The bidirectional fotolinera of Molins de Rei
City/Region : Metropolitan Area of Barcelona , Spain

A fotolinera is a photovoltaic pergola, usually located next to a public building, which is equipped with a charging spot for electric vehicles. Therefore, energy to charge cars is no longer coming from fossil fuels but from a renewable source. In addition, whenever there are no cars to be charged, the energy is used by the public building. In addition, the fotolinera of Molins is equipped with V2G technology, a type of connection which allows energy flow on both directions. The battery of the car can be used as an energy source.


Agendas addressed
Urban mobilityGreenfield land and natural spaceClimate change
Pathways followed
  • Involve citizens through participatory implementation
  • Encourage local private and civic engagement
  • Promote social innovation supporting inclusion
  • Implement sustainable procurement principles
  • Wisely select and apply smart technologies
  • Accelerate sustainability and innovation through public procurement

The metropolitan area of Barcelona is one of the most populated areas in the world, with 3.239.337 inhabitants. Therefore, there are a few challenges to be accomplished in order to improve the quality of life of the citizens and achieve the energy challenges set for 2030.

AMB is willing to make an impact towards energy transition, for that reason on 25 September 2018, the Climate and Energy Plan 2030 was approved. The plan establishes the axes, bases and actions necessary to achieve the objectives of energy transition and fight against climate change in the metropolitan area of Barcelona. The ENER 5-1 action includes the creation of a Metropolitan Network of Fotolineres.

In Action

Energy transition requires new methods for the energy storage. V2G (Vehicle to grid) charging stations are a powerful tool to fulfil this purpose. The charging station, powered by photovoltaic energy, has two main aims. First of all, providing clean energy to charge electric vehicles or, whenever there are no cars or those that are there are fully charged, the energy is used to supply public buildings. Furthermore, bidirectional energy flow allows car batteries to be an energy source whenever the building requires it.

From AMB, promoting and launching projects to meet the triple objective of 2030, air quality improvement, climate change and energy transition is a priority. This project is framed as a part to pursue those goals.

The Fotolinera (catalan expression meaning a solar photovoltaic charging station) presented in this application is a pioneering project in Spain, since it is the first one to be equipped with V2G technology. The objective of this type of infrastructure is the recharge of electric vehicles together with supplying with clean energy public buildings.

What’s new about this installation is the implementation of V2G. This new technology allows a bidirectional energy flow, which means that the energy stored in the car batteries can be used as an energy source as well. This new scenario has plenty of advantages. For instance, the car batteries can be used in punctual moments as an energy source to contribute to the energy demand of the public building whenever the photovoltaic generation is lower than the demand, leading to a decrease of the power peaks. It can also be useful when it comes to reducing the energy demand on periods in which the energy prices are higher.

Moreover, renewable generation is linked to a variability on its energy production which is not followed by the demand. In this context, V2G systems could consider the car as a battery connected to the grid so as to fit the lacks and excesses of the renewable generation by charging or discharging the car battery.

Finally, the use V2G systems could maintain the energy quality supply required by the loads, by means of continuity in the supply or the compensation of reactive power.


The Fotolinera started working on 15 February 2019. Since then, EV owners have used the fotolinera often. The charging spot equipped with V2G has seldom used the car as a battery source, only 83,3 kWh have flown from the car to the grid. There are a few reasons for that. First, not all cars are prepared to use V2G, in fact there are only two
vehicles of the Town Hall fleet (Nissan Leaf and eNV-200) which have access to the V2G. Moreover, people who charge their vehicles there are not familiarised with the advantages of V2G.

The fotolinera is also expected to overcome a few more challenges:

  • The working hours of the V2G charging spot are planned to be a 50% of the total hours of the year.
  • The energy injected to the building coming from the battery of the EV is 1000 kWh per year.
  • The annual savings are expected to raise up to 1200€.

The new evolution of the Fotolineres is in accordance with the energy revolution that is coming for the next decade; the integration of batteries for the storage of energy coming from renewable sources in a smart grid. AMB is trying to push energy transition, sustainable mobility and modal change; to promote the use of renewable energy sources in the electric vehicle charging network, to expand the use of EV in the metropolitan area besides promoting public transport and as a consequence improving the air quality of the metropolitan area. Needless to say the health benefits due to a drop in greenhouse emissions, coming from a self-sufficient energy consumption and an air free of pollution.

V2G Fotolineres are not only meant to reduce the use of energy coming from fossil fuels but also to cause impact among inhabitants and to set an standard for further projects to be executed in the metropolitan area. The roof pergola is also creating a new landscape alongside roads and highways aspiring to replace the standard gas stations and transmit in a simple way the new energy paradigm; local renewables and sustainable mobility.

Challenges and lessons learned

One of the most important challenges that the organisation is facing with these new installations are caused by the unfamiliarity of the people towards this new technology. People with EV are not used to the fact that their car can be also discharged when connected to a charging spot because they are not familiar with the benefits of the system.

Fotolinera V2G resume


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