Earthen Solar Cooker

earthen solar cooker

“The Earthern Solar Cooker is a large parabolicly shaped hole in the ground lined with reflective materials such as salvaged pieces of broken mirrors or reflective can lids. The mirrors reflect and concentrate sunlight to the base of the hole where ten one gallon black containers of water can be boiled per hour and used for drinking or food preparation. Cooking/water boiling containers are accessed via steps carved into the side of the Earthen Solar Cooker.”

“A 2.5m diameter hole, 1.5m deep cooks 10 gal of rice/hr from 11am to 3pm on an 85f summer day in south central Oregon. Since the power of a parabolic concentrator is proportional to the surface area of it’s aperature (A = 3.14 x r^2), doubling the radius of the hole increases the power of the Earthen Solar Cooker by a factor of four.”

“An Earthen Solar Concentrator the size of a small amphitheater might be capable of casting bronze or boiling the water near the surface of a shallow well located at the vertex, thus making possible the creation of a solar bubble pump that could lift pasteurized water to a tank above ground level.” Read more about the project at Appropedia.

Previously:

“Gravity Powered” Lights (and How to Make Them More Powerful)

gravity powered lights

The GravityLight uses a sack of sand or stones to gradually pull a piece of rope through a dynamo mechanism which generates electricity to power an LED. It is a cheaper and more sustainable option than a solar powered light, which requires not only a solar panel but also a battery. The product is aimed at the developing world and its makers raised 400,000 dollars at indiegogo.

The technology could be further improved by including pulley mechanisms that were used to operate human powered cranes and lifting devices in pre-industrial times. This would allow a person to lift heavier weights and thus power more powerful lights.

To be precise, the light is not powered by gravity. It is muscle-powered, while gravity stores the energy and fulfills the role of a battery. Hat tip to Bernd Vleugels.

Cargo Cycle for Egg Deliveries

cargo cycle for egg deliveriesThe Pashley Model CT2 is described as “a really handsome, well built and strong light delivery vehicle for confectioners, egg deliveries, grocers, accumulator stations, etc.”

Found at the Museum of Tradesman’s Delivery Bikes, which has a collection of (mostly) English cargo bicycles dating from 1905 to 1982. This is one of the few tricycles on the blog.

Related: Tandem Cargo Tricycle (1940) & More Vintage Dutch Carrier Bikes.

 

The Fastest Sailboat in the World

fastest sailboat in the world

The Sailrocket, a sailing boat that we have talked about before, is the fastest craft under sail, after breaking the 2010 record held by a kiteboarder.

During the last run in Namibia in November 2012, an improved version of this unconventional boat reached an average speed of 65.45 knots (121.21 km/h or 75.31 mph) over a distance of 500 meters. Earlier this year it set speed records of 59.23 and 59.37 knots.

Record sailing speeds have almost tripled since the beginning of the 1970s. Those who think that sailboats are a technology from the past, think again.

See and read more at YachtPals and Sailrocket.

Straw Bale Gardening

straw bale gardening

“Straw Bale Gardening is simply a different type of container gardening. The main difference is that the container is the straw bale itself and is held together with two or three strings.”

“Once the straw inside the bale begins to decay the straw becomes ‘conditioned’ compost that creates an extraordinary plant rooting environment. Getting the straw bales conditioned is an essential part of the process, and should be started two weeks prior to your target planting date wherever you are located.”

“This gardening technique works well anywhere in the country or the world for that matter.” Read more: here and here.

Light Your Organic Tobacco in a Sustainable Way

light your tobacco in a sustainable way

The Solar Spark Lighter is a pocket-size solar firestarter and lighter. It is a stainless steel parabolic mirror, like the one used to light the Olympic torch. It is designed to focus the sun’s radiant energy to a precise focal point that can reach hundreds of degrees. Just point it at the sun and it lights in seconds. Measures about 4.5″ diameter.