Washington DC Electrified with Raw Sewage

Completely unrelated to the current political climate in the United States, did you know Washington D.C. is partially powered by a sewage plant? No, seriously.

That’s right, just this week the D.C. Water utility company has announced a bioenergy facility that makes use of resident’s waste water into producing methane gas which can than be burned to generate electricity — To the tune of 10 megawatts! The facility is saving the company an estimated $10 million a year in energy bills.

Simply put, the liquid is removed from the sewage water and the solids are refined into a type of fuel. Those solids are heated, mixed, and sterilized into a form that can be easily digested by a certain type of microbe, which then in turn produce methane for burning. For a more detailed explanation, check out the info-graphic from the Washington Post explaining the entire process.

And on a smaller scale, you could do something like this in your very own backyard.

Mr. Trash Wheel Cleans Baltimore’s Harbor

Quite frankly we’re rather surprised we haven’t heard of Mr. Trash Wheel before. It’s a community project by the Baltimore Waterfront’s Healthy Harbor program where they are trying to make the harbor both swimmable and fishable by 2020. One of the coolest projects that resonates with us is Mr. Trash Wheel — a waterwheel-powered-trash-collecting-conveyor-belt. Say that 10 times fast!

It was built in early 2014, and according to the latest data it has removed a whopping 160 tons of garbage from the waterway already. Floating buoy-nets direct the garbage floating on top of the water into a narrow passage where the conveyor belt powered by a waterwheel slowly picks up the trash, and then deposits it into a large dumpster on a barge.

In fact, it’s even saved a python from the water too!

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Optical Rectenna Converts Light to DC

Using multiwall carbon nanotubes, researchers at Georgia Institute of Technology have created what they say are the first optical rectennas–antennas with rectifiers that produce DC current. The work could lead to new technology for advanced photodetectors, new ways to convert waste heat to electricity and, possibly, more efficient ways to capture solar energy.

A paper in Nature Nanotechnology describes how light striking the nanotube antennas create a charge that moves through attached rectifiers. Challenges included making the antennas small enough for optical wavelengths, and creating  diodes small enough and fast enough to work at the extremely short wavelengths. The rectifiers switch on and off at petahertz speeds (something the Institute says is a record).  Continue reading “Optical Rectenna Converts Light to DC”

Sensor Net Makes Life Easier for Rice Farmers

Rice is cultivated all over the world in fields known as rice paddies and it is one of the most maintenance intensive crops to grow. The rice paddy itself requires a large part of that maintenance. It is flooded with water that must be kept at a constant level, just below the height that would keep rice seedlings from growing but high enough to drown any weeds that would compete with the rice stalks for nutrients. This technique is called continuous flooding and a big part of the job of a rice farmer is to inspect the rice paddy every day to make sure the water levels are normal and there are no cracks or holes that could lead to water leakage.

This process is labor intensive, and the technology in use hasn’t changed much over the centuries. Most of the rice farmers in my area are elders with the approximate age of 65-70 years. For these hard working people a little bit of technology can make a big difference in their lives. This is the idea behind TechRice.

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Tech Journos Link Samsung To Volkswagen, Somehow

On Thursday The Guardian published information linking Samsung to the current Volkswagen emissions fiasco. Samsung is accused of installing a ‘defeat device’ on some televisions that uses less energy during official testing conditions than would be found during real-world use.

“The apparent discrepancy between real-world and test performance of the TVs is reminiscent of the VW scandal that originated in the US last week,” wrote [Arthur Nelson] of The Guardian. This report was based on an unpublished lab test by the research group ComplianTV which found discrepancies between real-world and test performance when measuring power consumption. According to ComplianTV, this is due to the ‘motion lighting’ setting included in some Samsung TVs. Samsung vehemently denies this ‘motion lighting’ saying that it is not a method of cheating the consumption tests.

Typical results recognized during testing. Source
Typical results recognized during testing. Source

Not one to let a good controversy go to waste, the BBC reports a Samsung TV will reduce its power draw shortly after the start of the test. A graph of the power draw of a TV – not explicitly a Samsung television – demonstrating this functionality was found in a PDF of a ComplianTV workshop from last year labeled as, “Typical results recognized during testing” with a decrease in power consumption being a recognized behavior when the appropriate test video was found.

This is not the first time ComplianTV tested a Samsung TV equipped with a ‘motion lighting’ setting. Earlier this year, ComplianTV measured the power consumption of the Samsung UE55H8090 television, and found this TV was compliant with energy regulations. Incredibly, all Samsung TVs listed on the ComplianTV database were found to be compliant with the relevant energy directives.

Samsung’s rebuttal to the Guardian article states the ‘motion lighting’ technology is an ‘out of the box’ feature, active in both the lab and at home. Unlike Volkswagen’s ‘defeat device’ for their diesel engines which is only active during emissions testing, the ‘motion lighting’ technology is active whenever it is enabled in the TV’s settings menu.

Anyone in the US who has shopped for a television in the last four years will have noticed cost-per-year estimates for operating the appliance. This is only an issue if the televisions don’t actually meet that advertised benchmark. Until we see a published study we’re raising our eyebrows at The Guardian, easily one of the most trusted journalistic institutions on the planet, and reserving judgement for Samsung.

Enormous Delta-bot 3D Designed to Print an Entire House

[Massimo Moretti] has a big idea – to build housing on the cheap from locally sourced materials for a burgeoning world population. He also has a background in 3D printing, and he’s brought the two concepts together by building a 12 meter tall delta-bot that can print a house from clay.

The printer, dubbed Big Delta for obvious reasons, was unveiled in a sort of Burning Man festival last weekend in Massa Lombarda, Italy, near the headquarters of [Moretti]’s WASProject. From the Italian-language video after the break, we can see that Big Delta moves an extruder for locally sourced clay over a print area of about 20 square meters. A video that was previously posted on WASProject’s web site showed the printer in action with clay during the festival, but it appears to have been taken down by the copyright holder. Still, another video of a smaller version of Big Delta shows that clay can be extruded into durable structures, so scaling up to full-sized dwellings should be feasible with the 4 meter delta’s big brother.

Clay extrusion is not the only medium for 3D printed houses, so we’ll reserve judgment on Big Delta until we’ve seen it print a livable structure. If it does, the possibilities are endless – imagine adding another axis to the Big Delta by having it wheel itself around a site to print an entire village.

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Omaha Mini Maker Faire: Recycle All the Things

A young maker named [Allie] drew a lot of attention at the 2nd annual Omaha Mini Maker Faire. Her booth was full of the various creations she has designed and built herself throughout the course of her short life. The biggest draw was her green design dollhouse, which focuses on environmentally friendly living. With the exception of the LEDs lighting the interior, some tape, and the requisite bit of hot glue, the entire structure and its contents were made from recycled materials.

green-dollhouse-thumbThe cardboard structure features a kitchen, living room, bedroom, bathroom, and attic. Every piece of furniture and all the decorations are made from salvaged materials and packaging. One side of the roof holds a Snap Circuits board with a solar panel that powers some blue LEDs on the bedroom wall. [Allie] poured water down the other side of the roof to demonstrate the rain water collection system. The house’s rain barrel was made from a grated parmesan cheese container, which is perfectly designed for the airline tubing running into it from the recycled plastic guttering.

owl-says-noOne of [Allie]’s other projects is a disagreeable owl fashioned from cardboard and a salvaged canister. Hidden away beneath the owl’s platform lies a simple gear system attached to a key on the front. Turning the key causes the owl’s head to swivel back and forth. We tried to make it spin all the way around, but the full range of motion is about 270 degrees. She also brought Mountain Dew, a hummingbird model made from a spark plug and other metal bits and bobs, including a pair of soda can wings.

mountain-dew-hummingbirdIn addition to her crafty skills, [Allie] is one well-spoken tween. She was more than happy to discuss her creations in detail to anyone who would listen, which included at least two local journalists and this impressed reporter. We learned through a bit of light research that a robot [Allie] built a few years ago inspired a British toy company to produce a new doll, the Robot Girl Lottie. She’s an inspiration to makers of all ages.