It’s been clear for a long time that the world has to move away from fossil energy sources. Decades ago, this seemed impractical, when renewable energy was hugely expensive, and we were yet to see much impact on the ground from climate change. Meanwhile, prices for solar and wind installations have come down immensely, which helps a lot.
As society transitions toward renewable energy sources, energy storage inevitably comes to mind. Researchers at the University of Illinois at Urbana-Champaign have found one way to store renewable energy that re-purposes existing fossil fuel infrastructure.
While geothermal electricity generation shows a lot of promise, it’s currently limited to a select few areas where hot rock is close to the Earth’s surface. Advanced Geothermal Energy Storage (AGES) stores energy underground as heat and recovers it later, even in places without high subsurface temperatures. For this study, the researchers located an old oil well and instrumented it with “flow meters, fiber optic
distributed temperature sensing (DTS) cable, surface pressure and temperature gauges, and downhole pressure and temperature gauges to monitor the thermal and hydraulic changes during the injection test.”
This field study found that AGES system efficiency could be as high as 82% and yield an “economically viable” levelized cost of electricity (LCOE) of $0.138/kWh. Using existing deep hole infrastructure speeds up site selection and deployment of AGES when compared to developing on an undisturbed location, making this a very interesting way to deploy grid-scale storage rapidly.
We’re all familiar with batteries. Whether we’re talking about disposable AAs in the TV remote, or giant facilities full of rechargeable cells to store power for the grid, they’re a part of our daily lives and well understood.
However, new technologies for storing energy are on the horizon for grid storage purposes, and they’re very different from the regular batteries we’re used to. These technologies are key to making the most out of renewable energy sources like solar and wind power that aren’t available all the time. Let’s take a look at some of these ideas, and how they radically change what we think of as a “battery.”
If you’ve ever aspired to live off the grid, then it’s likely that one of the first things you considered was how to power all of your electrical necessities, and also where to uh… well we’ll stick to the electrical necessities. Depending on your location, you might focus on hydroelectric power, solar power, or even a wind turbine. Or, if you’re [Kris Harbor], all three. In the video below the break, we get to watch [Kris] as he masterfully rebuilds his wind turbine from scratch and reconfigures his charging solution to match.
The Rotors Are Built With a 3d Printed Rotor Jig
A true hacker at heart, [Kris] has used a everything from 3d printing to broken car parts in order to build his new wind turbine. The three phase generator is constructed from scratch. A hand wound stator is held firmly between two magnetic rotors, where 3d printed jigs hold the magnets in place.
A CNC cut backing plate holds everything together while also supporting the automatically furling vane that keeps the entire turbine from self destructing in inclement weather. A damaged wheel hub from [Kris]’ Land Rover provides the basis for a bearing so that the entire turbine can turn to face the wind, and various machined parts round out the build. The only things we didn’t see in the build were hot glue and zip ties, but we remain hopeful. Continue reading “Scratch Built Wind Turbine Makes Power And Turns Heads”→
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.
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.
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.
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.
