Solar Power isn't Feasible!

Solar Power isn't Feasible!
This cartoon was on the cover of the book "SolarGas" by David Hoye. It echoes the Sharp Solar slogan "Last time I checked nobody owned the sun!"

Monday, April 4, 2016

Culhane's Solar CITIES Presentation to the National Science Teacher's Association conference in Nashville, April 1 and 2, 2016

Hi I’m T.H. Culhane, a National Geographic Explorer, a Google Science Fair judge for the past 6 years and… a science teacher.

And this is a picture of me working in “Garbage City”, a shanty town in Cairo Egypt where a proud and brave people who were displaced farmers now live by collecting the trash from the city’s 20 million inhabitants and carefully separate the inorganic from the organic, cleaning and shredding and selling the former to Chinese recycling companies, and feeding the latter to the pigs, cows, sheep, goats, donkeys, cows, chickens, ducks , rabbits and pigeons who they brought with them when they were driven off the land and who now live as refugees in the city with them in their self-built urban apartment buildings.

While living and working with these so called “Zabaleen” or “garbage people” in an environment that is a public health nightmare, filled with rats and flies and the stench of rotting meat and vegetables and the acrid smoke of burning plastic, my task has been to help improve conditions by working on the low-tech science of local household waste transformation using a form of livestock that everybody has: bacteria. My task has been to use simple applications of science, technology, engineering and math to design with the “other 90%” and make life better.

The innovations and technologies we’ve come up with over the years since I started applying home-brew microbiology to solving urban problems have taken me all over the world and are now being applied to help other displaced people caught up in the current refugee crisis.

I would like to share with you some of the details of these experiments and show you how you can get involved in these life saving efforts, but first I want to give you a little background on my story.

I basically wear two hats:

Hat number one:
For the past four years I have been a professor of Environmental Sustainability and Justice at Mercy College in New York, leading annual student service learning trips to the Middle East and the Caribbean to implement technologies we develop and test at the college, and in September I join the faculty of the Patel Center for Global Sustainability at University of South Florida to continue the mission.

Hat number two:

I am the co-founder and director of Solar CITIES Inc, a not-for profit organization we started 10 years ago in the Islamic historical slums and Christian trash pickers communities of Cairo Egypt, that ever since has been implementing citizen science projects in developing countries and poor communities, training trainers to turn sunshine, polluted water and organic wastes from problems into solutions for fuel, fertilizer and new nutritious food using local and low cost materials.

Prior to getting my Master’s degree in Urban Agroforestry and Ph.D. in the microeconomics of sustainable hot water demand, from 1989 until the turn of the century, I was a high school science teacher, working in our nation’s inner city schools with NASA’s Challenger Center, the Office of Naval Resarch and the Junior ROTC, applying Howard Gardner’s “multiple intelligence theories, creating curricula that would help students perform at the highest levels of “Bloom’s Taxonomy” and integrating interdisciplinary thematic, portfolio assessed vocational and academic education, creating what we now call “STEAMM” Education, Science Technology, Engineering, Art, Math and Music. I’m sure most of you here have also been involved in this for years and can relate! It’s quite a challenge!

Because of this history, It is delightful for me to be back on stage at the NSTA because I was a frequent presenter at these great gatherings in the early 90s, from LA to Hawaii to Kansas to Puerto Rico – for years I made an annual pilgrimage to convene with fellow science teachers and to share techniques and ideas to help raise the bar for science education.

In those early days of my teaching career, just as the “MTV era” was beginning, I was working with students on two programs, one called “Melodic-Mnemonics” where we brought our science textbooks to life through music and video, and another called “DEMMO Productions, which stood for “Digital Engineering for Multi-Media Productions” which we ran at Crenshaw and Jefferson High Schools in South L.A. and at Hollywood High’s academy for at-risk youth. What we were sharing with colleagues at the NSTA each year was our successes – and sometimes failures – to create not just think-tanks, but DO tanks, empirical experimental environments where students attempted to solve the problems of poverty, education alienation, drugs, gangs, crime, graffiti and environmental degradation and injustice through APPLIED science and art.

We did this by either trying to invent hands on solutions to real world problems – from alcohol powered trucks in the automotive department, to hydroponic food production in the biology classroom, or by writing poems, short stories and songs and making mini movies in which students solved science problems in a science fiction context, such as our work on biospherics through NASA’s Marsville program.

Those were marvelous heady days when, despite the ethnic and class tensions made explicit by the L.A. Riots of 1992 and the Earthquake of 1994, whose impact on infrastructure and provision of energy, water, sanitation, food delivery services and transportation was felt for months in the poorer parts of our cities, we science teachers and our students felt that we could use our spirit of inquiry, experimentation, exploration and open sharing, to rapidly realize the promises of our participatory democracy and guarantee a brighter future for all.

My mother is an Iraqi Lebanese immigrant who lost everything in a series of civil and international wars, and my father is an Irishman who told us of the unnecessary suffering caused by monocropping and the distorted political ecology of the potato famine, so when I left the US in 2003 for the middle east as war broke out in Iraq to spend 10 years outside America problem solving, I was determined to help improve science education there with the same promise. In Egypt I helped build up and direct the Wadi Environmental Science Center on a poultry and olive farm in between the pyramids and the library of Alexandria where for years we applied the same techniques to train both privileged and underprivileged Arab youth in problem solving.

Much of my time was spent working on low cost ways to capture and harness solar energy for water heating and cooking until my study of 900 urban households in the crowded city revealed that 12% of the population in my sample, representing millions of people, had no direct access to the sun because of shading from other buildings or poorly designed architecture. And meanwhile, the winters were disturbingly cold and people were resorting to burning what little wood was left from the denuded landscape, or using polluting charcoal and kerosene, and often burning trash just to heat their water.

 Did you know that over 4 million women and children die from indoor air pollution because of dirty fuels? And that the collection of wood and charcoal for heating water to bathe and cook is one of the primary drivers of deforestation, habitat loss, biodiversity loss, flooding and consequent topsoil loss, to say nothing of risk of fire and burns caused by these unstable fuels? It is sobering to think that something we take for granted – heating water and cooking – can have such a huge impact on human health, animal welfare and the state of our environment, but this is one of those inconvenient truths. And I was determined to help solve the problem.

Now you may have heard of the “clean cookstove” initiative that Julia Roberts and Hillary Clinton and others are working on, where, by providing improved stove designs we can reduce both the firewood and charcoal consumption and the attendant smoke by about 50%. And you have probably heard about attempts to replace the charcoal and firewood with something called “biochar” made from compressed waste straws or other biomass. All of these things are good because they reduce the impact and mortality. But here’s the problem: without the clean cookstove initiative we have 4 million deaths a year; with it we reduce that rate by half, which is laudable, but we still have 2 million deaths a year, and that is unacceptable. As students and teachers of science, can we really conscience settling for these losses?

And this is to say nothing of the losses of life and the suffering produced from the outputs of the very bathrooms and kitchens where the hot water produced by unclean fuels is being used.
Let’s talk about kitchens and bathrooms for a moment – think about it:

In terms of domestic use, Kitchens and bathrooms are the where all the fresh water is being consumed and contaminated. It comes in to our houses clean and goes out polluted with potentially deadly pathogenic bacteria and with soaps and detergents and chemicals that despoil our rivers and streams and oceans. Our kitchens and bathrooms are surprisingly the primary sources of disease and injustice, creating outbreaks of typhoid and cholera and dysentery with the sewage they create, and attracting rats and fleas and plague with the garbage they create. And this is to say nothing about the plastic bags we used to try and dispose of our organic wastes, which make their way to the landfill in diesel smoke belching garbage trucks or get blown or washed into the ocean, creating that horrible plastic vortex in the pacific.

All of this, because of the way we conceive of our kitchens and bathrooms as spaces of consumption rather than spaces of symbiotic consumption and production. I decided to dedicate my scientific research to figuring out how to design better kitchens and bathrooms and I moved into the slums of Cairo for 3 years to live the challenge. It was like being in a disaster zone almost every day, with water and electricity being cut off all the time and rats everywhere. In fact, rats killed the baby neice of a friend of mine in her crib, looking for food which the family diligently bagged up and put on the landing.

 Frustrated, the rats nibbled the child’s ears and nose and eyelids and gave her a deadly infection. This tragedy is not uncommon and I felt we had to stop it. Poisoning or trapping the rats wasn’t working.

In January of 2009 my friends from the Zabaleen school, where we were teaching kids the math and science necessary to be better trash recyclers, asked me to go to India to learn from their scientists how to better deal with urban wastes. What I found in the slums of Pune, India, two hours from Mumbai, astonished me and changed my life forever.

I would like to share this music-video, this melodic-mnemonic we made, with you that shows what we found.


At Solar CITIES we put home and community scale biogas at the center of our sustainable development efforts.  It is the missing piece of the sustainability puzzle. It is the solar plexus of sustainability, the literal "guts" of any system that tries to reduce, reuse, recycle and thrive. All the other forms of renewable energy struggle with intermittency problems -- the sun doesn't always shine, the wind doesn't always blow, there isn't always rain or snow and the rivers don't always flow. But toilet wastes and food wastes and organic residuals, these are always with us. And they need to be dealt with, so they pay their own costs, turning from problem to solution.

I am now convinced that the small scale urban biogas solution is the single most important intervention we can make in improving life for all of us, everywhere. They are easy to make and effectively eliminate all organic wastes, turning them from problem to solution.

Over the last 7 years, as you can see from this interactive map on our website,, I have built and trained people to build systems out of every possible material… from plastic water tanks to cement monoliths to pvc bags, and in places from Alaska to Botswana, from rural villages and urban apartments to schools and colleges and hospitals.

 We are part of an international movement; our facebook group, Solar CITIES Biogas Innoventors and Practioners, has over 7000 active members and we are all seeing the same results. On our community website,, people are doing citizen science and putting their projects on the map. We just need more science teachers and students and practioners doing this work, improving the systems. As we like to say, “we are science teachers and students, not waste management or energy professionals – so please DO try this at home!”

One of the major focuses of our research, that my students and I have been working on for the past two years, is the creation of literal “try this at home” “in-house” biodigesters, basement biogas systems like this one in a middle class house in New York and this one in a Menonite basement in Pennsylvania and this one in an ecolodge in the wilds of West Virginia, where all the food wastes are ground up in the insinkerator in the upstairs kitchen and then go down to the basement to be fermented so that within 24 hours of feeding the clean cooking fuel goes up to the kitchen and the rich liquid fertilizer or “compost tea” goes to the garden or to porch and rooftop soil free hydroponic and vertical aeroponic systems.

Recently, in my bathroom in New York in the city, based on work I pioneered in Germany, I’ve been working with a toilet waste biogas system that enables me to keep all of my toilet material in the apartment, providing solutions in case of earthquakes like the one I experienced in Los Angeles where sewage pipes were broken or long term power outages I experienced in the slums of Guatemala and Cairo and Ecuador that made it so the toilets couldn’t be flushed for weeks. This research expands on and makes practical theoretical work I was doing with my students in my high school classroom in south central when we were working with NASA to simulate living on a spacestation or the Moon or Mars, when we turned the classroom into a simulated biosphere. The only difference is that now we are working with a new NASA Next Gen Kitchens project trying to make it real. Biodigesters turn out to be the foundation of this simple approach to sustainability.

And I would like to convince you that while you may not want to deal with toilets at this point because of cultural taboos, when it comes to food wastes from your home or school cafeteria, the idea of teaching “applied microbiology to meet our sustainable development goals” is so easy to do, so safe and so accessible, and meets so many of our STEM and STEAM goals, that having students in schools everywhere experiment with this solution to so many problems should be a formal part of every science curriculum.

Millions of students in China and India and Nepal are already basing much of their curriculum on the benefits of anaerobic digestion of organic material. In one high school I visited in Shenzhen China with 3000 students and 700 faculty and staff, they had two digester systems. 100% of the food wastes from the cafeteria was being transformed into 100% of the cooking fuel for the cafeteria and much of the salad greens, while all the toilet wastes were being transformed into gas for electricity generation and landscaping fertilizer.

I have been blessed to be able to bring this same medium scale system, called the Puxin digester, to a school for abused girls in the Phillipines, a school built by Architecture for humanity in the favelas of Brazil, a muslim shrine in Iraq, an Ecovillage greenhouse geodesic dome in Sweden and several college research sites in Pennsylvania and New York.

 Meanwhile we have been building our simple Solar CITIES IBC tank based system in homes and schools, like this high school in Alaska and this one in inner city DC.

And our latest model is this simple salchicha or “sausage biogas” system made of a single sheet of hand welded PVC which fits in carry on luggage and can simply be rolled out, filled with a slurry of cow manure and water and then fed with ground up food wastes to provide up to two hours of cooking a day.

We will be deploying this system in refugee camps starting with Pakistan and Lebanon and Turkey this summer and fall. We are excited because this system that we’ve devised uses a self regulating heat coil that can be run on solar energy to keep it warm and productive on cold nights.

And the fertilizer that it creates is exactly what we need to close the cycle, growing rooftop and urban jungle gardens of nutritious food on a liquid fertilizer that is replaces all commercial fertilizers and is perfect for hydroponics, aquaponics and vertical aeroponics.

The basic point of all this is that these life saving interventions didn’t come out of some corporate laboratory or government think tank. These are innovations that come from citizen science, when students and teachers work together to explore the possible and refuse to let environmental degradation continue while waiting for politicians or experts do the solving for us.

We are science teachers. We teach a new generation to explore, to experiment, to create, to solve problems. We are science teachers. The world is in good hands when we work with our students to make a better world. We are science teachers. We got this.

Thank you!