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Optimism in an era of climate change 6: the mind-blowing IBA

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On the train to Hamburg, I had found an old magazine that mentioned the city’s status as Green Capital and also the Hamburg IBA.  What is that, I wondered.  So I made my way to a part of town where few tourists go: Wilhelmsburg.  That’s the island that was badly flooded in 1962, that has remained semi-rural, and where cheaper rents have concentrated a poor, and poorly assimilated, immigrant community.  It is also home to heavy industry such as the Arubis copper smelter, and is sandwiched between the two large coal power plants of the city.  Not promising.

It is precisely why Hamburg chose this site for the IBA – a perfect opportunity to tackle some thorny social, environmental, and land-use problems.  The IBA, Internationale BauAustellung, is a peculiar European competition where architects are challenged to demonstrate innovative approaches on a particular theme.  Sustainable, socially balanced development was Hamburg’s theme.   There are over 100 projects on this site, ranging from education, intercultural activities, and social space to new energy systems and efficient retrofits.  The old city landfill was turned into an “energy mountain”, complete with biogas capture, solar collectors, and windmills. New parks were created to host the international Floralies exhibition. New architectural approaches were pioneered, including a hypo-allergenic building that uses only wood in its construction (no glue or plastics) despite being energy efficient. All of the new IBA buildings were remarkable.  And to entice locals to move across the river, the Ministry of Environment offices relocated here, in a showy high-performance building.

The BIQ algae house may have been the most spectacular building of the IBA.  The only thing unique about this simple apartment building are the windows: they are green because of the algae-filled water between the panes.  The windows are like biological solar collectors: the algae are harvested every evening and turned into biogas that provides heat and electricity for the building.  Is it goofy?  Is it a cost-effective system?  The answer to both questions is a qualified yes.  What I particularly love about it, though, is the sense of risk that it embodies. Nobody knew whether this was going to work at all or leak all over the place.  They took a chance and tried – how else are lessons going to be learned?

Away from Wilhelmsburg is another development that was started in the context of the IBA: the Jenfelder Au complex.  This large project is still under construction; only a few buildings have been completed. But again, it is a demonstration of a new technology: instead of being flushed to the sewers, human waste is collected by a vacuum system.  This avoids dilution and makes the idea of producing biogas for the complex realistic.  There are also state-of-the-art techniques for storm water and greywater management.  But it is the scale that is amazing: with over 700 apartments, this is no hobbyist cabin.  Things are done in a big way here.

The Energiebunker of Wilhelmsburg may be the most important component of the lot. It is an old World War II bunker, 8 stories tall, that had been a blight in the neighbourhood until renovated for the IBA. Capped with a pub with one of the best views in town, it is an energy production, storage and distribution centre for the whole area. Integrated to the new network heating system of the community, it produces solar electricity and heat, as well as using either natural gas or biogas from the wastewater treatment plant for peak needs.  Its bulk means that it is also a massive thermal storage that is used to maximize the efficiency of the network.  This is what is key about it: its ability to function as part of an integrated system.  Hamburg has long moved past individual efficient buildings: it now operates as an organic system, adaptable, able to minimize energy requirements.

In fact, it’s not just Wilhelmsburg, it’s the whole city that can operate as a giant network. The slide above shows the components of the system: they range from thermal solar heat, solar electricity, industrial waste heat, biogas, wind energy, coal electricity, hydraulic and compressed air storage, batteries, and more.  I reviewed professor Gerhard Schmitz’s analysis of the system here – but the main point is not about the specifics, but rather this: by working as a whole integrated system, as an organism, as it were, Hamburg can achieve remarkable energy efficiencies.  This is a key lesson for Vancouver as it develops.  Showcase efficient buildings are great; but a networked system is essential to the next step.

But how did Germany, and Hamburg in particular, get to this point?  This is the topic of the next post in this series.

Part five of this series can be found here.


Written by enviropaul

August 21, 2019 at 4:41 pm

Optimism in an era of climate change 5: solar, wind, and energy storage

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Germany is famous for solar energy.  Even in northerly Hamburg, photovoltaic panels can be seen everywhere on roofs and fields.  This is paradoxical: Hamburg’s weather is mostly grey and rainy.  In winter, there are barely 10 hours of daylight, faint at that.  Yet, even there, panels are everywhere.  The pictures above show a typical rooftop installation in the Hamburg suburb of Hoisbuttel.  Above is a tracking pivot solar farm in a pasture north of Hamburg.

These are common because the German government created conditions favourable to the development of solar (and wind) power.  I’ll get back to this topic in the seventh post of this series.  But for now, I’ll just mention that solar power is well accepted and, if it contributes little to the energy supply in winter, the opposite is true in summer; last June (2019), solar was the largest source of electricity in Germany.  There is 43 GW of power currently installed, over 1.6 million panels, and this figure is expected to double by 2030.

Wind is equally ubiquitous; it is impossible to take a picture of the harbour without finding windmills in the background. The picture top right shows one of the three windmills installed over the former Wilhelmsburg landfill.  The wind farm shown below it could be found anywhere in northern Germany.

Wind power produced nearly one quarter of all electricity in Germany in 2018.  Windmills are growing in size and efficiency, and the power costs keep dropping (already below 5 euro cent per kilowatt-hour).  Offshore power has been growing the fastest (the North Sea winds are notorious).  With the Danish and Dutch governments, Germany is planning to build an artificial island, the North Sea Wind Power Hub, to further develop the resource, turning “a science-fiction plan into reality”, as titled by The Independent.

But isn’t there a big risk relying on wind and solar power? What happens when it is dark and still?

Of course, the Germans have had to tackle this, now that both sources are a large part of the electricity mix.  But what surprised me is how old energy storage systems are, and how long they have been integrated into the mix.  Here are two examples from Hamburg.

In Geesthacht, just east of Hamburg proper, is a pumped hydraulic storage facility.  When electricity demand is low, the extra available power (from wind or otherwise) is used to pump water up to an artificial lake.  When there is peak demand, the stored water flows downhill, the pumps become turbines.  This system operates on a daily cycle.  What surprised me is its age: it’s over sixty years old.  Energy storage is not a new concept.

The thermal solar system of the SolarSiedlung development in suburban Bramfeld is another example.  The panels generate hot air in the summer, and the heat is stored in the rocks of a funny looking squat silo in the nearby park (picture bottom right).  This provides about half of the heating needs of complex over winter.  And it been doing so for twenty years.

If these “old” systems are considered futuristic here (they don’t exist yet), imagine what the state of the art is.  Mind-blowing, it is.  They are solving problems that we aren’t even aware of yet.  For instance, one system recycles old lithium batteries that are too tired for the demanding use of electric cars but perfectly serviceable for longer-term storage.  Siemens has developed a hot-rock storage system, but one on steroids: excess electricity is used to heat air above 500C, and that heat is stored in red-hot rocks.  When electricity is needed, the process goes in reverse (hot gases turn a turbine, making electricity).  Like the lithium system, this is operating in an industrial neighbourhood of Hamburg.  Even more bizarre is the idea of using the saline aquifer deep under the city for year-round thermal storage: why spend energy to provide winter heat when water summer heat can be stored for free; all that is needed is pumps.  A local project uses excess electricity to make and store hydrogen, another a redox flow system. Whatever that means; we have along way to go before these are ever seen here (details can be found here).

But the lesson is simple: yes, energy storage is available, and works.  Some of it, for this BC boy, does feel like stepping into the future.  But for a real immersion, let’s visit the IBA, in the next installment.

Part four of this series can be found here.

Written by enviropaul

August 20, 2019 at 2:03 pm

Optimism in an era of climate change 4: energy efficiency

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DEcarbonizing?  That means doing stuff with fewer greenhouse gas emissions. Transportation is typically responsible for one third of greenhouse gas emissions, so it is key to make it more efficient.  In Hamburg, as in any large city, this means providing good alternatives to motor vehicles.

Hamburg is far from perfect in that respect.  In the sixties it did away with its street car system.  It also opened its downtown to large motorways such as the six-lane scar of Willy-Brandt-Strasse.  But at least it has made room for cycling commuters, and the Copenhagenize Index ranks Hamburg as the 20th best city for biking, just behind Vancouver (but still a long way from top-ranked Copenhagen or Amsterdam).

And the bikes can go on the commuter trains.  The U-Bahn, S-Bahn, and Regio system is where Hamburg really shines; there are very few places in town that are not within walking distance of a commuter train station.  The map (top-right) shows the extent of the system.  Metro Vancouver is plagued with controversies about rail transit: should we extend the Broadway corridor, or prioritize the Surrey extension? If Surrey, should it be Skytrain towards Langley, or light rail towards Newton and Guilford? Shouldn’t the old Interurban network be brought back instead?  All valid options.  But one gets a feeling that is this were Hamburg, the answer would be “all of the above”. Rail transport is such an essential part of daily life there that the subway system was one of the first priorities for rebuilding after the war.

Mind you, this is the country of VW and Porsche, BMW and Mercedes, where cars were invented.  If few people take their cars to commute downtown, few households are without a car. For some, transportation is a blind spot in Germany’s fight against climate change.  Indeed, the big car makers have been dragging their feet, opting for the disastrous diesel strategy rather than electric motors.  This is what led Deutsche Post, the private company similar to Canada Post, to a surprising decision: becoming a manufacturer of electric vans for its own needs. The mail company bought a fledgling electrical vehicle start-up and now produces over 20,000 small electric trucks every year. In downtown Hamburg, one often sees theses trucks, as well as posties on bicycles, often electric. (The post boat, bottom left, is from the Spreewald, near Berlin – nobody can say that Deutsche Post doesn’t adapt to local conditions.)

There’s more to energy efficiency than good transit, of course.  Space heating and cooling is a voracious consumer of energy. But beyond that, there seems to be something cultural, a kind of cult of efficiency. In Hamburg, I see it in magazine stores (I counted over twelve publications dealing with energy efficiency and home retrofits).  I see it at my friends, who bought a gizmo that steams eggs (it uses less energy to cook them, supposedly).  I see it in my wife’s uncle’s house: he contracted a cogen system for home heating (when natural gas is burned to warm up the house, it is burned in a stationary engine instead of a furnace; the engine produces electricity, sold to the utility).  But I also see it in this residential complex (picture at right), near Hagenbeck.  This new complex is fitted with green roofs, beautifully insulated, and costs little to heat.  And this, in a subsidized housing complex for poor or single-parent families.  Energy efficiency is not just for the elites.

The most effective way to decarbonize the economy may well be in improving the energy efficiency of housing.  This is not just making new construction energy efficient; it is mostly retrofitting.  In Hamburg, this means adding insulation to old brick apartment buildings – without altering their heritage character.  When I looked into it, I found several interesting case studies and wrote about them here. And it creates local jobs, of course.

For most low-rise building retrofits, the brick-looking insulation is added to the outside of the walls; this way, buildings can be renovated without expelling the tenants.  Our friends in the Rissen suburb, a 2-kid family, went through this process.  Noisy, dusty, but the results are a more comfortable apartment, and much lower heating bills in winter.

The block where my wife grew up underwent the same renos, too.  The basement, where storage and utilities are located, does not get an insulation upgrade, so it is easy to compare the look of the insulation to the original old brick.  Originally, the building had no balconies, either; these were added as part of the renovations.  Note that they are structurally independent of the building – which means that there is no thermal bridging.   Balconies, as they are built in Vancouver, often act as fins: heat dissipators that really harm the energy performance.

Something else that is common in Hamburg (and in many European cities): network heating.  Heat is produced by a central plant in the form of steam or hot water, and is distributed to buildings via a network of underground pipes.  This allows for economies of scale, but also provides opportunities for flexibility, allowing for a variety of energy sources, making the whole behave like an organic, adaptable system.  The heat sources may be as diverse as garbage incineration plants and rooftop solar collectors.  It is a system that facilitates adoption of decentralized sources of heating, such as solar panels.  The higher density of Hamburg makes district heating common place (the map, bottom left, shows the main central heating plants and the thermal mains).  Unfortunately this is currently rare in Vancouver, though newer developments such as the Olympic Village are now using them.

So Hamburg provides examples of using energy more efficiently.  But is it possible to generate the energy that is still needed without generating greenhouse gases?  And if solar or wind systems are privileged, is it possible to store that energy?  The next section addresses this.

Part three of this series can be found here.

Written by enviropaul

August 19, 2019 at 5:11 pm

Optimism in an era of climate change 3: flooding issues

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Above is one of my favourite slides: the waters of Hamburg.  Clockwise from top left are the waters tourists might see: watching the ships along the Elbe green promenade; touring the old harbor and the warehouse district (Speicherstadt) and the new philharmonic hall; walking around Alster lake, maybe renting a sailboat.  Continuing below are sights for the locals: the houseboats on the Eilbek Canal (from a competition to address new ways of living under climate change); after a beer on the lake, the Alster River proper (note the kayak); and a dam with a fish ladder on the Alster.  Water is at the core of Hamburg’s identity.

There are several dams on the Alster, many very old.  This one at Fuhlsbüttel is a flood control structure and a small hydropower plant. The fish ladder is a new addition, one of three along the river, including one downtown.  Like the Elbe, the Alster used to be badly polluted, dead for all practical purposes.  But an intensive pollution control and clean-up initiative has brought back fish.

But living with water all around entails an obvious risk: flooding.  Climate change means that sudden downpours are more frequent.  Often the regular drainage system (storm drains or combined sewers) cannot keep up with sudden cloudbursts, resulting in what is called pluvial flooding.  Hamburg has embarked on a large program of so-called green infrastructure – turning the city into a sponge that can absorb rain, easing the task of the drainage system.

The slide above shows four examples. At left is a green porous pavement smack downtown (a courtyard behind Grimm Strasse near St-Catherine church), the type that is sturdy enough to allow delivery trucks while letting the rain seep through. The picture in the middle shows a private house near the Hoheneichen station, with porous pavers and a green roof over the cars.  Less obvious is this example of a deep green roof, bottom right photo.  This is not a courtyard, but a roof two floors above street level (Geibelstrasse in Winterhude); the soil is deep enough for tree roots, and can absorb lots of rain (it also provides thermal insulation).

Top right is a picture of the Trabrenbann development.  Here the developers chose to create surface water features that can rise in level, absorbing rain waters without flooding the complex.  This was done because the clay soils (formerly used to make bricks) are nearly impermeable.  In fact, the open waters of the city play an important role in flood control.  Most creeks and small lakes are bordered by natural green spaces, which make for great linear parks, but also provide room for the waters to rise harmlessly.  In the greater Vancouver (eg, Surrey or Burnaby), many creeks are still flowing in their natural state – it is key to keep them so.  Daylighting lost ones may be good, too.

Green infrastructure, even on a large scale, cannot tackle the two other main types of flood: fluvial and coastal.  A fluvial flood occurs when a river overflows its banks, while a coastal flood results from the sea encroaching on land.  Weather folks speak of “deep throughs of low pressure”; atmospheric low pressure sucks up the ocean, so to speak, a phenomenon known as a storm surge.  Of course, the same low-pressure systems can produce enough rain upstream to cause a river to flood.  Hamburg can expect all three types of floods (and so can Vancouver).  The normally placid Elbe is notorious for its devastating floods (most recently in 2013).  Complicating the matter, at Hamburg, the Elbe is funnel-shaped, and this produces high tidal fluctuations even if the North Sea is 130 kilometers downstream.  During a storm surge flood, the same funnel shape can worsen a coastal flood.

Accordingly, dykes are common all along the Elbe shoreline.  Downtown, some are disguised as public amenities (picture in the middle). The height of these dykes is something to behold: about two stories or more, higher than anything along the Fraser. But the Alster flows into the Elbe – where does the water go when the Elbe itself is in flood?  This is where the three pumps at the Alster lower dam come in (left picture).  These 1000 horsepower monsters can deliver 35 cubic meters per second, enough to prevent the Alster itself from backing up and flooding the city.

None of these measures come cheap, but they are well accepted by the public.  It helps that reminders of past floods are common.  The February 1962 flood was a disaster (“flut 1962”, in the marker above).  But the flood of 1973, which reached higher levels, was not, thanks to better dykes and other measures. All the locals are well aware of this and don’t begrudge the costs.

But for the extreme floods expected to come with climate change, even these measures are is not enough.  Hamburg has increased the area designated as floodplain along the creeks that flow through the city, giving room for the rivers to swell up without flooding streets and buildings.  There’s a lot of buy-in; locals appreciate the fact that this increases the size of parks and green areas.  The Elbe itself also needs room to expand, of course.  Hamburg is slowly setting aside a large portion of Wilhelmsburg as floodable.  This low-lying island, the largest in the Elbe, is mostly agricultural.  New dykes have been re-routed so that much of the island’s north-east side can get flooded.  When not in flood, which is most of the time, the area that is not a wetland nature reserve can be used to pasture sheep and cows.

But this strategy can’t work for HafenCity, a new urban development (the largest in Europe). HafenCity is built on a formerly vacant old harbour site, and the topography (ancient piers and quays) is such that dykes would be unpractical.  Hamburg chose a radical strategy: let it flood! Every building is designed so that its ground floor can withstand a two-meter flood. This means either using doors and windows that can withstand the pressure of the rising waters (indeed, some doors have a feel of bank safes); or simply, ensuring that floods leaving no lasting damages (parking lots, for instance).  Nothing critical (computer servers, HVAC systems, etc) can be installed at ground level.  Wheel-chair accessible pedestrian walkways, gangways and bridges accessible from the first story above the design flood level connect the residents with the downtown area.  This is a design approach that Vancouver could consider for vulnerable areas such as the False Creek Flats.

But if this was all that Hamburg does to tackle climate change, it would be the equivalent of reaching for a mop rather than turning off the tap when a bathtub overflows. Decarbonizing the economy by developing efficiencies is the topic of the next post.

The previous post in this series can be found here.

Written by enviropaul

August 19, 2019 at 10:23 am

Optimism in an era of climate change, 2: Hamburg, Germany

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Before presenting Hamburg, let’s review what needs to be done to tackle climate change.

First, one has to accept the inevitable changes. For Hamburg, as for Vancouver, that means above all a higher risk of flooding. The next part of the talk addresses this.

But to combat climate change, the first thing to do is to remove the culprit, the greenhouse gases that are accumulating in the atmosphere. This is done by carbon sequestration.  There is little that a city can do by itself in that respect; carbon sequestration means, in practice, increasing the amount of carbon locked away in soils or in sediments, and that requires lots of land.

I talked little about that, because my focus was on Hamburg.  Still, it is a key topic.  Recently, an IPCC report mentioned the potential of reforestation for carbon management; this led a writer in Grist to title an article “stop building a spaceship to Mars and just plant some damn trees”.  Indeed.  Another item that caught people’s attention is the use of drones to plant trees, particularly in difficult terrain such as mangrove forests.  Ethiopia put the rest of us to shame by planting 350 million trees in a day, a world record.  Shorelines also have a huge potential for storing carbon (and enhance fish habitat), a technique called Blue Carbon.  Organic agriculture also has great potential, since its soil management practices tend to increase humus – a form of stable organic carbon locked in the soil.

But the other way to fight climate change is to prevent carbon from being emitted in the first place. This is done by decarbonizing the economy, that is, producing energy without releasing carbon, and making much more efficient use of the energy consumed.  That, Hamburg does in spades, as does the rest of Germany, and much of my talk focuses on this.

But first, let’s introduce Hamburg.

I first went to Hamburg because it’s my wife’s hometown.  By a happy coincidence, Hamburg has many similarities to Vancouver: a large port on a river, a city with a lot of green space, weather not all that different.  So what works in Hamburg may well work in Vancouver.  Hamburg was also Europe’s Green Capital in 2011, and this means that its environmental performance was well documented – including material in English, making my job easier. It was host to a number of significant events, chief among them the IBA (Internationale BauAustellung, or International Building Exhibition). When I first visited the IBA, I felt like I had stepped into the future. That is because the theme was sustainable buildings: architects were challenge to come up with solutions, and when you give them free reins, you do indeed glimpse the future. At any rate, being a Green Capital creates a legacy, and what that is can be found in this report here.

It is difficult to rigorously compare two cities.  I plotted both on the same scale using Google Maps.  Clearly Metro Vancouver is much bigger in area, but that is largely due to the mountains in the north, about a third of the whole area (electoral area A, 818 km2).  Hamburg, by contrast, is actually bigger than indicated by its political boundaries; suburbs connected to the city by public transit are found in the states of Schleswig-Holstein and Niedersachsen, so that the effective area of both metro cities is fairly similar.  But it makes stats messy (and where do you draw the line?), so I went with what I could for an imperfect comparison.

Hamburg has a population density that, if high by North American standards, is fairly low by European ones; in fact, it is very similar to Toronto’s.  Like Vancouver, Hamburg includes within its area large swaths of agricultural land that supply the city in fresh vegetables, but also in fruit (the Altesland, south of the Elbe, is the largest orchard area of Germany).

Hamburg, compared to Vancouver, has few towers; for a long time a rule stipulated that no building could ever be higher than the spires of its main downtown churches.  On the other hand, much of the inner residential core consists of mid-rise apartments arranged around an inner courtyard, something almost non-existent in Vancouver (hence the moniker “missing middle”; our city has either low or high density, nothing in between).

Despite all the solar and wind energy present everywhere, though, it is Vancouver that has the lower greenhouse gas emissions, not Hamburg: 5.77 tonnes of carbon dioxide equivalent per person, against about 9 for Hamburg.  These figures are similar when comparing Canada with Germany, for the same reasons: Canada has a legacy of abundant hydro-electricity, in contrast to Germany and Hamburg, dependent on coal.   This is still a long way from the recommended 2.5 tonne to reach the COP21 goal.  But what is remarkable is how quickly the figure has been dropping in Germany (and in Hamburg).

There are, of course, many differences between Vancouver and Hamburg.  Hamburg has a history of destruction by fire: the first large aerial mass bombing in 1943; an accidental fire that destroyed much of the city in 1842; an earlier one in 1284. In every case the city rebounded.  Clearing by fire made it possible to dig big cellars in 1284, leading to Hamburg’s role as the biggest producer and exporter of beer in the middle-ages. For the same reason, the 1842 fire enabled the digging of Hamburg’s first sewer system.  After World War Two, the city rebuilt, including its public transit infrastructure, but leaving room for the modern architecture seen in the city nowadays.  It is a place that has learned to bounce back.

That fire should be a defining characteristic of the city is ironic, because water is omnipresent.  Hamburgers (yes, that is what the inhabitants are called) will invariably tell the newcomer that the city has more bridges than Venice and Amsterdam put together. Those bridges span the many canals, but also countless creeks and streams that flow throughout the city.  Hamburg is unique in that respect; very few streams were ever buried in storm sewers.  The Isebek canal anecdote is characteristic: in the 60s, it was badly polluted and stank.  The city wanted to bury it, but had to back down when faced with the opposition of the locals (its water is now clean).  Locals are well aware of their waters; people fish in the small streams, boat in the canals and in the central lake, or watch ships enter the harbour from the beach on the Elbe.  When the largest container ship came to Hamburg for its maiden voyage, the beaches were filled with camera-wielding onlookers.  In Vancouver, we wouldn’t even know.

If the Elbe is the main river that defines Hamburg, the Alster is its heart. In the 1200s the river was dammed, creating the Alster Lakes.  These lakes play the same roles as Stanley park does in Vancouver: locals jog, bike or stroll around them.  Connected to the lakes are canals, formerly industrial, now used for recreation; all three photos above were taken either downtown or walking distance from it. And yes, that café, on the left, has indeed a take-away window for boaters.

So this is a city where modern developments mix with its heritage identity.  At the core of that identity is water – but what does that mean when floods threaten?  That is the topic of the next installment of this series.

The first part of this talk is found here.

Written by enviropaul

August 19, 2019 at 10:14 am

Optimism in an era of climate change 1: intro

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Last July I gave a talk at Science World.  It was part of series where KPU faculty partner with Science World.

Entitled “optimism in an era of climate change”, it is a summary of my experience in Germany, where I went to document technical solutions to the problems of climate change.  Not for me to deny that climate change is turning into climate crisis; rather, I wanted to show that the technology does exist to address the problem – and the sooner we do it, the better.  Here and in the following posts are the slides I presented.

I started with some basics.  Let’s be clear: I’m an optimist despite the situation – denying what’s happening would be pointless.  Besides, denying the physics of climate change mean denying that X-rays or MRI exist, or that radio waves are fictitious or cannot be caught by an antenna.  It’s all the same electromagnetic spectrum physics.

I added two graphs should anyone still need convincing. Left shows the ten warmest years ever measured, globally; except for 1998, they are all in this new century (2018 and 2019 belong on that graph, too – I just don’t have them yet). The plot of the global mean temperature anomaly, left, is equally clear: there is an undeniable trend.

The impacts are clear, too: we have always had weather extremes, but what was rare is becoming much more frequent.  I list a few of the extreme floods and fires, globally and in Canada, that have happened recently.  The hail storms in Dubai and Guadalajara didn’t make the cut, spectacular as they were. Maybe I should also have mentioned the poetic justice of the flooded White House.

There are other sorts of impacts: climate anxiety.  Maybe we need something to worry about: my generation worried about the bomb and radiation.  But climate anxiety seems to be of a different nature, convincing young people that their future has been stolen from them.  They have found an amazing spokesperson in Greta Thunberg.  The photo on the right was taken during a school strike in Vancouver last spring, inspired by Thunberg.

There are more events planned for this coming fall, including the week of Sept 20-27; see the Georgia Straight series about that here, here and here; also here.

As a bit of a joke, I put in a slide of what Vancouver would look like if all the glaciers melted, courtesy of Ursula Le Guin was the first writer to imagine Vancouver under water in The Telling (2000).  The better known The Lathe of Heaven (1971) is similarly set in a future drowned Portland, Oregon.  They’re both great books.

By now I hope that I have convinced everyone of the seriousness of the situation – and maybe depressed my audience. I hope not – but I made sure to put on my next slide some books written by bona fide environmentalists who, like me, think there is a way out.  There are many – this is just a sample – but two have stood out for me.  Michael Bloomberg, the former NYC mayor, and Carl Pope, former director of the Sierra Club, joined forces in Climate of Hope. There are many municipal examples, and I love urban planning, so the book stuck with me; but maybe the description of the remarkably effective campaign to prevent the construction of new coal-fired power plants in the US should take centre stage. David Boyd’s The Optimistic Environmentalist is a must-read, a personal view from the BC environmental veteran as he musters arguments for his daughter.  Or, to use the Guardian’s title, these are the dying days of a rancid old order.

So there is a way out, is there?  That’s the next part of my talk.

Written by enviropaul

August 19, 2019 at 9:59 am

Flintenbreite: the original vacuum toilets

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Flintenbreite eco-village in Lubeck

Last week when I described my visit to Jenfelder Au, I mentioned that Flintenbreite served as the inspiration.  Time to find out more about Flintenbreite.

Compared to Jenfelder Au, it’s a smaller development: 117 units in a mix of low-rise townhouses and duplexes over a 5.6-hectare site, in Lübeck, near Hamburg.  It is also older: it was built as one of the ecological complexes for the 2000 World Fair centered in Hanover, and permanent residents have lived in since 2002.

The World Fair was based on environmental concepts that became subsequently known as the Hannover principles.  Among these are:

  • the right of humanity and nature to co-exist in a healthy, supportive, diverse and sustainable condition.
  • the elimination of the concept of waste.
  • reliance on natural energy flows.

In Flintenbreite, this meant trying to use self-sustaining, integrated energy and wastewater concepts, as well as implementing innovative energy saving technologies, with an eye to minimizing interference with nature.  Yes, but how?  Remember, this is happening in the 90s, and some of things we now take for granted, such as cheap solar panels, don’t exist yet.

By all accounts an ordinary suburb -except for the toilets

This is where Dr Otterpohl came in.  He proposed to apply his conviction that human wastes are a resource. The core principle is simple: keep the wastes separated.  Much is the wastewater generated by a household: bath water, wash water, etc, is fairly clean and easy to treat. Toilet water is another story.  Otterpohl’s flash of insight was to use vacuum instead of flush water to dispose of these wastes – and then, ferment them, undiluted, into biogas.

None of the components of the system were new ideas.  Greywater separation was practiced in California. There were vacuum systems here and there, conveying ordinary sewage where large sewage pipes couldn’t be installed.  Methane digesters to produce biogas were already common in sewage treatment plants (but they fermented only sludge, not sewage, which is too dilute).

In Flintenbreite, the system designed by Dr Otterpohl uses an artificial wetland to treat greywater.  Urine, feces, and a small amount of water are conveyed to a central biogas digester which produces methane for the community; it is delivered to a cogeneration engine that supplies electricity and heat to the community. From what I could gather, the small volume of residual liquid produced by the digester is also treated in the wetland. (Originally the system was meant to digest kitchen wastes also; this part was never implemented, and biowastes are collected as part of the now-common municipal green wastes collection system.)

A bird’s eye view

A video, linked here, shows the site, with Dr Otterpohl explaining how the system works.  It is only available in German, and can’t be found in YouTUbe, but you still get an idea of what the place looks like.  It’s under ten minutes long; at 1:30, Otterpohl shows how silly it is to mix the large volume of greywater with the small concentrate of blackwater, using a shot glass and a Bavarian beer stein for comparison. Three minutes in you see the artificial wetland and how it was constructed: requires little energy, it looks good, it produces clear water.  According to a resident, the system never smells, and the kids adjusted quickly to the toilet (which, despite using vacuum, isn’t particularly noisy).  The guts of the system: collection tank, biogas digester, biogas collection tank, and cogen system (engine and generator), are shown from the 8th minute.

The water flows in Flintenbreite

If you’d like more details, you can listen to a podcast – in English, this time – narrated by Dr Otterpohl, here, or take a look at a set of presentation slides, here, or a summary, here.

With all this, you would think Dr Otterpohl is proud of his pioneering system at Flintenbreite, prouder yet that the system is now scaled up at a larger scale at Jenfelder Au.  But when I interviewed him, he was somewhat bitter about Jenfelder Au.  He has been elbowed aside, now that the design has been shown to work. I can imagine why, though – ha may not be an easy person to work with.  Ever the perfectionist, and the visionary, he says that the system should not be copied unless it incorporates one final separation: feces and urine should not be collected together.  Feces are the source of biogas, are semi-solid, and may contain pathogens.  Urine is a liquid that contains fertilizing elements.  It is foolish to blend them, he says.

I’ll be profiling Dr Otterpohl’s new research on separating toilets and management system in another post, because it is also quite remarkable.  But for now, I’d like to give him his due: if the vacuum toilets of Flintenbreite was the only system he ever designed, there would still be a lot to be thankful for.  I’m a bit awe-struck, myself.


Written by enviropaul

July 21, 2019 at 1:20 pm