Towards solar urban planning in Europe: The project "Polis"

25. October 2012 By:  Project POLIS

On the back of the European Union’s 20/20/20 energy targets, a number of initiative have been established, aimed at increasing the uptake of renewable energies. The project POLIS is just one, which seeks to identify solar’s potential – photovoltaics and solar thermal – and encourage its deployment in cities across Europe via various solar action plans. The project’s participants outline their goals and progress below.

Cities are not only home to the majority of a country’s population (around 80% in Europe), but also to goods and activities and, thus, have the highest energy consumption (75% of demand). They also produce the highest amount of pollution (75%).

In this regard, interesting initiatives have emerged in recent years in different European cities, which aim to identify solar potential – solar photovoltaics and solar thermal – and track its subsequent transformation through legislative measures.

In order to present those experiences and, hopefully, to transfer the knowledge to other cities, the project POLIS was established at the end of 2009. POLIS, an acronym for Identification and Mobilization of Solar Potentials via Local Strategies, is a project co-financed by the Intelligent Energy Europe programme though which six European cities have committed to developing strategies for urban planning, taking into consideration solar criteria; and promoting local policies that support the use of solar.

The belief is that only a local strategic approach will significantly increase the integration of decentralized renewable technologies and, in particular,  small-scale technologies, in cities.

The project, coordinated by consultant company Ecofys, has the participation of municipalities in five European countries – Munich, Germany, Vitoria-Gasteiz, Spain, Paris and Lyon, France, Lisbon, Portugal, and Malmö, Sweden – and  technical experts from various disciplines, including architecture, solar energy and the environment. Meanwhile, the recipients of the project are all actors involved in the urban planning processes, such as local authorities, planners, architects, investors and community owners.

Best practices for urban solar planning

An extensive compilation of good practices related to solar urbanism in European cities, classified into the following categories, has been carried out:

  • Identification of solar potential and definition of priorities (planning instruments);
  • Transformation of solar potential (initiatives to use the identified potential: awareness campaigns, subvention programs, local policies, information days, cooperation with existing programs/projects, etc.);
  • Development and implementation of measures of solar planning in new or existing urban planning developments; and
  • Development and approval of policies and legislative measures (e.g. introduction of a solar ordinance for buildings).

These experiences have been published in a handbook edited last September, which is available in different languages through the project website.

Solar action plans and pilot actions

The six cities participating in the POLIS project have committed to adopt long term strategies to integrate solar energy at the urban level, which are compatible with national, regional and local emission reduction targets and the use of renewable energy.

These strategies, or "Solar Action Plans" have been developed by working groups integrated by the municipalities and local technical partners over several months. In the short term, the Solar Action Plans defined 63 specific measures, of which one third were identified as priority "Pilot Actions" and were implemented throughout the project. The main features of the action plans and the pilot actions of the different cities are summarized below.


Munich is one of the pioneering German municipalities on issues related to sustainability, especially in the efficient energy supply. As the owner of municipal utility Stadtwerke Muenchen GmbH, which provides electricity, heating, gas and water, the city has developed interesting initiatives, such as the production and marketing of green electricity, the creation of incentives for the adoption of energy saving measures in buildings, and the establishment of requirements for public buildings, which include the target of installing photovoltaic panels by private non-profit organizations.

In relation to climate change, Munich has set ambitious targets that include progressive reductions of CO2 emissions (by 10% every 5 years and 50% in 2030), and the coverage of the electricity demand from renewable sources (the residential sector in 2015, all sectors in 2025).

Regarding the Solar Action Plan, the following objectives have been defined:

  • Exploit the urban solar potential for photovoltaic use identified by the "Solar Initiative Munich" (300 MW, related to roofs of buildings) to ensure that in 2015, 3.5% of the consumed electricity proceeds from photovoltaic systems are integrated into the urban structure;
  • Increase the previous percentage further by 3.5% in 2030 through measures taken at the urban planning level. Exploiting the solar potential for thermal use, so that in 2030 3% of the heating demand is supplied by solar energy; and
  • Ensure that, from 2012, at least 25% of the heating demand is supplied by solar energy (passive strategies) in new residential developments bigger than 100 houses.

In the short term, the plan includes a total of 21 measures, 2 of which are pilot actions performed under the POLIS project:

  • The creation of a "Guide for Solar Urban Planning" (2010 -2011). The main objective is to provide a systematic assessment of plans and planning projects that allows the incorporation of specific objectives of the Solar Action Plan into the planning process, to ensure a use of the solar potential.
  • The participative process of this pilot action and the guideline with its general solar urban planning rules, and specific options for integrating solar aspects in existing processes and instruments, could help to rise awareness of urban planners, architects and decision makers and lead to energy optimized town planning in the near future.
  • Application of the Guide for Solar Urban Planning in The Bayernkaserne area. It will be the first project where the guideline, requirements and necessary conditions will be implemented into solar urban planning and design, effectively embedded in daily planning practice. This will include an analysis of the development plans to identify the solar potential and to optimize the urban structure, the establishment of objectives, legal requirements and incentives linked to the solar use and technical assistance during the planning.


Vitoria-Gasteiz, Spain, is one of Europe’s most committed cities when it comes to fighting climate change. In the past two decades, the city has signed various international agreements and approved targets to reduce energy consumption by 9% over 2004 levels (Local Energy Plan 2007-2012). Today, as a signatory city to the Pact of mayors, Vitoria-Gasteiz has approved the "Plan to Combat Climate Change" and is working on a Plan of Adaptation to Climate Change (2010-2020), as well as on an Ordinance for the local energy management.

These documents establish the targets of reducing CO2 emissions by 24.6% by 2020 and the installation of 70,000 m2 of solar thermal collectors and 10 MW of photovoltaic modules. However, the city has identified as top priority, the need  to conduct a study on the realistic possibilities of using solar energy in urban areas, both on a  global, and a local level.

In particular, the Solar Action has established the following objectives:

  • Identify the solar potential (active and passive) at the municipal level by 2012;
  • Integrate solar requirements in the new General Urban Plan and in the future energy ordinance; and
  • Transform 10% of the solar potential identified in the industrial and services park/polygon Jundiz by 2015.

In the short term, the Action Plan identifies 5 measures, 3 of which are Pilot Actions implemented in the POLIS project:

  • Development of a methodology to identify the solar urban potential, compatible with local and national regulations (Technical Building Code) and its application in the district Lakua (2009-2010): Three groups of maps, of the Solar Passive, Solar Thermal and Solar Photovoltaic potential; A database with detailed information of solar potential for each constructive element; and An accompanying document that includes a description of the developed methodology, its application to the Lakua district and recommendations for the mobilization of the solar potential identified. The methodology, based on an analysis software tool of the solar potential developed by the Polytechnic University of Madrid, includes the passive and active solar potential of buildings, taking into account their location, environment (shadow effect) and main construction features. A description can be found in the planning instruments published on POLIS website (
  • Identification of the solar potential of the Jundiz industrial park (2010-2011). In particular, the solar potential for photovoltaic use in the roofs of the industrial and existing buildings has been determined.
  • Identification of the solar potential of the city of Vitoria-Gasteiz (2011). The methodology developed in the Pilot Action 1 have been adapted to the entire city, identifying homogeneous urban typologies in terms of structural characteristics, applicable regulations, etc., that were be analyzed afterward using the developed tools.


In 2007, Paris adopted a Climate Protection Plan, which aims to reduce 75% of the CO2 emissions in 2050, compared to 2004 levels. The plan also establishes targets of 25% for the reduction of emissions and energy consumption by 2020, and a 25% target for the contribution of renewable energy.

At the moment, several initiatives related to the plan are being developed in the field of solar energy, such as the establishment of environmental recommendations within the urban plans (mandatory in projects with public participation and optional for entirely private funded projects), as well as within the social housing projects (use of solar thermal energy), and within the information and awareness campaigns.

The Solar Action Plan has established the following objectives:

  • Identify the solar potential of the entire city by 2012, setting realistic targets through the integration of solar thermal and photovoltaic technologies in buildings;
  • Install 200,000m2 of solar thermal and photovoltaic panels by 2014; and
  • Establish requirements for solar use in the urban planning regulations for 2013.

In the short term, 12 measures have been identified, 3 of which are Pilot Actions have been identified and one implemented within POLIS Project:

  • Identification of the technical solar potential of the entire city (2010-2012). The limited development that Paris has had to date regarding solar energy is partly due to the lack of information on buildings potential. Through the improvement of an existing tool combined with the use of digital ground models (topographical representation of the city), data provided by Geographic Information Systems and other software tools (shading analysis, simulation of passive and active solar systems), it intends to develop a "solar cadastral registry" to identify areas with greater potential where the new legislative actions should be oriented. The results, which are offered in the form of interactive maps, will be in the first phase available to professionals in the field of urban development and renewable energies, and then to the general public.
  • Creating a tool for monitoring the solar facilities (2010-2011). Currently, the information about the existing facilities is scattered in various agencies and companies (building permits, contracts with electricity companies that buy the production from photovoltaic systems, operating agreements, etc.). The creation of a tool that centralizes the information of the current and future facilities will facilitate the tracking of the Action Plan targets and will optimize future actions in favor of the use of solar energy.
  • Establishment of solar requirements in the urban planning regulations (2011-2012). Until a few months ago, the local administrations in France could not impose measures that could establish legal obligations superior to those set up by national law. Recent new environmental law should have given the possibility to local governments by editing a specific decree. The decree was stopped because of the new government elections, but should be published by 2013. However, the city planning and law services studied how to enhance the development of solar energy. The results will be integrated in next Paris’ climate protection, which will be proposed to the city council at the end of 2012.


Like Paris, the Climate Protection Plan of Lyon shares the targets of reducing by 2050 75% of the CO2 emissions. The plan also aims to increase, by 2020, the use of renewable energy by 20% compared to 2000. To achieve these and other targets, in recent years studies and real projects of interest, such as an identification of the renewable potential in the area of Grand Lyon, and the project "Lyon Confluence" for regeneration of a degraded industrial area in terms of sustainability, have been carried out. Emphasis must also be given to the public-private initiatives that facilitate investment in renewable energies and to the companies for collective investment in photovoltaic installations.

The Solar Action Plan of Lyon, in which the Urban Planning Agency of Grand Lyon participated together with various municipal departments, the Local Energy Agency and the organization HESPUL, has defined the following objectives:

  • Ensure that from 2012, the passive use of solar energy supplies at least 20% of heating needs in new residential developments with more than 100 houses;
  • Help to achieve the set targets in the climate protection plan by increasing the surfaces of photovoltaic modules and solar thermal collectors currently installed by 50% and 40% per year, respectively.

In the short term, 11 measures have been defined, 3 of which are Pilot Actions in the POLIS Project:

  • An interactive website with detailed real solar potential for the Sainte Blandine district was created. The objective was to inform district inhabitants about the development potential of PV technology on their roofs. This was mainly done by publishing the solar cadastre. It has been online since December 2011 on the Grand Lyon Climat Action Plan blog: "blog du plan climat". The tool is available here:
  • Citizen jointly owned PV system at Lyon: The second Pilot Action is the mobilization of local investments in PV systems and the possibility for local citizens to participate in the development and production of renewable electricity. This jointly owned PV system could either be installed on a roof owned by a municipality, or on another type of private roof.
  • Solar planning scenario for a new development area:  A study on the solar potential and its optimization for the district of Bron Terraillon (within the city of Bron, Greater Lyon area) has been carried out. The master plan proposed by the town planner has been tested in terms of its strengths and weaknesses regarding solar gains. The weaknesses have been highlighted and some optimized solutions proposed.The conclusions of the work is available on POLIS website (under Solar Urban Planning in POLIS cities). Following the work done on Bron Teraillon, a guide presenting different steps for the optimisation of energy in urban planning projects has been written. It will be available on POLIS and Hespul's website by the end of 2012.


The Energy and Environment Strategy of Lisbon approved in 2008, aims reduce energy consumption by 9% by 2013, compared to 2004 levels. Moreover, as a signatory city to the Pact of Mayors, Lisbon has committed to reduce CO2 emissions more than 20% by 2020. In order to help achieve these targets and to promote the efficient use of renewable energies, Lisbon has recently introduced compulsory measures, such as the architectural integration of solar panels on buildings, installation of centralized solar thermal systems for the supply of ACS in new buildings, and tax incentives to encourage innovative projects that use renewable energies.

The Solar Action Plan, introduced 5 measures (Pilot Actions) to be carried out under the POLIS project:

  • Assessing the solar potential of Lisbon (2010-2011). This includes conducting a study of the solar potential for thermal and photovoltaic use, both in existing and new buildings.
  • Defining objectives for the adoption of solar technologies (2011). The results of the above mentioned Pilot Action will be used to define objectives which are consistent with the national legislation (National Energy Efficiency Plan) and local objectives (Energy and environmental strategy and the Pact of Mayors).
  • Assess the potential for integrating solar technologies in the Boavista district (2010- 2012). This district is undergoing a rehabilitation program funded with national funds and the incorporation of solar technologies is foreseen.
  • Identification of solar potential for public service buildings (2010-2012). A detailed study of the solar potential of public buildings in the service sector with medium-voltage power supply, including technical and economic aspects has been carried out.
  • Municipal training in concepts and solar technologies at the urban level (2011-2012). The use of solar energy at municipal level depends largely on the ability of local technicians to detect the added value of solar technologies and their knowledge of the existing integration possibilities. Two training workshops have been held on the integration of solar technologies at the buildings and urban levels, addressed to the departments related to architecture, engineering and planning of the City of Lisbon.


Malmö is one of the most active and dynamic Swedish cities concerning targets and strategies to combat climate change, including measures related to energy, urban planning and construction, transportation, education and lifestyle. In 2009, the City Council approved relevant initiatives such as the "Energy Strategy" with the aim that by 2030 the city is exclusively supplied by renewable energy sources and adopts a model of safe and sustainable energy use.

The Solar Action Plan includes the following objectives:

  • Establish by 2012, realistic and measurable targets for the integration of solar thermal and photovoltaic technologies at the urban level;
  • Introduce solar requirements in urban planning processes in 2012, complementing the legislative initiatives mentioned above; and
  • Carry out purchase and urban land exploitation agreements that incorporate solar requirements from 2011, using the possibilities established in the existing strategic programs (especially the "South Building Environmental Program").

In the short term, 8 measures have been defined, 3 of which are Pilot Actions have been implemented within POLIS Project:

  • Urban solar Planning in Sege Park (2010-2012). Sege Park is an urban area of Malmö, undergoing rehabilitation that is taking into account sustainability criteria, including the use of renewable energies. This action aimed to introduce solar requirements in the local urban plan that will facilitate the future implementation of solar energy facilities, both regarding the orientation of buildings and in relation to the possible locations of the panels. However, according to the Swedish planning and building-regulation, PBL, municipalities cannot set requirements of one specific energy source within the local plans. The reason is the fact that it would force the buyer of the land to use that specific source of energy, which would distort market competition. The local working group of Malmö has however discussed the possibility to view solar installations as a source of energy saving, rather than a source of energy production. Having this view, it should be possible to set a solar energy installation requirement in a local plan.
  • Detailed study of the solar potential in Sege Park (2010-2011). A specific method has been developed and can be used for larger areas in Malmö and other cities using LiDAR data. The method can be used for several purposes in order to create interest for the possibility to increase the use of solar energy – as well as the study of different building areas in order to categorize areas according to possible potential. This may encourage the use of solar energy as well as the knowledge of the potential. The impact on the long-term action plan is to function as a model method for future potential studies in the city and in the region.
  • Solar requirements in purchase and exploitation agreements (2011-2012). In Sweden, the municipalities have the possibility of establishing specific requirements in the agreements of purchase and of urban land exploitation.


Six European cities have committed themselves to developing long-term strategies to integrate solar energy at the urban scale, as well as specific measures in the short and medium term, in order to achieve the targets set out in these strategies. The results of the POLIS Project have been disseminated in seminars held in the participating countries during 2011 and 2012.

The final challenge is to incorporate the use of solar energy in the planning documents, which have a mandatory character. This will be an effective and timely solution to move from general objectives to specific actions, so that the twenty-first century city becomes a new model of generation and responsible use of clean energies.

The authors

Estefanía Caamaño Martín, INSTITUTO DE ENERGÍA SOLAR E.T.S.I. Telecomunicación, Ciudad Universitaria s/n E, Madrid, Spain (estefan( at )

Ignacio Useros, Grupo Arquitectura Bioclimática en un Entorno Sostenible –  Universidad Politécnica de Madrid, ABIO research group (n.useros( at );

Sigrid Linder, Consultant Energy in the Built Environment, Ecofys (s.lindner( at );

Emmanuelle Faysse, HESPUL énergies renouvelables & efficacité énergétique (emmanuelle.faysse( at );

Angela Saadé, Chargée de mission photovoltaïque et programme Européens
HESPUL énergies renouvelables & efficacité énergétique (angela.saade( at );

Disclaimer: The views and opinions expressed in this article are the authors own, and do not necessarily reflect those held by pv magazine.

Displaying results 1 to 4 out of 4

byron ryder

Tuesday, 16.12.2014 13:45

It`s great to hear that European cities started implementing these technologies, the “Polis” project will be very successful as people living in the urban regions will realize PV panels efficiency. Also my nephew noticed this trend is flourishing in our country when he was searching for Palm Springs real estate offers as a lot of houses had such photovoltaic panels installed on the roof.

byron ryder

Tuesday, 16.12.2014 13:44

It`s great to hear that European cities started implementing these technologies, the “Polis” project will be very successful as people living in the urban regions will realize PV panels efficiency. Also my nephew noticed this trend is flourishing in our country when he was searching for Palm Springs real estate offers as a lot of houses had such photovoltaic panels installed on the roof.

lenny karke

Thursday, 20.11.2014 23:32

Nowadays there are only a few cities that took measures to combat climate change by installing PV systems. The “integration of solar thermal and photovoltaic technologies at the urban level” is a very interesting concept that must be put into practice as soon as possible in all the major cities, the last year my uncle installed a high performance PV system on the rooftop along with wrought iron gates and the results are amazing, now his house looks very impressive and he even saw tourists making photos of the house.

david spacey

Tuesday, 05.08.2014 20:18

The urban solar potential is huge and the authorities should invest in programs meant to integrate such photovoltaic systems into the urban structure. My niece lives in the city but she prefers living at the countryside because having enough space for installing such PV systems is not a problem, also she saw very interesting custom pool designs and wants to install one for her kids.

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