Off-Grid, Solar-Powered, Zero-Battery Refrigerator

Joey Hess has designed, built and tested an off-grid, solar powered fridge, with no battery bank. Using an inexpensive chest freezer with a few modifications, the fridge retains cold overnight and through rainy periods. The set-up consists of a standard chest freezer, an added thermal mass, an inverter, and computer control. He writes: [Read more…]

Amish Hand-Demolish Building in Tennessee

Who to call when you need your building “hand-demolished”? To the general public, “Amish” often equates to handcrafted – meaning hand-milked cows, handmade quilts, hand-built furniture, and the like (whether that perception is always accurate is another question).

And in that spirit, one Tennessee city found that an Amish hands-on approach was exactly what they needed to remove a historic structure. The Clarksville Leaf-Chronicle reports that an Amish crew of workers has been deconstructing the city’s 140-year-old Hodgson/Dabbs building, brick-by-brick.

Read more: Amish Hand-Demolish Building in Tennessee, Amish America, June 27, 2019. Image by Henry Taylor for the Leaf Chronicle.

“Daylight Drive” DC Solar Power at the Living Energy Farm

Reader Goran Christiansson sends us a link to Living Energy Farm, a research and community project in Virginia, USA. Most notable is their use of “Daylight Drive” DC solar power without batteries for workshop tools — reminiscent of the ideas outlined in How to run the economy on the weather. Also of note is their choice for less efficient but more durable Nickel Iron batteries for lighting. [Read more…]

“Diseconomies of Scale”: High-tech Versus Low-tech Supply of Eggs

Summarized from [paywall]: Trainer, T., A. Malik, and M. Lenzen. “A Comparison Between the Monetary, Resource and Energy Costs of the Conventional Industrial Supply Path and the “Simpler Way” Path for the Supply of Eggs.” Biophysical Economics and Resource Quality 4.3 (2019): 9.

Traditional housing for chickens in Zembe, Mozambique. By Ton Rulkens – Traditional housing 2, CC BY-SA 2.0.

Global sustainability requires large-scale reductions in rich world per capita resource use rates. Globalised, industrialised and commercialised supply paths involve high resource, energy, dollar and other costs. However, “The Simpler Way” involving small-scale integrated localised settlements and economies can enable enormous reductions in these costs. This study uses input–output analysis of one product, eggs, to illustrate how big the difference between the two paths can be. [Read more…]

The Morrison Shelter

In the UK during World War Two, due to the lack of house cellars it was necessary to develop an effective type of indoor shelter. The Morrison shelter, officially termed Table (Morrison) Indoor Shelter, had a cage-like construction beneath it, and was designed to be able to withstand the upper floor falling, of a typical two story-house undergoing a partial collapse. [Read more…]

Evaporative Air Conditioning

Evaporative coolers have been known to purveyors of low-cost, sustainable technologies for years. Without the need for electricity, these cold containers have kept produce fresh from farms to tables, protecting against post-harvest losses in the field and food spoilage in hot pantries worldwide.

Now the concept has been applied to air conditioning. Manoj Patel Design Studio in Vadodara, Gujarat (India) has built evaporative air conditioners that can cool a room for days on a single tank of water. The studio designs new products from recycled materials, and they built their air conditioners from ceramics and stone, integrating them with potted plants. By filling rows of ceramic tubes with water, the prototypes maximize their surface area for optimal evaporation while retaining a small footprint.

Read more: This Air Conditioner for Homes and Offices Uses No Electricity, Engineering for Change. Previously: How to keep beverages cool outside the refrigerator: the botijo.