Of all the things that people traditionally discard, one that most of us likely think the least about repurposing is human feces and urine. Sure, we recycle our plastic and paper, and compost our fruits and veggies, but … that stuff? Actually, there are various worldwide projects aimed at using municipal raw sewage for things such as fertilizer or as a power source. While those projects only come into play once the waste has been flushed, however, the UK’s Loowatt system gets users involved from the bottom up (sorry), collecting waste directly from the toilet and using it to create biogas and fertilizer.

The Loowatt toilet itself is waterless and chemical-free, and is intended for use at outdoor events, campsites and other remote locations – pretty much the same places that a Porta Potty or outhouse would be used. Feces and urine drop into what is described as an “odorless” sealed cartridge, which incorporates a biodegradable liner. Once or twice a week, that cartridge is removed, and the liner and its contents are dumped into a nearby anaerobic digester.

The digester (which is also part of the system) utilizes microorganisms in an oxygen-free environment, to consume the waste and convert it into methane and carbon dioxide gas. That gas can then be burned for fuel, at which point it reverts back to CO2 and water vapor. Another by-product of the digester is a semi-liquid manure, in which the nutrients have already been homogenized, making them more accessible to plants. This can be separated into liquid plant food, and a more solid manure.

A pilot project is currently operating at a houseboat marina in West London. It consists of five toilets and a small-scale digester, and is apparently working well. “The toilets were successful and we are now in discussions with numerous potential customers,” Loowatt’s Virginia Gardiner told us. “The digester is producing a steady supply of biogas which we have hooked up for cooking.”

The company was recently awarded a US$100,000 Grand Challenges Explorations grant from the The Bill & Melinda Gates Foundation, to develop the technology further. Anyone interested in trying the system out at their location is invited to contact Loowatt.

A similar system is in place at Cambridge, Massachusetts’ Park Spark project, in which anaerobically-digested dog feces are used to fuel a gas lamp in an urban dog park.

Sourced & published by Henry Sapiecha

shows warming world

January 21, 2011 – 2:12PM

Last year tied for the hottest year on record, confirming a long-term warming trend which will continue unless greenhouse gas emissions are cut, the World Meteorological Organisation says.

The first 10 years of the millennium proved to be the hottest decade since records began in the 19th century, it said.

“The main signal is that the warming trend continues and is being strengthened year after year,” WMO Secretary-General Michel Jarraud told a news conference on Thursday.

“The trend, unfortunately, will continue for a number of years but the amplitude will depend on the amount of greenhouse gases released,” the Frenchman added. “It will depend on action taken to minimise the release of greenhouse gases.”

Mr Jarraud said the latest data should convince doubters about the growing evidence for man-made climate change.

“If they look at it in an unbiased way, it should convince them, or hopefully a few of them, that the sceptical position is untenable.”

2010 was also marked by further melting of Arctic ice – in December its extent was at its lowest on record, the WMO said – and by extreme weather, including Russia’s heatwave and devastating floods in Pakistan.

Rising temperatures, already about 0.8 degree Celsius above pre-industrial times, mean the world will struggle to limit warming to below 2 degrees Celsius, a target agreed by almost 200 nations at UN talks in Mexico last month.

Many experts see 2 degrees as a threshold for dangerous climate change, such as more heatwaves, droughts, floods and rising seas.

“We have to act very fast and strongly [to limit emissions],” said Bob Ward, of the Grantham Research Institute on Climate Change and Environment at the London School of Economics and Political Science.

He noted that many sceptics say global warming has stopped because of no new records since 1998, when temperatures were boosted by a strong El Nino event that warms the Pacific.

“But they cannot explain away the fact that nine of the 10 warmest years have occurred since 2000,” he said.

“Data received by the WMO show no statistically significant difference between global temperatures in 2010, 2005 and 1998,” the United Nations body, which compiles its ranking from data provided by British and US agencies, said in a statement.

Data from British institutes on Wednesday showed last year was the world’s second warmest behind 1998, while the other two main groups tracking global warming, based in the United States, said 2010 was tied for the hottest on record.

Over the 10 years from 2001 to 2010, global temperatures have averaged 0.45 degrees Celsius above the 1961-1990 average and are the highest ever recorded for a 10-year period since climate records began, WMO said.

The difference between the three hottest years was less than the margin of uncertainty in comparing the data, according to WMO, whose assessment is based on climate data from land-based weather and climate stations, ships, buoys and satellites.

The fight against global warming suffered a setback in the wake of the financial crisis, slowing funding for renewable energy projects and knocking momentum from international efforts to agree on a climate deal to succeed the Kyoto Protocol in 2013.

Reuters

Sourced & published by Henry Sapiecha

Lithium-air batteries are currently in the works, and IBM predicts that batteries “that use the air we breath to react with energy-dense metal” will result in smaller, lighter rechargeable batteries that last ten times longer than today’s lithium-ion types. Whilst such batteries could be used in everything from cars to home appliances, it is also suggested that small items such as cell phones might not need batteries at all. IBM is trying to reduce the amount power required for such devices to less than 0.5 volts per transistor. At those rates, it is claimed, they could be powered via “energy scavenging” – like already-existing kinetic wrist watches that get their power from the user’s arm movements, or experimental piezoelectric devices.

Sourced & published by Henry Sapiecha

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Received & published by Henry Sapiecha

Sahara Solar Breeder Project aims to provide 50 percent of the world’s electricity by 2050

This is ambition with a capital A. Universities in Japan and Algeria have teamed up on a project that aims to solve the world’s energy problems. Called the Sahara Solar Breeder Project, the plan is to build manufacturing plants around the Sahara Desert and extract silica from sand to make solar panels, which will then be used to build solar power plants in the desert. The power generated by the initial plant or plants would be used to “breed” more silicon manufacturing and solar power plants, which will in turn be used to breed more again, and so on. The ultimate goal is to build enough plants to provide 50 percent of the world’s electricity by 2050, which would be delivered via a global superconducting supergrid. Read More

Sourced & published by Henry Sapiecha

Groasis Waterboxx lets trees grow up in unfriendly places

It’s not often that you hear about an invention that was modeled after bird poop, but there’s a first time for everything. In fact, this fecally-inspired device could ultimately be responsible for reforesting billion of acres of parched land, and it just won Popular Science’s Best Invention 2010 award. It’s called the Groasis Waterboxx, and it’s a low-tech product that helps seeds or saplings grow into strong trees in eroded, arid and rocky environments. Read More

Sourced & published by Henry Sapiecha

Up the Battery-Free World

The idea behind wireless sensor networks is old, but a battery-free design would vastly expand its range of application. Voltree Power LLC of the US, a spin-off from the Massachusetts Institute of Technology (MIT) of the US, has been contracted by the US Department of Agriculture to construct a temperature sensor network in mountainous, forested regions of California ^{Note 6)}.

Note 6) The power source is based on technology developed by MIT utilizing the electric potential difference between the tree trunk and surrounding area, which is between 50mV and 200mV.

The objective is to detect forest fires and minimize damage. Considering the damage cause by such fires, and the cost of firefighting personnel, equipment and supplies, the economics of constructing and operating a wireless sensor network are clear indeed.

One application attracting considerable attention of late is health monitoring. Sensors are mounted on buildings and bridges, detecting structural change. The amount and speed of these changes are used to diagnose the health of the structure, with acquired data utilized in guiding maintenance and component replacement.

There is considerable demand for health monitoring in the motor and engine sectors, as well. Automobiles use a large number of sensors to detect the conditions of various components, and as a result use vast quantities of wire harnesses. If engine and motor heat and vibration energy can be used to drive wireless sensors, it would be possible to dramatically cut the number of wire harnesses needed.

Another application in the health monitoring field is the life recorder, managing people and animals. Mounted on livestock or wild animals, for example, it can provide not only position information, but also data such as body temperature and pulse. If they can be powered by animal body heat, then there is no need for battery replacement.

Simple Enough for Everyone

Energy harvesting technology is the key behind the popularity of wireless sensor network, and with continuing development and wider recognition, a host of new applications will no doubt be pioneered. One major change in the environment is that companies getting into the energy harvesting field can now pick up low-power peripheral components very easily.

A large number of generating devices are already available from companies like AdaptivEnergy LLC of the US and Perpetuum Ltd. of the UK. For wireless technology, modules on the market eliminate the need for specialized knowledge of high-frequency waves. Alps Electric Co., Ltd. of Japan, which is volume producing a sensor network module using GainSpan’s wireless transceiver IC, has received inquiries from over thirty firms already.

Japan “A Decade Behind”

While the technology seems to be taking off, there are some worries for Japan: Japanese industry is almost invisible in the field energy harvesting field. Some people in the field warn that Japan is a decade behind Europe and America.

Sourced & published by Henry Sapiecha

Powering Up

The Battery-Free World

Sensors and Microcontrollers, Too!

Sensors are another type of peripheral components evolving rapidly. Sensors designed to acquire information such as temperature and humidity are shrinking and consuming less power. The brightness sensors used to control lighting, for example, are being mounted on mobile phones now, and over the past few years current consumption has droppedto one-fifth. A source at Avago Technologies, Inc. of Japan says “We’ve confirmed that we can maintain sensitivity while suppressing noise, even running on low voltage.”

The microcontrollers used to control energy harvesting circuits and sensor drive are also showing up in lower-power versions. One widely used design is the MSP430, from Texas Instruments Inc. (TI) of the US, which sells for as little as US$0.25 apiece.

Fig. 5 Standby Current a Key Point

In applications such as wireless sensor networks, standby time is significantly longer than actual operation time. (Diagram by Nikkei Electronics based on material courtesy Renesas Electronics)

The key points in microcontrollers are a low standby current consumption, and a very short wake-up time. Operation is intermittent in almost all wireless sensor networks, so standby current consumption is crucial. A comparison of this characteristic alone shows that 16-bit microcontrollers from Renesas Electronics Corp. of Japan have current consumption low enough to put them at the very top of the list for candidates (Fig. 5).

Thermoelectric Conversion Devices through Thinfilm Technology

In addition to merely improving the characteristics of peripheral components, however, other firms are working on the generating devices that are the heart of energy harvesting. For example, a thermoelectric conversion device with high electromotive force has appeared. Slated for volume production start in 2011, the device comes in a small, thin package, and can get 140mV from a temperature difference of about 1°C. Conventional devices measuring several cm on a wide can usually generate only about 50mV.

Fig. 6 Miniature High-Performance Thermoelectric Converters

Micropelt has begun supplying thermoelectric conversion devices, and modules using them (a). Made with thinfilm technology, they can provide satisfactory generating capacity even in small sizes (b). (Diagram by Nikkei Electronics based on material courtesy Micropelt)

The device was developed by Micropelt GbmH of Germany. Wladimir Punt, Vice President, Sales & Marketing at the firm, is confident in the technology: “We are constructing a plant now that will be able to manufacture 10 million modules annually.” Engineers applied thinfilm technology to create a device combining small size with high efficiency (Fig. 6) ^{Note 5)}.

Note 5) In manufacturing, n-type and p-type devices are sputtered individually on separate wafers, which are then sandwiched together in alternation.

Sourced & published by Henry Sapiecha

No Power through

Energy Harvesting:

Powering Up

the Battery-Free World

Stepping Up from only 20mV

Co2 to energy

The impact of higher power supply circuit performance is dramatic, because just how efficiently the power supply can handle the minute trickles of power gained through energy harvesting-how little loss there is-is key. Recently, even ultra-low voltages can be harvested efficiently.

Linear Technology Corp. of the US began volume production of the LTC3108 DC-DC converter, offering relatively high step-up efficiency from even an extremely low 20mV, in December 2009. With a thermocouple, the firm says, it can produce electricity from a temperature difference of only 1°C. An engineer involved in power supply circuit development for years is amazed: “They can use voltages a whole order lower than we can as energy sources!” ^{Note 2)}.

Note 2) The LTC3108 uses an internal n-channel metal oxide semiconductor field effect transistor (MOSFET) with external step-up transformer and capacitor, forming a resonant step-up oscillator. A transformer with a 100:1 ratio would boost 20mV to 2.0V.

According to Tony Armstrong, Director of Product Marketing, Power Products at Linear, the firm began development of the LTC3108 in about the summer of 2007, predicting growth in the energy harvesting field.

Ultra-Low Dissipation Wireless ICs

Lower dissipation by wireless transceiver ICs has also had an enormous effect, along with power supply circuits. Standby dissipation, previously about 1?A, has now been slashed to about 0.2?A thanks to smaller geometry and innovations in communications control.

One company that stands out in the energy harvesting field when it comes to wireless transceiver ICs is venture firm EnOcean GmbH of Germany. The amount of power consumed by the firm’s “EnOcean” standard for wireless communication between equipment is one digit smaller thanother methods.

Fig. 4 EnOcean Emphasizes Low Power Consumption and Ease of Use

The single design means a signal is sent only three times in 30ms (a), helping reduce standby current to only 0.2?A (b). The wavebands used vary by nation and region. Ease of use has been enhanced by modularization (c).

Power consumption was slashed by eliminating unnecessary functionality. Frank Schmidt, Chief Technical Officer (CTO) of the firm, stresses the key is simple control. Wireless ICs used in switch applications, for example, send only three 1ms signals every 30ms for on/off control (Fig. 4) ^{Note 3)}.

Note 3) The latest specification further improved convenience by supporting feedback from the receiver to the transmitter.

There are also efforts under way to apply low-power wireless LAN to energy harvesting wireless communication. GainSpan Corp. of the US, with founders including engineers from Intel Corp. of the US, has developed a wireless LAN IC with a standby current consumption of no more than 1?A: between 10% and 1% of standard designs ^{Note 4)}. This is about the same level as ZigBee. It offers an advantage in that existing wireless LAN access points can be utilized. Standardization has also started on ZigBee Green Power, however, a version of ZigBee tweaked for energy harvesting applications. The standard is expected to be finished by the end of 2010.

Note 4) Lower dissipation was achieved in part by frequent clock gating and use of sleep mode.

Sourced & published by Henry Sapiecha

Powering Up

the Battery-Free World

The enormous attention garnered by the growing market, in spite of the tiny amounts of power available, is due to the high convenience it promises. The major selling point for energy harvesting is that equipment can use it to eliminate primary battery replacement, wiring and maintenance (Fig. 2). It will mean a switch from low power to no power.

Fig. 2 Battery-Free Design for Enhanced Convenience

The key point is that primary batteries and wiring are no longer needed (a). Vibrator “battery” combines a capacitor and generator (b). The same size as a battery, it can be swapped into a remote control. A remote control for relay truck jacks was jointly developed by NHK Toyama Broadcasting Station and Yuasa (c), driven by the force of the finger pressing the buttons.

The range of applications is gradually expanding as industry makes an effort to realize this convenience. The Hoki Museum in Chiba City, Chiba prefecture, which opened on Nov. 13, 2010, for example, adopted energy harvesting technology for voice guidance switches. The system is already in operation.

Control signals are handled via wireless, eliminating the need for new wiring for the switches. Setting up the power cables and other wiring for frequently changing exhibits has always been a major load for art museums, and energy harvesting’s wire-free strengths are invaluable here.

Changing Peripheral Components

A representative energy harvesting system consists of four major steps, namely (1) detecting the energy source and generating electricity, (2) converting the acquired electricity as needed in a power supply circuit for storage in capacitors or rechargeable batteries, (3) using the stored power to drive microcontrollers and sensors, and (4) using a wireless transceiver to pass information acquired from sensors to the outside world ^{Note 1)}.

Note 1) The price of a unit implementing these four functions, according to Linear Technology’s Armstrong, is “about US$12 in lots of 50,000.”

The concept of energy harvesting is quite old, and research in the field also has a long history. The rapid expansion in application fields of late is due to evolution in the peripheral components to make best use of the generating devices, corresponding to steps (2) through (4) above. This evolution has made it possible to utilize the technology in an increasing range of applications.

Fig. 3 Generated power Exceeds Self-Consumption

The performance of generating devices is rising, while the power needs of peripheral components drops. The appearance of high-tech startups with superior technical expertise is especially significant in radio transceiver ICs, which dissipated the most power.

Peripheral component evolution here refers to significant reductions in power consumption by the power supply circuits needed to efficiently utilize generated power, the wireless ICs that send and receive signals, microcontrollers and sensors (Fig. 3). Until recently, the electricity collected by the generating devices was expended by the peripheral components themselves, making the target function impossible to achieve. Now that there are a number of ICs available with high-efficiency, low-dissipation circuits, energy harvesting has finally entered the realm of the practical.

Received & published by Henry Sapiecha