Mapping the solar transformation in Budapest

Budapest, with its stunning landscape and rich architectural heritage, has long been regarded as a centre of great historical and cultural innovation. Now the city is also leading a local climate transformation, thanks to its ground-breaking plans to develop the huge potential of solar energy.

The city’s municipality has created an online solar map which provides the first ever estimation of the solar possibilities for every rooftop in Budapest. The map shows local people and businesses how much energy and money they can generate by installing solar panels on the roofs of their buildings.

Using the solar map as its first step, the ultimate goal of the project is to increase the use of solar energy across the city, leading to greater production of clean electricity and a significant reduction in urban carbon emissions.

Security and prosperity

“Extreme weather incidents are happening much more often in Budapest,” warns Ada Ámon, Head of the Department of Climate and Environment at the Municipality of Budapest Mayor’s Office. “The whole inner city is a big ‘heat island’ in the summer and can reach up to 40 degrees, affecting the health of older and vulnerable people.”

“Added to this, the Russian war in Ukraine means we have experienced a huge rise in energy costs that has placed a lot of pressure on local people.”

The map has huge potential for supporting Budapest’s rapid transition away from fossils fuels
— Ada Ámon, Head of the Department of Climate and Environment at the Municipality of Budapest Mayor’s Office

Responding to these significant challenges, the solar map is designed to educate people in the city about the benefits of installing solar panels in their homes. It is also being used by Budapest municipality to assess the overall theoretical electricity the city can potentially accumulate from solar power.

“Using the latest 3D technology, the map can tell people, house by house, how much of the surface of their roof is useful, what size the panels on their roof could be, what capacity and how much energy they can produce,” says Ámon. “The map has huge potential for supporting Budapest’s rapid transition away from fossils fuels, towards a prosperous, climate neutral future with increased security of supply.”

Budapest has enormous solar potential

Bold moves

Selected for the EU Mission 100 Climate Neutral Cities by 2030, Budapest has ambitious plans to reach its climate neutral objectives in the decade ahead. Having looked at several potential forms of renewable technology, the city has identified solar energy as its key means of accessing a clean and decentralised energy system and achieving net zero energy targets.

Ámon explains that the city considered several ideas for accelerating emission reduction, but they required large amounts of money that would be beyond their capacity. “The government does not let the city access EU funds and is redirecting a large portion of our tax income to the national treasury,” she says, “so our strategic thinking moved to solar investment, because instead of large public funding, we knew private investment would do the job.”

Our goal in the coming years is to reach a figure that would reduce carbon emissions by 20%
— Ada Ámon

The municipality is also working with local engineers, the energy sector and the wider public to improve regulations around urban planning so it can provide greater scope for local people and businesses to place solar panels on their buildings. A key part of this process is making sure the architectural beauty and heritage of the city are maintained.

The aim is to produce up to 1,500 megawatts of electricity from solar energy, ensuring that the city is moving towards self-sufficiency. At present, Budapest can consume up to 25% of the country’s daily electricity supply.

A map showing the daily power consumptions of Budapest, compared to the rest of Hungary. Depending on the time of day, the city’s consumption can reach 25% of the country’s overall use.


“Solar investment would account for about one fifth of our current reduction target,” states Ámon, before stressing: “But we believe our overall ambition should be even more bold.”

“To become a climate neutral city, we would need double that capacity, but at least it is a step in the right direction. If we are to truly achieve our climate neutral goals, we must have public and private resources working together to provide renewable energy that can support heating, cooling and sustainable transport for our city.”

Mapping solar potential

The solar map represents the first phase in the city’s actions to achieve these climate objectives. The online tool is being used to educate local people about the process of installing solar photovoltaic panels and make seemingly complex issues easier to understand.

The map calculates the amount of energy a solar panel on a building rooftop could generate by taking into account the roof’s orientation. It also determines the panel’s potential surface, given obstacles such as windows or chimneys.

“The solar map is proving very popular,” stresses Ámon. “Using the online system, people living in the city can click on any building and be provided with the useful surface from a solar point of view, then the capacity and the potential annual production.”

We are showing people that solar power is no longer too expensive or complex
— Ada Ámon

“The technology is very complicated, taking into account things like roof angle, surrounding possible shade, and all the chimneys, but the process for the person using the map, it is very straightforward. We are showing people that solar power is no longer too expensive or complex. It is an easy process that will benefit them.”

The map also offers opportunities for further innovation, with the potential to identify different ways that local communities and businesses can share, and/or own electricity production facilities based on solar technology. An area that is being considered is in multi-story apartment buildings, where flat owners could potentially lend their roofs or sell energy to local businesses.

“There are countless possibilities for communities to look at financing and supporting their local area, with consumers and producers working together to build positive change,” says Ámon. “For instance, a restaurant at the base of an apartment block could use the electricity produced on the roofs of the surrounding buildings. It would be a partnership that would benefit everyone.”

Barriers at national level

However, even with the many positive options that solar energy offers, the route to its development in Budapest has not been without its challenges, particularly given the recent policies of the national Hungarian government.

The launch of the solar map in September 2022 was followed just one month later by new government regulations on the installation of new solar energy panels. The national government announced that there would be no permits provided for either household or larger scale installations, while also making it clear that the new legislation prohibits solar energy to be fed back into the electricity grid across the country.

“It was a big shock for us,” says Ámon, making her deep concern clear. “These regulations hit Budapest really hard as we were just about structuring our energy and climate policy and financing schemes, creating a system that would allow solar energy to develop and flourish. On the other hand the Budapest grid is strong enough to easily absorb more than 50% of the theoretical potential according to our new load flow assessment.”

She adds: “The government is confusing people with this policy. It is not helpful in the longer term and we are still working out how we can move forward with our plans.”

Preparing for a solar future

Despite the difficulties at national level, the city of Budapest continues to accelerate its plans for solar deployment. At a recent meeting in Brussels, organised by the Budapest municipality, this position was given the strong support of the European Commission. Held to show the crucial role of solar energy in achieving Europe’s climate neutral future, the event brought together representatives from the Commission, the European Parliament, solar networks and other European cities.

It is important that cities are brought into national discussions about energy policy.
— Eero Ailio, Adviser on Energy Transition and Local Governance for the European Commission

Speaking at the event, Eero Ailio, Adviser on Energy Transition and Local Governance for the European Commission, explained that 70% of all energy legislation is taking place in Europe’s cities. “We have seen cities put energy communities into practice, where larger energy producers have failed,” said Ailio. “Cities manage to do this because they have trusted political leaders and they know how to engage local people.”

“As a result, it is important that cities are brought into national discussions about energy policy. Budapest, for example, should be consulted when Hungary is updating its national energy plans.”

Reflecting this stance, Budapest has produced a range of data, which it plans to share more widely, with the goal of holding discussions with the Hungarian government and the energy sector about the benefits of solar energy.

For Ámon, it is crucial that any discussion about the future of energy policy takes place at a city level. “This city serves three million people, we create 40% of the Hungary’s economic growth and we are responsible for a significant amount of the country’s carbon emissions,” she says. “Therefore, we should be at the heart of modelling energy policies that will benefit our citizens, businesses and build a better future. We believe discussions on solar energy must be the focus of those models.”

She adds: “If we have all this information, then we can initiate an evidenced based discussion at national level that would build on the work we have already done. I believe it would show that solar power is the cheapest, easiest and most practical energy source we have. It can provide energy security and economic development and prepare our cities and the whole of Hungary for a fossil free future.”


The new solar map of Budapest, developed by the Municipality of Budapest, can be viewed here

Andrew Kennedy Eurocities Writer