Solar And Wind Could Help Support Ethiopia’s Grand Dam Project

Ethiopia is in the midst of a major nation-building project, constructing the Grand Ethiopian Renaissance Dam (GERD). Upon completion, GERD will become the largest hydropower plant in Africa, providing much needed electricity for the country’s growing population.

The project dams the Blue Nile, a river which later flows into neighbouring Sudan, where it merges with the White Nile and then flows on to Egypt. Like all rivers that flow across political boundaries, concerns have been raised about the equitable management of the water resources to the benefit of those upstream and down. Too much water dammed upstream in GERD could have negative effects on Egyptian agriculture reliant on river flows, for example. Efforts are ongoing to find a peaceful solution that suits all parties. Recently, suggestions have been made to supplement the dam’s power output with solar and wind to minimise disruption to the river’s users.

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Hackaday Links: March 28, 2021

If you thought the global shortage of computer chips couldn’t get any worse, apparently you weren’t counting on 2021 looking back at 2020 and saying, “Hold my beer.” As if an impacted world waterway and fab fires weren’t enough to squeeze supply chains, now we learn that water restrictions could potentially impact chip production in Taiwan. The subtropical island usually counts on three or four typhoons a year to replenish its reservoirs, but 2020 saw no major typhoons in the region. This has plunged Taiwan into its worst drought since the mid-1960s, with water-use restrictions being enacted. These include a 15% reduction of supply to industrial users as well as shutting off the water entirely to non-industrial users for up to two days a week. So far, the restrictions haven’t directly impacted chip and display manufacturers, mostly because their fabs are located outside the drought zone. But for an industry where a single fab can use millions of gallons of water a day, it’s clearly time to start considering what happens if the drought worsens.

Speaking of the confluence of climate and technology, everyone problem remembers the disastrous Texas cold snap from last month, especially those who had to endure the wrath of the unusually brutal conditions in person. One such victim of the storm is Grady, everyone’s favorite YouTube civil engineer, who recently released a very good post-mortem on the engineering causes for the massive blackouts experienced after the cold snap. In the immediate aftermath of the event, we found it difficult to get anything approaching in-depth coverage on its engineering aspects — our coverage excepted, naturally — as so much of what we found was laden with political baggage. Grady does a commendable job of sticking to the facts as he goes over the engineering roots of the disaster and unpacks all the complexity of the infrastructure failures we witnessed. We really enjoyed his insights, and we wish him and all our friends in Texas the best of luck as they recover.

If you’re into the demoscene, chances are pretty good that you already know about the upcoming Revision 2021, the year’s big demoscene party. Like last year’s Revision, this will be a virtual gathering, but it seems like we’re all getting pretty used to that by now. The event is next weekend, so if you’ve got a cool demo, head over and register. Virtual or not, the bar was set pretty high last year, so there should be some interesting demos that come out of this year’s party.

Many of us suffer from the “good enough, move on” mode of project management, leaving our benches littered with breadboarded circuits that got far enough along to bore the hell out of us make a minimally useful contribution to the overall build. That’s why we love it when we get the chance to follow up on a build that has broken from that mode and progressed past the point where it originally caught our attention. A great example is Frank Olsen’s all-wood ribbon microphone. Of course, with magnets and an aluminum foil ribbon element needed, it wasn’t 100% wood, but it still was an interesting build when we first spied it, if a bit incomplete looking. Frank has fixed that in grand style by continuing the wood-construction theme that completes this all-wood replica of the iconic RCA Model 44 microphone. It looks fabulous and sounds fantastic; we can’t help but wonder how many times Frank glued his fingers together with all that CA adhesive, though.

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Increasing The Resolution Of The Electrical Grid

As a society in the USA and other parts of the world, we don’t give much thought to the twisting vines of civilization that entangle our skies and snake beneath our streets. The humming electrical lines on long poles that string our nations together are simply just there. Ever-present and immutable. We expect to flick the switch and power to come on. We only notice the electrical grid when something goes wrong and there is a seemingly myriad number of ways for things to go wrong. Lighting strikes, trees falling on lines, fires, or even too many people trying to crank on the A/C can all cause rolling blackouts. Or as we found out this month, cold weather can take down generation systems that have not been weatherized.

We often hear the electrical grid described as aging and strained. As we look to the future and at the ever-growing pressure on the infrastructure we take for granted, what does the future of the electrical grid look like? Can we move past blackouts and high voltage lines that criss-cross the country?

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Ask Hackaday: With Landline Use In Decline, What’s To Be Done With The Local Loop?

Walking is great exercise, but it’s good for the mind too: it gives one time to observe and to think. At least that’s what I do on my daily walks, and being me, what I usually observe and think about is the local infrastructure along my route. Recently, I was surprised to see a number of telephone company cabinets lying open next to the sidewalk. Usually when you see an open box, there’s a telephone tech right there, working on the system. But these were wide open and unattended, which I thought was unusual.

I, of course, took the opportunity to check out the contents of these pedestals in detail. Looking at the hundreds of pairs of brightly colored wire all neatly terminated and obviously installed and maintained at great expense, I was left wondering why someone would leave such a valuable asset exposed to the elements. With traditional POTS, or plain old telephone service, on the decline, the world may no longer have much use for the millions of miles of copper cable feeding back to telco central offices (COs) anymore. But there’s got to be something this once-vital infrastructure is still good for, leading me to ask: what’s to be done with the local loop?

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Our Trucks Won’t Need No Batteries! Electric Trucks Look To Overhead Wires For Power

As the world grapples with the spectre of the so-called “hockey stick” graph of climate change, there have been a variety of solutions proposed to the problem of carbon emissions from sectors such as transport which have become inseparable from the maintenance of 21st century life. Sometimes these are blue-sky ideas that may just be a little bit barmy, while other times they make you stop and think: “That could just work!”.

Such an idea is that of replacing the diesel engines in trucks with electric motors powered not by batteries but from overhead cables. An electric tractor unit would carry a relatively small battery for last-mile transit, but derive its highway power by extending a pantograph from its roof to a high-voltage cable above the road. It’s extremely seductive to the extent that there have even been trials of the system in more than one country, but does it stack up to a bit of analysis?

Time’s Up For Those Big Rigs

Siemens and Scania are justifiably proud of their electrified stretch of autobahn and electric trucks in Germany.
Siemens and Scania are justifiably proud of their electrified stretch of autobahn and electric trucks in Germany.

One thing that should be obvious to all is that moving our long-distance freight around by means of an individual fossil-fuel-powered  diesel engine for every 38 tonne or so freight container may be convenient, but it is hardly either fuel-efficient or environmentally friendly The most efficient diesel engines on the road are said to have a 43% efficiency, and when hauling an single load they take none of the economies of scale afforded to the diesel engines that haul for example a freight train. Similarly they spread any pollution they emit across  the entirety of their route, and yet again fail to benefit from the economies of scale present in for example a power station exhaust scrubber. However much I have a weakness for the sight of a big rig at full stretch, even I have to admit that its day has passed.

The battery technology being pursued for passenger cars is a tempting alternative, as we’ve seen with Tesla Semi. But for all its technology that vehicle still walks the knife-edge between the gain in cost-effectiveness versus the cost of hauling around enough batteries to transport that quantity of freight. Against that the overhead wire truck seems to offer the best of both worlds, the lightness and easy refueling of a diesel versus the lack of emissions from an electric. In the idealised world of a brochure it runs on renewable wind, sun, and water power, so all our problems are solved, right? But does it really stack up?

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Wall-Climbing Robot Grabs Prize

Gravity is a nice thing to have most of the time, but sometimes it would be nice to be able to ignore it for certain applications. Rock climbing, for example, would be much easier, as would performing bridge inspections in the way that a group of mechanical engineering cadets (students) at The Citadel, a military college in South Carolina, were tasked with doing. Frustrated with the amount of traffic backups that normal bridge inspections caused, they invented a robot that defies gravity, and won a $10k prize for their efforts.

The result is essentially an RC car with a drone built in, or looking at it another way it’s a drone with wheels. The car is able to drive on vertical surfaces to inspect the bridges by using its propellers to force itself onto the surface. The lack of complicated moving parts or machinery, like a cable suspension system or other contraption, makes this device exceptionally versatile for the task at hand, reduces the amount of time needed for inspections, and can do them more safely and without closing lanes of traffic. The group hopes to build a second prototype soon and present it to the Department of Transportation for approval for more widespread use.

The need for tools like these is in high demand now as well, especially in the United States where crumbling infrastructure is often not thought about, taken seriously, or prioritized. Even for bridges that aren’t major pieces of infrastructure, tools like these will prove to be very useful.

Thanks to [Ben] for the tip!

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

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.

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