From Apollo 13 to the Digital Building Twins

From Apollo 13 to the Digital Building Twins

“Houston, we`ve had a problem”

This phrase, which is now part of history and sounds familiar to most of us, even if we belong to a different generation, was used by the astronauts on board the Apollo 13 spacecraft after an oxygen tank on board explosion. This happened two days after the start of their spatial mission to land on the Moon, which had been launched on April 11, 1970. It was watched by millions of people around the world for days to find out what the destiny of the three astronauts on boards the spacecraft would be. Meanwhile, NASA worked against the clock to generate a digital replica using computer-controlled simulators that would replicate the conditions that were occurring in space. This model, which was true to reality, allowed them to predict how the spacecraft would behave in space in order to find the most appropriate solution to bring the crew back. This could be considered as the first approach towards the concept of Digital Twin.

There are many different definitions of the concept of Digital Twin, one of the first being given by Michael Grieves, an expert in Product Lifecycle Management (PLM). The definition of Grieves was focused on the virtual comparison between what had been produced with the previous product design (produced vs designed), with the aim of improving production processes1. The field of application of Digital Twin is very broad, as are the possible definitions. In general terms, we can consider a Digital Twin as a digital representation of a physical asset, or a process or system, from the real physical world.

Digital twins are based on their fidelity to reality, to the physical world, allowing us to make future predictions and optimisations. The intention is that both ecosystems, that of the physical world and the ecosystem of the Digital Twin (with the representation of the virtual world), have a co-evolution with each other. That is, they are affected by each other in a synchronised manner. This is possible because both models are automatically connected in a bi-directional way. When there is only the automatic connection in a uni-directional way, and that would go from the real model existing in the physical world to the digital model of the virtual world, we cannot call it as such a Digital Twin. For these cases it would be called Digital Shadow. A digital model by itself could not be considered a Digital Twin if there is no automatic connection between the physical and the virtual world. The use of Information and Communication Technologies (ICT) together with Artificial Intelligence (AI) techniques, including Machine Learning (ML), allow the Digital Twin to learn, predict and simulate future behaviour to improve its operation.

And all this Digital Twin thing, for what’

The use of digital twins can be used in numerous fields, for example in industrial manufacturing lines, to improve production processes, or aspects such as energy and environmental sustainability, fields in which projects such as ECOFACT are currently working. Another use of digital twins could be their applications in Smart Cities, which could improve road management, waste collection, etc. At the building level, its application can be useful both at the tertiary level (those buildings dedicated to the service sector), for example an airport, where it could be used to predict and manage the building more adequately based on usage patterns associated with scheduled air traffic. It is also useful in commercial or industrial buildings, focusing in this case on the building itself, and not on the production line mentioned above. At the residential level, the Digital Building Twin (DBT) could also be of great use to us, as we could predict the thermal behaviour of the building, associated with usage patterns, in order to improve the thermal conditioning of the indoor environment and minimise the energy consumption, among other options.

CARTIF has been working for some time on the creation of Digital Models of building based on BIM (Building Information Modelling), for different purposes, such us improving decision-making when carrying out deep renovation buildings projects. In this case, the use of BIM is intended to achieve a more appropriate renovation, and to reduce the time and cost in this renovation projects, with projects such as OptEEmAL or BIM-SPEED. The use of BIM models would function as a facilitator for the integration of the static (Physical world) and dynamic (logical and Digital world from IoT-Internet of Things network data) systems of a building. In addition, the use of BIM provides control over all phases of a building’s life cycle, from design, construction, commissioning of systems, the operation and maintenance phase, as well as possible demolition.

linking the physical and digital world through BIM-based diigtal tein
Concept of linking the Physical and Digital world through BIM-based Digital Twins

The challenge ahead of us in the coming years, focused on achieving climate-neutral cities that are more sustainable, functional and inclusive, suggests that the use of digital twins will be increasingly used in these areas, thanks to the benefits they can bring.


The spanish position at the Climate-Neutral and Smart Cities Mission

The spanish position at the Climate-Neutral and Smart Cities Mission

As already mentioned in other posts, climate change and the degradation of the environment is an existential threat and one of the main challenges Europe and the rest of the world are facing nowadays. Acting in a pretentiously ambitious way, the European Commission decided at the end of 2019 to launch the EU Green Deal that looks for the transformation of our continent into a strong and competitive economy, with the mandate to be efficient in the use of available resources and whose final objective is being the first continent with net zero carbon emissions in 2050. That is to say, European citizens must be able to avoid emitting to the atmosphere, before 2050, all the greenhouse gas emissions that our territory is not capable of absorbing.

This ambitious transition should guarantee that the economic growth generated by this activities isn´t associated to a bigger use of resources. This means changing the historic paradigm of economic evolution whereby phases of economic growth have been always accompanied by a bigger energy resources and/or raw materials use. Furthermore, solutions must follow a just transition principle, in a way that nobody or no place is left behind, favoring therefore the weakest or disadvantage in case it is necessary.

In this framework, and in parallel to this global initiative, it was launched the Climate Neutral and Smart Cities Mission of the European Commission, as one of the most visible instruments to reach this goal due to its exemplary nature. One of the objectives of this platform is that at least 100 European cities can achieve this pretended climate neutrality goal 20 years in advance to the rest, so that they can act as innovation hubs for the rest of the cities to come. The first contact of the cities with this cities mission was through a volunteer commitment, formalized as an Expression of Interest that was intended to pulse the motivation of cities with this so ambitious commitment. The result of this open call couldn´t be more promising. The impressive answer, mobilizing 377 cities that showed interest in participating in the initiative assures, at least, this motivation and commitment of our cities with this ambitious challenge. Focused in Spain, the unique requirement applicable to our country was that applicant cities have to count with more than 50,000 citizens. In the selection procedure, the unique selection factor was to count on with at least one city from each member state (27) among the 100 cities selected.


As expected from previous experiences, in Spain not only the mobilization has been impressive, but the results as well. Barcelona, Madrid, Sevilla, Valencia, Valladolid, Vitoria and Zaragoza have been selected by the Climate Neutral adn Smart Cities Mission of the European Commission among the total 112 selected cities (100 EU and 12 from the associated member stataes). That is to say, 7% of the selected cities are Spanish cities. Moreover, they will be supported by NetZeroCities project (in which CARTIF takes part among other Spanish partners such as UPM and Tecnalia). The first step of this transformation consists on the development of the so-called Climate City Contract, a commitment of the Municipal Government with the European Commission but more important, with their citizens, accompanied by an action plan and financial plan.

The challenge for these 7 cities is tremendous. Considering a review of Material Economics, it is considered that the transition through climate neutrallity in 100 European cities would have an approximate total cost of 96,000 million euros. The Cities Mission counts only with 1,000 million euros for all the research programme. That is to say, arpproximately only 1% of the funds will be available from the Mission.

So, through public-private partnerships up to the 99% of the remaining funds must be leveraged, a huge challenge. The 7 Spanish cities, have been organized in the so-called Spanish mirror group of the cities mission (Comunidad de Transformación de Ciudades, CitiES 2030). This group of 8 cities ( the 7 selected cities plus Soria) have signed with the Ecological Transition and Demographic Challenge Spanish Ministry the commitment of working together towards climate neutrality. Therefore, it is now time to give shape to all these good ideas as solid commitments of financial support, aligning European, national, regional and local initiatives so that the necessary resources can be made available to local innovation ecosystems to take the first steps of such a transformation.

We need that good intentions are transformed into tangible programs. And we needed them now if we want to have chance to reach the commitments with which our cities have committed themselves. We shouldn´t leave them alone.

You may end up owning a power generation company.

You may end up owning a power generation company.

You thought it would never happen, but you´re watching it happen. Your world upsidedown at an unexpected speed. Ecologists announced a different world according to their believes, but it turns out that in the end it will be the cold sceptics of the Excel sheet who will do it. Ukraine war has caused an energetic crisis, and we wil se if it won´t also be food, that it doesn´t only brings us high energy prices, but also could cause shortage of gas, petroleum and offshots.

We are seeing that in order to resolve this situation it is being proposed to tap into Europe´s subsoil resources, especially shale gas, and to increase generation capcity based on nuclear fission. All these measures could serve to alleviate the energy crisis, although it does not seem at this stage to be willing to disengage from greenhouse gas and pollutant emissions. So it is likely that we will not see much hydraulic breakup, we will probably see more nuclear reactors and, above all, we may see a strengthening of the energy efficiency and renewable generation policies that the European Union has been promoting for some time. And it will not be for environmental reasons, but simply to maintain an economic system that does not take us back to the 18th century.

The sun and its child, the wind, will increase their weight in the electric system faster than expected if access to the raw materials needed to manufacture generators is not interrupted. The stoarge of energy could be developed with intensity and we end up getting acquainted with hydrogen as we have made in the past with butane. But surely what we have the hardest time getting usd to would be the new figures that will appear in the energy system management.

The energy communities are one of the news that are getting shape in Spain. Although still aren´t frequent, there are several examples of people that joint to generate and manage the energy they consume. The downgrading of the photovoltaic panels favours their installation in domestic roofs, which achieves that generation and consumption are close. Energy management could be done from the cloud thansk to Internet of Things and specialized companies could offer this service to communities. Hydrogen and batteries seems to be called to be the energy storage medium, although it will depend on the cost and availability of raw materials. Internet of Things woul allow to manage demand flexibility inside the community. It seems to start being possible that a group more or less big of citizens constitute their own electricity generation company.

But for these participative companies, this capitalism at a human scale, could be possible, we have to defeat some obstacles. And leaving aside reluctance to change, the mosr important is the cost of setting up such a community. Are being made huge efforts to understand people motivations1 to get involved in an energy community and to design mechanisms to set them in motion2, but perhaps not as much effort is being put into designing the business models that would make them economically viable.

We can think of some business models for energy communities. The most clear is the save in energy purchase. If the community generates their own energy and distributes it betweent their members, they will save at least the trasnport tolls that are payed in a conventional bill. Other possible business would be the sale of energy surplus, but current legislation imposes limitations on the distance at which the buyer can be located. The demand flexibility could also give rise to another businees model based on promote a distribution grid of auxiliary services, but this is not easy. If this were to be attempted through balancing markets, the regulations impose minimum power values that will be difficult for many communities to achieve. Moreover, it should be borne in mind that it is not possible to interact with the network without complying with a whole series of complex technical rules. It becomes necessary the independent aggregator figure, which is already provided for in existing legislation, but which is not fully developed and which would have to intermediate between the community and the electricity grid. These problems could be solve if they existed energy local markets or flexibility markets, but in Spain are in an embryonic state and it will still take some time to see them in operation.

But, despite of these deficiencies, nowadays energetic crisis overview joint with the directives that came from the European Union will boost the development of energy communities. The problem will be finding resources to do so. Administrations and the cold sceptics of Excel spreadsheets who come up with innovative business models may have the last word.


2 LocalRES.

House and moon

House and moon

It is common knowledge that the moon goes through phases depending on its relative position between the earth and the sun. Thanks to that nights can be a showcase for looking to the starry skies or the perfect environment so that lycanthropes can take on vampires.

In science there are also phases, and the phase shifting, relative to the state in which matter is found. However, changes in this case have to do with temperature and heat and not with the states of the moon.

State transitions, have an important advantage and is that they are produced at constant temperature, allowing the matter to acquire and give up heat without changing temperature and thus reducing the impact over the environment that surrounds them. Are changes that, unlike the transformation suffered by David Naughton in “American Men in London” (film that achieve an Oscar in 1981 to the best makeup), aren´ t visible, but they are perceived.

The application of phase change materials, in particular those that have inside the homes usual transition temperatures between 18ºC-25ºC, can be used as recoveries in walls with which can reach a bigger comfort by stabilising the inside radiant temperature. It´ s not rare to found homes that because of a bad insulation are like thermic vampires, they remove us the heat, increasing the energy bill.

Inside the SUDO-SUDOKET project, which objective is the development of Key Enabling Technologies (KET) applied to innovative buildings, phase change materials dissolved in mortars have been studied to check its effect over the inside comfort conditions, as well as the effect over the climatization consume.

The results of the project had led to conclusions such as that a better stabilization of inside temperatures are reached if the radiant temperature is improved and, moreover, a reduction in the consume of climatization equipment, reaching energy saving, working as if it were a ring of garlic tied around the neck of our air-conditioning system.

The same as our favourite satellite goes from new to full, the enclosures of our homes will evolve to a future with a better control in superficial temperature and evenmore with adaptative enclosures that change of phase depending on the outside conditions.


The work has been done inside SUDOKET – mapping, consolidation and dissemination of Key Enabling Technologies (KETs) project for the construction sector at the SUDOE space, ref: SOE2/P1/E0677 that is co-financed by the Europeand Found of Regional Development (FEDER) through the INTERREG SUDOE programme.

Will we gave out of the cave?

Will we gave out of the cave?

Caves were our first home but, have we stopped to think about how our ancestors felt in the cold mornings of winter? And in hot summer days? We may be surprised…

Humanity had had multiple and different homes. From the tipis of the american indians to the skyscrapers that flood nowadays the city of New York. Currently, buildings represents 40% of the energy consume and 36% of the greenhouse effects. Much of them, moreover, are from the 70s. Definetly, we need a change if we want to mitigate the climate change.

In the Palaeolithic, the first dwellings, in the form of huts made of animal skins and logs, protected our ancestors from the cold and wind. During the Neolithic period, the construction of villages with adobe houses provided our ancient inhabitants with habitable conditions. And all this without consuming a single kilowatt hour and using the resources that nature offered them to obtain certain conditions of comfort.

If we look at the evolution of buildings throughout history, we can see that adobe houses gave way to the dwellings of ancient Egypt, which were made of straw and wood. Ancient Rome introduced concrete and stone, as well as technologies such as the round arch, the arcade, the vault and the doem. Leaping forward to the Renaissance, this era marked an architectural breakthrough, including materials such as marble, stucco and tiles. Until the evolution towards the brick that makes up the majority of existing buildings. But despite the evolution in the use of materials… are we really improving our comfort conditions and the energy efficiency of buildings?

The answer today is that we need more efficient and smarter buildings, but what is stopping us froom changing the way we use buildings? Platón, in his myth of the cave, tells us that it is a lack of knowledge that hides reality from us. Extrapolated to the present day, the lack of useful and valuable information limits us when it comes to making more objective decisions, based on knowledge and reducing subjectivity.

To answer the question of how we improve the knowledge of buildings, the concept of intelligent buildings comes into play. According to the European Commission, an intelligent building is one that is connected, is able to interact with the systems around it, including users, and can be managed remotely. In other words, it has to behave interactively both with the building´ s energy sytems and with other buildings and even the users themselves. Furthermore, it changes its behaviour from reactive to pro-active to make efficient and effective use of its own resources.

The main enablers of smart buildings are new technologies. Firstly, the IoT (Internet of Things) which, in a nutshell, is defined as the connectivity through the Internet of common elements such as household appliances, cars, mobile phones, etc. It is this technology that makes it possible to turn a traditional building into a connected building, capable of providing data thanks to IoT sensors. Secondly, Artificial Intelligence, which uses data to extract knowledge; the same knwoeldge that, following Platon´ s myth, will guide us out of the cave. Artificial Intelligence is a technique capable of learning from data, extracting patterns of behaviour and predicting future situations. In this way, it is able to anticipate events and enable the building to act proactively. In other words, it is bringing human reasoning to buildings, but making decisions based on objective information.

At CARTIF, we have been working for years in the line of research for the transformation of current buildings into samrter, more comfortable and environmentally friendly buildings. Projects such as BRESAER are a clear example of this transformation. In this project, a decision-making system based on Artificial Intelligence has been developed. This solution allows the building to determine one hour in advance the energy needs to meet the comfrot conditions and to choose the available sources to heat or cool the building.

All this without forgetting that buildings are for us and, therefore, users must be the protagonists. Consumers must be better informed about the behaviour of the building, just as the building must adapt to the preferences of the inhabitant. For example, smart thermostats that learn our habits to ensure a comfortable temperature without the need to configure it. Or even detecting when we leave to switch off and stop consuming gas or electricity, which makes even more sense with today´ s prices. The example of this technology is part if the COMFOStat project.

In conclusion, smart buildings represent the perfect solution that combines today´ s better living conditions with the reduced gas emissions of old. Data and Artificial Intelligence generate the necessary knowledge that will have guided us out of the cave. If you still can´ t find your way, our door is always open to help you.

There is only one good: knowledge. There is only one evil: ignorance.

Sustainable mobility plans: It´s now or never

Sustainable mobility plans: It´s now or never

It is undeniable that the coming decades will be crucial for both the society and the Earth´ s environmental health, so it will be determined if our Planet is able or not to support all the world population. Nowadays, it seems that the situation is more than complicated, and it is becoming worse day by day.

sustainable mobility plans

Taking into account this situation, the creation of new policies focused on the reduction of greenhouse gas emissions is more than needed, fizing a set of clear objectives from now to 2050. In this sense, the main objective of the Estrategia de Descarbonización a Largo Plazo (ELP 2050) created by the Spanish Government calls for a 905 reduction in greenhouse gas emissions by 2050 in relation to 1990, considering that the other 10% will be absorbed by carbon sinks.

Sustainable mobility plays a very important role within all the objectives defined in the aforementiones ELP 2050, so it will be essential to work together to try to change the way we move (specially travelling to and from work). Encouraging the use of electric vehicles and alternative means of transport will be key of achieving a much more sustainable mobility, and it will be also necessary to inform the citizens (e.g. the employees) using the proper information and reasons to do so.

The number of transit journeys on working days surpassed 123 million in 2007, according to the Mobility Survey of the People Resident in Spain of Movilia. Approximately 83% of the Spanish population carries out at least one journey each working day and more than a 16% of these journeys were to go to the workplace. Considering the aforementiones data coming from Movilia (please, note that Movilia does not consider the latests crisis and COVID19 effects due tot he fact that the study was done before), the number of in itinere transit journeys in 2006-07 was around 37 million out of a total of 123 million (so, around a third), and around a 63% of these in itinere transit journeys were made by private vehicle as indicated in the E-Cosmos project.

As it has been detailed before, in Spain, the labor mobility has a very important influence on collective mobility, according to data from the Observatory of Logistic and Transport in Spain, having a big environmental, social and economic impact specially when those journeys are done by private vehicle.

Additionally, using the private vehicle to go to work is a very important health hazard. In Spain, traffic accidents have become the primary cause of death for accidents at work (around an 11,6% of the accidents at work were related to in itinere traffic accidents according to the Job, Migrations and Social Security Ministery, Spain Government. The amount of sleep time loss to try to avoid traffic jams, the stress caused by driving in peak hours or by being thinking and thinking about being late increases a lot the risk of traffic accident.

To solve these issues, a very good collaboration between companies, public entities and mobility providers (among others) is extremely needed. The establishment of frameworks of collaboration between the aforementioned entities will make possible the creation of real and effective employee´ s sustainable mobility plans taking into account employee´ s needs. These sustainable mobility plans will lead to real and fruitful interventions focused on reducing the amount of in itinere transit journeys done by private car.

Given the great need of encouraging sustainable mobility, from CARTIF we are collaborating with multiple entities with the main aim of developing real sustainable mobility plans. In this sense, we are working with some enterprises (and with all the involved stakeholders) in order to make more sustainable the in itinere transit journeys of their employees.

It is responsibility of everyone to try to take the leap and to actively contribute to Planet decarbonization, so… let´ s fight all together to make an effort to not continue damaging our planet in order to let the new generations to develop themselves in the same (or better) conditions than us.

CARTIF has the know-how to accompany the institutions in thei path to contribute to pur planet decarbonization, and not only concerning sustainable mobility plans, but also in a lot of other actiones that can be carried out in this sense. It´ s now or never.