The Sustainability Problem of Digital Currencies

Bitcoin is back in the spotlight these days thanks to some wild price movements and central bank meetings. The decentralized currency has recently been trading over its all-time high of $1200 on some exchanges. But the higher the price goes, the more it exacerbates bitcoin’s dark side: shocking levels of electricity consumption.

In 2015, I wrote that bitcoin had a big sustainability problem. Back then, each bitcoin transaction represented roughly enough electricity to power 1.57 American households for a day— approximately 5,000 times more energy-intensive than a credit card transaction. Since it’s been two years, it’s time for an update.

Updated calculations with optimistic assumptions show that in a best-case hypothetical, each bitcoin transaction is backed by approximately 90 percent of an American household’s daily average electricity consumption. So even though that’s still about 3,994 times as energy-intensive as a credit card transaction, things could be getting better since 2015.

Unfortunately, it’s more likely that things are getting worse. A new index has recently modeled potential energy costs per transaction as high as 94 kWh, or enough electricity to power 3.17 households for a day. To put it another way, that’s almost enough energy to fully charge the battery of a Tesla Model S P100D, the world’s quickest production car, and drive it over 300 miles.

Read more: A Single Bitcoin Transaction Takes Thousands of Times More Energy Than a Credit Card Swipe, Christopher Malmo. Thanks to Renaud d’Avout d’Auerstaedt.

Hacking Consumer Electronics: The Low-tech Way

The paragraphs below are taken from “100 Deadly Skills: The SEAL Operative’s Guide to Eluding Pursuers, Evading Capture, and Surviving Any Dangerous Situation“, a book that’s not available on WikiLeaks but on Amazon. Written by a retired Navy Seal, Clint Emerson, the book describes skills “which all rely on low-tech or no-tech tools, because complicated instructions are the last thing you need when facing imminent peril”.

Skill No.55: TURN A SPEAKER INTO A MICROPHONE

“Stashing a voice-activated recording device in a target’s room or vehicle is relatively simple, but without sound amplification, such a setup is unlikely to result in audible intelligence — a proper audio-surveillance system requires amplification via microphone. In the absence of dedicated tools, however, the Nomad can leverage a cell phone, an audio jack, and a pair of headphones into an effective listening device.”

“Because microphones and speakers are essentially the same instrument, any speaker — from the earbuds on a pair of headphones to the stereo system on a television — can be turned into a microphone in a matter of minutes. The simple difference between the two is that their functions are reversed. While a speaker turns electronic signals into sound, a mic turns sound into electronic signals to be manipulated and amplified…”

“Any small recording device can be employed, but using a phone set to silent and auto answer as a listening device has two advantages: It captures intelligence in real time and does so without the operative having to execute a potentially dangerous return trip on target to collect the device…”

From: “100 Deadly Skills: The SEAL Operative’s Guide to Eluding Pursuers, Evading Capture, and Surviving Any Dangerous Situation“, Clint Emerson, 2015.

Medieval Heating System Lives on in Spain

The Meseta Central is a vast plateau in the heart of Spain with long, cold winters and short, scorching summers. The locals say that there’s “nine months of winter” and “three months of hell”. The region has little trees, so heating (and cooling) has always been a challenge.

In the early middle ages, the Castillians developed a subterranean heating system that’s a descendent of the Roman hypocaust: the “gloria”. Due to its slow rate of combustion, the gloria allowed people to use smaller fuels such as hay and twigs instead of firewood. [Read more…]

Anti-Surveillance Clothing

The use of facial recognition software for commercial purposes is becoming more common, but, as Amazon scans faces in its physical shop and Facebook searches photos of users to add tags to, those concerned about their privacy are fighting back.

Berlin-based artist and technologist Adam Harvey aims to overwhelm and confuse these systems by presenting them with thousands of false hits so they can’t tell which faces are real.

The Hyperface project involves printing patterns on to clothing or textiles, which then appear to have eyes, mouths and other features that a computer can interpret as a face.

Read more: Anti-surveillance clothing aims to hide wearers from facial recognition

Human Powered 3D Printer

human-powered-3d-printer

The Trophy is a 3D Print Machine, consisting of an Ultimaker 3D printer and a stationary bicycle to power it. Pierre-Clement Niviere designed it to make people aware of the high energy consumption of printing a 3D-object, criticising a technology that’s usually presented as an environmentally friendly way of production. The set-up also involves the maker in the creation process, raising questions about how 3D printing is changing making.

See it in action. Previously: Mechanical 3D-printer. Thanks to Pim Rooymans.

Pigeon Towers: A Low-tech Alternative to Synthetic Fertilizers

pigeon-towers-iranPhoto credit: Bekleyen, A. (2009). The dovecotes of Diyarbakır: the surviving examples of a fading tradition. The Journal of Architecture, 14(4), 451-464..

Many societies, ancient and contemporary, have innovated ways of supplying their fields with fixed nitrogen and phosphorus—two crucial ingredients for crop productivity. One is crop rotation, which alternates nitrogen-fixing and nitrogen-exhausting crops. Farmers around the world make use of chickens, ducks, and geese to add “fresh” guano to their fields. Cattle manure is another useful alternative—although it often lacks in phosphorus. Much more labor intensive than simply adding fossil-fuel derived synthetic fertilizer, these practices tend to build up soil, limit greenhouse gas emissions, and lead to less run-off into rivers, lakes, and oceans.

Persian pigeon towers are one of the more elegant solutions to the nitrogen-phosphorus problem. These are essentially castles built for thousands of wild pigeons, strategically placed in the middle of the fields. Their droppings were shoveled up once a year and sold to nearby farmers. While most pigeon towers existing today are in disrepair, the oldest still standing are dated to the 16th century (but they are assumed to have existed over 1,000 years ago) and helped fuel the cultivation of Persia’s legendary orchards, melons, and wheat production.[1] [Read more…]

Wind Power System Made from Plastic Buckets

A wind power system made from plastic buckets is seen on boats at a floating village in Hanoi, Vietnam June 29, 2016. REUTERS/Kham

A wind power system made from plastic buckets is seen on boats at a floating village in Hanoi, Vietnam June 29, 2016. REUTERS/Kham

“Vietnamese families living in slums along the Red River in Hanoi are using red plastic buckets and old printers to help light homes, cook meals and slash electricity costs by as much as a third.

The recycled goods form the blades and motors of electrical generators that power old motorcycle batteries to illuminate lamps with a brightness equivalent to a 45-Watt light bulb.

Though the output generated is small, it makes a significant difference for families previously denied power because they lived too far from a power station or had to ration supply because of the expense.”

More pictures and information at Reuters: Plastic buckets, broken printers shine light on Hanoi’s poor. Via Playground Magazine.

See all our low-tech windmill posts.

Lamella Roofs

lamella roof

A lamella roof, also known as the “Zollinger roof” (after Friedrich Zollinger), is a vaulted roof made up of simple, single prefabricated standard segments (mostly in timber) as a way to span large spaces. The individual pieces are joined together with bolts and/or plates to form a rhomboid pattern. Wooden sheathing covers the structure on the outside. The lamella roof was patented in 1910 and became popular between the World Wars, especially in Germany when metal for construction was in short supply. Some of these structures are now almost 100 years old and many of them remain in very good condition.

Read more: Lamella Roof, Open Source Ecology.

Battery Powered Rail Vehicle Claims New Efficiency Record

battery powered rail vehicle

Students from Dalarna University, Sweden, have won a competition for creating efficient rail-based transport, claiming a world record in the process. Team Eximus 1 was competing in Delsbo Electric, where teams must design and build a battery-operated railway vehicle that uses as little energy as possible. Delsbo Electric is open to college and university students. It was inspired by the Shell Eco-marathon, with the concept translated for rail-based rather than road-based travel.

Vehicles must carry between one and six passengers weighing a minimum average of 50 kg (110 lb) each. Vehicle efficiency is measured on a per person basis, meaning vehicles carrying six passengers are not at a disadvantage. The Eximus 1 carries five passengers. The vehicle is estimated to weigh about 100 kg (220 lb) and to measure about 5,500-mm (217-in) long by 1,500-mm (59-in) wide. It was powered by four 12 V, 45 Wh batteries linked together in parallel and a 500 W motor.

The team’s final efficiency score was 0.84 Wh/person-km (watt-hours for every kilometer traveled by each passenger). Delsbo Electric claims that is a new world record. “We have done research and not found any information about somebody or something traveling as efficient rail-based in the world. In fact, it seems like Eximus 1 achieved a lower energy consumption per person than the current Shell Eco Marathon record.”

See & read more at Gizmag: Silver machine rolls down the track to new efficiency record. Vehicles from other participants can be found here. Thanks to Frank Van Gieson.

Related:

Zero Electricity Air Cooler

Eco-Cooler airco without electricity

Over 70% of Bangladesh’s population live in corrugated tin huts across the countryside. During the long summer months, temperatures reach up to 45° Celsius, making these huts unbearable to live in.

To address the issue, Grey Dhaka teamed up with volunteers from Grameen Intel Social Business Ltd to create the Eco-Cooler – a zero electricity air cooler, which uses re-purposed plastic bottles cut in half and put into a grid, in accordance to available window sizes.

Based on wind direction and airflow pressure, the Eco-Cooler has succeeded in decreasing the temperature in tin huts by up to 5° Celsius. After initial tests, blueprints of the Eco-Cooler were put up online for everyone to download for free.

Thanks to Adriana Parra.