solar energy

15 Articles

Australia’s Controlled Loads Are In Hot Water

August 15, 2024 by 125 Comments

Australian grids have long run a two-tiered pricing scheme for electricity. In many jurisdictions, regular electricity was charged at a certain rate. Meanwhile, you could get cheaper electricity for certain applications if your home was set up with a “controlled load.” Typically, this involved high energy equipment like pool heaters or hot water heaters.

This scheme has long allowed Australians to save money while keeping their water piping-hot at the same time. However, the electrical grid has changed significantly in the last decade. These controlled loads are starting to look increasingly out of step with what the grid and the consumer needs. What is to be done?

Continue reading “Australia’s Controlled Loads Are In Hot Water” →

New Solar Spheres Claim To Be Better Than Solar Panels

July 6, 2024 by 83 Comments

When you think of solar energy, you probably think of flat plates on rooftops. A company called WAVJA wants you to think of spheres. The little spheres, ranging from one to four inches across, can convert light into electricity, and the company claims they have 7.5 times the output of traditional solar panels and could later produce even more. Unfortunately, the video below doesn’t have a great deal of detail to back up the claims.

Some scenes in the video are clearly forward-looking. However, the so-called photon energy system appears to be powering a variety of real devices. It’s difficult to assess some of the claims. For example, the video claims 60 times the output of a similar-sized panel. But you’d hardly expect much from a tiny 4-inch solar panel.

Continue reading “New Solar Spheres Claim To Be Better Than Solar Panels” →

Solar Energy Plant Creates Fuel

June 29, 2024 by 24 Comments

Normally, when you think of solar power, you think about photovoltaic cells or using the sun to generate steam. But engineers at Synhelion — a spin off from ETH Zurich — had a crazy idea. Could you reverse combustion and change waste products back into fuel? The answer is yes if you can use the sun to turn things up to 1,500°C.

The input is water, carbon dioxide, and methane into syngas. The pilot plant in Germany is set to begin operations using a thermal storage device to allow the plant to operate around the clock. The new plant is slated to produce several thousand liters of fuel a year. Future plants will produce more, and they are targeting a cost of $1 per liter of fuel. The pilot plant has a 20-meter-tall tower and around 1,500 square meters of mirrors, producing 600 kW of output. The hexagonal mirrors are very thin, and the plant uses drones to aim the mirrors quickly compared to other methods.

Syngas shows up a lot lately. Getting to 1,500 degrees is a big ask, although we’ve seen ETH Zurich get to 1,000 using solar.

An image of an orange, translucent glowing quartz rod. Thermocouples can be seen at intervals along the rod looking in.

Industrial Solar Heat Hits 1000˚C

May 21, 2024 by 17 Comments

While electricity generation has been the star of the energy transition show, about half of the world’s energy consumption is to make heat. Many industrial processes rely on fossil fuels to reach high temps right now, but researchers at ETH Zurich have found a new way to crank up the heat with a solar thermal trap. [via SciTechDaily]

Heating water for showers or radiant floor systems in homes is old hat now, but industrial application of solar power has been few and far between. Part of the issue has been achieving high enough temperatures. Opaque absorbers can only ever get as hot as the incident surface where the sun hits them, but some translucent materials, like quartz can form thermal traps.

In a thermal trap, “it is possible to achieve temperatures that are higher in the bulk of the material than at the surface exposed to solar radiation.” In the study, the researchers were able to get a 450˚C surface to produce 1,050˚C interior temperature in the 300 mm long quartz rod. The system does rely on concentrated solar power, 135 suns-worth for this study, but mirror and lens systems for solar concentration already exist due to the aforementioned electrical power generation.

This isn’t the only time we’ve seen someone smelting on sunlight alone, and you can always do it less directly by using a hydrogen intermediary. If you’re wanting a more domestic-level of heat, why not try the wind if the sun doesn’t shine much in your neighborhood?

Team members Madeleine Laitz, left, and lead author Dane deQuilettes stand in front of a tidy lab bench equipped with oscilloscopes and computers. Laitz has a snazzy yellow jacket that pops compared to the neutrals and blues of the rest of the picture.

More Progress On Perovskite Solar Cells

March 8, 2024 by 20 Comments

Perovskites hold enormous promise for generating solar energy, with the potential to provide lighter and cheaper cells than those made from silicon. Unfortunately, the material breaks down too rapidly to be practical for most applications. But thanks to some recent research, we now have a better understanding of the nanoscale changes that happen during this breakdown, and how to combat it.

The research is focused on the topic of passivation, which seeks to increase the useful lifespan of perovskites by studying the surface interface where they meet other materials. Most of the perovskite material is a perfect latticework of atoms, but this structure is broken at the surface. This atomically “jagged” interface introduces losses which only get worse over time. Currently, the best way to address this issue is to essentially seal the surface with a very thin layer of hexylammonium bromide.

While this technique significantly simplified the passivation process when it was discovered, the effect had yet to be adequately characterized to further advance the field. According to lead author, [Dane deQuilettes], “This is the first paper that demonstrates how to systematically control and engineer surface fields in perovskites.”

Prefer to roll your own cells? How about a DIY dye sensitized cell or this thermionic converter model?

DIY Shredder Creates Insulation

October 23, 2023 by 28 Comments

Plenty of us have experience with paper shredders, but there are all kinds of machines designed to completely destroy other materials as well, from metal and plastic, to entire cars. [Action BOX] built their own heavy-duty shredder capable of dismantling things like cell phones and other robust handheld objects, but after seeing what it would physically shred they decided to give it an actual job creating insulation for the attic space in their garage.

The shredder itself uses opposing metal plates arranged on sets of two cylinders, with each cylinder powered by it’s own large motor. In total, the entire system uses around 1.5 kW, so to make their green insulation project as green as possible they decided to power it with an equivalent amount of solar panels. For the insulation they’re using a year’s worth of boxes from various deliveries, and after a time-consuming process preparing the boxes for the shredder, shredding the strips of cardboard, and packaging it in garbage bags their efforts netted them enough to partially fill the space between four ceiling joists. Continue reading “DIY Shredder Creates Insulation” →

Bending Light To Fit Technology

September 22, 2023 by 3 Comments

Solar power is an excellent way of generating electricity, whether that’s for an off-grid home or for the power grid. With no moving parts maintenance is relatively low, and the downsides of burning fuel are eliminated as well. But as much as it’s revolutionized power generation over the last few decades, there’s still some performance gains to be made when it comes to the solar cells themselves. A team at Stanford recently made strides in improving cell efficiency by bending the properties of sunlight itself.

In order to generate electricity directly from sunlight, a photon with a specific amount of energy needs to strike the semiconductor material. Any photons with higher energy will waste some of that energy as heat, and any with lower energy won’t generate electricity. Previous methods to solve this problem involve using something similar to a prism to separate the light out into colors (or energies) that correlate to specific types of cells calibrated specifically for those colors. This method does the opposite: it changes the light itself to an color that fits the semiconductor material. In short, a specialized material converts the energy from two lower-energy photons into a single higher-energy photon, which then strikes the solar panel to create energy.

By adding these color-changing materials as a layer to a photovoltaic solar panel, the panel can generate more energy with a given amount of light than a traditional panel. The major hurdle, as with any research, is whether or not this will be viable when produced at scale, and this shows promise in that regard as well. There are other applications for these materials beyond photovoltaics as well, and the researchers provide an excellent demonstration in 3D printing. By adding these color-change materials to resin, red lasers can be used instead of blue or ultraviolet lasers to cure resin in extremely specific locations, leading to stronger and more accurate prints.