Appropriate Technology

Our rocket stove, pictured above, was mentioned on BoingBoing last week and we thought we’d use the occasion for a brief roundup of similar “appropriate” technology concepts. The term appropriate technology evolved out of political economist E. F. Schumacher’s book Small is Beautiful and is easier to show rather than describe. While not always low-tech, appropriate tech concepts feature elegantly simple (but not simplistic) design, efficient use of energy and are usually aimed at poor countries. What Homegrown Evolution would like to prove is that these technologies have a place in developed western countries as well. Here’s three of our favorite appropriate tech ideas and websites:

1. Rocket Stoves: our brick rocket stove and a link to a video on how to make a simple metal version.

2. The glorious Solar Cooking Archive which has links to dozens of simple solar cooker plans that you can build yourself. We built our cardboard and aluminum foil Pavarti cooker with plans from the solar cooking archive.

3. AfriGadget. The subtitle of this blog says it all, “solving everyday problems with African ingenuity.”

Rainwater Harvesting with Joe Linton

With the driest spring on record here in Los Angeles, water and where to get it ought to be on all of our minds in this drought prone metropolis. Thankfully, artist, author, Los Angeles River expert and co-founder of the Los Angeles County Bicycle Coalition Joe Linton will be teaching a workshop on rainwater harvesting at the Los Angeles Eco-Village on Saturday, June 14, 2008 from 9 am to 3 pm at L.A. Eco-Village (Directions)

Here’s a description of the workshop from the Eco-Village’s website.

This workshop is part of a continuing series in “hands-on” urban permaculture and includes:

  • An overview presentation on Los Angeles water issues, including local multi-benefit watershed management efforts.
  • A tour of Los Angeles Eco-Village stormwater harvesting landscape features, including the Bimini Slough Nature Park.
  • A hands-on workshop to build terraced swales to detain and infiltrate storm water
  • This workshop focuses on building earthworks that gather and infiltrate rainwater in the landscape. It does not cover rainwater harvesting with cisterns, which we anticipate will be the subject of a future hands-on permaculture workshop, hopefully in early fall 2008. Watch for details.

Fee: $35 (sliding scale available) – bring a bag lunch.
Registration required: 213/738-1254 or [email protected] (workshop size limited)

About Joe Linton
Joe is an artist and urban environmental activist. He’s been involved for many years in efforts to restore and revitalize the Los Angeles River, including writing and illustrating the guide book Down By The Los Angeles River (Wilderness Press 2005). Joe is a long-time resident member of Los Angeles Eco-Village and a co-founder of the LA County Bicycle Coalition.

Cooling with Beer . . . Cans

Root Simple dropped by Houston’s famous Beer Can House, created by John Milkovisch in the 1960s and 70s. We won’t plumb the messy depths of the meaning of “visionary art”, the academic art Mafia’s euphemism du jour for this stuff–we’ll leave that to our art bloggin’ amigo Doug Harvey.

So sidestepping the whole debate over the intentions of its creator, we’ll point out that all of Milkovisch’s house mods have both aesthetic and practical benefits. The beer can cladding that covers the entire exterior of the house means never having to paint the underlying wood. The concrete yard means never having to mow a lawn (we’d prefer vegetation but Milkovisch’s concrete work is, like the rest of the house, magical).

But on to our favorite detail. It’s damn hot in Houston most of the year, and to deal with the blazing sun on the south side of his humble bungalow, Milkovisch crafted this intricate, shimmering screen made of beer can tops and bottoms that hangs from the roof line like an aluminum grass skirt. Not only does it shade the windows and walls, producing a dramatic decrease in cooling bills, but it also functions as a pleasing wind chime.

We’ve been thinking of doing something similar on the hot south side of our house, except with deciduous vines. That way, we’ll let light in during the winter and have a living shade wall during the summer. Perhaps we’ll grow beans and become Los Angeles’ Bean House.

The Beer can house is located at 222 Malone Street in Houston, Texas and is lovingly cared for by the Orange Show Center for Visionary Art.

A Parvati Solar Cooker

Damn, is solar cooking easy! Put some rice in a pot, place the pot in this simple panel cooker, made with cardboard and aluminum foil, stick it out in the sun and two hours later you have lunch.

We built our “Parvati” solar cooker with plans designed by Shobha Ravindra Pardeshi that can be found here. Pardeshi, who runs an “appropriate technology” company with her husband in India has another design for a similar dish-shaped cooker here. We found both of these cookers (and many more) via the amazing Solar Cooking Archive.

For the Parvati cooker, we cut the cardboard according to the plans, and affixed the aluminum foil with spray glue. For our first pot of rice we used a black enamel pot to better absorb the heat of the sun’s rays, and wrapped it in a roasting bag to increase the efficiency of the cooker. A five gallon bucket made a convenient stand and did not have to be rotated in the two hours it took to cook the rice. Longer cooking times would require re-aiming the cooker as the sun moves across the sky. Temperature in the pot quickly went over 180º F, the point at which food begins to cook. The two hour cooking time is much longer than it would take on a conventional stove, but with a solar cooker there is no danger of burning, making the process, in our opinion, easier than stove-top cooking. Consider a solar cooker a kind of low-powered crock pot for lazy and cheap people–good for things like rice, beans, soups and stews, but not good for sauteing. Just remember the oven mitts–this thing gets hot!

When the sun gets higher in the sky, as we move into summer, this cooker will reach even higher temperatures. We don’t remember where we read this but some folks say that panel cookers like this one cook best when your shadow is shorter than you are which, here in Los Angeles, is right about now. We tried this cooker back in January and it performed well, but did not get above 140º F, which is not hot enough to cook.

Perhaps here around the Root Simple compound we’ll get around to turning our Parvati Solar Cooker into a low rent attraction. Just add some ostriches and we’ll repeat this early 20th century tourist trap in nearby Pasadena (click to biggify):

Planting a Mini-Orchard

Ignore the bucket in this illustration! See update below.

Update 3/13/2011: I met Brad Lancaster last night and he told me that he and Art Ludwig no longer use the upside down bucket described in this post. The reason is that detergents can build up in the hole. In my experience the bucket was also an unnecessary step. While I have a clay soil, the hillside drains fairly well. A properly sized mulch basin should suffice to allow greywater to infiltrate. Also, the new generation of washing machines use a lot less water than the old one that I still have. Other than the unnecessary bucket and the persimmon tree (died, for some unknown reason) this greywater application has worked very well. Our fruit trees are lush and happy.

With the news that Lake Mead could go dry by 2013 we figured it was about time to figure out how to grow food with very little water in a Mediterranean climate that gets on average 15 inches of rain a year (3 inches last year). Our water worries sparked the beginnings of our draught tolerant mini-orchard. Thankfully greywater and some tough, water sipping trees make it possible.

Step one was figuring out how to reuse our washing machine water (read our earlier post on the washing machine surge tank we built). Step two was matching that washing machine water output to the right kinds of plants for the mini-orchard. We settled on the three “Ps” — pomegranate, persimmon, and pineapple guava, plus a mission fig tree to replace the substandard one we cut down (even though God Hates Figs!). The advantage with these four trees is that they can survive, once established, should we find ourselves unable to use any water due to the aforementioned bad-ass draught scenarios.

Our house sits on a small hill, with the front yard sloping down towards the street. We placed the trees at the top of the slope and made mulch basins like the one illustrated above. The outlet chamber consists of a upside down three gallon bucket with a bunch of holes punched in it. The purpose of the outlet chamber, which is buried in the mulch basin, is to help the greywater infiltrate our heavy clay soil. To use it we simply place the hose coming from the surge tank into the hole in the top of the outlet chamber. We cover this hole with a brick when not in use. The photo below shows the digging of the mulch basin and the installation of the outlet chamber in progress:

The completed mulch basin and (hard to see) pomegranate tree to the right. We used straw for mulch We use wood chips for mulch (replaced the straw):
These craptacular photos don’t show the details very well, but the mulch basins were dug in such a way to also catch rainwater as it flows down the hill. Both rainwater and greywater work their way into the soil and slowly move down the hill over the course of many months. Since installing the greywater system we’ve seen previously sad plantings we did years ago of rosemary, wormwood and Mexican sage thrive. And we’ve got lots of nopalitos coming our way from the prickly pear plants.

For more information on these simple, water saving strategies see Brad Lancaster’s excellent book Rainwater Harvesting for Drylands.

Greywater Linkage

Outlaw water activists the Greywater Guerillas have added a nice set of examples to their website showing some creative greywater strategies. As figuring out how to get greywater out to your garden depends a lot on, say, if your shower is higher than your bamboo grove, it’s great to see some real world examples.
Next step around our little crackhouse will be to figure out how to reuse our shower water. The GGs have given us some ideas . . .

Using Greywater from your Washing Machine

With our current bad drought conditions it makes no sense to pour perfectly good water down the sewer. So we just joined the greywater underground with our illegal washing machine surge tank, and the installation was a piece of cake.

We built our washing machine surge tank based on the design in Art Ludwig’s book Create an Oasis with Greywater. The purpose of the surge tank is to prevent the built-in pump in the washing machine from burning out, which might happen if you tried to pump the water through pipes. The tank also slows down the flow of water going out to the garden, allowing more time for it to percolate into the soil. In addition the tank lets the water cool a bit, should we run a load in hot water.

Bottom of barrel showing fittings

Top of the barrel where the hose from the washing machine comes in

For the tank we picked up a used and cleaned 55 gallon plastic drum with two “bung holes”, and plumbed it based on a design from Aquabarrel.com. The folks at Aquabarrel offer kits or a DIY video. We put our barrel together ourselves with a couple of common pvc fittings from the hardware store and omitted the overflow pipe, since our washing machine load will never exceed 55 gallons. The basic idea behind the Aquabarrel design is to turn the barrel upside down and use the preexisting threaded bung holes to connect up a garden hose. It took just a few minutes to complete, and our washing machine surge tank was ready to use. We highly recommend the Aquabarrel design, and you could combine a washing machine surge tank with a rain barrel with the addition of the overflow pipe and a fitting for the gutter.

When we do a load of laundry the waste water that collects in the barrel flows immediately out the garden hose and down towards the front slope of our little compound. Ludwig warns against keeping grewater around as it will quickly turn septic. We use Oasis Biocompatible detergent which is manufactured specifically for greywater systems. Regular “eco” detergents, while not harmful to aquatic plants, often contain substances that will kill terrestrial plants so you must use a greywater specific detergent.

Our next step will be to figure out some plantings that will take advantage of our laundry schedule, and to construct some simple earthworks and mulch basins to accommodate the water flow. Right now we just let the water percolate into the front slope, and our rosemary and Mexican sage look a lot healthier for it.

Our Rocket Stove

 
  • Editor’s note: we have a new design for a portable rocket stove here.

Low-tech is the new high-tech, and the best example of the low-tech revolution is the miraculous rocket stove–a stove that makes it possible to cook with small twigs–no logs needed! Best of all rocket stoves are easy to build. We liked the idea so much that we decided to build a permanent one just off our back deck for entertaining and as a backup to our gas stove should an emergency take out our utilities.

The rocket stove was developed for use in poor nations where wood used for cooking has led to the vast, wholesale, deforestation of large swaths of the earth’s surface. Rocket stoves can be built out of metal or masonry and consist of a L shaped tube, at the bottom of which you place your wood. The chimney effect creates a highly efficient, largely smoke-free burn. There’s no need to cut down a tree to cook your dinner–all you need is a few small branches or twigs.

Before we built the rocket stove we considered making a cob oven, a mud domed wood fired oven in which you can cook bread and pizza. There’s a trend in the eco-world to build cob ovens and we felt a certain pressure to keep up with the eco-Joneses. We started to build the base for one and then began to think about how often we would actually build a fire, especially considering that it has to burn for several hours before a cob oven gets hot enough to cook in. Also, where would we get the logs? And how good is it to burn such a fire and contribute to Los Angeles’ already smog choked air?

Staring at the bricks we had scavenged to build the base of cob oven, we realized that we could re-purpose them for a permanent backyard rocket stove that we would actually use. Furthermore we realized that our rocket stove could burn some of the palm fronds that regularly tumble down from the iconic palm trees that line our old L.A. street.

Here’s the materials we used:

36 bricks
4-inch galvanized steel stove pipe elbow
4-inch stove pipe
ash (scavenged from park BBQs)
1 tin can
50 pound bag of premixed concrete for the base
mortar mix
grill (scavenged)

The first step was to make a small foundation for the rocket stove. We fashioned a 18 by 18-inch by 4-inch slab with 2 x 4 lumber and a bag of premixed cement. Folks in cold places will need to make a deeper foundation to avoid frost heave.

Next we built a brick cube, leaving a small hole for the bottom of the stovepipe. For advice on how to build with brick we recommend taking a look at this. As you can see our masonry could use some more practice, but the results are not too bad–we like to think of our stove as being a bit “rustic”. You can avoid the hassle of brickwork by making a simpler rocket stove–check out these two instructional videos, one for a metal model, and another version using bricks. We chose brick largely for aesthetic reasons and we’re satisfied with the results.

Drawing from Capturing Heat

The next step is to put the pipe together fitting the elbow up into the longer pipe, and sized so that the top of the pipe is just below the bottom of the grill. Check out our earlier post for a video that can help with this part of the assembly. Serendipitously, on a bike ride, we found a grill in the middle of Sunset Boulevard that fit the opening in our brick rocket stove exactly.

You pour the ash into the completed brick cube to fill the space between the pipe and the inside wall. The ash acts as insulation to increase the efficiency of the stove. You could also use vermiculite but note that sand or soil will not work. Insulation works because of small pockets of air between particles, hence the need for ash or vermiculite, which are also non-combustible. We used a piece of scrap sheet metal with a 4-inch circular hole cut in it to keep the ash from spilling out the gap between the pipe and the squarish opening at the bottom.

Lastly you use a tin can sliced down the side and flattened out to form a shelf which you insert into the elbow at the bottom of the stove. Note the drawing above for the shape of the shelf. You put your twigs and kindling on this shelf and start the stove up with newspaper underneath the shelf. As the twigs burn you push them in over the edge to keep the fire going.

Our first test run of the stove was very successful–we boiled a pot of water and cooked some eggs in a a pan. The fire burned cleanly with little smoke except during start up. For more info on rocket stoves check out the Aprovecho Research Center.

And please people don’t burn wood inside and watch out for embers. Make sure you put the fire out completely when you are done cooking!

Plantain!

Homegrown Revolution neighbors Annelise and Eric intercepted us on our nightly dog walk and not only invited us up to their front porch for a glass of wine, but also sent us away with a couple of plantains harvested from their next door neighbor’s tree. It’s exactly what we’d like to see more of–folks growing food instead of lawns and everyone sharing the abundance.

While there’s a lot of banana trees in Los Angeles they tend not to yield edible fruit since our climate is not quite hot and humid enough. But plantains, judging from the delicious taste of the ones we fried up, are a different story. They do require a lot of water to grow, but greywater expert Art Ludwig calls bananas (the same family as plantain) “the premiere plant for greywater in warm climates”. You can bet that as soon as the building inspectors sign off and leave the scene of our newly retrofitted foundation at our crumbling 1920s vintage compound we’re going to try to figure out a way to route the shower drain out to a new mini-grove of plantain.

We’ll be our own banana republic and do the world a favor considering the amount of blood that has been spilled bringing bananas to North America. Witness Chiquita’s recent admission to teaming up with right wing terrorist groups in Columbia.

In the meantime, for the Homegrown Revolution readers out there in warm climates here’s the lowdown on growing bananas and plantain.

Rainwater Harvesting for Drylands


“The bricoleur, says Levi-Strauss, is someone who uses “the means at hand,” that is, the instruments he finds at his disposition around him, those which are already there, which had not been especially conceived with an eye to the operation for which they are to be used and to which one tries by trial and error to adapt them, not hesitating to change them whenever it appears necessary, or to try several of them at once, even if their form and their origin are heterogeneous.”

-Jacques Derrida

Homegrown Revolution loves cheap low-tech solutions (not to mention pretentious quotes), which is why we especially like “bricoleur” and Tucson rainwater harvesting guru Brad Lancaster and his ongoing book series Rainwater Harvesting for Drylands. Volume one is already out and volume two is due out this summer. Landcaster’s ingenious methods involve little more than careful observation and some work with a shovel. He suggests that harvesting rainwater begins with considering the flow of water from the highest point (which for most people will be the roof) to the lowest point in your yard and then simply figuring out simple ways to get that water to percolate into the ground to nourish your plants.

We’re especially fond of his method of hijacking street gutter runoff and directing it with a small improvised check dam into a dug out basin in the parkway. We’ve watched our neighbor’s lawn watering runoff for years and wondered if we could find a way to use that water. You can watch two videos showing Lancaster at work here. And a podcast here.