S.T.E.V.E.N.
Website: http://www.virtualithaca.com/francis/stevenhomepage.html
NEWSLETTER 2006
STEVEN
FOUNDATION
WORK IN 2006
This year most of our technical work consisted in our return to the STEVEN low-cost Solar House, conceived of some ten years ago in conjunction with our consulting mission to Ghana, and in particular inspired by a flight from Geneva to Accra over the enormous expanse of the Sahara. We have also continued to work with the Engineers for a Sustainable World organization at Cornell, and to respond to inquiries about the STEVEN technologies.
THE STEVEN SOLAR
HOUSE AND ITS POSSIBLE APPLICATION
The STEVEN solar house is a structure that combines lodging with solar energy generation. A concrete description and analysis of such a solar house, combining simple and inexpensive modern technologies with traditional/millennial concepts of the near-equatorial tents and pagodas, is given in Chapter 23 of Jaroslav’s UNIFIED THEORY OF SOCIAL SYSTEMS. This book can be accessed online at the following URL: http://hdl.handle.net/1813/642
The essential idea, besides low-cost work and materials, is the realization of multiple externalities. Specifically, the house energy is supplied by a simple solar collector with five simultaneous functions: 1. roof of the house; 2. a collector of solar energy for mechanical power, refrigeration, and heat provision; 3. a collector of water during periods of rain; 4. a permanent cooling effect because the inner house is always shaded by the parabolic roof which transforms the solar heat into other forms of energy; and 5. the water collection also provides for automatic washing of the reflective area.
As is shown in the book chapter referred to above, the mechanical power of the house comes from a simple steam engine. At the time of the first conception and testing, that engine was expected to consist of a simple low-pressure construction using off-the-shelf or recycled pipes, ball bearings, et cetera. Later exploration has shown that such engines tend to be not very durable, and rather inefficient.
A NEW STEAM ENGINE
DESIGN
The main endeavor of this year was to seek a more efficient and inexpensive form of transformation of solar heat into mechanical power. Of course, this could be done using photovoltaic panels, but these are rather expensive and they would dispose of the multiple-purpose of the parabolic roof collector. Efficient thermal engines are turbines but to be efficient, they must be large as in power stations, and use high pressures. Neither attribute can be fulfilled with a relatively small and simple solar house.
But there is another solution, which was the focus of our work in 2006: transformation of a small internal combustion engine into a steam engine. Specifically, we turn a roughly three horsepower four-stroke internal combustion engine into a double two-stroke steam engine. Thousands if not millions of discarded rotary lawnmowers could be used, eliminating all the carburetor and electric ignition components and keeping the rest of the engine, adapting the timing mechanism of the motor. The prototype model of such a transformation runs extremely well, can be used with relatively high steam pressures, thus increasing the [Carnot] efficiency and durability of the motor.
In our work we used a discarded lawn-mower purchased at 20 dollars. But such a new Briggs & Stratton motor can be bought in retail for below 200 dollars, and if the electrical and carburetor components are eliminated, on a large scale the cost could be reduced to some 50 dollars at most. Indeed, the more primitive transformation that we have performed could be produced directly in the factory if thousands of such solar houses were to be built for sub-Saharan and Saharan developmental communities. Alternatively, large numbers of obsolete lawnmowers could be collected through a philanthropic and ecological effort in the advanced economies of the super-Saharan world.
STEVEN Foundation collaboration with the Engineers for a Sustainable World (ESW) Chapter and engineering course at Cornell has now entered its 4th year, with Francis Vanek taking an increased role in teaching and research related to this project. Starting in August 2006, Francis has taken over as co-instructor of Civil & Environmental Engineering 492 “Engineers for a Sustainable World”, a three-credit service learning course in which students participate in one of four team service projects, ranging from water supply systems in rural Honduras to analysis of contaminants in the water at the southern end of Cayuga Lake (next to our home town of Ithaca, NY). Francis’s role in the course is to serve as a faculty liaison to the projects, which are directly overseen by an advisor (typically a professional in the related field) and a contact from a community partner organization. He also taught a number of the lectures for the lecture component of the course, which covered topics ranging from the history of solar energy to a discussion of the aftermath of Hurricane Katrina. His co-instructor for the course is Prof. Park Doing of the Science and Technology Studies program at Cornell, who attended workshops of the STEVEN Foundation in the early 1990s while a graduate student at Cornell.
Francis had a close connection to one of the team service
projects involving solar ovens. This
project is actually a continuation of a project for which STEVEN Foundation
served as a community partner, during the 2004 Fall
semester. Since that time, ESW has
developed a strong connection with “Grupo Fenix”, and NGO based at the National University of
Nicaragua in
For information about the projects, lectures, and links to slideshows, interested readers can surf to http://eswserver.cee.cornell.edu/esw/.
STATUS OF OUR SOLAR ICEMAKER
We continue to receive inquiries about the STEVEN solar
icemaker described in HOME POWER magazine 10 years ago, 6/1996. We are pleased, and certainly agree that this
is a promising and needed technology.
Intended improvements of the model are still on hold, since our lead
technician, Steven Vanek, has been occupied elsewhere—currently, doing Ph.D.
research on soil improvement in the Bolivian Andes, therefore spending a lot of
time away from home base. Let us hope
that summer 2007 will provide time for progress on the icemaker project. Those interested should communicate with us,
to be kept updated.
REFLECTIVE MYLAR FILM
STILL AVAILABLE
We have received several requests to purchase aluminized 3-M Mylar film from our excess supply. Having filled one order, we could certainly handle more, if for a modest quantity—for example, for a solar box cooker, or one solar collector. We are asking $1. per square foot of material, plus payment for shipping (typically about $4).
If interested, please contact: jv19@cornell.edu
Or telephone: 607 257 7109
Or write to the address on this newsletter. Thank you!