Ecojustice – Page 7 – Yet Another Unitarian Universalist

Concrete block rocket stove

This past Sunday, the middle school ecojustice Sunday school class cooked on rocket stoves. We based our stoves on design principles developed by Dr. Larry Winiarski, who is affiliated with the Aprovecho Research Center. A rocket stove makes more efficient use of biomass fuels (wood, twigs) through more complete combustion; this also results in fewer harmful emissions. According to the Aprovecho Research Center:

“Improved cooking stoves address at least 5 of the 8 United Nations’ Millennium Development Goals: [1] ending poverty and hunger; [2] gender equity; [3] child health; [4] maternal health; and [5] environmental sustainability.”

So while we don’t really need rocket stoves here in the Bay area (except perhaps in disaster situations), learning about and building them is a great introduction to using appropriate technology to meet ecojustice goals of human well being and environmental sustainability.

If you’re not familiar with rocket stove design principles,Aprovecho Research Center has an excellent introduction on this Web page. Scroll down and click on document no. 8, “Design Principles for Wood Burning Cook Stoves,” June, 2005.

Enough background. Here are instructions for building a concrete block rocket stove, followed by photos of our rocket stove in action:

Click the image above for a drawing of how to build our concrete block rocket stove. You will find other plans for a concrete block rocket stove on the Web, but those plans typically require a concrete h-block, an oddball type of block that we were unable to find. However, most bit home improvement stores carry 8 x 2 x 16 inch concrete cap blocks, and 4 x 2 x 8 inch concrete brick — two cap blocks and two concrete brick can be arranged in an “H” shape to make a stove. In fact, this is a better solution than a concrete H-block, because you can adjust the concrete brick such that you have a constant cross-sectional area throughout the L-shaped combustion chamber (see “Design Principles for Wood Burning Cook Stoves,” principle 7).

BlogJan2715c

Above: The concrete block rocket stove after use. We placed two concrete bricks on the top on which to place cooking implements, etc. The bottom concrete block serves as a convenient place to store fire wood. Notice that our firewood is all salvaged building materials and wood pallets, split to appropriate size for burning.

BlogJan2715b

Above: Cooking on the stove. “Design Principles for Wood Burning Cook Stoves” states that a combustion chamber with a 12 x 12 cm cross sectional area is “usually sufficient for a family sized cooking stove.” Our concrete block rocket stove has a cross sectional area of 12.5 x 15 cm. It put out a good amount of heat for cooking scrambled eggs for half a dozen people. Note that one person is feeding the fuel into the stove, while the other cooks — we found it was challenging to cook and tend the fire at the same time.

We did not try to boil water on our concrete block rocket stove, to see how long that would take. Maybe that’s a task for a future class.

Update, one year on: This has proved to be a good, but not excellent, rocket stove design. The chief problem with this design is that the concrete block acts as a fairly large thermal mass, and it takes a while to heat the block. Once the block is warm, the stove functions pretty efficiently; while the block is still cook, it’s not as good. Another problem is that the stove is finicky, and requires constant attention to feeding fuel in order to maintain a fairly constant temperature. Nevertheless, given the low cost of materials, and the ease of construction, this remains a practical design.

16 brick rocket stove

In our middle school ecojustice class, one of the things we’re doing is experimenting with alternative low-cost, low-impact cooking methods, such as a solar oven made out of cardboard. Now we’re experimenting with rocket stoves, designed originally by Dr. Larry Winiarski and colleagues at the Aprovecho Research Center. Rocket stoves use biomass to cook, but are much more efficient than traditional cooking fires, and because they’re more efficient produce fewer pollutants such as smoke and harmful gasses. Not really something we need in the first world, except in disaster situations, but a huge advance for the developing world.

Last week in class, we put together a simple brick rocket stove but couldn’t get it to light. So I spent some time this week building and using a simple rocket stove made of 16 bricks. This stove is based on Larry Winiarski’s 16 brick stove, but instead of using adobe bricks I used clay bricks commonly available at masonry supply houses and building supply centers. Specifically, I used nominal fifteen 8 x 2-1/4 x 4 inch clay bricks, and one 8 x 1 x 4 inch clay brick, as shown in the sketch below:

For fuel, I split an 18 inch long 2 x 10 into finger-sized pieces. To light the stove, I balled up a piece of paper and dropped it down the center hole, dropped some shavings, small scraps of wood, and slightly larger scraps of wood on top, then dropped a lighted match in. When the fire was burning well, I began feeding 3 to 4 pieces of fuel in from the bottom, adjusting the air intake gap as needed to get a hot flame.

The rocket stove needs you to pay attention to it. The fuel burns pretty quickly, and you have to keep pushing it into the combustion chamber, adding new fuel as needed. Once the fire was going strong — which took seven or eight minutes — I got ready to cook.

BlogJan1515

Continue reading “16 brick rocket stove”

REA: Ecology and RE

In a Sunday morning colloquium at the Religious Education Association 2014 conference, Miriam Martin of Saint Paul University in Ottawa spoke on the subject “Ecology, Christian Discipleship and the Role of RE.”

When considering environmental problems such as global climate change, Martin said, “We have to recognize that a situation of violence exists.” To unmake violence, she added, first we have to acknowledge “the situation of violence.”

“Violence against against nature is basically predicated on the fact that we have such a deep separation from it and a false sense of disconnect,” Martin said. Just as we justify human violence against other humans by demonizing the “other,” so too human violence against other beings is justified by thinking of other organisms as the “other.”

Therefore, Martin said, we humans must look at ourselves and ask: Who do we say we are? Citing such thinkers as Sallie McFague (A New Climate for Theology, 2008), Elizabeth Johnson (Ask the Beasts, 2014), and Francois Euve (“Humanity Reveals the World,” in Ilia Delio, ed., From Teilhard to Omega, 2014), Martin called for a new theological anthropology.

In thinking about a theological anthropology, Martin reflected on the uniqueness of humankind. The unique ability of human beings to reflect on the whole emergence of the universe story comes with a great responsibility. “Humans are the uniquely responsible animals,” she said.

She came at the issue of responsibility from another angle, turning to recent work by religious Gabriel Moran, who asks: Are humans superior? Moran asserts that we cannot understand differences at higher or lower levels. Moran says there is one place where humans are superior, and that is “we are uniquely responsible.”

In terms of specifically Christian religious education, Martin referred to Sallie McFague, who says we cannot continue to “live in a way that consumes the world’s resources and undermines its most basic systems.” Thus, said Martin, there is not a separation between the damage being done to the poor, and the damage being done to the environment.

So what do we need to do? Martin said that Elizabeth Johnsons’ recent work offers a solution: “[Theology] needs to reclaim the natural world as an essential element both theologically and in practice.” Then, Martin said, we must bring these rigorous theological conversations into wider interdisciplinary dialogue. Finally, as theology reclaims the natural world, this can be brought out through ritual and through the arts. As a partial demonstration of this, Martin closed her presentation by singing one of her songs on the relationship between humankind and the natural world.

Adventures in solar cooking

Yesterday in Sunday school, two groups of kids started making solar ovens. While they were working, we had solar s’mores cooking in the solar oven I made on Saturday. However, it took a long time for the solar s’mores to cook. First problem: the morning clouds didn’t begin to clear until halfway through Sunday school. Second problem: thin clouds persisted most of the morning, and even the thinnest of clouds caused the temperature to drop at least ten degrees inside the oven. We started cooking the s’mores at about 10:00, and they weren’t really done until just before noon — after most of the kids had already gone home.

The clouds finally cleared away completely, and I left the solar oven outside my office for several hours in the early afternoon. The inside temperature rose to over 200 degrees Fahrenheit (200 degrees is as high as the meat thermometer goes), with outside air temperature in the high 70s. I heated up a mug of water, to over 170 degrees, and made a nice cup of tea. While I was making tea, Fred Z., from the Green Sanctuary Committee, stopped by and suggested trying cast iron cookware in the oven — it’s dark and absorbs heat well, plus it provides a good thermal mass to even out cooking temperature.

So this morning I dug out a small cast iron frying pan, and decided to try cooking a fried egg in the solar oven. The air temperature was about 65 degrees, but in spite of clear skies I couldn’t get the inside temperature over 190 degrees — which suggests I need better insulation in the oven. I cooked a fried egg, over easy:

BlogSep0814

It took about twenty minutes, and was really more of an egg baked in butter than it was a fried egg (it tasted good, though); obviously there is a lot more to be done to improve the efficiency of the oven.

Solar oven prototype

Tomorrow, the middle school ecojustice class in Sunday school is going to make solar ovens. So of course I had to make a prototype:

BlogSep0614

I started with a basic design made out of carboard boxes, a design that is sometimes called the “Minimum Solar Box Cooker.” But instead of just nesting one smaller box inside another box, I took the smaller box, cut out the ends, and turned it 45 degrees:

While this reduces the amount of cooking space inside the oven, it also reduces the amount of air that has to be heated. And then, too, it’s easy to run a couple of dowels through the inner box to make a support for a cooking pot.

In preliminary tests, the oven worked reasonably well. I set the oven out at 2:45 p.m., stuck a meat thermometer in one end of the oven, and within twenty minutes, the thermometer was reading between 190 and 200 degrees F. (the thermometer only goes up to 200). At about 3:10, I put in a cup of water in a glass container. By 3:40, the water temperature was 155 degrees F., and the glass container was more like 190 degrees F. (Air temperature is 75 degrees F. this afternoon.)

Tomorrow comes the real test: we’ll set the oven out at the beginning of Sunday school and see how quickly we can make solar s’mores.

Update, one year on: This solar oven prototype proved to be only marginally effective. After using it fairly extensively, it has one big problem: when you open the lid, much of the hot air escapes; there is very little thermal mass, aside from the heated air. At the very least, I need to provide a significant thermal mass (preferably black in color, to better absorb heat). In addition, it would make sense to place the door low on one side of the oven, to minimize the loss of heated air.

Pee on Earth Day 2014

Pee on Earth Day is an annual holiday designed to remind us that we are an integral part of the water cycle. Pee on Earth Day is celebrated on the first day of summer (June 21 for the northern hemisphere), since it is likely to be warmest then, and we don’t want to freeze any delicate bits.

I just celebrated Pee on Earth Day. It is somewhat challenging to do so in an urban setting. Let’s just say I waited until dark, and now there is a very happy plum tree.

Sutra

The headlines on today’s newspaper screamed: “U.S.CLIMATE HAS ALREADY CHANGED, STUDY FINDS, CITING HEAT AND FLOODS” [New York Times, 7 May 2014, p. A1]. This is news because we didn’t already know what this report, the National Climate Assessment, is telling us. A related story tells us that “Polls Find Americans Skeptical On Climate” [ibid., p. A13]. And why? “Scientists predict that climate change will cause larger problems for poor countries than rich ones….” And the U.S. is way ahead of all other countries in per person emissions of climate-changing gasses.

Smokey the Bear This is human nature: the ones who are causing the problem are least likely to be affected by the problem, so they believe they are not causing the problem. The minority of U.S. citizens who are aware of the magnitude of the problem attempt to convince other U.S. citizens of the truth with rational arguments, but since when did humans change their behavior as a result of rational argument?

No, it is time to call on a higher power. One of the growing problems caused by climate change is the increased incidence of forest fires, and so we immediately know on whom we must call. We will follow the example set by poet Gary Snyder in 1969. Both Buddhists and non-Buddhists, both those who follow the circumpolar Bear cult and those who don’t, should call on the Boddhisattva of Compassion Avalokitesvara — who is also Kamui Kimun of the Ainu — who is also a consort of She Who Saves, Boddhisattva Tara, Mother of Liberation — who is he who carries the vajra-shovel.

Abandon rational argument, and chant together:

Smokey the Bear Sutra

Once in the Jurassic, about 150 million years ago, the Great Sun Buddha in this corner of the Infinite Void gave a Discourse to all the assembled elements and energies: to the standing beings, the walking beings, the flying beings, and the sitting beings—even grasses, to the number of thirteen billions, each one born from a seed—assembled there: a Discourse concerning Enlightenment on the planet Earth.

“In some future time, there will be a continent called America. It will have great centers of power called such as Pyramid Lake, Walden Pond, Mt. Rainier, Big Sur, Everglades, and so forth, and powerful nerves and channels such as Columbia River, Mississippi River, and Grand Canyon. The human race in that era will get into troubles all over its head, and practically wreck everything in spite of its own strong intelligent Buddha-nature.”

“The twisting strata of the great mountains and the pulsings of volcanoes are my love burning deep in the earth. My obstinate compassion is schist and basalt and granite, to be mountains, to bring down the rain. In that future American Era I shall enter a new form, to cure the world of loveless knowledge that seeks with blind hunger, and mindless rage eating food that will not fill it.”

And he showed himself in his true form of

SMOKEY THE BEAR.

Continue reading “Sutra”