Clever energy saving

Trend Energy Harvesting

In the past, things were mechanical and work without energy. pixabay.com, the fifth
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Our households are digitized, workplaces automated, mobility centralized - our daily lives are increasingly determined by machines, machines and systems. It all costs a lot of electricity. Energy Harvesting should ensure that the energy consumption decreases.

Saving energy means saving money: well-known vs. innovation

Of course, there are many well-known tips that advise you to use energy-saving devices and to keep a close eye on your own power consumption. In addition, clever scientists are concerned with not simply letting existing energy evaporate, but use it imaginatively.

Private households currently have two options: book cheap rates and reduce energy consumption

While policymakers promise to fund innovative technologies for sustainable energy use, private households without government grants on a small scale need to cut their energy needs on the one hand and costs on the other. There are two ways to increase costs: once above the price of electricity and secondly through consumption.

The first step that consumers should do to relieve their own wallet is to book a cheap electricity rate. Stiftung Warentest is quoted on the website of Stromvergleich.de with these words: "If you want to benefit from high new customer bonuses, you have to choose a new provider every year." Only this way, consumers get every year the optimum in economic terms for themselves out.

The second step is to reduce your own energy consumption. In practice this means that consumers use energy-efficient appliances and adjust their consumption behavior. The Federal Environment Agency has published a variety of tips, brochures and tips on Umweltbundesamt.de. display

Pioneering or mistaken belief: recycling energy from household appliances

A new energy saving trend that could reduce the consumption costs in private households in the long term is Energy Harvesting. It is for the private user to let already existing energy from the immediate vicinity of a toaster, a coffee maker, a refrigerator or a stove not ineffective fizzle, but to use them.

What is Energy Harvesting?

The term Energy Harvesting is synonymous with the terms Power Harvesting, Energy Scavenging and Ambient Energy Harvesting, although differences may be revealed upon closer inspection. As a rule, it is about gaining and using energy from the immediate surroundings of an electrical device. The following sources of energy are considered:

  • rotation
  • Linear motion
  • Vibration / impact
  • wind currents
  • water currents
  • heat flows
  • light
  • temperature differences
  • radio waves
  • sound

Lively and well-known practices for the intelligent use of existing energy in nature are, for example, solar wind turbines or solar plants. These dimensions are not meant by the concept of energy harvesting. Energy Harvesting is about much smaller dimensions. Although the principle is similar to use existing energy - but in detail, the approaches differ from each other, as the following examples show.

Surprising examples from science

One step in the direction of biophysics is taken by scientists who use energy from bodily fluids and use them sensibly. Researchers have developed biofuel cells that generate electricity from welding. The biofuel cell looks like a big patch and it consists of small flat gold discs. One half of the gold discs are anodes, the other cathodes. Twisted gold wires connect the individual gold points. This will make the patch elastic.

It is glued to the forearm, for example. An enzyme in the fuel cell causes the lactic acid in the sweat to oxidize. The released energy is converted into electricity and fed to the MP3 player or the fitness tracker on the wrist. So far, the biofuel cells are still in the test phase. An American research team around Amay Bandodkar has developed a prototype, which is not yet ready for production (as of December 2018). Her innovative project was presented in the renowned Journal Energy & Environmental Science . An interview with the scientist can be found at Siebelscholars.com.

As soon as the energy-converting plaster is commercially available, this means for private individuals: Never recharge the battery of a smartphone, a smartwatch or other small appliances via the socket. In view of the growing number of smart wearables, this is very good news, because that saves a great deal of energy globally.

Perpetuum mobile: The self-charging camera sensor

Amateur photographers know how high the energy demand of a complex camera is. You have to charge your device regularly to be able to pursue your hobby carefree. No electricity no photos, so the situation could be summed up. Now a group is working around the researcher Euisik Yoon, whose scientific profile can be found at Mcircc.umich.edu, at the University of Michigan in Ann Arbor on a camera that delivers photos without charging the battery via an external power source SEN. Two other teams of scientists have already tried this problem in the past: One group pursued the approach of using part of the sensor area for photovoltaics. However, the image quality suffered as a result of too little light being absorbed. The second approach envisaged the changing use of the sensor area. The sensor once functioned as an image sensor and once as a solar cell. The problem was that it made the system very complex and expensive and that fewer pictures could be taken.

The new concept, on the other hand, opens up the possibility of not only powering the sensor and the processor, but also enabling a WLAN chip to transfer images. For this purpose, the image sensor surface absorbs light and transforms it into electrical signals. An additional solar cell absorbs light and transforms it into electricity. In combination, this results in a sensor that supplies itself with power. The prototype delivers up to 15 frames per second. Behind this information is the fact that the development is an image sensor with the hitherto highest power density in the energy harvesting sector.

In practice this means: If the sun shines brightly from the sky with an average of 60, 000 lx, the sensor makes 15 frames per second. Normal daylight between 20, 000 and 30, 000 lx reduces the frame rate to 6-8 frames per second. Amateur photographers and professional photographers could use the combination sensor to save a lot of energy worldwide. If the research team around Yoon brings the development to market maturity, cameras could soon be making a high-performance job without external energy supply. For the hobby sector, the development level would probably already be sufficient today.