While in "power generating clothes 1" scientists are using thermoelectricity to create power, there are also other physical principles that can be applied to turn clothes into little power plants. Different research groups have managed to apply two different principles simultaneously to maximize total electricity output. A research group of KIST combined the principles of:
1. A triboelectric generator (TEG) that can turn body movements into electricity by generating electric charges. It has to do with the effect that we can observe sometimes when putting on a synthetic pullover (generating static electricity). For body movements there is by the way also the possibility to use the effect of pietoelectricity which occurs in some solid materials when under mechanical stress. That effect is used in this study. Or in this study.
2. A perspiration generator (PEG) that can turn sweat into power (Whereas there is also a way to turn sweat into electricity with the help of a biofuel cell as they do in this study). The perspiration generator (PEG) the scientists of KIST are using works in a seemingly similar way as the hygroelectric generator described on this site here. Only this time it is not the water in the air passing nanotubes but sweat passing a fabric from body towards the air due to evaporation.
As mentioned in another post, it is possible to generate electricity from the difference in temperature (thermoelectricity). Because our body temperature is usually warmer than the temperature of our environment, we could in theory use that temperature gap for energy generation. Many researchers are and have been in the past trying to turn that theory into practice by creating wearable fabrics that work like a thermoelectric generator. One of the main challenges so far was the fact that the required metals were not very flexible and the fabric would lose its thermoelectric features easily. Researchers from Swedish Chalmers University of Technology now have created a silk thread that is coated with a carbon based conductive polymer that was recently discovered. This polymer is much more flexible and durable than the metals used in formerly invented elecricity generating cloth. In their trials they could proof that with such a fabric it is absolutely possible to create clothes that can generate enough power to make small sensors work. Or maybe even charge a phone. Only by body-heat. Another positive side effect of using such a carbon based conductive polymer is that no rare earth metal is needed.
It sounds almost too good to be true but apparently there is (in theory) a way to extract huge amounts of electricity out from the air. As long as there is some humidity. Even in the desert. The reason for that has to do with the Armstrong effect which was discovered in the 19th century. It is the same effect that is causing lightnings during thunderstorms. When water molecules (H2O) are rubbing against other molecules, this can lead to static charges. Scientists from University Massachusetts Amherst have developed a small device not bigger than a finger nail with tiny pores of around 100 nanometers in diameter. When water molecules of the air (humidity) pass those pores, the device gets loaded up with electrical charges on the side of the device where the molecules are exiting. Since there is some important amount of humidity in the air almost anywhere around the globe, such a "free power" generator could deliver instant electricity day and night wherever and whenever we need it. In normal atmospheric conditions, such an energy device could - if stacked up one nano poor layer over another - power an entire house if scientists manage to scale it up to the size of a fridge. It is pretty obvious to me that this technology has the potential to solve our global warming problem nearly all by itself (not even considering all the other available green energy technologies). Jun Yao and his team have formerly been experimenting with nano tubes that were generated by bacteria. They seem to work just as well as nano tubes made from other materials. Offering a whole range of options to build affordable "free energy" generators that have a small ecological footprint. There are currently several researchers investigating the feasability of different kinds of hygroelectric generators. A "fridge sized free energy generator" that can power a whole building could not be realised yet. But scientists of Japan´s
AIST could already build a hygroelectric cell based on a slightly different approach (difference of humidity levels throuout the day) that was able to power a wireless sensor for more than four months. Proving that the technology of hygroelectricity can be of practical use already now. It is likely that with the help of AI, the things that we know are possible in theory will be possible to be turned into reality in a much shorter amount of time.
Similarly to the post below, researchers of Stanford University are using radiative cooling to boost power outcome. But other than generating power with a Stirling machine they are using a thermoelectric generator. Like a Stirling engine can turn a temperature gap into mechanical energy a TEG can turn the temperature difference (directly) into electricity. Prof. Shanhui Fan and his team proofed that by using radiative cooling, their TEG can produce enough electricity to power small devices like lights, sensors or communication devices. Thanks to the fact that it can provide power 24/7 the use of batteries in off-grid areas could be reduced or completely avoided. Reducing ecological footprint and creating some additional green energy for the world. Shanhui Fan and his team tried to use as many "off the shelf"- components as possible so it should be easy to reproduce.
Scientists at UC Davis have combined two already existing technologies to create a power generator that offers free electricity at night. The two technologies are namely; 1. Radiative cooling 2. Sterling engine.
The sterling engine was invented in the 19th century to create a machine that is safer than the well known and formerly invented steam engine. It can work with any kind of heat (it is the acquired temperature difference that is key). What Prof. Jeremy Munday and his team discovered is that a Sterling engine can run solely by the temperature difference between the ground and the surface by cooling the cool part of the system with radiative cooling (radiative cooling->Planck´s law). Radiative cooling works best when there aren´t any clouds so the radiant energy won´t get reflected and can leave into space. Thanks to the radiative cooling, the cold part can be cooled beneath the surounding air temperature. Providing a big enough temperature gap to create a couple of Watts of mechanical power per square meter. This newly invented system could be an ideal free energy source for air circulation in greenhouses or residential buildings at night.
Earth's underground is warm. In Switzerland for example, the temperature increases by 30° Celsius for every 1000 meters. So in 5000 meters depth the temperature is around 160° Celsius. This energy can be extracted for example with the use of water that is being pumped and extracted from a kilometers deep hole. That warm water can then be used to heat homes in winter or even to produce electricity. In
Reykjavik, Iceland, 95% of homes are being heated like this. Normally, no greenhouse gases are being extracted which is why it is a potentially completely green technology. (Deep) geothermal energy is of the same principle as heat pumps for homes but on a larger scale and with much deeper drill holes. Maybe a slitghtly different category of geothermal energy: Company KMT and its "near magma technology" that is currently being developed.
Mushrooms may play an important role in the future. After we got to learn that mushrooms can digest certain types of plastic and can replace certain types of plastic, now scientists found out that mushrooms can also act as biodegradable batteries. Not necessarily to power smartphones or laptops. But so far, scientists of the Swiss research facility Empa were able to develop mushroom batteries that are able to produce up to 600mV. They therefore could be ideal for small electronic devices like (temperature) sensors in agriculture or in natural surroundings.
The energy of the tides (the water currents) can also be harnessed. A tidal stream generator works similar to a windwheel. Because water is denser than air, the speed of the water current can be much lower than wind to harness the same amount of energy. There are different kinds of tidal power stations.
Switzerland's ETH has found a way to turn the CO2 of the air back into fuel by only using the power of the sun. So in the future we might use airplanes that fly with 100% renevable fuel.
Human feces can be turned into methane (=biogas) and CO2. And the CO2 can be fed to algae who turn the carbon dioxide into biofuel once again. The biofuel will then be used to heat and power the building. 0.5kg of feces can generate 0.5kWh of electricity. In addition, the toilet also needs much less water. Cho from the South Korean UNIST called it the beeVi. Another company created a similar toilet (the loowatt) which is supposed to be able to work in any place and off grid without any water. Methane is a bad greenhouse gas but when it burns it produces energy and turns into CO2 and water. In nature, untreated feces turn into methane all by itself. So when we use that methane to turn it into power no methane will get into the air (methane is a worse greenhouse gas than CO2) plus we have extra power that we would have had to produce otherwise. Since humans eat plants (that grew by catching CO2) in the end no additional CO2 is being produced. It is the same principle as trees being cut and burnt to create energy and (!!) being replanted.
Cyanobacteria (also known as blue-green algae) are a type bacteria that can fix CO2, a key component of butanol. By altering the bacteria's DNA scientists may be able to turn them into renevable fuel production machines. The special thing about cyanobacteria is that they are capable of photosynthesis same as plants who are turning energy from the sun into carbon bonds (e.g. wood). But as a bacteria their produced carbon bonds are more similar to the carbon bonds of usable fuel. Since biofuel produced by those bacteria are made of the same carbon molecules that they took from the air (CO2), when we are burning that fuel we are overall not adding additional CO2 to the admosphere. Which is not the case when we are burning fossil fuel that has been deep in the ground for millions of years. Algae and cyanobacteria are very similar although algae are closer to plants because they have a defined nucleus (eukaryotes).
In contrast to natural gas that comes from the ground and is contributing to global warming we can produce the same kind of gas out of organic waste. Biogas is 100% renevable and can be made of any organic material, including grass or human feces.
Hydropower currently accounts for 37% of total U.S. renewable electricity generation and about 7% of total U.S. electricity generation.
In 2020 hydropower generated one sixth of the world's electricity,almost 4500 TWh, which was more than all other renewables combined and also more than nuclear power.
Solar pannels are a well known technology to turn sunlight into electricity (or heat). In order to make them even more cost effective than they already are, scientists are currently testing printable slar pannels that woukd further reduce the cost of solar energy.
Wind is currently the second largest renewable energy production source worldwide (after hydropower). Wind power produced more than 6 percentof global electricity in 2020 with 743 GW of global capacity (of which 707.4 GW onshore and the rest is from winswheels in the sea).