In Part 1 of this series on German cleantech innovation, I gave an overview of the extraordinary expansion in German cleantech since the passage of a pioneering feed-in tariff in 2000; in Part 2, I explained how offshore wind power has become the workhorse of the second phase in Germany’s shift from conventional to renewable energy. These changes are impressive enough in themselves, but one of the things that’s truly inspiring about Germany’s embrace of sustainability is that it goes far beyond how energy is made.

Case in point: HafenCity, the enormous, crazily ambitious, stupendously well-executed urban re-design project now unfolding in the decommissioned docklands of Hamburg.

Now, the name Hamburg has long been synonymous with seafaring, and it remains Europe’s second busiest container port. But as cargo ships have exploded in size in the age of globalization, parts of the old harbor are no longer deep and wide enough to accommodate them.

In the mid-1990s, Hamburg’s municipal overseers recognized that a large swath of the harbor would soon be superfluous. They also realized that Hamburg’s downtown core was in desperate need of re-densification — its population had peaked in the second half of the 19th century at about 170,000 and was now home to just 14,000 permanent residents (only 2,000 of these in the cobblestoned Altstadt). The soon-to-be-decommisioned docklands, less than a mile from the historic city center, could solve both problems.

HafenCity’s numbers are pretty astounding: almost 400 acres of old industrial harbor, a 25-year project lifespan, somewhere in the neighborhood of $10 billion eventually invested to house 13,000 people and provide office space for 45,000 more. (The bulk of that money is from private developers, and the city is building state-of-the-art flood protection systems and other critical infrastructure using more than $1 billion earned from selling off the land itself.)

From the tip of the main pier — which is crowned by a distinctive new home for Hamburg’s philharmonic that is already drawing favorable comparisons to Sydney’s Opera House — to the opposite end of the redevelopment area is a span of nearly two miles. Just eight years in, one-fifth of the land has been redeveloped, and fully half of it will be built out by 2015. Already, nearly 70 separate architects have contributed to the new community, and it is home to the European headquarters of consumer goods maker Unilever and soon to be home to Greenpeace’s main German office and a major design school.

Never mind the data, though. The real test of a neighborhood is how it feels to meander around it. And I can report firsthand that even in its infancy, HafenCity’s vibe is excellent. My guide was Hamburg city planning director Jörn Walter, and he launched his tour by declaring pretty much the entirety of 20th century urban planning “a disaster” — in particular, he said, in its enslavement to single-use planning, its artificial, community-eroding separation of home and work and shop. My kind of urban planner.

A few highlights from the tour:

This is the heart of HafenCity’s first phase. Up either side of the harbor are mixed-use buildings in a range of styles, crowned by the singular structure of the new Elbe Philharmonic Hall. HafenCity has adopted the concept of mixed use not as an add-on feature but as its raison d’etre — every single building in the new development has to serve more than one purpose. In some cases, this means ground-floor retail with residences or offices above, but many HafenCity buildings go much further. The philarmonic hall, for example, houses not only a concert hall but a hotel, 43 apartments and a parking garage.

Here’s the view in the other direction. Note the modern take on the classic European urban form and scale to the left and the integration of funky new architecture with the harbor’s history as working port. Also note the mix of architectural styles at work, thus to avoid the sort of stage-set uniformity that can make big developments like this feel antiseptic.

Here’s an even more radical embrace of the nautical: a broad floating plaza on pontoons, serving as a main square for this phase of the development. The fact of water — both embracing it and keeping it at bay — was a central design challenge for the project, and HafenCity has been deliberately built as “a three-level public space” (as Walter put it). As defense against future floods and potential sea-level rise, much of the new neighborhood is built on a street level raised 15 feet above the level of the old dock; the original dock level has been preserved in the form of 10 kilometers (about 6 miles) of meandering quayside promenades; and this pontoon-level development was included to add contextually appropriate “parkland” to the community’s mix of public space.

Here’s another element of HafenCity’s flood control system: a dock-level retail space has been equipped with portal doors in the style of a cargo ship, which can be closed against rising waters.

This scene demonstrates the thoroughness of HafenCity’s commitment to mixed-use development: the foreground section of the building at left is an elementary school; at ground level in the background section is a kindergarten; and above it, a cluster of apartments. Not only is living and educational space tightly integrated, but Hamburg’s planners didn’t wait till after developing all of the neighborhood’s commercial and residential space to think about the necessities of life. The school is already up and running; the first supermarket will open this fall; and the first of two planned subway stations linking HafenCity to the rest of Hamburg will open in 2012.

As a result of such thoroughness and care, HafenCity, just a few years old, already has begun to feel lived in. Here, a central retail promenade welcomes not just pedestrians but an installation for an art festival. Ten years ago, this spot was a shuttered port facility, an industrial wasteland. By paying such close attention to every detail, HafenCity’s designers have set it up to thrive right out of the gate — to look not like some show-suite model but an actual, functional neighborhood.

And more than functional, this is a model of sustainable redevelopment — walkable, adaptable, resilient. A welcome correction to the urban design disasters of the last century.

To enthuse about green building in 140-character bursts, follow me on Twitter: @theturner.

Also on MNN:

Welcome to HafenCity -- Germany's crazy ambitious urban redesign project
The German port city of Hamburg had a fading harbor and a declining downtown population base. The solution to both problems? HafenCity — a massive, magnificen