energy storage

18 Articles

Building Experience And Circuits For Lithium Capacitors

December 2, 2024 by 22 Comments

For the cautious, a good piece of advice is to always wait to buy a new product until after the first model year, whether its cars or consumer electronics or any other major purchase. This gives the manufacturer a year to iron out the kinks and get everything ship shape the second time around. But not everyone is willing to wait on new tech. [Berto] has been interested in lithium capacitors, a fairly new type of super capacitor, and being unwilling to wait on support circuitry schematics to magically show up on the Internet he set about making his own.

The circuit he’s building here is a solar charger for the super capacitor. Being a fairly small device there’s not a lot of current, voltage, or energy, but these are different enough from other types of energy storage devices that it was worth taking a close look and designing something custom. An HT7533 is used for voltage regulation with a Schottky diode preventing return current to the solar cell, and a DW01 circuit is used to make sure that the capacitor doesn’t overcharge.

While the DW01 is made specifically for lithium ion batteries, [Berto] found that it was fairly suitable for this new type of capacitor as well. The capacitor itself is suited for many low-power, embedded applications where a battery might add complexity. Capacitors like this can charge much more rapidly and behave generally more linearly than their chemical cousins, and they aren’t limited to small applications either. For example, this RC plane was converted to run with super capacitors.

Poking Atomic Nuclei With Lasers For Atomic Clocks And Energy Storage

May 5, 2024 by 5 Comments

Although most people are probably familiar with the different energy levels that the electron shells of atoms can be in and how electrons shedding excess energy as they return to a lower state emit for example photons, the protons and neutrons in atomic nuclei can also occupy an excited state. This nuclear isomer (metastable) state is a big part of radioactive decay chains, but can also be induced externally. The trick lies in hitting the right excitation wavelength and being able to detect the nuclear transition, something which researchers at the Technical University of Wien have now demonstrated for thorium-229.

The findings by [J.Tiedau] and colleagues were published in Physical Review Letters, describing the use of a vacuum-ultraviolet (VUV) laser setup to excite Th-229 into an isomer state. This isotope was chosen for its low-energy isomeric state, with the atoms embedded in a CaF2 crystal lattice. By trying out various laser wavelengths and scanning for the signature of the decay event they eventually detected the signal, which raises the possibility of using this method for applications like new generations of much more precise atomic clocks. It also provides useful insights into nuclear isomers as it pertains to tantalizing applications like high-density energy storage.

Continue reading “Poking Atomic Nuclei With Lasers For Atomic Clocks And Energy Storage” →

A Smarter Solar Water Heater

February 25, 2024 by 81 Comments

Installing solar power at a home is a great way to reduce electricity bills, especially as the cost of solar panels and their associated electronics continue to plummet. Not every utility allows selling solar back to the grid, though, so if you’re like [Rogan] who lives in South Africa you’ll need to come up with some clever tricks to use the solar energy each day while it’s available to keep from wasting any. He’s devised this system for his water heater that takes care of some of this excess incoming energy.

A normal water heater, at least one based on electric resistive heaters, attempts to maintain a small range of temperatures within the insulated tank. If the temperature drops due to use or loss to the environment, the heaters turn on to bring the temperature back up. This automation system does essentially the same thing, but allows a much wider range of temperatures depending on the time of day. Essentially, it allows the water heater to get much hotter during times when solar energy is available, and lets it drop to lower values before running the heater on utility electricity during times when it isn’t. Using a combination ESP32 and ATtiny to both control the heater and report its temperature, all that’s left is to program Home Assistant to get the new system to interact with the solar system’s battery charge state and available incoming solar energy.

While it’s an elegantly simple system that also affords ample hot water for morning showers, large efficiency gains like this can be low-hanging fruit to even more home energy savings than solar alone provides on paper. Effectively the water heater becomes another type of battery in [Rogan]’s home, capable of storing energy at least for the day in the form of hot water. There are a few other ways of storing excess renewable energy as well, although they might require more resources than are typically available at home.

a) Schematic illustration of energy storage process of succulent plants by harnessing solar energy with a solar cell, and the solar cell converts the energy into electricity that can be store in APCSCs of succulent plants, and then utilized by multiple electrical appliances. b–d) The energy is stored in cactus under sunlight by solar cell and then power light strips of Christmas tree for decoration.

Succulents Into Supercapacitors

January 11, 2024 by 17 Comments

Researchers in Beijing have discovered a way to turn succulents into supercapacitors to help store energy. While previous research has found ways to store energy in plants, it often required implants or other modifications to the plant itself to function. These foreign components might be rejected by the plant or hamper its natural functions leading to its premature death.

This new method takes an aloe leaf, freeze dries it, heats it up, then uses the resulting components as an implant back into the aloe plant. Since it’s all aloe all the time, the plant stays happy (or at least alive) and becomes an electrolytic supercapacitor.

Using the natural electrolytes of the aloe juice, the supercapacitor can then be charged and discharged as needed. The researchers tested the concept by solar charging the capacitor and then using that to run LED lights.

This certainly proposes some interesting applications, although we think your HOA might not be a fan. We also wonder if there might be a way to use the photosynthetic process more directly to charge the plant? Maybe this could recharge a tiny robot that lands on the plants?

Liquid Tin Could Be The Key To Cheap, Plentiful Grid Storage

January 8, 2024 by 143 Comments

Once expensive and difficult to implement, renewable energy solutions like wind and solar are now often the cheapest options available for generating electricity for the grid. However, there are still some issues around the non-continuous supply from these sources, with grid storage becoming a key technology to keep the lights on around the clock.

In the quest for cost-effective grid storage, a new player has entered the arena with a bold claim: a thermal battery technology that’s not only more than 10 times cheaper than lithium-ion batteries, but also a standout in efficiency compared to traditional thermal battery designs. Fourth Power is making waves with its “sun in a box” energy storage technology, and aims to prove its capabilities with an ambitious 1-MWh prototype.

Hot Stuff

Simple heating elements turn electricity into heat, putting it into liquid tin that then heats large graphite blocks. Credit: Fourth Power, Vimeo screenshot

The principle behind Fourth Power’s technology is deceptively simple: when there’s excess renewable energy available, use it to heat something up. The electrical energy is thus converted and stored as heat, with the idea being to convert it back to electricity when needed, such as at night time or when the wind isn’t blowing. This concept isn’t entirely new; other companies have explored doing this with everything from bricks to molten salt. Fourth Power’s approach involves heating large blocks of graphite to extremely high temperatures — as high as 2,500 °C (4,530 °F). Naturally, the hotter you go, the more energy you can store. Where the company’s concept gets interesting is how it plans to recover the heat energy and turn it back into electricity.

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Will Nickel-Hydrogen Cells Be The Energy Storage Holy Grail?

September 27, 2023 by 38 Comments

You may have heard us here remarking in the past, that if we had a pound, dollar, or Euro for every miracle battery technology story we heard that was going to change the world, we would surely be very wealthy by now. It’s certainly been the case that many such pronouncements refer to promising chemistries that turn out only to be realizable in a lab, but here there’s news of one with a bit of pedigree. Nickel hydrogen batteries have a long history of use in space, and there’s a startup producing them now for use on the ground. Could they deliver the energy storage Holy Grail?

The cathode in a nickel-hydrogen battery is formed by nickel hydroxide, and the anode is formed of hydrogen. If a gas as an anode sounds far fetched, we’re guessing that their structure is similar to the zinc-air battery, in which zinc hydroxide forms in a paste of powdered zinc, and works against oxygen from the air over a porous conductive support. What gives them their exciting potential is their ability to take more than 30,000 charge/discharge cycles, and their relative safety when compared to lithium ion cells. Hydrogen in a pressure vessel might not seem the safest of things to have around, but the chemistry is such that as the pressure increases it reacts to form water. The cost of the whole thing is reduced further as new catalysts have replaced the platinum used by NASA on spacecraft.

We really hope that these batteries will be a success, but as always we’ll wait and see before calling it. They may well be competing by then with the next generation of zinc-air cells.

MIT Cracks The Concrete Capacitor

August 1, 2023 by 60 Comments

It’s a story we’ve heard so many times over the years: breathless reporting of a new scientific breakthrough that will deliver limitless power, energy storage, or whichever other of humanity’s problems needs solving today. Sadly, they so often fail to make the jump into our daily lives because the reporting glosses over some exotic material that costs a fortune or because there’s a huge issue elsewhere in their makeup. There’s a story from MIT that might just be the real thing, though, as a team from that university claim to have made a viable supercapacitor from materials as simple as cement, carbon black, and a salt solution. Continue reading “MIT Cracks The Concrete Capacitor” →