Read about Barcelona's first lessons learned from the implementation phase of low energy district solutions: learn the importance of business models, regulatory framework and finding value proposition for energy consumption visualization platforms. Get more details on the refurbishment of the Escola Sert center, a part of The College of Architects of Catalonia (COAC). 

Action area 1: Low-Energy Districts - Lessons learnt

The main objective of the GrowSmarter work package called "Low energy districts" is the deployment of energy efficiency measures to reduce the environmental impact of the existing building stock in cities.

To date, we have already reached the stage within the GrowSmarter project where practically all measures are completely executed and the corresponding monitoring phase has started. This has allowed the collection of the first conclusions and lessons learned from the last 2 years of implementation work required to make the proposed measures reality.

In total, 123 000m2 of constructed surface area have been refurbished in the three Lighthouse cities (including private and public buildings, tertiary and residential buildings), and local energy generation has been promoted by connecting buildings to District Heating and Cooling networks, on-site renewable electricity production, and advanced smart energy management of the local energy generation. The project has also promoted the deployment of Home Energy Management Systems to raise awareness on energy efficiency among the citizens. In this context, each Lighthouse city has implemented Smart solutions of different nature but with the same goal: the demonstration of measures leading to a more energy efficient city building stock.

In Barcelona, the partners involved in the Low energy districts work package have highlighted the importance of the following topics:

• Explore feasible business models behind the private building energy retrofitting in relatively low heating demand areas (Mediterranean zone): The industrial partner responsible for the demonstration of private building energy retrofitting in Barcelona highlights the general need for Public-Private partnerships and, in case of commercial buildings, the need for agreements between building owners and operators. In Barcelona, the feasibility of actions related to the energy retrofitting of private buildings by an industrial partner has been possible through the figure of an ESCo (Energy Service Company) that has promoted Public-Private partnerships in order to find a favourable funding for the building owners.  
• Define the value proposition of energy consumption visualization platforms prior to installation: The two energy consumption visualization platforms deployed in Barcelona have shown different value propositions. The Municipality deployed the free Virtual Energy Advisor, which aims at empowering citizens to decrease the electricity consumption in the residential sector. The local utility GNF deployed a commercial HEMS (Home Energy Management System), which will increase consumers’ energy efficiency awareness while providing valuable information on energy consumption consumers’ habits.
• Consider the strong dependence on National regulation for the implementation of Self-consumption systems (Photovoltaics + Battery systems) with Smart energy management systems: Considering the existing regulation in Spain at the time of the GrowSmarter project’s implementation phase, a distributed photovoltaic (PV) energy generation installation can only feed a single consumer. Hence, in order to implement this measure, the PV systems had to be installed at the common rooftop of the residential building and can only satisfy the common end-uses of the building (i.e. elevators and lighting). Moreover, the current legislation does not allow any retribution from the injection in the grid of surplus renewable electricity generation. This limits the possibilities that the smart energy management can offer.

Refurbishment of Escola Sert (COAC)

Sert School is a continuous formation centre through which The College of Architects of Catalonia (COAC) offers a systematic program of training and accompaniment to the professional group. The College of Architects of Catalonia is an institution, established in 1931. Its building was built between 1959 and 1962 and it is located in Plaça Nova, Barcelona.

The project will affect the College building’s façade where the Sert School will be located after the refurbishment. This is a protected building catalogued as historical heritage. Therefore the intervention has been designed and executed respecting the composition and aesthetic of the original building while improving its energy performance and comfort.

On February 2017, the final agreement between Gas Natural Servicios and COAC was signed in order to take part in the GrowSmarter project. At that moment, COAC was already carrying out a global reform, not limited to an energy refurbishment. The municipal permissions were obtained during 2015. The scope of Growsmarter within the global project consists in implementing façade-integrated PV plant and a Building Energy Management System (BEMS).

The implementation started in June 2017 with the PV glass and the electrical installation engineering. The works related to the façade started in October 2017 and they finished in January 2018. The Building Energy Management System (BEMS) was installed once all the refurbishment works finished. The collaboration is taking place under an Energy Services contract, through which the Energy Services Company (Gas Natural Servicios, GNF’s ESCo) provides a turnkey solution and performs the investment in exchange for an annual fee. GNF is responsible for the PV glass supply and its integration in the building electrical installation and also the design and implementation of the BEMS.

The school and the whole building are undergoing a global refurbishment complemented by the GrowSmarter project:

• Façade refurbishment, incorporating mostly glass surface: Improvement of the sound insulation and reduction of the thermal losses
• Implementation of a 19.5 kWp façade-integrated PV plant for self-consumption.

Specific photovoltaic glasses have been selected taking into account both technical and aesthetic properties.

Added Value

Data gathered by the BEMS will be used for better energy management by the building operator resulting in further reductions in energy consumption that achieved using that data. In addition, one of the main aspects to highlight in this refurbishment is the definition of an optimal PV installation design integrated in a building façade, minimizing the visual impact and maximizing the power production that can be obtained through self-consumption.

Gonzalo Cabeza

Site Manager, Barcelona

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