A solar power system in the form of the BVB logo that adorns the roof of Dortmund's stadium supplied around 485,000 kilowatt hours of electricity for the local power grid in 2018. In cooperation with a green electricity supplier, Borussia is aiming to save a total of 81,365 tons of CO2 or one ton per seat. The training areas are irrigated with rainwater collected on site.

At Schalke's stadium, used plastic cups are collected after the games and processed to granulate, from which new cups are made. The dishwashers are water-saving and a special process is used to generate water from food waste. Environmental protection is also anchored in the club's code of conduct.

In 2011 Mainz declared themselves to be the "first climate-neutral Bundesliga club." The roof of the stadium features a solar-panel system which, according to the club, saves 470 tons of CO2 per year. Further CO2 emissions are offset by the purchase of certificates to promote climate protection projects. The club also produces its own honey at the stadium.

The relegation strugglers participate in a waste prevention project and use energy-saving methods to heat their pitch. Billy goat Hennes, the club mascot, is driven to the stadium for games in an electric car from Cologne Zoo. However, Effzeh are unpopular with environmental groups over plans to build three new training facilities in a conservation zone that is the habitat of protected bats.

To reduce paper usage, the autograph cards handed out in the club shop are printed on a paper made from grass. Hoffenheim are the only top-flight outfit to support Alliance for Development and Climate of the Federal Development Ministry and offset their carbon footprint with projects in Uganda. Also, anyone who buys a ticket can then buy any amount of tree seedlings for a euro each.

Like Hoffenheim, Werder also support the "Sports for Future" initiative, which aims to use the connecting power of sport to overcome the climate crisis. Bremen try to avoid using plastic packaging where possible and the club has their own beehives. Fans are also encouraged not to drive to the game by car and the Weserstadion is the only Bundesliga stadium that can be reached by ferry.

The Wolves were the first Bundesliga club to use LEDs for stadium lighting and have been using 100 per cent green electricity since 2011. Meanwhile, the water used at the stadium comes from the nearby Mittelland Canal and electric cars are made available to club employees. Wolfsburg also have their own forest, where over 2,000 trees have been planted.

The Berliners focus their sustainability efforts primarily on the garbage that accumulates around the Olympic Stadium. It is separated and the club have their own waste press for bulkier items. Each year there's a refuse collection campaign around the stadium while cleaning agents with an environmental certificate are used when washing clothes and cleaning.

As much as possible, the products that Union Berlin have on offer at the concessions stands have the Fair Trade stamp and/or come from local producers. Only reusable cups are on offer at their home ground, the Stadion An der Alten Fösterei. In 2016 Union received the Environmental Action Germany (Deutsche Umwelthilfe) award as the leader in waste management among first and second-division teams.

In terms of being ecologically friendly, Freiburg were a pioneer in the Bundesliga. They installed a solar panel system on the stadium roof, all the way back in 1995. This was followed a year later by waterless urinals. Freiburg have also been working for years with the World Wide Fund for Nature on nature conservation projects.

As is the case in many other Bundesliga stadiums, at Gladbach you will find only LED lights and reusable cups - both have been in use for around 20 years. The club buys its food from local producers and unused food is distributed to charitable institutions. Borussia also promote the use of renewable energy sources through their own electricity company, in cooperation with a local supplier.

Starting this season, only returnable cups that can be reused up to 150 times are in use at the BayArena. Like many other clubs, Leverkusen use electricity from renewable sources and well water to irrigate the pitch. Since 2016 the club has also been offering local youngsters classes on environmental protection - in the stadium's own classroom.

Fortuna are a tenant in their stadium, so their influence on sustainability is limited. However, the club is in negotiations with the city about improving ecological standards at the Merkur Spiel-Arena. The one major step they have taken so far is to introduce the exclusive use of reusable cups in the stadium.

Augsburg say that theirs is the world's first CO2-neutral stadium. It uses geothermal energy and up to 200,000 liters of water per hour are pumped from two wells through heat exchangers to which the heating system is connected. Augsburg say this saves more than 750 tons of carbon dioxide emissions per year.

RB Leipzig are currently still working on a comprehensive Corporate Social Responsibility strategy, and were not able to provide DW with any details of what's in the works. An interesting fact, though, is that RB Leipzig never take the train to away games, flying instead to most. The club uses the team bus to get to three away venues in the Bundesliga.

In 2011, Eintracht Frankfurt built its youth academy in accordance with the latest ecological standards. The club has also done away with the use of disposable plastic cups at its home games.

Having switched to reusable cups, Bayern received the Reusable Award at the European REUSE Conference, which is awarded by the Environmental Action Germany (DUH) amongst others. The club have been members of the Bavarian Climate Alliance since 2015. The Allianz Arena is kitted out with LED technology and, at the end of 2019, one of the parking garages was equipped with a photovoltaic system.

With just 15,000 seats, Paderborn's stadium is on the small side, but the area with which the roof is covered in solar panels is not. 4,750 square meters produce almost 500,000 kilowatt hours of clean electricity, while under the roof, fans drink from reusable cups. The Benteler Arena also boasts the biggest bike parking lot of any European football stadium with roughly 2,000 parking spots.