energy efficiency

If Earth’s water were drained into a single drop, it would measure about 950 miles in diameter. Roughly three percent is fresh water, and just one-third of that is easily accessible. Meeting the growing need for water is a critical challenge. Many countries rely on desalination to produce fresh water, but current techniques are typically energy-intensive, using enough energy globally to power nearly seven million homes. That’s why today GE is launching an open innovation challenge to improve the energy efficiency of water desalination. Find out more about the challenge here. GIF by Julian Glander and based on data from Woods Hole Oceanographic Institution.

Advocating For Glow-in-the-dark Roads With Vincent Van Gogh

A glow-in-the-dark bike route inspired by Vincent van Gogh’s “Starry Night” debuted this week in the Netherlands. It’s part of a larger vision to illuminate infrastructure with solar energy captured during the day.

The kilometer-long “Van Gogh Bicycle Path” is located in Eindhoven, its swirls composed of thousands of glow-in-the-dark stones embedded in concrete (along with some guiding LEDs fueled by solar panels). It’s the latest component of the Smart Highway project. Led by Dutch designer Daan Roosegaarde’s Studio Roosegaarde with Heijmans Infrastructure, the goal is “to make smart roads by using light, energy and road signs that interact with the traffic situation.”



These Smart Streetlights Only Get Bright When They’re Needed

Cities spend massive amounts of money on electricity to light the street. But most of the time no one is there. This smart technology can sense when a car or pedestrian is approaching.

As much as half of a city’s electricity bill is from simply powering streetlights. Now a Dutch company’s design for smart street lights, which brighten only when needed, might help save massive amounts of that energy.

The Tvilight system works by sensing someone on the street—whether it’s a car, cyclist, or pedestrian—and instantly gets brighter in exactly the right place, while other lights stay on at a dim level. It’s quite a bit more complicated than the typical motion sensor lights you might see inside an office. Instead of just one light, the system illuminates multiple lights all around a moving vehicle or pedestrian.

The company’s founder was inspired to design the lights while working at another job that required frequent travel. “When I was flying, I was amazed to see how many streetlights are burning all night even when there’s no one around,” says Chintan Shah, CEO of Tvilight. "With a little research, I found out that Europe pays over €10 billion each year only to power streetlights. And this is shocking. Why do we need so much light when no one is there?”

Shah likens the effect to the spotlight that followed Michael Jackson around the stage as he danced the moonwalk. No matter where someone goes, a “safe circle of light” is always there. That means each of the lights needs to be able to communicate, in microseconds, with its neighbors.

The sensors inside are also smart enough to know not to activate the lights when a bird flies by, or when wind moves tree branches. The system can even tell what type of object is approaching; since a car moves faster, the lights around it are a bigger diameter and start brightening farther down the block.

“Five years ago, wireless sensors were not ready for this challenge,” says Shah. Now that reliable low-power sensor network technology is available, his team was able to build a custom combination of sensors that could filter out movement to know how and when to illuminate.

Soon, the company will also program custom lights for certain situations—a fire truck driving down the street, for example, will be able to turn the streetlights red as it passes to help alert other drivers.

Since Tvilight’s first installation of the lights in 2011, hundreds of the systems have been installed—at train stations, parking lots, a castle in Germany, and even an entire town in the Netherlands. Now the company hopes to move from selling directly to cities to work with distributors and other streetlight manufacturers, so it can spread the technology more quickly.

Everywhere the lights have been installed, Shah says they’ve had a positive response. Since the lights are never fully turned off, but just dimmed by 30%, it’s easy to see even if you’re just looking out the window of a house and nothing is driving by. And just by dimming the lights, energy usage can be cut 50% to 60%.

“The world talks about the challenge of climate change, but there are really practical solutions like this,” Shah says. “If we apply them, we’ll achieve our 2020 targets. I think it’s time that the world gets serious about implementing solutions that are readily available.”

Source: Fast Co.Exist

Related: 'Borrowed Light' and Light Pollution

This High Concentration Photovoltaic Thermal System (HCPVT) can harness the energy of 2,000 suns and provide fresh water and air conditioning in remote locations. The prototype HCPVT system under development uses a large parabolic dish, made from a multitude of mirror facets, which is attached to a tracking system that determines the best angle based on the position of the sun. Once aligned, the sun’s rays reflect off the mirror onto several microchannel-liquid cooled receivers with triple junction photovoltaic chips — each 1x1 centimeter chip can convert 200-250 watts, on average, over a typical eight hour day in a sunny region.

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Can you actually explain what makes LEDs so special? (Guest Post: PART 1)


Last week, the three scientists who invented blue light emitting diodes received the Nobel Prize.  It was certainly well deserved, as this was nothing short of a revolution for lighting.  

That revolution began with their invention 20 years ago and has brought us the newest in efficient light emitting diode (LED) lighting.  These lights are so efficient that they have taken vertical farming from the pages of eco-utopian manifestos to tangible reality. 

Navigant Research modeled a 63% adoption rate of LED lights for retrofitting projects by 2021.  The numbers speak for themselves.

This is the first of a two-part piece that will explain what LEDs are in a way that anyone can understand.  First, I’m going to look at what ‘efficiency’ means for LEDs, and the implications of increased efficiency. Then, in part two, I want to show you the companies breaking new ground on the vertical farming applications of LEDs right now. 

Why is this so critical to vertical farming?

Before diving into the basics of LED lighting, let’s touch on why vertical farms require such a massive amount of light.  Though a simple problem to understand, there is no universal lighting solution to efficiently illuminate multi-level farms because higher levels shade lower ones.  Essentially, any move to intensify the number of seedlings per square foot, a primary function of vertical farming, is going to increase the shade over seedlings already in place as in the image from VertiCrop below. 

As a result, prominent critics cite lighting as the main limiting factor any successful vertical farm would have to overcome.  One such critic is Dr. Ted Caplow.

I first ran into Caplow’s work after learning about the Science Barge experiment he was running in New York.  Caplow and his team were trying to figure out exactly what it would take to reach efficient, sustainable production in the middle of a city.  The barge was a success, but it hinted at failure for vertical farming.

Based on his experience, Caplow came up with a rough estimate for roughly calculating lighting requirements for hydroponic growing facilities fueled by solar panels (like vertical farms).  Basically, he estimates that to light a single layer of plants using energy exclusively from solar panels requires an area 20x larger than the square footage of that layer.

With improvements in LEDs and solar panels, Caplow’s estimates may soon be wrong if they aren’t  already.

LED lights have become increasingly efficient and their energy requirements are declining rapidly.  I want to explain what LEDs are, what ‘efficiency’ even means, the implications of increased efficiency, and finally in the next part, I want to show you the companies innovating existing lighting technologies even more.

First things first: LEDs? 

LED stands for light emitting diode.  So what’s a diode? 

A diode, pictured below, is an electronic component with two points of opposite charge.  In between those two points is a semiconductor.  The semiconductor acts on the electric current as that current passes across the two points of the diode, dropping down the energy levels of the electrons in the current.  It may help to think of the semiconductor as a permeable surface that allows the electrons to fall down out of their normal orbits, much like a sieve.  The energy released in that reaction is what produces light, and in more wasteful systems, heat.  The differences between semiconductors will produce various colors of light like the blue ones the scientists who won the Nobel Prize discovered. 

What really matters more than the explanation is why that technology is better.  The answer to that question lies in its efficacy. 

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MiniHome Solo - 480 Square Foot Prefab

The company has been designing and manufacturing eco-friendly and sustainable prefab homes since 2002, and their latest model offers a great balance between wide market appeal and price. The Solo 40 is longer, wider, more spacious, and resembles conventional homes in its layout. It measures 480 square feet and the fully equipped model costs only $195 per square foot… continues…” – Jetson Green

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Vehicle-Mounted Cameras See When Buildings Leak Energy

by Txchnologist staff

Residents of Boston and Cambridge, Mass., may have noticed a black SUV prowling their neighborhoods over the last couple of years. Like the now familiar Google Street View car, this one zigzags through town with a camera rig mounted to its roof. But while Google’s vehicle operates in the day, the black truck rides through the midnight hours.

What the night owls who caught a glimpse of this machine witnessed was not some secret government surveillance program recording citizens as they slept. Instead, this project had a much more domestic focus—finding the invisible places on the outsides of homes and businesses where energy escaped.

A company called Essess spun off from research at MIT has been sending video camera- and sensor-laden vehicles to take high-quality thermal imagery of building envelopes from the street. These images show hotspots where heat—and money—is escaping from windows, poorly insulated roofs and basement ducts and piping. The vehicle-mounted system can capture thermal scans on both sides of the car at the same time at the rate of thousands of buildings per hour.

“We’ve made thermal imaging very automated on a very large scale,” says Sanjay Sarma, a mechanical engineering professor and Essess cofounder.

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Friendly reminder that tomorrow is Earth Hour! Be apart of the global event to help save energy by switching off any lights and unnecessary power devices from 8:30 to 9:30pm — after all, every minute counts in a world of finite resources. :)

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Downsizing in a Prefab Container Home

The premade container home maker Cargotecture now offers a prefab home that is a perfect way to downsize yet retain the comforts of living in a larger space. The c-series 640 Lookout model measures 640 square feet, and features a large living area with a kitchen, a spacious bedroom and bathroom, a media room and a lofted sleeping area for guests…” – Jetson Green

Continue reading at Jetson Green…

See smaller homes by Cargotecture…

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Streetlights that only Light up when Needed | White Spaces

Tvilight, based in The Netherlands is working to better an ongoing issue within Europe; their power expenditure. Research has shown that Europe spends 13 billion per annum powering street lights, which translates to 40 percent of their total energy costs. Tvilight has made it their purpose to cut this cost by 80 percent with the product CitySense.