Researchers at Duke have built a metamaterial array that harvests free energy sources like ambient wifi and microwave radiation:
The device wirelessly converts the microwave signal to direct current voltage capable of recharging a cell phone battery or other small electronic device, according to a report appearing in the journal Applied Physics Lettersin December 2013.
It operates on a similar principle to solar panels, which convert light energy into electrical current. But this versatile energy harvester could be tuned to harvest the signal from other energy sources, including satellite signals, sound signals or Wi-Fi signals, the researchers say.
The key to the power harvester lies in its application of metamaterials, engineered structures that can capture various forms of wave energy and tune them for useful applications.
Undergraduate engineering student Allen Hawkes, working with graduate student Alexander Katko and lead investigator Steven Cummer, professor of electrical and computer engineering, designed an electrical circuit capable of harvesting microwaves.
They used a series of five fiberglass and copper energy conductors wired together on a circuit board to convert microwaves into 7.3V of electrical energy. By comparison, Universal Serial Bus (USB) chargers for small electronic devices provide about 5V of power.
"We were aiming for the highest energy efficiency we could achieve," said Hawkes. "We had been getting energy efficiency around 6 to 10 percent, but with this design we were able to dramatically improve energy conversion to 37 percent, which is comparable to what is achieved in solar cells."
An incredible breakthrough that could lead to ambient charging of mobile devices, simply through the addition of a small array circuit. Carried to a logical conclusion, we could potentially do away with wires, and items as basic as light bulbs could be powered by wifi or cell signals. The communication medium can become the power supply, as well.
This graph dramatically illustrates the rapidly decreasing price of solar power.
Solar power’s massive price drop, in one graph.
1977 price = $76.67/watt. 2013 price = $0.74/watt. Falling exponentially, and now less than 1% of 1977 price.
Stanford researchers — Professor Shanhui Fan and graduate students Aaswath Raman and Eden Rephaeli — have developed a material suitable to be used as paneling on houses and buildings that reflects light so efficiently, it could passively replace air conditioning, as well as radiating heat in a way that will escape the Earth’s atmosphere.
The trick, from an engineering standpoint, is twofold. First, the reflector has to reflect as much of the sunlight as possible. Poor reflectors absorb too much sunlight, heating up in the process and defeating the goal of cooling.
The second challenge is that the structure must efficiently radiate heat (from a building, for example) back into space. Thus, the structure must emit thermal radiation very efficiently within a specific wavelength range in which the atmosphere is nearly transparent. Outside this range, the thermal radiation interacts with Earth’s atmosphere. Most people are familiar with this phenomenon. It’s better known as the greenhouse effect – the cause of global climate change.
The new structure accomplishes both goals. It is an effective broadband mirror for solar light – it reflects most of the sunlight. It also emits thermal radiation very efficiently within the crucial wavelength range needed to escape Earth’s atmosphere.
Radiative cooling at nighttime has been studied extensively as a mitigation strategy for climate change, yet peak demand for cooling occurs in the daytime.
The Stanford team has succeeded where others have come up short by turning to nanostructured photonic materials. These materials can be engineered to enhance or suppress light reflection in certain wavelengths.
The new device is capable of achieving a net cooling power in excess of 100 watts per square meter. By comparison, today’s standard 10-percent-efficient solar panels generate about the same amount of power. That means Fan’s radiative cooling panels could theoretically be substituted on rooftops where existing solar panels feed electricity to air conditioning systems needed to cool the building.
To put it a different way, a typical one-story, single-family house with just 10 percent of its roof covered by radiative cooling panels could offset 35 percent its entire air conditioning needs during the hottest hours of the summer.
Radiative cooling has another profound advantage over other cooling equipment, such as air conditioners. It is a passive technology. It requires no energy. It has no moving parts. It is easy to maintain. You put it on the roof or the sides of buildings and it starts working immediately.
This is an enormous breakthrough if it can be manufactured cost effectively.
The Japanese New Energy and Industrial Technology Development Organization (NEDO) has been working on autonomous truck convoys, and a recent experiment with a single human-operated lead truck and 3 autonomous follower trucks led to fuel consumption savings of 15%.
Paris is known as the City Of Light principally because of the gas lights of the 1800’s, but it may be time to turn the lights off, at least late at night.
Andrew Price, Will The City Of Light Go Dark To Save Energy?
A proposal from Delphine Batho, head of the Ministry of Ecology, Sustainable Development, and Energy, would require stores, offices, and public buildings across the country to turn off the lights between 1 a.m. and 7 a.m. The point of the policy, according to Batho, is not only to save energy and money but also “to change the culture” in a time of economic crisis, making people aware of the importance of using energy resources efficiently.
If the new policy is approved by Parliament, it will take effect in June, with certain exceptions for hospitals, police stations, and other critical operations. Indeed, the target of the policy seems to be shops that keep their lights on all night long. Or at least that’s what some proprietors seem to think. France’s Commerce Council has made statements opposing the idea, claiming that it will turn off tourists and hurt business. Predictably, the light bulb and lighting systems industries have also objected.
The savings could be considerable — $261 million per year — but the biggest impact could be the cascade out to other cities and towns that might follow Paris’ lead.
A Bluecar is pictured in Paris, on the first day of a test session of the Autolib electric car pick-up service. Self-service electric cars appeared on the streets of Paris Sunday, as a French group launched a public car-hire scheme modelled on the capital’s popular bicycle-sharing system and designed to become the world’s largest of its kind.
Self-service electric cars appeared on the streets of Paris Sunday, as a French group launched a public car-hire scheme modelled on the capital’s popular bicycle-sharing system and designed to become the world’s largest of its kind.
These 10 global infrastructure and tech companies are among the early leaders in smart-city programs.
“Like Siemens and ABB, most of the beneficiaries of urbanization will be infrastructure and technology outfits that provide or utilize smartphones, sensors and software and services to track the use of a city’s assets and commit resources when and where they’re needed. Cloud technology, which can cut costs while boosting computing capacity, will play a big role. Even social media will participate, as cities multiply the ways a citizen can spot a problem–anything from a water-main break to a traffic snarl–and then alert others to avoid it or do something about it.
Technology researchers at IDC estimate the size of the smart-city information-technology market is now $34 billion annually and will gain 18%-plus a year to $57 billion by 2014. That’s not a huge amount to global giants, but certainly enough to help drive growth. (The companies don’t break out earnings related to these projects.) The market has broadened to include items like broadband connectivity, green belts, renewable energy, green buildings and other intelligent-city systems. “You are talking about smart water, smart transportation, better public safety,” says Jennifer Bélissent, a consultant at Forrester.”
I think that all of the most successful companies of the next 20 years will be software-driven, and will act like software companies, not like energy, media, or finance companies of the last economic era.