Solar Energy Use in Freiburg, Germany

As the need for sustainable technologies increases, Freiburg, Germany is
emerging as an important city that greatly contributes to solar research and development.

Germany’s policy programs are designed to increase demand for solar
technologies. Consequently, there will be lower production costs and an increase the price effectiveness of solar energy. In order to encourage the adoption of solar technology, Germany has passed a law rewarding those using renewable energy sources. The Renewable Energy Law requires power companies to pay a specified price per kWh produced at the peak rate, guaranteed for twenty years, to individuals who have installed PV’s on their own private buildings. On average, the payback period to recuperate one’s initial investment is ten years. After this period, all energy generated by the solar array can be considered profit. This program has proved successful as demonstrated by the prevalence of solar technology in Vauban, a small neighborhood in Southern Germany.

Vaauban is a new innovative neighborhood that has demonstrated significant solar technology. With more than 1800 hours of sunshine each year Freiburg has an annual radiation intensity of 1117 kilowatts per square meter, it is one of the sunniest cities in Germany. The pilot building for this innovative neighborhood was the Heliotrope, a rotating solar tree house which follows the movements of the sun. Vauban quickly expanded as architects from all over the world exhibited their most cutting edge building designs that incorporated highly efficient and aesthetically integrated solar technologies. Solar arrays are not only installed on residential homes, but also form a long sound barrier to shield the noise from the adjacent freeway.

The experimental community demonstrates the benefits of solar energy in terms of climate protection, economy, and urban development and continues to inspire the next generation of architects, engineers, planners, designers, students, and citizens.

As a class we visited the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg, Germany. It has been instrumental to the development of solar technology. On our class tour of the institute on July 28th, 2009, the hallway was lined with numerous solar technology inventions. For example, a press statement was released recently announcing a 99% efficient inverter.

Other ISE innovations draw their inspiration from nature. A solar hot water heater piping system is modeled after human blood vessels, which have the most efficient heat transfer. In addition, the institute has developed an anti-reflective material that imitates the light intensity mechanism in a moth’s eyes.

Odense: Bike City Denmark?

We visit Odense each year on our sustainability tour, not so much because of their sustainable technologies or new developments, but because they have transformed their transportation infrastructure into a bike-first system, and for the gracious, inter-connected system of green spaces, parks, rivers and creeks that dot the city-scape. Each year, the city plays host to 30 of us, lending us their city bikes (which are of great quality), and leading us on a wonderful bike tour in and around the city. This year’s tour included all of the bike system facilities (various parking options, different types of on street and off street paths, cycle lighting and signage, cycle signals, cycle counters, air pumps, stairway ramps and other conveniences), plus many highlights of the park system including the river, and a new landfill park at the edge of the city along its port/canal. The landfill park is particularly impressive as one of the first of its kind in Denmark and a place for mountain biking, hiking, sledding (in summer!), picnics, walking, kids play areas and wildlife observation. We were hosted this year by Nanna Enriques and Dora of the city, who were generous, helpful, and very knowledgeable about how the city promotes and facilitates bike travel for all of its citizens, young and old. They even brought us coffee, tea and cakes to the landfill park as we relaxed during our bike ride.

The key elements in a bicycle system that goes beyond novelty and beyond recreation are: (1) a land use pattern and densities that make bike travel possible; (2) an inter-connected system of facilities that really think through origins and destinations; (3) facilities that overcome perceived or actual obstacles (like train tracks and highways); (4) convenience, safety and clear routes and signage; and (5) marketing and promotion that educates the residents and visitors about biking and makes it fun and important to ride to work, school or play.

The Odense bike system and park system may not be the best in the world (or maybe not even the best in Denmark – just ask the bike planners in Copenhagen!), but for this modest sized city without a lot of new development or new economic activity, it is impressive and keeps us coming back to learn, enjoy a bike ride, and appreciate the kindness and generous spirit of the city.

Aero Island in Denmark: Behind the Times or Way Ahead?

Aero is a small, idyllic island off the coast of Svenborg. To many people it is a quaint, historic relic, clinging to its past architectural and economic heritage. But, for us, their impressive ability to preserve and restore historical buildings, sites and landscapes, and their unique form of using renewable energy for most of the island’s needs is really quite progressive and certainly sustainable. Aero’s economy is mostly agricultural and tourism based; the island has three small towns (as a result of dividing up the original island land holding amongst three brothers); and it boasts one of the highest levels of renewable energy in the world, all based on local resources and design ingenuity. Our host for our day on Aero was Jess Heinemann, the community’s engineer involved in renewable energy as well as historic preservation. In fact, there seems to be little that Jess is not involved with. He lives in a restored historic house in Aeroskobing, the first town you encounter as you depart the ferry.

Aeroskobing remains as it has for hundreds of years with narrow cobblestone streets, historic houses and shops, and intimate plazas and public spaces. Their regulations for preserving history are strict and exacting, leaving little room for change and growth. Even windows and doors must conform to historic requirements. While this may seem limiting, it is designed to fulfill the community’s vision and serves to give the island its charm and tourist appeal. Preserving and reusing older buildings is a sustainable activity for various reasons: (1) retains the embodied energy of a built structure; (2) does not require new energy for construction; and (3) maintains physical scale and character at a time when auto use did not exist. They make provisions to upgrade buildings for energy efficiency, insulation and improved lighting and heating. Still, for many, the restrictions are too onerous and creativity in design reduced.

The most surprising thing about this small isolated island is the long track record with renewable energy, something in which Jess has certainly played a major role. The island boasts three massive wind turbines that generate a good bit of their electricity, modern in every way and based on our up close and personal look, quite quiet. They would have more, but residents were concerned about too many turbines changing the views. The island also has a series of small district heating plants, all based in large measure on renewable sources. Each of them uses an ingenious and fairly low tech solar thermal system including the one at Marstal, the largest of its kind in the world. Each of them also uses various bio-fuels to add to the mix in winter. In one, the primary fuel is wood pellets from waste from the Danish furniture industry. In another, they use crop waste from local farming, and also some vegetable oils like rape seed. Each has a unique mix and a unique sizing and design connected to what resources are available. Over half of the island is connected to these district heating facilities (in the towns), while the houses and farms in the countryside must fashion their own solutions. Some have so. We visited two homes (one a working farm, the other a beautifully restored farm building and leisure garden). One used heat pump technology, and solar thermal, while the farm ran mostly on bio-fuels.

Aero might look quaint as if the world and time has passed it by, but, maybe they are just a bit ahead of their time.

Waste-to-energy treatment plant in Malmö

While in Malmö, Sweden, our class visited the SYSAV waste-to-energy plant. SYSAV processed more than 800,000 tons of waste in 2008 through incineration and recycling. Through a multi-step process that includes combustion, they extract energy from waste to generate electricity and hot water for district heating. While SYSAV serves the province of Skåne, it seems that the SYSAV plant is part of Malmö’s larger planning vision for reduced waste, increased recycling and renewable energy generation. SYSAV is successful in diverting the overwhelming majority of waste away from landfill. Additionally, the advanced cleaning system of waste reduces harmful emissions down to only CO2 in the final stage.

The plant is located in a heavy industrial area with views of the largest wind turbine in Sweden in the distance. We were still able to bike to the plant, but it was not centrally located in the city. Along the way to the plant, we rode past community garden plots and past Solar City Malmö.

Before starting a tour of the plant, we talked with the SYSAV Communication Director, who gave us an overview of the incineration process. While on the tour, there was signage throughout the building, providing an overview of each step in the process. Still, at times it was difficult to understand some of the waste-to-energy process because we did not hear a full explanation of the science behind some of the steps. As a result, many students had questions about the safety measures taken by SYSAV to prevent the burning of harmful chemicals in plastics and styrofoam.

From what we were told, styrofoam and plastic bags are burned along with other waste received by SYSAV. The SYSAV staff assured us that the smoke generated in that process is cleaned and that the release of dioxin is minimized. To many students, that didn’t seem safe. Other students had questions about the level of CO2 emissions from the plant. It was clear that the plant measures dioxin emissions and has decreased those emissions by significant amounts, but during the tour it was not clear if the carbon emissions are considered or evaluated. Lack of attention to carbon emissions and greenhouse gases (GhG) seemed to contradict the vision for Malmö to be a fully sustainable city. As some cities in the U.S. focus on reducing GhG, it seems that an incineration plant like SYSAV’s would not be considered a viable option in the U.S. without data on the amount of carbon emitted during the incineration process.

After the tour, one of the students researched carbon emissions from the plant. He found a great article on the growing role of waste-to-energy plants in the U.S. He also learned that CO2 emissions are minimized using a process like SYSAV's. Still, we will continue to ask questions and look for data that helps us understand systems and technology that we don’t typically use in the U.S.

*It is also worth mentioning that the plant had great and simple technology for tours. Along with our hardhats, SYSAV loaned us a set of earbuds that received a radio transmission. These allowed us to stay in tune with what our tour guide spoke about as we walked around, up and down the plant which was quite noisy at times.

Architecture in Copenhagen

While Copenhagen is walkable and bikable for a myriad of reasons, it is worth noting that its architecture is one such reason. Monotonous facades make for a dull pedestrian experience. While sculptural or large buildings don’t cater to the human scale at the street level, they provide a point of reference and landmark for pedestrians and cyclists. Additionally, the variety that such structures add to the city skyline increases visual interest.

Another way in which the architecture of Copenhagen contributes to sustainability is in its skillful incorporation of new buildings amidst older ones. This strategy takes advantage of the embodied energy in existing buildings while increasing density with the addition of new buildings.

Innovation on the Waterfront: Bo01 in Malmo

Malmo, Sweden is in the process of transforming itself from industrial port city to a modern metropolis based on new jobs, universities, and tourism. Much of the city’s success is predicated on creating and promoting sustainable design. The landmark for Malmo’s transformation is the Vestra Hamnen (or western harbor) and the Bo01 housing area, part of an international exposition on housing design in 2001. The most prominent and famous of the residential structures is the Turning Torso designed by Santiago Calatrava, a 45 story tower seen from all over the region, and the symbol of Malmo’s turnaround.

The photos you see below are based on three themes we offered the students: innovative housing design; visible storm water management as art, and the water’s edge as a recreation and aesthetic space. Bo01 is sustainable in a number of ways: virtually car free, dense and well served by city busses, walk-able, surface storm water drainage, solar water heating, 100% renewable and efficient energy for heating and electricity (wind, solar, waste to energy, heat pump using the sea and the limestone sub-surface, district heating), high level of recycling, and unique design.

We spent a lot of time at the waterfront on bikes, on foot, and basking in the July sunshine enjoying the cool waters of the North Sea (and the occasional ice cream).

Augustenborg Green Roof

Most ecologically based communities are relatively wealthy and relatively new. Augustenborg in Malmo, Sweden is neither. Fashioning a sustainable neighborhood out of a working class 1950’s manufacturing and public apartment district is a difficult and impressive undertaking, but, starting 11 years ago with some funds from the European Union and Swedish government, they began to retool the aging suburb. The main features you see are green roofs (lots of them), surface storm water drainage and various types of photo-voltaics and solar water heating units. What you do not see are years of careful participatory work with residents and neighbors to find out their views, assess what sustainability means to each person and create solutions that can transform this area quietly and slowly. Some of the other gems hidden from view include a soccer (football) field of clay underlain by water tubes, that send solar heated water to the co-generation plant and help cool the field in winter allowing a more consistent ice rink. In addition, new insulation, paints and surfaces are improving the health for residents. But, in the end, it is the many types and intensities of green roofs (and the wonderful educational presentations put on by Louise Lundberg of the Scandanavian Green Roof Association) that most impressed our class. It is one thing to start from scratch with a large site, and a lot of funding; it is quite another to chip away at an existing neighborhood, board by board, plant by plant to make a difference.

By the way, happy Bastille Day!