Electricity generation

3 Articles

Harvesting Energy From Ambient Moisture

April 11, 2020 by 24 Comments

Generating electricity out of thin air is the fantasy for our modern technology dependant world, but still falls squarely in the world of science fiction. However, researchers from the University of Massachusetts Amherst claim that they have found a way to do exactly that, using protein nano-wires to produce tiny amounts of electricity from ambient humidity.

The protein nano-wires in question are harvested from the microbe Geobacter sulfurreducens, to create a 7 µm thick film that is placed between two gold electrodes. One electrode completely covers the back of the film, while the front electrode covers only a tiny portion of the surface area. When the film is exposed ambient moisture, researchers measured 0.4 V – 0.6 V produced continuously for more than two months. The current density was about 17 µA/cm². This is only a fraction of the output of a commercial solar panel, but it can be layered with air gaps in between. The electricity is supposedly produced due to a moisture gradient through the thickness of the film. Harvesting energy using ambient humidity is not new, but the improvement in power density on this study is at least two orders of magnitude larger than that of previous studies.

The researches have named the technology Air-Gen and hope to develop it commercially. As we have seen many times before, promising lab results often don’t translate well into real world products, but this technology is definitely interesting.

We’ll continue to see all sorts of weird and wonderful ways to free up electrons, like using sweat, but we’ll have to wait and see what sticks.

Thanks for the tip [William Polo]!

Floating Power Plants; The Coastal City Solution Sure To Be Increasingly Popular

October 3, 2019 by 62 Comments

Building new things in an existing city is hard. Usually, new development means tearing down existing structures. Doing so for apartment complexes or new skyscrapers is one thing, but infrastructure is much more complicated, both from an engineering perspective and an economical one. Not only do people not want to foot the tax bill for things they may not see an immediate benefit from, but it can be difficult to find the space for bigger roads, more pipelines, or subway tunnels in a crowded urban area. It’s even harder for infrastructure that most consider an eyesore, like a power plant or electric substation. It’s no surprise then that some of the largest cities in the world have been making use of floating power plants rather than constructing them on dry land.

The latest city to entertain a bid for a new floating power plant (FPP) is New York, which is seeking to augment its current fleet of barge-based power stations already in operation. It already operates the largest FPP in the world at Gowanus in Brooklyn, which is able to output 640 MW of electricity. There’s also a 320 MW plant nearby as well, and the new plants would add eight 76 MW generators to New York City’s grid.

Let’s take a look at what goes into these barge-based generator designs.

Continue reading “Floating Power Plants; The Coastal City Solution Sure To Be Increasingly Popular” →

Energy Harvesting Peltier Ring

December 2, 2013 by 51 Comments

[Sean] is by no means an electrical engineer, but when he discovered the magic of Peltier plates he knew he had to make a project with them. This is his Energy Harvesting Peltier Ring.

The effect he is harnessing is called the SeeBeck Effect — the process of generating electricity through temperature differentials. He has shown how peltier plates work to many people, and, as you can guess, most people think they are amazing (free energy wow!). Unfortunately, most peltier plates are rather large and bulky, so [Sean] decided he wanted to try to design something small enough that could fit on a ring. Just a proof of concept, to light a tiny SMD LED.

The tiny Peltier plate he found generates about 0.3V with a temperature differential of about 20C — not bad, but it won’t light up any standard LEDs at that voltage! He started looking into voltage steppers and discovered Linear Technology’s 3108 Ultralow Voltage Step-up converter and Power Manager — a surface mount chip capable of scaling 0.3V to 5V. The only problem? [Sean’s] never done surface mount soldering.

His first circuit was built on a prototyping board, and after it worked successfully, he designed a PCB using Fritzing. Another success! Prototyping complete, it was now time to try to downsize the PCB even more to fit on a ring. Realizing there was no way he was going to fit it on a single ring, he decided to make a double ring out of CNC machined aluminum. He made use of his school’s CNC shop and the ring came out great. It works too! The room has to be fairly cool for the LED to light, but [Sean] definitely proved his concept. Now to make it even smaller!