Renewable Energy - Solar, Biomass, and more, in Freiburg

Freiburg is known as Europe's "solar city". Solar energy in Freiburg has guaranteed feed-in tariffs (thanks to Germany's Renewable Energy Law). As the primary obstacle to increased solar has been cost, especially with regard to solar rooftop PV, the fixed price for electricity and renewable energy feed-in tariffs guaranteed by German law, have helped solar to be cost-competitive.  Vauban is a city district in Freiburg in which the majority of homes run on solar energy generated on-site. Vauban is known as one of the most sustainable city districts in the world. 

The city of Freiburg was home to the Solar Summit 2013 to focus on the global energy transition. Solar Summit Freiburg 2013 was an event for investors, scientists, utility executives, and government officials worldwide, in which new solar thermal technologies were featured. 

Bioenergy in Freiburg

In addition to using solar power as a major energy source, Freiburg uses biomass for the majority of the rest of the city's energy needs. Over 40% of Freiburg consists of woodland and green spaces, and over 5000 hectares of forest surrounds the city. Biomass energy is generated from wood and forestry byproducts in Freiburg, but the city also turns trash into biomass energy to power residences and businesses.

Biomass plants in Freiburg substantially rely on methanization; a process which turns organic matter (in the case of Freiburg, mostly forestry/agricultural waste, and garbage from residential/ commercial buildings) into biogas. Methanization-based biomass plants at the edge of the city are fed with collected organic waste to generate energy (over 36,000 tons per year) provided by city residents (mostly farming, kitchen, and garden waste).

Wood is burned, in addition to waste, in the biomass plant in the city district of Vauban; landfill gas and organic waste are both used in the other biomass plants in Freiburg. These biomass plants, along with another biomass plant in Freiburg that uses mostly rapeseed oil to produce biodiesel, are designed to create combined heat and power (cogeneration) to supply district heating and electricity in the city.

In addition to biomass power plants in Freiburg, are smaller anaerobic digesters on farms in the city, which also convert organic matter to energy. Biomass plants and solar energy are not the only sources of renewable energy in Freiburg. Other than solar and biomass, small wind farms and small hydropower projects also provide energy to the city (wind and hydroelectricity, provide a relatively minor share of Freiburg's energy. Conventional energy sources provide the rest of Freiburg's energy needs).

This quote provides a summation of renewable energy generation in Freiburg:

Biomass
Biomass has the largest share of Freiburg’s renewable electricity generation. In Freiburg organic waste has been collected separately since 1997.  A biogas installation transforms the organic waste into biogas and compost. The energy produced from this biogas covers 2% of Freiburg's electricity needs.Organic waste from Freiburg’s households is fed into a digester that produces biogas and compost. The biogas is burned in a CHP plant.20 km north of Freiburg lies a unique mechanical-biological waste treatment plant, one of a kind in the world that has been patented within Europe. Since 2006 it has been producing valuable materials from left-over waste, alternative fuels, and mineral products as well as biogas that is used for electricity and district heating.

When Freiburg landfill was closed, a modern garbage incineration started functioning.  It has an annual capacity for treating 150,000 tons of household and business waste and produces electricity for about 25,000 households.  Its four-stage flue gas cleaning system ensures that strict emission limits are adhered to.

Solar
Freiburg has 150,000 m2 of solar cells producing over 10 million kWh/year. New "plus energy homes" produce more energy then consumed, extra energy can and earn profits of 6000 Euros per year for their residents.

Other renewable energy and Freiburg transportation

The [few] windmills in the city are situated on hilltops...[and} small, eco-friendly run-of-the-river [hydroelectric] facilities are on the river and on smaller canals and streams. Since January 2009, Freiburg’s 60 trams have been running on 100% renewable energy (80% hydropower and 20% a mix of other renewables. Another notable aspect of Freiburg’s transport policy is traffic calming. For most streets (other than main streets) the speed limit is 30 km (19 mi) per hour. On some streets cars can travel no faster than walking speed, and children are allowed to play in the streets.""  FROM  -    germanyfreiburgmabel.weebly.com

Green Building and Alternative Transit in Freiburg

Freiburg remains at the forefront of green building technologies, mandating that all new construction uses only the latest cutting-edge energy efficiency designs- passivhaus standards. Energy conservation is central to all new building in the city, and energy efficient retrofits are being applied to existing structures. Residential recycling programs go beyond standard measures, as compost is also collected in the form of kitchen and garden waste.

Freiburg promotes biking and walking, which have become increasingly popular means of alternative transit in the city. Freiburg features a pedestrian-only zone in the city center, where no cars are allowed. Biking accounts for over 1/4 of all transportation in the city. Over 300 miles of bike paths in the city help to reduce automobile use.

In order to help make alternative modes of transit even more attractive, all roads in Freiburg, other than major roads, have a max speed limit of 50 km/h. The city offers the Regio Card (Regiokarte), which enables residents full access to all of Freiburg's trams, streetcars, trains, and buses. Increasing city residents' ease of access to Freiburg's mass transit options, 70% of the population live within 1/2 km from a tram stop.

This snippet from BBC summarizes some of Freiburg's major accomplishments in sustainability over the last 30 years:

Freiburg has quickly developed as an environmental economics and solar research hub with a packed green CV:

• 1994: Builds Heliotrope: the world‘s first energy-plus house

• 2002: Elects Germany’s first Green Party mayor, Dieter Salomon

• 2010: Wins national award for its climate protection efforts

• 2012: Named most sustainable city in Germany

• 2017: New Town Hall becomes world’s first public building producing surplus energy

FROM-  bbc.com/freiburg-germanys-futuristic-city-set-in-a-forest

Here's more information about Freiburg's Town Hall:

During the course of the year, the building generates more energy than it consumes. The excess energy is fed into the city grid. In accordance with the strict criteria of the PassivHaus standard, the primary energy demand of the town hall for heating, cooling, ventilation, and hot water supply [is sourced from renewable energy and passive heat gains].

...electric energy is generated by photovoltaic panels on the roof and in the facade. The energy for cooling and heating is obtained from a geothermal installation. Thermal mass activation is used for heating, which can be individually controlled in each office. The mechanical ventilation has been enhanced by highly efficient heat recovery.

FROM-  archello.com/project/freiburg-town-hall

Urban planning in Freiburg

Green urban planning is paramount in Freiburg; and the city has designated green areas as a priority in land-use decisions. Almost half of the city remains protected as parks, forest, or green landscaped spaces- a big reason why biking and walking remain so popular in the city. In the city district of Vauban, entire neighborhoods run on energy provided by rooftop solar panels, as well as a municipal biomass plant.

Careful urban planning helped to create a city layout in Vauban which lends itself to cycling as the primary mode of transit. The terms “filtered permeability” and “fused grid” refer to a plan that ultimately means connected streets throughout the town, as well as plenty of pedestrian and bike paths. Residents primarily live in co-op buildings, such as the “solar ship”, a large area of co-op buildings that run strictly on renewable energy.

Freiburg has a goal of achieving 100% renewable energy and carbon neutrality for the entire city by 2035.

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Europe's most sustainable city district (the city district of Vauban in Freiburg)

and for more on Vauban- The World's Most Successful Model for Sustainable Urban Development? via Smart Cities Dive