Solar Wood Drying Kiln

“Lumber is usually dried to a specific moisture content prior to further manufacturing or use. While lumber can be air-dried, the humidity in most localities prevents the lumber from reaching the moisture content required for the stability needed for interior use. The kiln discussed is designed to be inexpensive to construct and be simple to operate.”

solar wood drying kiln“The solar kiln described was designed, constructed, and tested at Virginia Tech. This design is based on 25 years of research and development on the solar drying of lumber in the United States and foreign countries. Drawings for two versions of this kiln are available; one for 800-1,000 bd ft and the other for 1,500-2,000 board feet of lumber. Both kilns will dry a load of lumber in approximately one month of moderately sunny weather at its location in Blacksburg, VA.”

“Drying lumber can be a complex process where accelerating drying without having quality loss often requires extensive knowledge and experience. The design of the Virginia Tech solar kiln is such that extensive knowledge, experience and control are not required. The size of the collector keeps the kiln from over-heating and causing checking and splitting of the wood. The kiln is simple to construct and utilizes a passive solar collector, four insulated walls and an insulated floor. The roof is made of clear, greenhouse rated, corrugated polyethylene.”

Virginia Tech Solar Kiln. Via Build It Solar.

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.


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.

An Engineering Exploration of Stonehenge

An Engineering Exploration of Stonehenge

The Britons worked out how the heavens move thousands of years before the Greeks started thinking about it. That is, in a nutshell, the story of engineer and author  Jonathan Morris.

His hypothesis originated from a solar renewable energy concentration system which he developed, using small fixed pieces of flat reflectors.

By chance, he discovered that the structural support of the solar energy system appears to be duplicated at Stonehenge, the enigmatic monument built 4,000 to 5,000 years ago. Every single one of the technical features required are precisely duplicated in size, height, location and orientation at Stonehenge.

Morris outlines his ideas in a novel (“The Broken Stone”) and a technical outline, available via his website: “Heavens’ Henge: A geocentric worldview“.

The Most Effective Solar Cell

Solar cell embodied energy“One can note that the carbon intensity of China at 788 g/kWh is greater than that of Canada at 184 g/kWh. (…). The most effective carbon-mitigating PV cell would be produced in Canada and sent to China. The low carbon intensity of the electric grid in Canada and corresponding low embodied carbon of the cell would combine with the high mitigation potential in China to produce an optimized mitigation technology.”

Unfortunately, it is the other way around. Solar cells are produced in China, and shipped to countries with relatively clean electric grids.

The quote is from: “Towards real energy economics: energy policy driven by life-cycle carbon emission“, Energy Policy 38, 2010.

Build a Solar Thermal Direct-Air Heater for $200

solar thermal direct air heater

“The town I live in is located near the Alberta-BC border, about 100 miles north of the US Canada border. Winters here are long and cold, but many days are crystal clear and sunny.”

“Our tool shed has a south-facing wall which was ideal to mount a solar thermal direct-air collector panel. The collector panel exterior dimensions are 48” high x 49.5” wide. Total budget: $200.00 Result: 16 sq ft harvest up to 6 kWh/day.”

Build a Solar-Thermal Direct-Air Heater (PDF). Introduction (and another project) here.