July 5, 2013

Harnessing the sun

In June, we celebrated the milestone of 9.5 tonnes of fuel produced at the Beta GreenHeat factory! Meanwhile, this last month our engineering team has been focused on hashing out the design details for a larger scale plant.

Part of these efforts includes running detailed experiments on the drying properties of sludge in a passive solar dryer – more interesting than watching paint dry, we promise. The solar drying stage is one of the most critical parts of turning mostly liquid waste into dry, combustible GreenHeat. In Ghana where electricity can be expensive and unreliable, using a greenhouse for drying with minimal power needs is a huge advantage and cost saver. Nothing like free, available energy from the sun!

The team constructed a small prototype low-roof greenhouse with a fan to test how sludge behaves under different controlled conditions and varying consistencies (see pictures of the prototype, and our two Cal Energy Corps interns, below). Wind speed, the amount of sunshine in a day, temperature, and humidity all play huge roles in how sludge dries, and ultimately how fuel is made. The results so far have allowed us to begin creating a model of how sludge dries on bad days, good days, and everything in between to aid us in decisions about how frequently to mix sludge in the drying beds and which greenhouse designs are best.

The findings we’re gathering are crucial for the next stage – constructing a larger prototype sludge drying greenhouse. Stay tuned for more progress as the march toward large scale fuel production continues!

John Palfreyman (top) Troy Hodges (bottom) setting up the prototype low-roof solar dryer for drying experiments.

May 10, 2013

GreenHeat in flames: Industrial trial #1

This week we ran our first industrial-scale burning trial with GreenHeat! Does it combust? Can it maintain the steam pressure in a boiler? Check and check.

However, we also got an education about boilers. It turns out this particular furnace was designed to burn paper waste, and uses fans to distribute the fuel throughout the combustion chamber of the furnace. The GreenHeat being granular, was too dense for the fans to push across the combustion chamber. In the midst of the trial, the operators came up with a work-around: they opened the doors to the furnace and spread the fuel across the floor of the combustion chamber with rakes. This worked but is no permanent solution, as it was labor-intensive and cut down on the efficiency of the furnace.

So what next?

The cement industry remains the most obvious match for GreenHeat, as cement kilns already burn bulk granulated fuel. But if we can make GreenHeat work with furnaces like this one, we’ll be able to greatly expand our customer base. So, next week we’ll get to work on making some modifations. We are going to try varying the particle size, density, and composition of GreenHeat to see if we can produce something light enough to be transported by the moving air in the furnace. We also have ideas for small modifications to the furnace that would allow for combustion of granulated GreenHeat. Hopefully we’ll have some promising updates to share in the coming weeks.

And lest you’ve forgotten why we’re really doing this…yesterday’s 1/2-tonne burning trial marked the first significant diversion of human waste from the ocean to a furnace, and that’s something to celebrate!

March 17, 2013

Beta GreenHeat Plant now open!

This past Monday, 11 March 2013, marked opening day for our Beta GreenHeat Plant. Our entire team was at the site – getting gloved hands dirty – as we ran fecal sludge through each piece of equipment for the first time.

Wheelbarrel full o’ fecal sludge.

Filling the press.

Press at work.

Loading the drying trays.

Cookin’ with gas.

February 12, 2013

Toilet blocks: Yep, they’re profitable

Ever wondered whether public toilet blocks are really financially viable? Well, so have we. So we hired John Harris, PhD in urban studies, to help us explore the question.

First, a little background on our curiosity and the impetus for the study. The project emerged from a question we often ask ourselves: “If we could generate enough revenue from the sale of GreenHeat that we could afford to reinvest a portion back into the sanitation sector, what kind of investment would have the highest impact?” Our instinct was that subsidizing the emptying of full pit latrines/holding tanks in low-income communities would be the answer. This, we thought, would improve the quality of sanitation services to the poor while giving us access to FS that we may not have otherwise acquired (and enabling us to make more fuel). Before implementing such a program, we wanted to quantify the extent to which toilet block owners defer emptying, and just how ‘too expensive’ emptying services are in low-income communities.

Ultimately, Harris’ research proved our instincts wrong. After interviewing 41 toilet block owners and eight additional key informants in Accra, he found that profit margins are healthy enough that owners do undertake basic maintenance, like emptying, as needed. Wow. Toilet blocks do get used. They do fill up. And they even get emptied. This suggests solving the urban sanitation crisis really does come down to finding cost-effective solutions for treatment (and better yet, reuse!) of human waste. But before I digress into my favorite rant, let’s come back to toilets.

Harris’ study shed new light on the nuances of the toilet block business, identifying three important operational barriers: Access to water, access to reliable exhauster services (N.B. this is different from the cost of emptying), and access to affordable and effective cleaning products. The latter is the first expense that owners cut when margins are tight, which in turn steers customers away, and undermines the integrity of the sanitation service for those who visit.

Harris presents two key recommendations for enhancing sanitation services for the poor without increasing prices:

1. Provide targeted investments that improve access to freshwater for partner toilet blocks;
2. Establish effective partnerships with disinfectant providers that grant preferential pricing to partner toilet block owners.

While these findings are valuable for Waste Enterprisers, the results and recommendations are broadly applicable to how development dollars could best be spent, and where political pressure could be best applied when it comes to improving access to sanitation. Where the focus of an institution or organization is on toilets – or in industry jargon, “access at the point of use” – there may be higher impact, more cost-effective interventions than simply building the toilet itself. And perhaps more importantly, as Harris concludes, the cost recovery logic of toilets is well intact and it’s critical to focus on interventions that enhance, rather than interfere with, a proven business model.

See Harris’ full report, Expanding Sanitation Access in Accra’s Public Toilets, for all of the details.

January 25, 2013

GreenHeat equipment takes shape

As the adventure of building sludge drying equipment locally continues, the work of the engineering team has started to bear tangible fruit. A local bread oven manufacturer has almost completed a custom tray dryer that will produce batches of 200-300 kilograms of fuel. The dryer will run on LPG during initial testing, but eventually we’ll use GreenHeat as its source of thermal energy. Using our own fuel will drastically cut operating costs, as well as provide the team with valuable experience and insight into the combustion characteristics of GreenHeat.


Tray oven, nearly complete.

(more…)

January 4, 2013

And yet again, necessity proves the mother of invention

Over the past couple of weeks, the engineering team has had a bit of a reprieve from their hands-on experiments with fecal sludge. While they’re no doubt longing for the good ol’ days, there’s now a more urgent priority to tackle: sourcing locally produced equipment.

As we get closer to the target opening date of our small-scale commercial GreenHeat plant (or “Beta plant”), most of the engineering team’s time has been spent sourcing dewatering and drying equipment. Buying the necessary equipment from an international manufacturer is an option, but purchasing equipment locally has several advantages, chief among them a quicker timeline for installation and availability of local expertise and parts for maintenance and customization.

It turns out, however, that finding manufacturers in Ghana is a real challenge. The local manufacturing sector is fragmented, and built-up only in areas where it can exert a cost or convenience advantage over products made in Asia. Unfortunately, industrial sewage-processing equipment is not one of those areas, and the vast majority of such equipment is imported.

So why do we remain committed to sourcing locally? Well, our goal is to get into production as quickly as possible, and to preserve the flexibility to tweak our processing equipment as we learn from operating the plant and get feedback from clients. Working with a local fabricator will better serve the latter priority, and we’re convinced will be quicker than navigating the Asian manufacturing scene (an option we do intend to explore for our full-scale commercial plant, however).

And this is where necessity sparked creativity among the engineering team…Surely a bread oven can be converted into a sludge dryer. So that’s what they’re doing: purchasing a commercial bread oven (manufactured a few hundred meters from our site and pictured below) and turning it into a biomass-powered sludge dryer. While not a long-term solution, such a dryer should allow us to produce fuel sooner and learn more about the process while we ramp up production at the Beta plant. Stay tuned!

December 17, 2012

Design for small commercial GreenHeat plant taking shape

The engineering team has been hard at work in the weeks since the Collaborative Innovation Workshop. They’ve been getting their hands dirty running numerous fecal sludge dewatering and passive drying experiments, all of which are guiding the development of a small-scale commercial plant. Within a few months that plant will be built, operating, and producing a few tonnes of GreenHeat fuel per day!

In designing the plant, the team is particularly focused on getting the most “bang for their buck” with mechanical dewatering and solar drying. By combining and optimizing these technologies, we can drive down the cost and environmental footprint of producing GreenHeat as compared to using active thermal dryers. And plus, at 5 degrees north of the equator there’s an abundance of solar radiation to harness!

For each process component, the team is also focused on making the most of locally available resources – this will help minimize cost and the risk of maintenance challenges. They’re currently testing locally fabricated screw presses for mechanical dewatering and are designing the solar greenhouses with rugged materials and limited infrastructure. Check out their works in progress below.


Pilot-scale screw press being evaluated for the GreenHeat production process.


John Reeves building screens for drying trials.


John Rosenwinkel building a small greenhouse for solar drying trials.


Fecal sludge in transition to GreenHeat inside solar greenhouse.

November 2, 2012

GreenHeat Collaborative Innovation Workshop

In any field of human endeavor, policy makers and practitioners are accustomed by training and experience to thinking within familiar sets of parameters, and while aware of the shortcomings associated with these parameters, find it difficult to step outside of them. In principle, radical new thinking is always desired but rarely produced. When produced it often meets with resistance even from those who sought it simply because it steps outside those parameters – outside of the box – of preset assumptions, experience and capacity. –Summary Report of Bellagio Expert Consultation on Environmental Sanitation in the 21st Century, Eawag, February 2000.

It often feels like Waste Enterprisers is up against a fundamental human condition that resists change from the status quo. I mean, why else would conventional wastewater treatment plants still get built in developing cities when their failure is so predictable? But during the last two weeks we found kindred spirits in our genuine desire for radical new thinking about sanitation.

In partnership with the technical strategy firm, Point380, we convened a two-week intensive design workshop with the goal of developing a cost-effective and Ghana-appropriate process for producing GreenHeat on an industrial scale. It was a meeting of incredibly diverse minds, including specialists in sludge dewatering, greenhouse construction, solar modeling, natural treatment systems, and utilities.

This was an experiment that would only work if our participants came prepared to think outside the box…Came ready to think about non-traditional solutions to fecal sludge management…Ready to co-create radically efficient and cost-cutting solutions. And that they did.

Every day for two weeks we held two virtual workshops on a given theme. For example, one day it was mechanical dewatering and passive thermal, another it was thermal energy and power supply. Thanks to technology, we were able to hold interactive sessions, complete with live “whiteboard” drawings from the comfort and convenience of our respective offices. For some, of course, this was more convenient than others. Our Ghana-based crew did struggle to keep laptops alive with battery power and the internet running with cellular modems, as our workshop coincided with consistent load-shedding across Accra. If nothing else though, it did drive home the importance of back-up power supply for our plant!

At the end of each day’s sessions, our engineering team worked into the night to flesh out the ideas that emerged – estimating numbers like size (footprint), electricity demand, capital and operating costs for each of the concepts. Developing glorified napkin sketches, if you will.

We’ve emerged from these two weeks having taken giant steps forward with the design of our industrial-scale fecal sludge-to-fuel plant. None of this would have been possible without the inspired minds, hard work, and commitment from our partners at Point380 and all of the experts who joined us. We can’t thank them enough for helping us to build this sanitation revolution.

Now the work of further refining and testing the design begins. We’re looking forward to unveiling our industrial-scale GreenHeat production process in the coming months.

September 5, 2012

Hitting pause on aquaculture

In just a few weeks, we’ll harvest our last batch of catfish…at least for the time being.

Over the last two plus years we’ve come a long way both with aquaculture and as a company. On the aquaculture front, we rehabilitated two waste stabilization ponds in Kumasi, built rearing infrastructure for our fingerlings, and increased stock survival rates from less than 5% to 75% over the course of three cultivations.

Along the way, Waste Enterprisers has become much more than a wastewater-fed fish farming company. Actually, we’ve become more and more a fecal sludge-to-energy company. We’re on the brink of building our first commercial GreenHeat plant, and we’re making steady progress toward developing a technology and business around converting fecal sludge to biodiesel.

All of these new developments have forced us to face a reality. As the entrepreneurship blogger Mark Suster writes, “The scarcest resource in your company is management bandwidth. Spend it wisely.” It’s time for us to heed that advice and focus our efforts on our FS-to-energy businesses.

The hardest part about suspending our aquaculture business is that we still have a lot of belief in its potential as a profitable waste-based business. I’m reminded of the words of Steve Jobs who said, “I’m as proud of what we don’t do as I am of what we do.” We’re proud of the advances we made with our aquaculture work and our aquaculture business model, and will be very proud to see others pick up where we left off.

Our local research partners at the Kwame Nkrumah University of Science and Technology and at the International Water Management Institute have plans to continue research trials at the site. We’re also very happy to share all that we’ve learned with anyone who would like to start wastewater-fed aquaculture in Ghana or elsewhere. Please get in touch if you have any questions!

August 8, 2012

Six weeks in Boulder, CO culminate with the Unreasonable Climax!

Remember back in January when we begged you all to help us raise $10,000 in order to win a spot at the Unreasonable Institute? Well, that we did thanks to your help, and just a couple of weeks ago our six weeks at the Institute came to a close.

It was six weeks of living on pure adrenaline; of living in close quarters with 21 other entrepreneurs (as in triple-bunk rooms in a rented Fraternity house); of intense coaching, mentorship, and feedback; of due diligence sessions with investors; and of presenting our GreenHeat business model.

The biggest event was the Unreasonable Climax, attended by nearly 800 people from the Boulder community and beyond. Watch Ashley’s presentation here.

Unreasonable Climax 2012: Ashley Murray – Waste Enterprisers Ltd. from Unreasonable Institute on Vimeo.