Renewable Hydrogen Sucked From Thinish Air

September 11, 2022 by Dave Rowntree 26 Comments

Stored hydrogen is often touted as the ultimate green energy solution, provided the hydrogen is produced from genuinely green power sources. But there are technical problems to be overcome before your average house will be heated with pumped or tank-stored hydrogen. One problem is that the locations that have lots of scope for renewable energy, don’t always have access to plenty of pure water, and for electrolysis you do need both. A team from Melbourne University have come up with a interesting way to produce hydrogen by electrolysis directly from the air.

Redder areas have more water risk and renewable potential

By utilising a novel electrolysis cell with a hygroscopic electrolyte, the so-called direct air electrolysis (DAE) can operate with humidity as low as 4% relative, so perfectly fine even in the most arid areas, after all there may not be clouds but the air still holds a bit of water. This is particularly relevant to regions of the world, such as deserts, where there is simultaneously a high degree of water risk, and plenty of solar potential. Direct electrolysis of saline extracted at coastal areas is one option, but dealing with the liberated chlorine is a big problem.

The new prototype is very simple in construction, with a sponge of melamine or a sintered glass foam soaked in a compatible electrolyte. Potassium Hydroxide (alkaline) was tried as was Potassium Acetate (base) and Sulphuric Acid, but the latter degraded the host material in a short time. Who would have imagined? Anyway, with electrolysis cell design, a key problem is ensuring the separate gasses stay separate, and in this case, are also separate from the air. This was neatly ensured by arranging the electrolyte sponge fully covered both electrodes, so as the hygroscopic material extracted water from the air, the micro-channels in the structure filled up with liquid, with it touching both ends of the cell, forming the circuit and allowing the electrolysis to proceed.

Hydrogen, being very light, would rise upward through holes in the cathode, to be collected and stored. Oxygen simply passed back into the air, after passing though the liquid reservoir at the base. Super simple, and from reading the paper, quite effective too.

You can kind of imagine a future built around this now, where you’re driving your hydrogen fuel cell powered dune buggy around the Sahara one weekend, and you stop at a solar-powered hydrogen fuel station for a top up and a pasty. Ok, possibly not that last bit.

The promised hydrogen economy may be inching closer. We covered using aluminium nanoparticles to rip hydrogen out of water. But once you have the gas, you need to store and handle it. Toyota might have a plan for that. Then perhaps handling gas directly at all isn’t a great idea, and maybe the future is paste?

Thanks to [MmmDee] for the tip!

We Can’t Switch To Electric Cars Until We Get More Copper

August 31, 2022 by Lewin Day 205 Comments

Reducing emissions from human activity requires a great deal of effort in many different sectors. When it comes to land transport, the idea is generally to eliminate vehicles powered by combustion engines and replace them with electric vehicles instead. At a glance, the job is simple enough. We know how to build EVs, and the technology is getting to the point where they’re capable of replacing traditional vehicles in many applications.

Of course, the reality is not so simple. To understand the problem of converting transportation to electric drive en masse, you have to take a look at the big numbers. Focus in on the metrics of copper, and you’ll find the story is a concerning one.

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Mining And Refining: Lithium, Powering The Future With Brine

February 9, 2022 by Dan Maloney 28 Comments

Many years ago, I read an article about the new hotness: lithium batteries. The author opened with what he no doubt thought was a clever pop culture reference by saying that the mere mention of lithium would “strike fear in the hearts of Klingons.” It was a weak reference to the fictional “dilithium crystals” of Star Trek fame, and even then I found it a bit cheesy, but I guess he had to lead with something.

Decades later, a deeper understanding of the lore makes it clear that a Klingon’s only fear is death with dishonor, but there is a species here on earth that lives in dread of lithium: CEOs of electric vehicle manufacturing concerns. For them, it’s not the presence of lithium that strikes fear, but the relative absence of it; while it’s the 25th most abundant element in the Earth’s crust, and gigatons are dissolved into the oceans of the world, lithium is very reactive and thus tends to be diffuse, making it difficult to obtain concentrated in the quantities their businesses depend on.

As the electric vehicle and renewable energy markets continue to grow, the need for lithium to manufacture batteries will grow with it, potentially to the point where demand outstrips the mining industry’s production capability. To understand how that imbalance may be possible, we’ll take a look at how lithium is currently mined, as well as examine some new mining techniques that may help fill the coming lithium gap.

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Impressive Off-Grid Hydroelectric Plant Showcases The Hacker Spirit

November 26, 2021 by Ryan Flowers 11 Comments

We all know the story arc that so many projects take: Build. Fail. Improve. Fail. Repair. Improve. Fail. Rebuild. Success… Tweak! [Kris Harbour] is no stranger to the process, as his impressive YouTube channel testifies.

Among all of [Kris’] off-grid DIY adventures, his 500 W micro hydroelectric turbine has us really pumped up. The impressive feat of engineering features Arduino/IOT based controls, 3D printed components, and large number of custom-machined components, with large amounts of metal fabrication as well.

[Kris] Started the build with a Pelton wheel sourced from everyone’s favorite online auction site paired with an inexpensive MPPT charge controller designed for use with solar panels. Eventually the turbine was replaced with a custom built unit designed to produce more power. An Arduino based turbine valve controller and an IOT enabled charge controller give [Kris] everything he needs to manage the hydroelectric system without having to traipse down to the power house. Self-cleaning 3D printed screens keep intake maintenance to a minimum. Be sure to check out a demonstration of the control system in the video below the break.

As you watch the Hydro electric system playlist, you see the hacker spirit run strong throughout the initial build, the failures, the engineering, the successes, and then finally, the tweaking for more power. Because why stop at working when it can be made better, right? We highly recommend checking it out- but set aside some time. The whole series is oddly addictive, and This Hackaday Writer may have spent inordinate amounts of time watching it instead of writing dailies!

Of course, you don’t need to go full-tilt to get hydroelectric power up and running. Even at a low wattage, its always-on qualities mean that even a re-purposed washing machine can be efficient enough to be quite useful.

Thanks to [Mo] for alerting us to the great series via the Tip Line!

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The Dark Side Of Solar Power

December 2, 2020 by Kristina Panos 302 Comments

Everybody loves solar power, right? It’s nice, clean, renewable energy that’s available pretty much everywhere the sun shines. If only the panels weren’t so expensive. Even better, solar is now the cheapest form of electricity for companies to build, according to the International Energy Agency. But solar isn’t all apples and sunshine — there’s a dark side you might not know about. Manufacturing solar panels is a dirty process from start to finish. Mining quartz for silicon causes the lung disease silicosis, and the production of solar cells uses a lot of energy, water, and toxic chemicals.

The other issue is that solar cells have a guanteed life expectancy of about 25 years, with average efficiency losses of 0.5% per year. If replacement begins after 25 years, time is running out for all the panels that were installed during the early 2000s boom. The International Renewable Energy Agency (IREA) projects that by 2050, we’ll be looking at 78 million metric tons of bulky e-waste. The IREA also believe that we’ll be generating six million metric tons of new solar e-waste every year by then, too. Unfortunately, there are hardly any measures in place to recycle solar panels, at least in the US.

How are solar panels made, anyway? And why is it so hard to recycle them? Let’s shed some light on the subject.

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Liquid Air Energy Storage: A Power Grid Battery Using Regular Old Ambient Air

July 24, 2020 by Kristina Panos 83 Comments

When you think of renewable energy, what comes to mind? We’d venture to guess that wind and solar are probably near the top of the list. And yes, wind and solar are great as long as the winds are favorable and the sun is shining. But what about all those short and bleak winter days? Rainy days? Night time?

Render of a Highview LAES plant. The air is cleaned, liquefied in the tower, and stored in the white tanks. The blue tanks hold waste cold which is reused in the liquefaction process. Image via Highview Power

Unfavorable conditions mean that storage is an important part of any viable solution that uses renewable energy. Either the energy itself has to be stored, or else the means to produce the energy on demand must be stored.

One possible answer has been right under our noses all along — air. Regular old ambient air can be cooled and compressed into a liquid, stored in tanks, and then reheated to its gaseous state to do work.

This technology is called Cryogenic Energy Storage (CES) or Liquid Air Energy storage (LAES). It’s a fairly new energy scheme that was first developed a decade ago by UK inventor Peter Dearman as a car engine. More recently, the technology has been re-imagined as power grid storage.

UK utility Highview Power have adopted the technology and are putting it to the test all over the world. They have just begun construction on the world’s largest liquid air battery plant, which will use off-peak energy to charge an ambient air liquifier, and then store the liquid air, re-gasifying it as needed to generate power via a turbine. The turbine will only be used to generate electricity during peak usage. By itself, the LAES process is not terribly efficient, but the system offsets this by capturing waste heat and cold from the process and reusing it. The biggest upside is that the only exhaust is plain, breathable air.

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Wind Farms In The Night: On-Demand Warning Lights Are Coming

March 24, 2020 by Sven Gregori 117 Comments

There appears to be no shortage of reasons to hate on wind farms. That’s especially the case if you live close by one, and as studies have shown, their general acceptance indeed grows with their distance. Whatever your favorite flavor of renewable energy might be, that’s at least something it has in common with nuclear or fossil power plants: not in my back yard. The difference is of course that it requires a lot more wind turbines to achieve the same output, therefore affecting a lot more back yards in total — in constantly increasing numbers globally.

Personally, as someone who encounters them occasionally from the distance, I find wind turbines mostly to be an eyesore, particularly in scenic mountainous landscapes. They can add a futuristic vibe to some otherwise boring flatlands. In other words, I can not judge the claims actual residents have on their impact on humans or the environment. So let’s leave opinions and emotions out of it and look at the facts and tech of one issue in particular: light pollution.

This might not be the first issue that comes to mind when thinking about wind farms. But wind turbines are tall enough to require warning lights for air traffic safety, and can be seen for miles, blinking away in the night sky. From a pure efficiency standpoint, this doesn’t seem reasonable, considering how often an aircraft is actually passing by on average. Most of the time, those lights simply blink for nothing, lighting up the countryside. Can we change this?

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