions, which could be reduced by 65% and 72% respectively.
In the Mosaics Study, the replacement of radiators with waterloop type terminals for heating and cooling is also envisaged. The air-conditioning system will be completed by a special controlled mechanical ventilation system, capable of sucking in the indoor air near the workstations, removing micro-dust from the workings. The flow of air taken from the rooms will be balanced by a supply duct connected to the ventilation unit, equipped with a thermodynamic heat recovery unit. As for the artificial lighting, it will be made more efficient through the installation of new LED lamps, reducing consumption by more than 60%. In particular, the precision spotlights used by the mosaicists will have high colour fidelity with variable focus and light intensity.
The results achievable through the application of the proposed measures were then analyzed, which would lead to a 62% reduction in emissions and 43% reduction in current energy consumption.
Finally, the residual impact in terms of emissions, which would still be achieved even if the proposed measures were applied, was estimated at a total of approximately 230 t/year of CO2 equivalent. These are expected to be offset by the installation of photovoltaic systems with a total capacity of approximately 700 kWp. (Edited by: Niccolò Aste, Claudio Del Pero, Fabrizio Leonforte).
Intervention of Dr. Mario Jorizzo
Resource efficiency and energy saving represent fundamental tools to confront the challenges of climate change and to promote a more sustainable and circular economy. In this context, the capacity to reduce the consumption of materials and resources is an essential element in improving overall efficiency in cultural heritage management systems.
In 2023, in line with international objectives such as the United Nations Sustainable Development Goals, the European Green Deal and Pope Francis' principles in Laudato Si', St. Peter’s Basilica was the subject of a non-energy resource diagnosis carried out by ENEA, with the aim of identifying margins for efficiency gains and improving the operational sustainability of this world landmark site.
The analysis involved Saint Peter’s Basilica, Palazzo della Canonica and Palazzo di Santa Marta, examining the flows of water, materials and energy, in order to identify solutions intended to reduce waste and make more conscious use of available resources. The efficiency scenarios developed highlighted strategies to save water and energy, reduce waste and valorise materials, promoting more sustainable management. The methodology adopted also considered environmental and economic aspects, such as carbon footprint calculation and cost-benefit analysis, to ensure that interventions were feasible and had a real impact.
An interesting aspect of this project was to apply this methodology in an historic and cultural context, showing that it can also be replicated in other similar places, such as churches, museums or major events. All this connects well to Pope Francis’ message, which invites everyone to take care of creation and to work together for a more sustainable future. The experience of the Fabric of Saint Peter can become an example to be followed to improve the environmental and management efficiency of other cultural and religious sites. The project opens the way for new ideas and strategies to protect and enhance our art-historical heritage.
Intervention of Professor Gianluigi de Gennaro
Throughout the last thirty years, the attention paid by the international scientific community to the evaluation of air quality in indoor spaces, both public and private, has grown exponentially. This scientific fervour on the them is justified both by the awareness that in modern society the population spends a relevant portion of its time (more than 90%) in confined spaces of life and work, and by increasingly consolidated and documented evidence that shows that the levels of pollution inside domestic spaces and public buildings are at times higher than those outdoors. The reason for the higher concentrations of pollutants indoors may be found in the many and diversified sources of pollution inside buildings, which have an adverse synergic effect on air quality. The health emergency caused by the COVID-19 pandemic gave further relevance to the themes of indoor pollution with regard to criticalities caused by reduced ventilation and the limited effectiveness of poor air exchange within confined spaces. Hence the need to monitor the concentrations of gases and dust present in such environments in order to assess their impact on the health of those who frequent them, as well as to relate them to the risk of contagion due to the spread of viruses and bacteria.
The ongoing Project aims to evaluate the air quality in Saint Peter’s Basilica, one of the largest places of worship in the world, and to study the temporal profiles of the concentrations of pollutants in order to evaluate potential critical features as well as the risk of airborne transmission of pathogens among visitors in the Basilica.
For this purpose, in 2023 a high-resolution spatial and temporary monitoring system was installed, which is now active, using low-cost sensors installed in 7 different sites inside the Basilica and able to provide real-time concentrations of particulate matter (PM), total volatile organic compounds (TVOC), carbon dioxide (CO₂) and microclimatic parameters. These sensors were also supported, at specific stages of the monitoring campaign, by analysers capable of monitoring in real time the concentrations of Total Polycyclic Aromatic Hydrocarbons (Total PAH) in order to verify the impact of emissions from incense and their incidence on carbon dioxide concentrations.
The results collected to date show that, although Saint Peter’s Basilica is a very busy place, with an estimated daily average of 45,000 people, and is characterised by numerous daily celebrations, it has an effective mechanism for dispersing pollutants, even during the hours when the faithful are most present, by virtue of its large volume and excellent natural ventilation. The study has verified that incense emissions during certain celebrations do not make a significant contribution to the increase in CO2 concentrations that are closely related to the presence of bystanders, although they should be mitigated in relation to their intrinsic impact, as already known in the literature. (Contributors: Alessia Di Gilio, Jolanda Palmisani, Annalisa Marzocca, Marirosa Nisi, Lucia Pastore, Fabio Cerino).
