Find answers to all the common questions

What are the objectives of the project?

Balkan Solar Roofs is a new project to support municipalities in the Balkan region to increase the installation of solar energy.  The programme offers capacity building and training for municipalities and is developing a communications package to promote solar installations in the local community.

This ambitious project aims to enable 500 new solar roof installations by 2024. The project will support 40 replicating areas to increase solar in their towns and cities via the Balkan Solar Roofs campaign and will reach out to policy makers to make sure national frameworks are supportive of citizen energy.

Balkan Solar Roofs is organising three national events, as well as bespoke capacity building, to ensure wide political support and a multi-disciplinary approach. Participating municipalities will learn about the different forms and benefits of urban solar community energy, they will learn about the benefits of mapping relevant local stakeholders. The municipalities will also develop local community energy roadmaps that outline key opportunities to support the municipality, citizens and SMEs in installing solar.

Energy Cities is leading the programme and working with three pilot cities; Porec-Parenzo (Croatia), Mostar (Bosnia and Herzegovina) and Kragujevac (Serbia). Technical support is being provided by ZEZ Green Energy Cooperative based in Zagreb, Croatia, and our strategic project partner, the Regional Education and Information Centre for sustainable development in South East Europe (REIC) based in Sarajevo.

Balkan Solar Roofs is financed by EUKI a project financing instrument of the German Federal Ministry for Economic Affairs and Climate Action (BMWK) https://www.euki.de/en/

How much does it cost?

It is free and designed to help municipalities in the Balkans promote and enable new solar installations and energy communities in their towns and cities. If you are interested in joining us please go to our contact page.

1. Go to the JOIN section in the top menu and choose ‘Cities’.

2. Fill in the form. Note it is compulsory to fill in information where there is an asterisk.

3. Once you have filled in the form you will receive an email with the Balkan Solar Roofs charter that your administration will need to sign scan and then send back to us.

If you have any questions concerning this process please don’t hesitate to use our contact option.

By joining the campaign, you will:

  • Increase your city’s visibility locally, nationally and Europe-wide
  • Upgrade your political and city profile
  • Stimulate investments, boost the local economy, and contribute to job creation
  • Motivate your city’s staff, empower young people and keep them in the country.
  • Strengthen local knowledge, encourage the identification and mapping of roofs that could host PV panels, etc

The campaign is primarily made for municipalities or cities in the Balkans (Serbia, Croatia, Bosnia and Herzegovina, Montenegro, Macedonia, Albania and Slovenia). Local governments from other parts of Europe are also welcome.

Look at the section of this FAQ that is dedicated to citizens and businesses.

If your city has requested to join the campaign, they will be contacted directly. If your city has not already signed up, the website administrators will follow-up and encourage your city to join.

The aim is to get as many cities involved in the Balkan Solar Roofs Campaign so please send the website link to as many of your city contacts as possible.

What if I am not a city representative?

If you are a citizen or part of a local business or association, and you would like to communicate about the solar roof(s) that you have installed, you can join the campaign as an individual.

1 -Go to the JOIN section in the top menu and choose ‘Individuals.

2 - Fill in an online form. 

Please note that if you live in a city that is already part of the Balkan Solar Roofs project, i.e.  Mostar, Kragujevac and Poreč – but there will be more cities in the future, your request will be sent to the campaign manager in the city in question. They will contact you  to get the information and materials they need to produce a poster that will be added to the online gallery https://www.balkan-solar-roofs.eu/gallery.

If you are from another city your request will be sent to Energy Cities or REIC.

As relay organisations, they will contact you to get the information and materials required to produce a poster, and may discuss with you how to motivate the city you live in to join Balkan Solar Roofs!

Please note that you will also need to add in your location details and information about the installation that you have on your roof.

How is ‘Generated renewable energy’ calculated?

These figures are calculated when a user fills in specific information linked to the photovoltaics or thermal (hot water) installations on their roofs.

There are two different calculations that are carried out. One for photovoltaics and one for thermal (hot water)

For photovoltaics you need to choose the drop-down option – photovoltaics. This includes both monocrystalline and polycrystalline installations. Note that the calculation can only be done if you fill in the solar roof power and click on 'yes' for the question 'Is the power plant installed' and add the date of installation as shown on the screen print below. 

The following calculation is then used to calculate the renewable energy for photovoltaics.

Generated renewable energy = ''Specific photovoltaic power output'' x total kW installed i.e. Solar roof power x total number of days in operation

The Global Solar Atlas https://globalsolaratlas.info provides ''Specific photovoltaic power output'' data which is easily retrievable for all cities that will join the campaign and for the moment the following figures are used for our 3 pilot cities:

  • Poreč-Parenzo: 3,833 kWh/kWp per day
  • Mostar: 3,871 kWh/kWp per day
  • Kragujevac: 3,532 kWh/kWp per day

Below is a screen shot taken for Poreč to show how the data is sourced.

For Thermal (hot water) the calculation is different and thus requires the user to fill in different data as shown by the screenshot below.

For this calculation it is essential that you fill in your solar roof area in m2. The following calculation is then used.

Total energy produced = ((direct normal solar irradiation x efficiency factor of a solar thermal panel (default 70%) x surface area of solar thermal panel)/365) x total number of days in operation

The ''direct normal irradiatiation'' is sourced from the Global Solar Atlas https://globalsolaratlas.info for all participating cities and here are the figures for the three pilot cities: 

  • Poreč-Parenzo: 1.475 kWh/m2 per year
  • Mostar: 1.470 kWh/m2 per year
  • Kragujevac: 1.240 kWh/m2 per year

Below is a screen shot taken for Poreč-Parenzo to show how we find the figures.

Please note that we have chosen to use a default average efficiency factor of 70 percent taking into account that types of solar thermal panels made by different manufacturers can vary between 60 – 85% efficiency but that these figures are difficult to obtain.

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The CO2 figures are based on the ‘Generated renewable energy’ figures calculated for  both the photovoltaic and thermal installations using the following computation.

CO2 saved =  Generated renewable energy x grid mix factor

For the grid mix factors we use primary energy factors sourced from the following website  https://app.electricitymaps.com . We use 5 year consumption figures per country and below are the figures that we are currently using for the 3 pilot cities:

  • Croatia: 0,000305 tCO2/kWh
  • Bosnia and Herzegovina: 0,000574 tCO2/kWh
  • Serbia: 0,000556 tCO2/kWh

Below is a screen shot to show how we use these figures.

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Again like for the CO2 figures the base figure is the total energy produced which is then multiplied by the electricity price as shown in the following calculation.

Saved so far = Total energy produced x electricity price

Electricity prices are sourced from the following website  and are provided per country https://countryeconomy.com/energy-and-environment/electricity-price-household. Here are the figures that are currently being used but they will be updated if we have cities joining from other countries:

  • Croatia: 0,1354 €/kWh
  • Bosnia and Herzegovina: 0,0887 €/kWh
  • Serbia: 0,0808 €/kWh

Below is a screenshot to show how the figures were sourced for Croatia.


For this calculation we make use of the figures that were calculated for CO2 saved and we carry out the following calculation

CO2 offset by trees = ((CO2 emission reduction/total number of days in operation)x365)/1 tree CO2 offset i.e. 0,024

The figure 0,024  for 1 tree CO2 offset is sourced from https://www.encon.eu/en/calculation-co2-offsetting-trees

How to use the poster tool?

As a city, you first need to register by clicking on the option Join in the top menu and the tab Cities (https://www.balkan-solar-roofs.eu/join/city).If you are unsure of what to do next, please visit the FAQ - The Campaign for Cities/What do I need to do to join the campaign?

Once you have registered, you will receive your password within a couple of days. Once you have a password, please go to the private area of the website, and sign in: https://balkan-solar-roofs.eu/user/signin

When you have logged in, you will reach this landing page (note that the example below is for the city of Mostar – your page will have the name of the city that you registered).

The first thing you should do is change your password

If you click on “edit city details”, you will be able to add information about your city in your national language and include photos. Available languages are English, Croatian, Serbian and Bosnian.

You can also add any document from your city that other cities in the campaign will find useful by clicking on “edit city resources”. Please make sure to indicate in which language the document is available.

If you have any city buildings or citizens that want to create a poster of their solar roof and have high quality photos available please note that you will need to first click on Add a new record within the Address book.

You will need to provide the following details – there is an asterisk for the fields that are compulsory to fill in.

Once you have added a contact, please save it. It is only possible to create a poster if you add the geographical location of the (private or public) building with a solar roof.

If the owner of the building has not provided consent to share its location, please select “hidden”. One contact can be related to more than one location.

This can be done by adding an address or pinpointing the place on the map.

If a citizen comes to your office, you should collect some technical information about the solar installation.

This includes among others the type of technology:

  • Photovoltaic
  • Thermal (hot water
  • Other

Once the address has been saved you will be able to click on 'Add new poster' button

Choose the image that will be used to create the poster, preferably an image of the building and the solar roof with the people that were involved  in the installation.

Please try to add an image with the highest quality possible. This will then allow you to create large posters to print. You can produce a poster in landscape or portrait or for social media (lower quality) and in A2/3/4 or B2/3/4 formats.

There are a number of choices for the Balkan Solar Roofs logo. The logo is currently available in Albanian, Bosnian, Croatian, Greek, Macedonian and Serbian (latin and Cyrillic). Each country will have their National language plus English as an option.