Designing with the other 90%: New tools for meeting our millenium goals through biogas!

  I have just returned  from a very productive and enjoyable time in Shenzhen China (about an hour inland from Hong Kong)  with the Puxin Technology company.   The most wonderful result for our Solar CITIES Solutions biogas initiative  is that they actually  designed a new biogas system specifically to help us meet our needs in Rio de Janeiro and other locations around the world where we face uncertain terrain conditions and have to dig and prepare with shovels and hand tools.  Talk about "Design with and for the other 90%"!

This felicitous offer on the part of Puxin inventor and CEO Dr. Jianan Wang, lead engineer Mr. Jong and CAD designer Jeremy Wong came when we found that the standard 10m3 system molds we ordered and were about to ship for our builds this year with Architecture for Humanity at the school in Niteroi and with Catalytic Communities in the favelas of Rio  would be very very difficult to use if we wanted to  create smaller (shorter stature) systems (6 and 4 cubic meters) in the field where ground conditions don't permit installation of a full size 10m3 digester. 

Culhane simulates building conditions in Rio and discusses possible difficulties with Puxin founder and inventor Dr. Jianan Wang

It is recognized that in some situations one set of 10m3 molds can also be used to build a 6 cubic meter system if you simply don't use the bottom ring of plates.  But when I was doing the training I  discovered that what is true on paper and a few field trials  is not always what you get when you are in the real world and out of the lab or factory or idealized setting, and I wanted to be sure I wouldn't arrive in Rio only to find that "for want of a nail the shoe was lost".  It turned out that getting a single ring of plates to form the perfect circle necessary to complete the dome for a 6 cubic meter system  is almost impossible if you don't have a way to draw a perfect circle on level ground and don't have  a team of people surrounding the molds  able to kick them into shape from outside to form the circle with proper tolerances. 

I had been assured  that making a 6 cubic meter digester with the top half of the 10m3 system was possible but I said, "I trust you on that, but I'm the guy who has to make all this work in locations where the proper tools and support are lacking, and we learned a lot from our experiences in the Phillipines and Israel about what can go wrong.  So if you don't mind,  let me pretend this week here in China that I am actually in Rio at the school site, in a 1.5 meter deep mud pit on uneven ground where it is impossible to draw a good circle, with a tiny team of workers and no ability to intervene from the outside".  I had learned in graduate school in Urban Planning the famous adage "The map is not the territory" and that ground truth varies wildly from even the most tolerant schematics and the best laid plans of mice and men.

Solar CITIES' Culhane explains the problems they will have with the current system in Rio if they try to use the existing plates to make a shorter 6m3 system.

 When we ran this kind of a training  simulation on the warehouse floor without using the perfect circle they had inscribed there, and disallowing anybody to help from outside the mold assembly,  we found it absolutely impossible to get the molds together in the end.  We would pull and shove and bang and twist and lift and wiggle, but tiny differences in curvature without the reinforcement of a bottom ring of molds, overlapping so the curvature of one ring reinforced the gap of the other ring, added up to a situation where the last of the mold plates simply would not fit. Where the dome plates connected to the top ring we had a gap of almost 8 cm.

Chief Puxin Engineer Mr. Jong calculates what will be needed to redesign the system so the same molds can be used for three different sized biodigesters.

The gap that results when a single ring is used with no way to enforce good curvature.

For the six cubic meter system, if an outer mold is used, one needs both outer molds as the lower one alone is too short.

 The inventor and his chief engineer came over to discuss this with me and we determined that in fact nobody had ever built the 6 cubic meter system under the difficult conditions I would be facing in Brazil.  Normally a site will be prepared with a tractor and backloader and leveled and one can inscribe the circle on the floor and there is plenty of room for builders to surround the molds from the outside and kick it into form.  But in our case in Brazil we have very little space to work in, can't use the outer molds at all and there is certainly no room for people to stand outside the diameter of the tank molds. Also we have to dig by hand with shovels in rocky terrain where we can only go down at most 1.5 meters and since the digesters need to be completely buried so that a small playground can be built above the digesters we need the flexibility of deciding in the field, once we have dug as deep as we can, whether we can build a 6m3 system or need to go even smaller to 4 cubic meters. And that option isn't available from the standard Puxin family molds to begin with.

The site we are building on in Niteroi, Brazil: The green area to the left is the only space we have to build three digesters, one to treat the kitchen wastes from the building on the far left top and two to treat the sewage from the bathrooms in the building on the bottom right. Since we can only dig down at most 1.5 meters and must cover the digesters with dirt and grass to create a playground area, being able to have flexible height possibilities is critical.

A top view schematic of the site in Niteroi Brazil gives a good idea of the contraints.

Photograph of the Architecture for Humanity site in Niteroi where we will build the 4 or 6 cubic meter Puxins.  The exact location is shown in the picture on the right, to the left of the existing building which is where the molds will be stored until the systems are built. Subsequently that building will be taken down and the school building constructed in its place.

 I explained that the costs and difficulties of importing molds (especially with exorbitant shipping fees and import fees and possible demurrage) meant we could only make one order, and that most non-profit organizations would be in our situation and could not order more than one set of molds. The fact that we never know how deep we can dig in so many locations  meant we would have to determine at each site if we had the space for a 4, 6 or 10 cubic meter digester.   Puxin does sell a dedicated 4 cubic meter mold set but it is too small for most of our builds so even though we might need it for one of the locations in which we are working  for our Brazil project, it wouldn't be the right allocation of our limited funds. Puxin advertises that the 10 can be reconfigured to make a 6 but they said, "we caution against it in your situation  because  we haven't had the experiences you are describing up until now as we've only had a couple of clients who decided to build the 6 cubic meter variant. We wouldn't recommend deviating from the normal 10m3 configuration under the kinds of circumstances you will encounter in the field , for the reasons you discovered in your simulation training... without a conforming ring made of two opposing mold plates, it is very difficult to get the tolerances right " 

In light of this we sat down and discussed all the environments Solar CITIES Solutions works in, the difficulties we encounter in the field; the lack of machinery or electricity in many of our project areas  and how we most often  have to improvise and do things with hand tools.

 I mentioned that Insinkerator engineers had helped us respond to these challenges by creating a bicycle powered food grinder for the places without electricity and then asked, "what could we come up with so that we could order a single set of molds to be shipped to a remote location that could be used to accommodate any kind of terrain and size constraints."


Puxin's visionary  inventor, Dr. Jianan Wang, said, "we are happy to redesign our system so it can be used by people like you. We want to make our systems the best in the world for developing countries and for helping the poor.  Most of our business is actually the 100, 200 and 300 cubic meter industrial or institutional systems while the 10 m3 and smaller are something I invented to help the world, not for business. Anyway, my philosophy for inventing the Puxin system was that we make biogas as inexpensive and easy as possible, something everybody can do.  We want to stop the problems associated with wastes and pollution. I've always felt that if we can get to a time when everybody is turning wastes into biogas and fertilizer because it is so easy and the market becomes saturated and there is no more business for companies like ours, then we would consider that a success.  We would simply go into another business. This is not about the money, this is a social good, something we are obliged to do to make people's lives better, like the invention of penicillin.  So I want to learn from the experiences of non-governmental  organizations like yours and figure out what the field challenges are so we can make it as easy as possible for the poor to get biogas" 

With that said  Dr. Wang  set to work with his designers and engineers as we walked around the 6m3 mold we were having trouble assembling, discussing the pros and cons of different solutions.  I lay on my back with a hammer simulating what it would be like to be inside the digester at 4m3 and 6m3 as it was being built underground in Brazil and  based on the length of my arms and how easy it or hard it would be to get the screws and bolts and hooks and plates in place, they took measurements.   The most important thing was to have a conforming ring to force the circle into shape. I suggested that that ring be made of a section of the top portion that already had the angle for afixing the existing top dome plates and they liked that.



We finally  hit upon a solution where a single shallow ring at the top of about 10 cm height keeps the circular form and allows the bottom rings to be used individually or stacked, giving us the possibility to reliably build three different sized systems out of one set of molds in the toughest field conditions!



This was one of the great things about being in China, a country where rapid retooling and creative manufacturing are part of everyday life.   They said that getting the factory to retool to produce this special Solar CITIES Solutions ready system would only add another week or two to the order, but since we were looking at an early to mid September delivery anyway because of shipping logistics (ships leave Shenzhen for Brazil only once a week, on Tuesdays, and we'd missed one of those boats already; it takes 25 days from China to the port of Santos, and there all 20 foot containers like those the Puxin comes in must await consolidation into 40 foot containers before making the additional 5 day journey into Rio)  and we don't want anything to go wrong since we have one shot at this, the President of Puxin thus determined that  reinventing his product for the type of application environment we are facing  was the only to way to go. He said he  wants to make sure that Puxin's reputation as provider of the best, easiest to use and least expensive biogas systems in the world benefits from  the focus we and other non profit organizations are making toward helping communities in extreme situations and in turn benefits the world.

CAD Designer Jeremy Wong and Chief Engineer Mr. Jong model the new Puxin design for Solar CITIES.

A very satisfactory result indeed!  I've attached the CAD 3D drawings they just sent.  This, in combination with the bicycle powered food grinder Insinkerator corporation created for our mission , will make for a very nice story of companies supporting our millennium goals with targeted innovation -- a true design for and with the "other 90%"!


 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::



 In the new Puxin design, instead of having two vertical plates to work with, we now have three. Whereas in the old design the bottom of the two plates was 50 cm tall with a flat top to allow the 77 cm tall top  plate to stand on top of it, with the top plate having an angled surface for adhering the 80 cm long, 29 cm high dome plates, now both the bottom plate, which is slightly smaller than 50 cm, and the top plate, which is smaller than 77 cm, now have flat surfaces on top.  The bottom and top plates have the flat top surface so that a new ring of approximately 10 cm can be adhered to either the bottom or top plates. This new ring has the angled surface for attaching to the usual 80 cm long, 29 cm high dome plates.

Now, thanks to the Puxin inventor and engineers truly designing with and for us, the other 90%,  Puxin users can now  use the same set of molds to create 4 cubic meter, 6 cubic meter and 10 cubic meter systems! 

 Above we see two of the 16 triangle pieces that form the top dome. 15 of them are  80 cm long with apex of the triangle being 25 cm and the wide base part 53 cm.  The 16th is cut into two pieces (shown on left) with a section about 10 cm being the last section to go in.  Unless the molds underneath are almost perfectly circular this thin final piece simply won't go in. This is why one needs two sets of plates, stacked like bricks overlapping, to hold the curvature.
Above the triangular pieces we see the 4 neck rings -- the bottom neck ring which binds the triangular pieces on the left and the 4 wider neck rings for the top of the neck. These, and the neck pieces are identical to what we had in the previous design.

 Above we see the new bottom plates for constructing the 4m3 digester. The top conforming ring has ot yet been put on.

 Here above we see the new "middle plates" used for constructing the 6m3 digester. Again, the top conforming ring has not been put on.

 Here we see all the plates assembled to make the normal 10m3 digester. You can see the bottom plates used for the 4m3 on the bottom and the middle plates, used for the 6m3 digester placed on top but rotated so that the gaps of one ring are covered by the curvature of the other, similar to the way bricks are laid.  On top we see the new top ring with its angle lip.  It is also placed so that its gaps cover non gap surfaces, imbricating for curvature reinforcement.

The above picture shows the new 4m3 digester possibility, witht he bottom plates covered by the top conforming ring, the dome plates attached and the neck ring assembled.

The above picture is a partial assembly of the 6m3 configuration.  Without the new top ring one gets to a point where the very last dome piece simply won't fit because of losses in curvature.

 Above we see the 6m3 system with neck ring ready for the neck to be placed upon it.  Note the "gap plates" and how they are in different locations.  The major difference between the new design build and the old design build is that we no longer imbricate the dome plates with the top ring -- in this case, because the curvature is held by the two rings of the vertical plates, we can assemble each dome plate with its associated top ring plate. This, Dr. Wang explained, makes it easier to preassemble sections of the top dome outside of the working pit and should simplify a build when it is hard to get inside the tank comfortably, as with the very shallow 4m3 builds.

 The above picture shows the 6m3 mold with neck rings.

 The above picture shows the full 10m3 molds assembled. with bottom neck ring.

 The above model shows the full 10 cubic meter mold assembled with both neck rings (but without the neck which is not shown but which is the same as the original Puxin model. Note that the original neck molds, which are used to make the hydraulic pressure gas holder system,  can be used with almost any sized Puxin -- not just 4, 6 or 10 m3 but even 100, 200 or 300 m3 systems.  This unique design allows one cubic meter of gas to accumulate and pressurizes it under 1 ton of water pressure (the weight of the 1000 liters of water displaced when the fiberglass gas holder is full of biogas) which then can send it to the storage balloon or other gas holders. An elegant and simple design indeed!

We at Solar CITIES Solutions are excited to be the first to field test this new improved Puxin system that was created specifically for organizations like ours, and look forward to sharing the results with the world community.

If you want to be part of that community, come and join us in our facebook group: Solar CITIES Biogas Innoventors and Practitioners
https://www.facebook.com/groups/methanogens/

We look forward to continuing the journey and are deeply grateful to Puxin for designing for and with the other 90% and to Insinkerator for sponsoring the training trip to China and the builds we are doing in Brazil.  Xie Xie, Muito Obrigado!

Solar CITIES e.V. Report: Where we've been and whither we are tending...

"If we could first know where we are, and whither we are tending, we could better judge what to do, and how to do it." -- President Abraham Lincoln, Illinois Republican State Convention, Springfield, Illinois June 16, 1858

 Solar CITIES Solutions e.V. is a German  based  "Verein" or association, a  non-profit organization dedicated to bringing the promise of home and community scale biogas and associated solar energy based  'independence tech' solutions around the world that received funding from the Blackstone Ranch Foundation and National Geographic, among others, to pursue a vision of collaboration across disciplines to meet the innovation challenges of the 21st century.

 Biogas was placed front and center of our efforts in Solar CITIES because we had discovered that it is the simplest and most effective form of solar energy capture, storage and use available to humanity, given that it's clean fuel and nutrient rich fertilizer outputs can be produced from kitchen and toilet wastes.  These normally troublesome and often disease causing outputs of society are  two things that every human being and community has in abundance, and in the process of their transformation through harnessed anaerobic digestion we found that they are ironically the best bet for our species in our efforts to meet our UN Millennium Goals.  We found that small scale biogas and fertilizer created from food and toilet wastes in our burgeoning  urban areas can help eliminate indoor air pollution, deforestation, soil erosion, malnutrition, and conflict over scarce resources.

  Formalizing our non-profit into other entities around the world that can pursue similar goals multi-laterally, in a rhizomal rashion, represents a  "levelling up" of our vision (to use gamer lingo), a culmination of work I had done since 2006 when I and my wife and colleagues living in the slums and informal areas of Cairo started  a German/Egyptian/American partnership that would operate as an open-source green-collar technology training hacker space initiative  dedicated to  "Connecting Community Catalysts Integrating Technologies for Industrial Ecology Solutions"

Maintaining that vision, I am  now assisting Catalytic Communities, an NGO created by my friend and fellow biological anthropologist trained urban planner Theresa Williamson, who was an inspiration for Solar CITIES' approach, working in the  favelas of Rio De Janeiro to continue work we started together there this summer to help solve urban waste problems in preparation for the World Cup and Olympics, hoping to move awareness of the small scale biogas solution to the world stage. When we prove the value of easy to build community and home scale biogas systems in Brazil, we hope to set the stage for a rapid multiplier effect to take place.

As we grow, now working in turn with a partner organization, New York based Solar CITIES Solutions, Solar CITIS e.V., looks back over the past three years of activities and progress achieved since completing our first biogas education training tours of the Middle East and Africa and Nepal on our first Blackstone Ranch Foundation/National Geographic Innovation Challenge Grants that got us started (those achievements are covered elsewhere).

 This report has been prepared primarily for Dr. Katey Walter Anthony as a summary for our funders and friends at National Geographic.

Background:

In 2010, in preparation for synergistic work with Dr. Katey Walter Anthony on small biodigesters and the potential to extend their range using psychrophilic anaerobic microbes in Alaska, I returned to our Solar CITIES NGO site team in Egypt to develop inexpensive biogas systems out of ubiquitous local materials that could be found in every country in the world.  The work was funded by the Blackstone Ranch Foundation through National Geographic working with the University of Fairbanks and the Denali Commission.

There are two basic kinds of biodigesters in the world – the Chinese fixed dome system and the Indian Floating Drum digester.  Neither seemed suited for temperate zone climatic zones or for small scale builders with limited resources.

What emerged from the trip to Egypt was our development of a low cost DIY biogas system based on the use of pallette based 1 cubic meter International Bulk Containers (IBC Tanks) that are relatively easy to find on the after market (normally they are used for shipping liquids and other amorphous materials around the world) and can be sealed and insulated for use in cold climates. We knew that the traditional Indian Floating Drum digestor, even when built from local plastic water tanks, and the Chinese fixed dome digestor, built using local bricklayers, both of which we were experimenting with in Egypt, would not be appropriate for colder climates or situations where budgets, space and land use permissions were limited (Figure 1).

In Alaska Katey and I, along with our teams and with Adam Lowe and his students from Cordova High School, developed a laboratory based on deployment of these tanks and began experimenting with mixed tanks containing both cold tolerant microbes (psychrophiles) and warm loving microbes (thermophiles), finding that they do well together and increase gas production when used together as opposed to used alone, possibly because they inhabit different niches in the tanks. (Figure 2).

From these experiments I began tinkering with small scale biogas on my own home porch in Germany, and was able to create a reliable system that provided about ½ hour of cooking (and occasional gas lamp lighting and electricity generation) most days of the year.  Innovations such as using solar heated shower and bath and grey water to keep the tank temperatures above 20 C helped. (Figure 3,4)

I experimented with using psychrophiles gathered in the winter from local duck ponds and started mini-digesters in my bathroom using my baby's diaper wastes (Figure 5) I also demonstrated to my satisfaction that in cold climates we could use PVC bags for reliable gas storage rather than a water based system, eliminating the need for anti-freeze or heating as long as the digester itself were kept at 20 C or higher.(Figure 6)

New York
When I took a post as a visiting faculty researcher at Mercy College, New York in January of 2013, I created an indoor lab based on our work with Katey in Alaska, to test various scenarios for food and toilet waste based biogas. In this relatively  unventilated and confined space we captured the gas in truck inner tubes and demonstrated the safety of closed tank biogas system for indoor use.  We kept methane alarm sensors on hand and demonstrated that we could get useful yields throughout the winter without extra heating using food scraps from the cafeteria.  We also demonstrated that we could grind the cafeteria waste using a bicycle powered food grinder (Figures 7 through 10).  Unfortunately Mercy College later decided they needed that indoor space for other purposes.

Using Mercy college as  my academic home base I started  experiments  outside on campus with Envisaj Mercy, the Environmental Sustainability and Justice Club and began working with the  Greenburgh Nature Center and  Hartsbrook Nature Preserve. We designed a new way of using the IBC tank so that it more nearly approximated the engineering of the Chinese Fixed Dome digester design, and hybridized it with the ARTI type Indian floating digester design for gas collection, creating the “Solar CITIES IBC/ARTI Hybrid'.  This system enables both tanks to be used in the warmer months but permits the gas collector to be located outdoors and the main digester indoors so that one of them can work all year round in a heated indoor environment.  Discharge of warm water in the overflow to the gas holder helps keep it unfrozen in winter in most situations. The tanks can be heated by waste shower and bath and dishwasher  water.
With the students in our Envisaj Mercy club we also developed a classroom based mini-digestor demonstration system and made public appearances and did workshops that lead to collaborations and fund raising opportunities (Figure 11 and 12).

  We were able to leverage these experiences into a new grant from the Blackstone Ranch foundation that enabled us to purchase a new design of Puxin Chinese biogas molds that were created for the Solar CITIES Solutions effort  by the Puxin company when I was in Shenzen China last summer (Figure 13, 14)

 The grant also enabled Solar CITIES Solutions to  bring 10 of the world's small scale biogas experts to New York to gain experience in building the Chinese Puxin mold system  (ultimately only 7 could make it, from Israel, Babylon, Egypt, Italy, Oregon, Washington and New York; our colleagues from India and Kenya and Palestine had travel problems but will come to our training meeting next year)  (Figure 15 and 16). Through this Blackstone Grant we were able to create what we call the “Best BET” – an international Biogas Education Team – that can improve systems and do trainings all over the globe. This event was covered in local newspapers like the Rivertown Enterprise and the Indy Star.

Philippines
We chose to use the Puxin molds because I had tried them out in the Phillipines in 2011 with a group of German doctors (Chance for Growth e.V.) doing preventative medicine at a retreat school on the island of Palawan for abused girls from the slums of Manila.(Figures 17, 18)

(One thing we learned from this experience was that when people build they need to understand the hydraulic pressure function of water level in pushing gas out of a digester -- the feed inlet and fertilizer outlets need to be taller than the top of the gas holder and as tall as the maximum height that the water will reach above the holder and filled so that when the gas holder is filled with gas the water reaches the top of the basins and when it is empty the water still covers the gas holder. In the Phillipines these basins were built too low and had to be made higher for proper functioning).

Brazil
From what we learned in these preliminary experiments and conversations, we went on to the favelas of Brazil and  started teaching small scale biogas construction with colleagues from  Architecture for Humanity and Catalytic Communities, an NGO dedicated to empowering local groups in poor areas. (Figure 19,20).

The effort led to funding from Insinkerator corporation (manufacturer of food waste grinders)  to build larger scale Chinese Puxin biodigesters sized for entire communities.

We now have three digesters at a new  elementary school in the impoverished section of Niteroi that is near  the site of a landfill collapse that claimed many lives, and one under construction in a favela in the rain forest favela "Vale Encantado" (Enchanted Valley)  overlooking Rio. We use Blender 3D to create models and animations and renderings as part of our previsualization and education campaign across cultures (Figure 21, 22, 23, 24)

Israel and Palestine
In the meantime, projects I had started in Israel and Palestine on the original grant that Katey and I got from the Blackstone Ranch foundation needed tending, so I followed up by introducing my new Solar CITIES Hybrid IBC solution there.  I took my  Envisaj Mercy students and a young biogas engineer working on our project in Brazil on a two week “Biogas research and construction tour”  from the West Bank with Engineers without Borders, the Palestinian Wildlife Society and Brother's Engineering Group  to Eco-Gas Israel, the Arava Institute for Environmental Studies and  Kibbutz Lotan Eco-Village "Green Apprenticeship Program." It culminated in a workshop build of the new  improved biogas system we had tried out at Mercy college based on our initial work in Alaska (Figure 25, 26). One important finding we are investigating is that it appears that manure from cows fed on grain seem to lack active methanogens as we haven't produced gas in the 8 weeks since the system was loaded.  One study suggests that grain fed cows produce too much acidity for a good balance of microbes. These experiences -- especially the "failures" -- are very important to our efforts.  Without a dedicated laboratory able to run large numbers of real world trials, these kind of experiments can only be effectively done if we have enough builds around the world in different.countries and if  we can cross compare data from dedicated citizen scientists. That open source collaborative engagement is what our facebook group "Solar CITIES Biogas Innoventors and Practitioners" helps us to achieve.

Bicoastal US:

There was also interest in the US as several community leaders in impoverished areas of California and Washington DC asked if I could help them get started in home scale biogas. Most found us through the wonderful promotion we've received since I was awarded as a National Geographic Emerging Explorer in 2009.  Schools and individuals find out about Solar CITIES through National Geographic Learning and we are asked to do talks and workshops around the country and the world. We did a training workshop and build in “the 'hood” in South L.A. with  a former student of mind in an area once  famous for drug deals and gangs where he is leading "green collar job training" to revitalize the community, and we built with  friends trying to go "off the grid"  in the San Pedro National forest area (Figures 27) .

 I was also  able to build at a foreclosure house in Northern California and then to bring one of our original Solar CITIES Egyptian colleagues, former carpenter and Solar CITIES founder Mostafa Hussein, from the slums of Cairo,  to Washington DC and New York to assist in the effort of building in inner city schools, continuing a practice of East/East, South/South, Community/Community technology and knowledge transfer that  Katey and I had started when we brought another Egyptian  Solar CITIES founding leader, Hanna Fathy, from the trash recycling community  (Zabaleen) to four countries in Africa to share knowledge (Figure 28).

Iraq and Turkey:
News of these successes spread through the networks of  development specialists we had worked with in the US Embassy in Jerusalem and contacts we had made through National Geographic, and in the spring of 2013 I found myself called to my mother's native Baghdad Iraq and Kurdistan and then on to Turkey to continue the trainings and builds.

 From the US Embassy in Baghdad with Public Affairs chief Frank Finver to the “Greening of the Blue” at the  United Nations (working with Humanitarian officer Karin Mayer) to the Ministry of Science and Technology to Kurdistan  and on to the streets of Istanbul, we did  builds and hands-on trainings and lectures that showed how small scale biogas systems turning kitchen and toilet wastes into clean fuel and rich fertilizer were the “missing piece of the sustainability puzzle.” (Figure30 through 33).

I even put my Iraqi grandfather's ashes into one of the tanks in Erbil to celebrate the cyclical and transformative nature of this technology, a simple technology  which environmental journalist Hillary Rosner, in Popular Science magazine, in an article on our work, declared the  “low hanging fruit” of sustainable development (Figure 34)

From Africa to Eastern Europe to Western Europe, to the Americas to the Middle East and Asia and back again I've been cross pollinating areas with the fertile ideas of biogas  in an endless cycle, visiting on average 10 different countries a year and watching with excitement as others in our network do the same.

As the network expands, the model of itinerant, peripatetic “apostles of sustainability”  preaching the “gospel of biological transduction” grows rhizomally. People I had met in Nairobi while on the first National Geographic/Blackstone Innovation Challenge asked me back to teach in the Mukuru slums there with the German  Arts NGO Simama e.V, and while working there I met Christian missionary groups who asked if I would introduce the technology to Hungarians and Slovakians to help with other issues that could benefit from this easy waste-to-energy-and-fertility technology such as the problems facing the gypsies and other marginalized groups in Europe.  Through presentations at UNESCO the network grew to include former President Obasanjo of Nigeria who invited me to  build systems and teach workshops at his home and in several schools and church hospitals.  Presentations I had made at the Los Angeles Eco-village led to introducing this technology to the Global Eco-village network in Damanhur Italy and the Solar village of Tamera, Portugal. This in turn led to our Solar CITIES Open Source Biogas system being deployed in the favelas of Sao Paolo by students I trained in their global campus  in Portugal. Through our facebook group “Solar CITIES Biogas Innoventors and Practioners” our solution has also been adopted in several other countries and locations I've never had the chance to visit, including Senegal, shown here (Figure 35, 36).

Meanwhile, the builds in the Middle East go on, with a large scale Puxin from the molds  that we brought to Iraq recently completed by the marvelous Baghdadi engineer Taha Majeed and the team from MOST (Figure 37) at a sacred Shiite Shrine in the desert , while I continue my own research into small scale DIY biogas systems for colder climates using local material and thank all of the people and institutions who have invested in this work.

My vision and hope now is twofold:

1) To introduce the larger Chinese mold based systems of 4m3, 6m3, 10m3 and larger in strategic community locations around the world  for institutions with significant amounts of food and toilet waste that can help spread awareness and build capacity.

2) Use the public awareness that the community builds and workshops create to inspire  an interest and demand for the true (r)evolution in waste management and renewable energy: the introduction of market based mass produced home scale biogas systems that can create true independence from centralized and unwieldy and disaster vulnerable systems.  As Solar CITIES e.V. we already have partnered with several suppliers of home biogas and will be helping them introduce their products (like the TevaGas systems integrated with hydroponics gardens shown below)  into the appropriate locations in the world until we reach a time when kitchen and toilet wastes cease to be considered a problem in development, and are seen as the solution to our troubles that they really are once we create a truly recycling economy (Figure 38, 39)

.
Food and toilet wastes are embedded solar energy. They are the only resources we ALL have in common, whether we live in Alaska or New York or Baghdad. They will always be with us.  And as such, properly transformed through biogas systems,  they are the real solutions that Solar CITIES e.V. believes can be our true path to creating a sustainable "Heliopolis", an enduring and joyful "City of the Sun".