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.
If you watch YouTube long enough, it seems like going “off the grid” is all the rage these days. But what if the thing that goes off the grid is the grid itself? In the video below the break, [Grady] with Practical Engineering explores the question: How do you restart an entire power grid after it’s gone offline? It’s a brilliantly simple deep dive into what it takes to restore power to large amounts of customers without causing major damage to not just the grid, but the power generators themselves.
The hackers among us who’ve dealt with automotive alternators know it must be excited in order to generate electricity. What does that even mean, and how does it affect the grid? Simply put, it takes power to make power. For example, old heavy equipment had what they called pony motors — a small easy to start engine that’s sole purpose was to start a much larger engine. Aircraft have auxiliary power units (APUs) for the same purpose. What do power grids have? You’ll have to watch the video to find out.
Once at least two power generators are online, grid operators can just flip the switch and start feeding power to customers, right? Not quite. [Grady] once again uses a clever test jig and an oscilloscope to show the damage that can occur if things aren’t done just right. It’s a fascinating video well worth watching.
Nowadays, some people in Europe worry about energy prices climbing, and even if all the related problems disappear overnight, we’ll no doubt be seeing some amounts of price increase. As a hacker, you’re in a good position to evaluate the energy consuming devices at your home, and maybe even do something about them. Well, [Peter] put some solar panels on his roof, but couldn’t quite figure out a decent way to legally tie them into the public grid or at least his flat’s 220V network. Naturally, a good solution was to create an independent low-voltage DC network in parallel and put a bunch of devices on it instead!
He went with 48V, since it’s a voltage that’s high enough to be efficient, easy to get equipment like DC-DCs for, safe when it comes to legal matters concerned, and overall compatible with his solar panel setup. Since then, he’s been putting devices like laptops, chargers and lamps onto the DC rail instead of having them be plugged in, and his home infrastructure, which includes a rack full of Raspberry Pi boards, has been quite content running 24/7 from the 48V rail. There’s a backup PSU from regular AC in case of overcast weather, and in case of grid power failures, two hefty LiFePO4 accumulators will run all the 48V-connected appliances for up to two and a half days.
The setup has produced and consumed 115kWh within the first two months – a hefty contribution to a hacker’s energy independence project, and there’s enough specifics in the blog post for all your inspiration needs. This project is a reminder that low-voltage DC network projects are a decent choice on a local scale – we’ve seen quite viable proof-of-concept projects done at hackercamps, but you can just build a small DC UPS if you’re only looking to dip your feet in. Perhaps, soon we’ll figure out a wall socket for such networks, too.
With climate change concerns front of mind, the world is desperate to get to net-zero carbon output as soon as possible. While direct electrification is becoming popular for regular passenger cars, it’s not yet practical for more energy-intensive applications like aircraft or intercontinental shipping. Thus, the hunt has been on for cleaner replacements for conventional fossil fuels.
Hydrogen is the most commonly cited, desirable for the fact that it burns very cleanly. Its only main combustion product is water, though its combustion can generate some nitrogen oxides when burned with air. However, hydrogen is yet to catch on en-masse, due largely to issues around transport, storage, and production.
This could all change, however, with the help of one garden-variety chemical: ammonia. Ammonia is now coming to the fore as an alternative solution. It’s often been cited as a potential way to store and transport hydrogen in an alternative chemical form, since its formula consists of one nitrogen atom and three hydrogen atoms.However, more recently, ammonia is being considered as a fuel in its own right.
Let’s take a look at how this common cleaning product could be part of a new energy revolution.
We’ve all experienced power outages of some kind, be it a breaker tripping at an inconvenient time to a storm causing a lack of separation between a tree and a power line. The impact is generally localized and rarely is there a loss of life, though it can happen. But in the video below the break, [Grady] of Practical Engineering breaks down the Northeast Blackout of 2003, the largest power failure ever experienced in North America. Power was out for days in some cases, and almost 100 deaths were attributed to the loss of electricity.
[Grady] goes into a good amount of detail regarding the monitoring systems, software simulation, and contingency planning that goes into operating a large scale power grid. The video explains how inductive loads cause reactance and how the effect exacerbated an already complex problem. Don’t know what inductive loads and reactance are? That’s okay, the video explains it quite well, and it gives an excellent basis for understanding AC electronics and even RF electronic theories surrounding inductance, capacitance, and reactance.
So, what caused the actual outage? The complex cascade failure is explained step by step, and the video is certainly worth the watch, even if you’re already familiar with the event.
It would be irresponsible to bring up the 2003 outage without talking about the Texas ERCOT outages just one year ago– an article whose comments section nearly caused a blackout at the Hackaday Data Center!
Depending upon where in the world you live, AC mains frequency is either 50Hz or 60Hz, and that frequency is maintained accurately enough over time that it can be used as a time reference for a clock. Oddly it’s rarely exactly that figure though, instead it varies slightly with load on the network and the operators will adjust it to keep a constant frequency over a longer period. These small variations in frequency can easily be measured, and [jp3141] has created a circuit that does exactly that.
It’s a surprisingly straightforward device, in which a Teensy takes its power supply from a very conventional if now a little old-school mains transformer, rectifier, and regulator. A sample of the AC from the transformer passes through a low-pass filer and a clamp, and thence to the Teensy where it is fed into one of the on-board comparators from which its period is measured using one of the timers. Even then the on-board crystal isn’t considered accurate enough, so it is in turn disciplined by a 1 pulse per second (PPS) signal from a GPS receiver.
The Teensy then reports its readings over a serial line every five seconds to a Raspberry Pi, which collates and graphs the data. In case you are wondering what the effect of mains frequency variations might be, we once covered the story of how an entire continent lost six minutes.
The electric power grid, as it exists today, was designed about a century ago to accommodate large, dispersed power plants owned and controlled by the utilities themselves. At the time this seemed like a great idea, but as technology and society have progressed the power grid remains stubbornly rooted in this past. Efforts to modify it to accommodate solar and wind farms, electric cars, and other modern technology need to take great effort to work with the ancient grid setup, often requiring intricate modeling like this visual power grid emulator.
The model is known as LEGOS, the Lite Emulator of Grid Operations, and comes from researchers at RWTH Aachen University. Its goal is to simulate a modern power grid with various generation sources and loads such as homes, offices, or hospitals. It uses a DC circuit to simulate power flow, which is visualized with LEDs. The entire model is modular, so components can be added or subtracted easily to quickly show how the power flow changes as a result of modifications to the grid. There is also a robust automation layer to the entire project, allowing real-time data acquisition of the model to be gathered and analyzed using an open source cloud service called FIWARE.
In order to modernize the grid, simulations like these are needed to make sure there are no knock-on effects of adding or changing such a complex system in ways it was never intended to be changed. Researchers in Europe like the ones developing LEGOS are ahead of the curve, as smart grid technology continues to filter in to all areas of the modern electrical infrastructure. It could also find uses for modeling power grids in areas where changes to the grid can happen rapidly as a result of natural disasters.