Ja tuo kuvan vehje tuottaa jotain 100-50 kW.Koska omavaraistelu kiinnostaa, ja varsinkin metanolilla sähkön tuottaminen, niin pakkohan se oli työntää päänsä syvemmälle kaninkoloon tässä polttokenno asiassa. Tälläinen tuli vastaan:
Kukaan ei ihmetellyt, kun tietoliikenne katkesi Aapeli-myrskyn kourissa ympäri Pirkanmaata, mutta Parkanossa puhelimet toimivat – salaisuus löytyy kennosta, jota on käytetty Nasan raketeissaParkanon taajamassa ja maaseutukaupungin länsiosissa kukaan ei osannut ihmetellä, miten matkapuhelimet pelasivat moitteetta Aapeli-myrskyn pitkän sähkökatkon aikana.www.aamulehti.fi
Ilmeisesti tekniikka on ottanut roimia harppauksia, koska lähemmäs kymmen vuotta sitten nuo linkkimastot sähköistettiin (ainakin virka-apu harjoituksissa) verkkosähkön lamaannuttua tämänkaltaisilla laitteilla:
Katso liite: 50937
muoks: löysin etsimäni pienellä vaivannäöllä
Since World War II, the U.S. Army has used approximately 20 times more energy per soldier while reducing the number of soldiers deployed. This undoubtedly will continue in the future as new capabilities with higher-power weapons, novel sensors and robots, and advanced computing are envisioned. This highlights the importance of energy supply and management for the future battlefield.
When considering Army maneuver, one key objective is minimizing the number of trucks carrying materials to the battlefield. As Army Futures Command explores future autonomous vehicles and active protective systems, the concern becomes less about lost lives (which was a major factor in Iraq and Afghanistan) and more about lost transport vehicles, fuel, water, munitions and other supplies, as autonomous systems would not require the physical presence of a human.
Looking at the transportation fuels used today, diesel, JP8 and biodiesel clearly have the highest volumetric energy density. And this is the most important measurement, as supply trucks generally “cube out” before they “weigh out.
Some sodium battery developers are using activated carbon for the anode, which holds sodium ions in its pores. "But you need to use high-grade activated carbon, which is very expensive and not easy to produce," Sun says.
Graphite, which is the anode material in lithium-ion batteries, is a lower cost option. However, sodium ions do not move efficiently between the stack of graphene sheets that make up graphite. Researchers used to think this was because sodium ions are bigger than lithium ions, but turns out even-bigger potassium ions can move in and out easily in graphite, Sun says. "Now we think it's the surface chemistry of graphene layers and the electronic structure that cannot accommodate sodium ions."
He and his colleagues have come up with a new graphite-like material that overcomes these issues. To make it, they grow a single sheet of graphene on copper foil and attach a single layer of benzene molecules to its top surface. They grow many such graphene sheets and stack them to make a layer cake of graphene held apart by benzene molecules.
The benzene layer increases the spacing between the layers to allow sodium ions to enter and exit easily. They also create defects on the graphene surface that as as active reaction sites to adsorb the ions. Plus, benzene has chemical groups that bind strongly with sodium ions.
This seemingly simple strategy boosts the material's sodium ion-storing capacity drastically. The researchers' calculations show that the capacity matches that of graphite's capacity for lithium. Graphite's capacity for sodium ions is typically about 35 milliAmpere-hours per gram, but the new material can hold over 330 mAh/g, about the same as graphite's lithium-storing capacity.
British engineering and aerospace giant Rolls-Royce has secured funding to build nuclear power stations based on small modular reactor (SMR) technology.
A consortium of BNF Resources UK LTD, Exelon Generatuion Lt and Roll-Royce Group will invest £195m roughly over a three-year period. This cash injection will allow the companies to qualify for a £210m grant from the British government, specifically the UK Research and Innovation Funding.
The path forward includes Rolls Royce entering the UK Generic Design Assessment process and closing in on sites for the factories to build the modules that will allow for on-site assemply of the power plants.
The funding could see four SMRs built based on nuclear submarine technology. Rolls Royce said a SMR power station will be the size of two football pitches and power circa one million homes.
Supercapacitors are definitely not the same as batteries, we all know that. They tend to have a very low operating voltage, and due to their operating principle of storing charge on parallel plates, their discharge curve is quite unfriendly for modern microcontroller devices. Energy storage efficiency per unit volume is also low compared with modern lithium polymer (LiPo) batteries so all in all they don’t look all that useful for many of our projects. However, as [Andreas Spiess’] latest video demonstrates, they do have some redeeming features that might make them useful for certain embedded applications.
The low operating voltage initially looks like an issue for devices operating at a typical 3.3V, and it’s tempting to simply wire a few in series and roll with it. But as [Andreas] explains in his typically clear manner, it would be necessary to have a complex power stage, operating in buck mode with capacitor voltage above the required level, and in boost mode when it heads below. Too complex – it’s much easier to simply stick with a low voltage bank of paralleled supercaps, and just operate always in boost mode. Even doing this, you’re not realistically going to get more than a handful of hours operating voltage with an always active device.
So why bother at all with supercaps, surely using a LiPo is so much easier and better? In many cases the answer is definitely a yes. But LiPo cells must not be charged in freezing temperatures (apart from certain special low temp products), else the cell can rapidly be destroyed due to lithium metal deposition at the anode. Also you need to be careful charging them, especially when they’re heavily discharged, as they are easily damaged without the proper treatment. LiPo cells operate based on chemical principles – lithium ions literally have to move around inside the structure, and eventually the battery will wear out.
Supercapacitors have the advantage of very long life (but sometimes, they do leak) much more aggressive charging and discharging behaviours and will operate down to very low temperatures. This makes them very useful when a large amount of power is available sporadically (for super fast charge cycles) or in places where temperatures stay persistently very low, such as up a mountain were solar will work, albeit slowly, but LiPo batteries will definitely not be suitable.
Other battery chemistries are available, such as Lithium Iron Phosphate which can tolerate the cold. Also you can always just insulate the battery with an integrated heater and preheat the battery to a safe charging temperature as well. So, just like everything with electronics, it’s important to choose the correct parts for your application, and it all starts with the power source. Supercapacitors might just hit an appropriate price/performance point for that special application you had in mind.
Supercapacitors aren’t really suitable for many applications, like powering an eBike or running your laptop, but hey, they did it anyway.