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Page added on February 28, 2014

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In a Host of Small Sources, Scientists See Energy Windfall

Alternative Energy

The emerging field of “energy scavenging” is drawing on a wide array of untapped energy sources­ — including radio waves, vibrations created by moving objects, and waste heat from computers or car exhaust systems — to generate electricity and boost efficiency.

Computers feasting on their own exhaust heat. Super-efficient solar panels snaring lost thermal energy and recycling it into electricity. Personal electronics powered by stray microwaves or vibration-capturing clothing. Cellphones charged with a user’s footsteps. These and more innovations may be possible with free, green energy that is now going to waste.

Ubiquitous sources like radio waves, vibration and pressure created by moving objects, heat radiating from machines and even our bodies — all have the potential to produce usable electric power. Until recently, ambient energy was largely squandered because of a lack of ways to efficiently exploit it. Now, advances in materials and engineering are providing tools to harvest this abundant resource and transform it into cheap, clean electricity.

polar jet stream

Photo credit: Lawrence Berkeley National Laboratory The Bacteriophage Power Generator is made of biopolymer layers that produce electricity when squeezed.

“This power is simply available and it’s not doing anything right now, so it’s truly being wasted,” said Steven Cummer, a Duke University electrical and computer engineering professor working on harvesting ambient electromagnetic radiation to power electronic devices. “And as people think of useful things to do with it, then you’re doing those things with available power instead of requiring new power.”

This up-and-coming technology, some experts say, can save energy, liberate portable electronics from the grid, and all but do away with disposable batteries. Although it won’t begin to replace solar and wind for generating utility-scale electricity, energy harvesting can serve as a multiplier for these and other sustainable resources, boosting productivity by feeding escaped power back into the system, expanding the range of sunlight that can be harnessed, and powering controls that keep equipment functioning at its peak. If obstacles of size and efficiency are overcome, repurposed ambient power can be an important contribution to the renewable energy supply.

The concept isn’t new — in a sense all energy drawn from the environment is “harvested.” Nor is there a standard definition for the emerging technology known as energy harvesting or energy scavenging, but it primarily involves collecting low-power electromagnetic, thermal, mechanical, or light energy and converting it to electric current.

Exploiting free, ambient energy is “an interesting idea and you’re going to see more applications of it,” said Jonathan Koomey, research fellow at Stanford University’s Steyer-Taylor Center for Energy Policy and Finance. But the technology has a long way to go, he said. Constraints on space and the amount of energy that can be gleaned in many settings now limit its use to small, fairly low-power devices. “It’s not this magic bullet,” Koomey said.

Still, in today’s power-hungry world, energy scavenging can help ensure that no watt goes to waste.

“Your computer, hot asphalt, there’s a million things that are fairly hot but not really viable for standard thermoelectrics,” said Harry Radousky, a physicist at Lawrence Livermore National Laboratory in Northern California and co-developer of a nanoscale harvester for low-temperature heat, such as exhaust from appliances. In contrast to high-temperature, waste-heat capture systems — in which sources like flue gas provide a steep heat gradient for thermoelectric generators — the small heat differences between low-temperature sources and their surroundings are much harder to convert into electricity. But new low-temperature thermal harvesting technology could turn these overlooked resources into working power.

For instance, Radousky said, “we park our cars in hot parking lots all over the U.S. in the summer, so in principle we could charge batteries in electronic devices, [and] run coolers to keep food cold” with heat from the pavement. Other prospects for reaping low-temperature thermal power include light bulbs, hot ovens, and plastic seats inside cars baking in the sun. “My rule of thumb is that if it is too hot to touch, it’s a candidate source,” he said. “So we were looking for things that could harvest that low quality of heat … where a small amount of energy can get you a long way.”

As energy harvesters become increasingly efficient and cost-effective, a growing number of products such as light switches, thermostats, gas detectors, and avalanche alarms are going off-grid and battery-free.

“Our motto is ‘No wires, no batteries, no limits,’” said Graham Martin, chairman of EnOcean Alliance, a California-based consortium of companies promoting a wireless standard for automated building controls that run on scavenged power.

Regulating building heat, cooling, and lights with devices like room occupancy sensors can cut energy use by as much as 40 percent, Martin said. EnOcean Alliance reports that more than 250,000 buildings worldwide contain its energy-scavenging devices, like wireless, battery-free controls with tiny, integrated photovoltaic cells that harvest energy from room lights, or vibrations that agitate a pressure-sensitive material, releasing electrons. Martin estimates that EnOcean devices have saved 50 million batteries, and predicts that 3 billion switches, sensors, thermostats, transmitters, and other low-powered, self-contained gadgets will be in use within five years.

While the market for energy-harvesting devices is currently “not massive,” it is growing steadily, said Harry Zervos, senior technology analyst with the consulting firm IDTechEx. Some of the biggest uses at present include vibration-driven equipment monitors on oil rigs and other remote settings, and car tire pressure sensors running on mechanical energy from the wheels. The technology is now at a tipping point with advances in efficiency, reliability, and affordability, according to Zervos, who expects revenues to hit roughly $4 billion in a decade or so.

Future applications could range from powering a car’s electrical systems with heat captured from the tailpipe, which University of Houston physicist Zhifeng Ren estimates would increase mileage by 5 percent, to a film that can be attached to human skin, converting a person’s movements into energy for portable devices.

Energy harvesting’s greatest benefits, however, may lie in cutting waste and amping up output from existing sustainable electricity resources.

Self-powered wind turbine monitors, for instance, could warn of problems in time to keep turbines from going off-line. And capturing lost heat would significantly boost solar production. Mahmoud Hussein, an assistant professor of aerospace engineering sciences at the University of Colorado Boulder, has come up with a process that could convert heat to electricity much more efficiently: topping thermoelectric material with nano-sized pillars to slow escaping heat vibrations called phonons. The pillars stem heat loss by interacting with, rather than impeding, the phonons, leaving the electric current undiminished, a significant gain over existing thermoelectric materials.

Improved thermoelectric technology can help recoup energy lost by photovoltaic cells that utilize only part of the light spectrum while the rest escapes as heat, Hussein explains. Harnessing waste heat “adds to the field of harvesting energy from the sun,” Hussein said.

Engineers and entrepreneurs are also coming up with a host of other ingenious ways to put ambient energy to work.

At the Lawrence Berkeley National Laboratory on the University of California, Berkeley campus, bioengineer Seung-Wuk Lee is harvesting energy produced by a virus. Genetically engineered to contain a protein that generates electricity when squeezed, the virus infects bacteria and makes them create “zillions of copies,” Lee said. The result is layers of piezoelectric biopolymer with strong positive charges on the inside and negative charges on the outside that transform pressure into power.

Piezo means press,” Lee explained, “so when we mechanically press, we break the symmetry and induce their electric potential.” He demonstrates, tapping a super-thin, fingertip-sized biopolymer sandwich. A few inches away, a small display lights up, spelling out “Virus.”

This so-called Bacteriophage Power Generator can produce enough electric current to power LEDs, but the output would need to be increased a thousand-fold to illuminate a light bulb. Lee and colleagues are now working on boosting that performance.

Another possible application is biomedical devices powered by motions from the body’s organs — especially useful for implants like pacemakers now driven by batteries that must be surgically changed. “We can convert small energy from our heartbeat,” Lee said. “The potential is endless.”

polar jet stream

Photo credit: Sole Power Shoe inserts from Sole Power store enough energy from walking to power a cell phone.

At the University of California, Los Angeles’ Henry Samueli School of Engineering and Applied Science, Professor Kang Wang and colleagues are developing a way to power appliances and electronics with their own excess heat. The process channels heat given off by a working computer, for example, into spin waves able to power and speed up the machine at the same time.

Reprocessing waste heat can save electricity used not just in powering up computers, but also in cooling them down. Such savings would be especially significant at large server farms, where Wang says the dissipation of power is “an enormous drain on energy.”

Lawrence Livermore’s Radousky and partner Morris Wang, meanwhile, combined two technologies to wrest energy from low-temperature sources. Their hybrid harvester contains a phase-change material that deforms when heated and stresses a piezoelectric surface, producing current. Although the output is less than a volt, it could be deployed in arrays of miniscule sensors and processors known as MEMS (microelectromechanical systems), currently used as autonomous controls in cars, airplanes, imaging systems, and numerous other applications, Radousky said.

“The basic idea is to create energy which is used locally, rather than needing to be transmitted,” he said.

But don’t plan on getting rid of that tangle of chargers and power cords just yet. Satiating sophisticated portable electronics like cell phones with ambient radio waves sounds great, but unless you’re standing next to a transmitter, pulling in enough signal requires an antenna larger than the phone, according to Koomey. And even that can only power a very basic model, he said. “Your iPhone is not going to get charged.” Alternatives are in the works: Researchers at Georgia Tech have developed cell phone-powering shoe inserts, and a company called Sole Power plans to market footwear late this year that charges your phone while you walk. Both, however, need “many steps” — on the order of a 10-mile hike — to get the job done.

To Koomey, the greatest value of energy-harvesting is information: enabling small, self-contained sensors to provide data that can optimize power use and trim waste. “The way we operate the economy now, there’s all this inefficiency because we just don’t know, we’ve never been able to measure the inefficiency before,” Koomey said. “There’s huge efficiencies that can be wrung out of the system.”

As Zervos put it, “By using just microwatts, you can save kilowatts of energy that would have gone to waste.”

Yale Environment 360



25 Comments on "In a Host of Small Sources, Scientists See Energy Windfall"

  1. Davy, Hermann, MO on Fri, 28th Feb 2014 2:16 pm 

    More Subaru environmentalist looking to technological exceptionalism to save us. Some of this may have a niche place in society but for the most part it is the same old worn out regurgitated meme that technology will save us. In this case it is a diminishing returns game of spending allot of energy to recover a small amount of energy. What we need is simplicity, Low tech, low power, seasonal, variable energy strategies. We all know here conversion kills energy efficiency. We also know if we are heading down an energy gradient then we have to look to sources other than high energy density fossil energy and its relatives the “so called renewables”. These other sources will require a rethink. Using wind, solar, hydro, and thermal to power a society stuck in technological exceptionalsim only makes the matters worse. Current renewables are nothing more than offshoots to the fossil energy that spawned them. We need a rethink back to 19th and early 20th century mechanical style technologies. These need to conform to the energy constraints of low source energy like what is provided by our environment. We need to rethink animal power and “YES” human power. We will have to live seasonally and variably according to climate and seasons. That is if we have a human friendly climate in the near future. “And” Yes some fossil fuel use will continue in a contracted/collapsed world. Will this happen in our global society from the top down, I would say almost no chance. Can the bottom up experiment and attempt a renaissance of these older technologies I hope so. It will have to take place from the bottom up primarily because the top down is paralyzed by the complex global society it has created. We don’t have to drop our hard fought technological achievements but they have to be adapted to an energy constrained world facing contraction/collpase. We will only have a short time to implement these strategies before the floor drops out of status quo BAU and our ability to communicate globally, muster capital, and trade will be severely disrupted. Then the process will slow to a crawls in a greatly poorer world

  2. Arthur on Fri, 28th Feb 2014 2:38 pm 

    It would be ridiculous to write off the enormous repository of scientific and technological knowledge as a means to combat the conseqences of resource depletion. That’s going to make all the difference. You can stay perfectly warm with thermo-wired clothing, for 3$ per month. You can work remote, with an internet connection (like I am doing now) and eliminate the need for cars.

    Technology will make all the difference.

  3. Davy, Hermann, MO on Fri, 28th Feb 2014 3:35 pm 

    @Arthur said – Technology will make all the difference.

    Until it desn’t. Technology is subject to the weakest link in a complex interconnected world.

  4. Arthur on Fri, 28th Feb 2014 4:09 pm 

    In the future millions of roads, airstrips, billion cars, planes are going to be replaced by glass fiber cables in the ground. In the West that is already the case, at least in Western Europe. Current energy budget internet + all the hardware: 1-2% of total energy budget. Tendency: downwards.

  5. GregT on Fri, 28th Feb 2014 4:09 pm 

    The addicts are getting desperate.

  6. Davey on Fri, 28th Feb 2014 4:19 pm 

    Good luck Arthur with your technological exceptionalism when the grid goes unstable

  7. Dave Thompson on Fri, 28th Feb 2014 4:27 pm 

    Feel good fluff with a touch of reality can go a long way I suppose.

  8. ghung on Fri, 28th Feb 2014 5:04 pm 

    Will these gizmos ever return their embodied energy? Will they produce more energy than it took to produce them? That’s all that matters. It’s the question most of these proposals never answer; usually don’t even ask.

  9. GregT on Fri, 28th Feb 2014 5:21 pm 

    “You can stay perfectly warm with thermo-wired clothing, for 3$ per month. You can work remote, with an internet connection (like I am doing now) and eliminate the need for cars.”

    So we will all be comfortably sitting at home, in our 3 dollar per month thermo-wired clothing, working at our remote ‘jobs’. Sounds like quite the life. It might actually work, if somebody could figure out a way to remotely feed us. Maybe we could design bigger ‘glass fibre cables’? Or maybe, the Matrix is more realistic than I thought?

  10. bobinget on Fri, 28th Feb 2014 5:23 pm 

    On COLD clear days our PV’s crank out more KW’s
    than hot cloudless summer days. (fewer winter hours)
    We should be looking to capture and turn into increased generation capacity. The best any scalable efficient PV’s is under 24% . All because sitting all day, in the sunlight in a black or dark blue background robs
    energy by turning ity into heat.

    One interesting bit of news about solar power and heat; It seems ‘reflected’ thermal solar power plants hit a a snag. Thousands of MIRRORS directing sunlight at a central tower thereby making a steam turbine turn is also a powerful death ray for birds that happen
    to fly by. The problem; most turkeys and chickens
    can’t be coaxed to fly high enough to be properly
    roasted. If them avians that crapped on my PVs’
    got toasted, I have less sympathy.

    If airports can’t seem to manage Big Bird how are
    the dozen men whose main job is cleaning three thousand mirrors going to cope?

    Playing loud, bird scary music might help.

    Arthur, We have three separate fiber optic cables buried under the highway that fronts my farm.
    (backbone for entire West Coast data)
    The problem, can’t access any of them for under
    $600. a month.

  11. GregT on Fri, 28th Feb 2014 5:33 pm 

    “The problem, can’t access any of them for under $600. a month.”

    I’m sure they wouldn’t be too difficult to ‘access’ with a pick axe and a shovel.

  12. ghung on Fri, 28th Feb 2014 5:40 pm 

    @bobinget:

    h ttp://www.newformenergy.com/technology/hybrid-solar-solution

  13. J-Gav on Fri, 28th Feb 2014 7:05 pm 

    “Energy scavenging” is likely to resemble something more along the lines of stealing from your neighbors woodpile or other biomass source.

  14. Arthur on Fri, 28th Feb 2014 7:39 pm 

    Yes bobinget, that is the advantage of living in an ‘overpopulated’ western Europe, in contrast to living in the 2nd largest country in the world, with relatively few people.

    http://business.upc.nl/producten/alles-in-1-zakelijk/

    200 MB/s, 65 euro/month

    More than enough for sharp video connections & screen sharing, where you can see your demanding client during video calls in much greater detail than you would actually care for.

    Traveled twice to Vienna to my client during my current contract and twice it was superfluous. Just convention, these meetings and tiresome and costly travels.

  15. Arthur on Fri, 28th Feb 2014 8:03 pm 

    So we will all be comfortably sitting at home, in our 3 dollar per month thermo-wired clothing, working at our remote ‘jobs’. Sounds like quite the life. It might actually work, if somebody could figure out a way to remotely feed us.

    Not necessarily at home, you can walk to your neighborhood office and log in at an available workstation, uhh king size tablet. Just add a water-cooler and coffee machine and nobody will ever notice the difference. But, hey, if you want to live a Walden-Thoreau life up north in the bush, nobody is going to stop you. Just like Thoreau, you will probably have enough of going ‘back to nature’ after a year or so.

  16. Stilgar Wilcox on Fri, 28th Feb 2014 8:33 pm 

    Are we suppose to make a magical leap from depleting resources, declining EROEI, entropy, to slight improvements in efficiency that miraculously rejects physics to save BAU? Ha!

    Maybe if we can develop a drug that slows everything down to a crawl, we can increase the time until the cliff. Ssssuuuurrrreee iiiiittttt mmmmmuuuuusssstttt bbbbbeeeeeeeeee pppppooooosssssssiiiiibbbbblllllleeeeee.Thanks, I needed to start today with a laugh.

  17. DC on Fri, 28th Feb 2014 9:20 pm 

    Uhh, Arthur, I have to ask, just how is it, that an energy constrained society, that is to say, a society that has little or no surplus energy for people to sit@home telecommuting and send each other updated spreadsheets to one another, and still get,….paid? for it? We were not headed for a post-scarcity star-trek world where Earth is basically a garden you know. One could argue, successfully too, that the peak abstraction in the workplace, will peak right along with the oil. After that, even if the net survives in some form, no form of abstracted hyper-symbolic work-from-home economy will exist. Right now, and maybe for a few more years-is about as good as its going to get as far as your work-at-home vision of future.

    Actually, I take that back, most people WILL in fact, work from home. Trying to grow food in there toxic suburban dirt patches and maintaining there rainwater catchment systems(ie whatever barrels they could scavenge that will hold water). Telecommuting will consist of walking to the neighbors to see what you can barter. Old Ijunks will not be considered sought after items, once theyve been harvested of there valuable RE elements that is.

  18. Makati1 on Sat, 1st Mar 2014 2:50 am 

    Guys, Arthur is wrapped so tight in his Techie dreams he can no longer entertain anything but a techie variation of BAU. Wait until the war in the Ukraine starts and the gas to Europe is cut off along with the many other problems coming down the collapse road. The EU is a dying idea but he cannot see/accept that fact either. Reminds me of Americans…

  19. Arthur on Sat, 1st Mar 2014 4:44 am 

    I am saying that there is a way to keep basic functions of society going after the end of the fossil fuel age. I am not saying that ‘BAU’ is going to happen. We are moving into a radical new world, largely without cars and planes and the whole world falling apart along ethnic and religeous lines. When Slavic Orthodox Ukrainians can’t live together with Slavic Orthodox Russians you shoukd know what is going to happen to America.

    Perhaps the EU is going to fall apart, but for the moment everybody is banging on the door to be let in. There is another possibility, namely that the EU is going to be a model for the future, notably for a Balkanizing North-America, where the European parts are going to secede and loosely reconfederate againg. Turkey led neo-Ottoman empire, same story. Everybody is going to be a ‘fundamentalist’.

    There is absolutely not going to be BAU. But world-made-by-hand, that is too doomer cultish.

  20. Arthur on Sat, 1st Mar 2014 5:26 am 

    Russia invaded the Crimea and as such crossed the Rubicon. And has the oil & gas weapon, just in case foolish European politicians let themselves being dragged by the US in a conflict with Russia… and China.

    It is 1939 al over again, when the Nuland’s du jour (William Bullitt) sicked the Poles against the Germans. Russia is the new Germany and Ukraine the new Poland. Unfortunately for the NWO, China will side with Russia. China is the new Japan, ten times as big and with nukes and strategic depth, like Russia. Kiss the West goodbye?

    BAU, anyone?

  21. Arthur on Sat, 1st Mar 2014 5:48 am 

    Should have added: the Crimea is the new Danzig. Danzig was 97% German and wanted to be part of Germany, but was not allowed to be by UK, F and US and they declared war. The Crimea is Russian, but the NWO will try yo use this as an issue to start WW3, or at least a new cold war.

  22. GregT on Sat, 1st Mar 2014 7:00 pm 

    “I am saying that there is a way to keep basic functions of society going after the end of the fossil fuel age.”

    Food production is a basic function of society, and all trends are pointing to food production as being very problematic. Computer tech, electricity, and the internet are not basic societal functions. They will be amongst the first things lost, post fossil fuels. We are not headed towards a star-treckie future, we are headed towards the 1600s.

  23. Davy, Hermann, MO on Sat, 1st Mar 2014 7:16 pm 

    @Arthur – The World according to Arthur is quite riddled with inconsistencies. He likes to base his views upon a 20th century style cold war doctrine of opposing camps. Despite the fact that the new normal is one of a global interconnected economy in a multipolar world. He can’t help but blame and complain about America and relishing the idea of its demise. Yet he offers no concrete reasons for its death. His statements about the end of BAU fail to account for how the world is going to be fed, clothed, and homes heated. He just says there will be no transport and everything else will function just nicely. His love of the China/Russian axis of the powerful is ridiculous. The Chinese will slowly annex much of western Russia as Russians are unable to keep the fabric of their society in operation. The Russian army and missile arsenal will decay and become ineffective very quickly. This Chinese invasion will not be a hostile invasion but a slow advance of a huge population into a dying and contracting Russian population.

  24. Arthur on Sat, 1st Mar 2014 11:33 pm 

    He likes to base his views upon a 20th century style cold war doctrine of opposing camps.

    Not necessarily opposing, but separate.

    Despite the fact that the new normal is one of a global interconnected economy in a multipolar world.

    The reality of resource depletion is going to question whether there is much future for that global interconnected world.

    He can’t help but blame and complain about America and relishing the idea of its demise.

    I believe in the rapid decline of the US empire, yes, and true, I won’t shed a tear about it, just like Americans could not care one bit about the demise of the Europeans empires, especially if that demise of the US empire will go hand in hand with the re-rise of a constitutional America, that’s no longer a threat to the world.

    Yet he offers no concrete reasons for its death.

    That’s easy: it is not in the line of reason that 180 million IQ100 Euro-Americans, dominated by a few million IQ115 Jews, are going to dominate for ever 500 million IQ100 Europeans, 250 millions IQ100 Slaves and 1300 million IQ100 Chinese.

    He just says there will be no transport and everything else will function just nicely.

    I never said that. There will be no mass individualized mass transport, but there is certainly going to be transport, but in much less intensity. And I expect a period of massive belt-tightening and things will not be ‘nicely’.

    His statements about the end of BAU fail to account for how the world is going to be fed

    Just like how the Russians fed themselves during the difficult transition years 1991-2000: scratching the potatoes out of the ground yourself.

    His love of the China/Russian axis of the powerful is ridiculous.

    ‘Love’ is a big word. But yes I am glad that SCO will effectively block any attempt to realize a US run multicultural, multiracial global empire; communism via the western backdoor. Thanks, but no thanks.

    The Chinese will slowly annex much of western Russia as Russians

    You probably means eastern Russia (Siberia), but yes, that is a very realistic prospect, but that prospect can and should be countered by a coalition of Europe, Russia and North-America, after the fall of AIPAC/FED/$/CFR/NGO/Wallstreet-American COMINTERN.

  25. Davy, Hermann, MO on Sun, 2nd Mar 2014 12:05 am 

    fair enough Arthur…nice debate