Capturing unclaimed energy from underutilized sources
Our world is full of amazing technologies, but they all become dead weight once their batteries run out. Fortunately, there’s energy all around us, even if tapping into some of it hasn’t been easy thus far. As the world tries to get away from fossil fuels that pollute or require costly extraction, researchers have been finding pockets of power from our leftovers to ourselves to help keep the lights on a bit longer.
Colorful solar cells
Starting with what is becoming an increasingly common source of power, new materials aim to make collecting solar energy easier. While most photovoltaic cells are expensive and need to be carefully installed, a new kind of ink allows for solar collection on more surfaces, and at lower cost. Since normal inks naturally absorb energy as heat, the trick was finding a way to transfer that energy to a useful outlet. While they don’t provide an enormous amount of power, these inkjet-dyed solar cells have been found to be very durable, making them a great way to make a visual design element, like paint on a bus, into an unobtrusive energy collection device to augment other reserves.
Wattage from your warmth
For colder days without as much sun, your own body might prove to be a good way to charge up a device. Your body naturally keeps a nice warm internal temperature, but if it’s warm outside its hard to capture much of a current from your body heat. When there’s a bigger gap between temperatures, energy as heat is transferred in quantities large enough to capture and make use of. This idea isn’t new, but recent improvements in designs with electrolyte gels have been able to capture enough power to start charging a battery. For instance, an array of thermocells in a pair of gloves was able to produce 0.7 volts and 0.3 μW. The goal now is to further optimize the system, allowing for more power to be grabbed at warmer temperatures.
Farming algae oils
The above options are nice for reclaiming smaller amounts of energy, but one of the reasons we’ve had a hard time getting over fuels like coal is scale. At this point we have a lot of infrastructure in place to make massive amounts of electricity by burning these fuels, but that doesn’t mean they’re the only game in town. Looking to the water, scientists are working on ways for algae to grow us fuel in large quantities. These plants do some of the hard work for us, using photosynthesis to turn sunlight into sugars and crucially, oils. Those oils can then be harvested and burned or used in manufacturing like crude oil, all without the need for drilling, mining or fracking.
So once we’ve got all this collected power, we might need more places to store it. The world has lots of batteries, but even more organic food waste that is often left to rot without doing anyone any good. However, a byproduct of that food’s decomposition is sugar alcohols, which are great at holding onto energy in the form of heat. With that in mind, researchers are exploring how carbon nanotubes might be able to make those alcohols into reliable, efficient media to store power. We wouldn’t really be plugging our coffee makers into our compost piles, of course, but it would be a way to get more out of materials that were otherwise dumped as waste.
Source: We Can Power The World With Algae! by Glenn McDonald, Seeker