3D Printed Homes Are All The Hype, But What Is Their Real Impact?

September 1, 2024 by Maya Posch 67 Comments

Additive manufacturing (AM) has been getting a lot of attention over the years, with its use in construction a recurring theme. Generally this brings to mind massive 3D printers that are carted to construction sites and assemble entire homes on the spot. That’s the perspective with which a recent ZDNet article by [Rajiv Rao] opens, before asking whether AM in construction is actually solving any problems. As [Rajiv] notes, the main use of such on-site AM construction is for exclusive, expensive designs, such as ICON’s House Zero which leans into the extruded concrete printing method.

Their more reasonable Wolf Ranch residential homes in Texas also use ICON’s Vulcan II printer to print walls out of concrete, with a roof, electrical wiring, plumbing, etc. installed afterwards. Prices for these Wolf Ranch 3 to 4 bedroom houses range from about $450,000 to $600,000, and ICON has been contracted by NASA to work a way to 3D print structures on the Moon out of regolith.

Naturally, none of these prices are even remotely in the range of the first-home buyers, or the many economically disadvantaged who make up a sizable part of the population in the US and many other nations in the Americas, Africa, etc. To make AM in construction economically viable, it would seem that going more flatpack and on-site assembly is the way to go, using the age-old pre-fabrication (prefab) method of constructions.

This is the concept behind the University of Maine’s BioHome3D, which mainly uses PLA, wood fiber and similar materials to create modules that contain insulation in the form of wood fiber and cellulose. These modules are 3D printed in a factory, after which they’re carted off to the construction site for assembly, pretty much like any traditional prefab home, just with the AM step and use of PLA rather than traditional methods.

Prefab is a great way to speed up construction and already commonly used in the industry, as modules can have windows, doors, insulation, electrical wiring, plumbing, etc. all installed in the factory, with on-site work limited to just final assembly and connecting the loose bits. The main question thus seems to be whether AM in prefab provides a significant benefit, such as in less material wasted by working from (discarded) wood pulp and kin.

While in the article [Rajiv] keeps gravitating towards the need to use less concrete (because of the climate) and make homes more affordable through 3D printing, AM is not necessarily the panacea some make it out to be, due to the fact that houses are complex structures that have to do much more than provide a floor, walls and a roof. If adding a floor (or two) on top of the ground floor, additional requirements come into play, before even considering aspects like repairability which is rarely considered in the context of AM construction.

Swiss Researchers May Have Solved Hydrogen Storage

September 1, 2024 by Jenny List 104 Comments

If you follow the world of clean energy, you will probably have read all about the so-called hydrogen future and the hydrogen economy. The gas can easily be made from water by electrolysis from green solar electricity, contains a lot of stored energy which is clean to recover, and seems like the solution to many of our green energy woes. Sadly the reality doesn’t quite match up as hydrogen is difficult to store and transport, so thus far our hydrogen cars haven’t quite arrived. That hasn’t stopped researchers looking at hydrogen solutions though, and a team from ETH Zurich might just have found a solution to storing hydrogen. They’re using it to reduce iron oxide to iron, which can easily release the hydrogen by oxidation with water.

Their reactor is simplicity itself, a large stainless steel tank filled with powdered iron ore. Pump hydrogen into it and the iron oxide in the ore becomes water and iron which forms the storage medium, and retrieve the hydrogen later by piping steam through the mixture. Hydrogen generated in the summer using solar power can then be released in the winter months. Of course it’s not perfectly efficient, and a significant quantity of energy is lost in heat, but if the heat is recovered and used elsewhere that effect can be mitigated. The hope is that their university might be benefiting from a pilot plant in the coming years, and then perhaps elsewhere those hydrogen grids and cars might become a reality. We can hope.

Meanwhile, in the past we’ve looked at a not quite so green plan for a hydrogen grid.

An L-shaped orange mounting structure with two white reservoirs on top, a set of pumps on the outer bottom edges, and a membrane cell bolted together in the center. The parts are connected by a series of transparent tubes.

Open Source Residential Energy Storage

August 15, 2024 by Navarre Bartz 20 Comments

Battery news typically covers the latest, greatest laboratory or industry breakthroughs to push modern devices further and faster. Could you build your own flow battery stationary storage for home-built solar and wind rigs though?

Based on the concept of appropriate technology, the system from the Flow Battery Research Collective will be easy to construct, easy to maintain, and safe to operate in a residential environment. Current experiments are focusing on Zn/I chemistry, but other aqueous chemistries could be used in the future. Instead of an ion exchange membrane, the battery uses readily attainable photo paper and is already showing similar order of magnitude performance to lab-developed cells.

Any components that aren’t off-the-shelf have been designed in FreeCAD. While they can be 3D printed, the researchers have found traditional milling yields better results which isn’t too surprising when you need something water-tight. More work is needed, but it is promising work toward a practical, DIY-able energy storage solution.

If you’re looking to build your own open source wind turbine or solar cells to charge up a home battery system, then we’ve got you covered. You can also break the chains of the power grid with off-the-shelf parts.

Australia’s Controlled Loads Are In Hot Water

August 15, 2024 by Zoe Skyforest 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?

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The Ultimate Seed Vault Backup? How About The Moon

August 4, 2024 by Donald Papp 44 Comments

A safe haven to preserve samples of biodiversity from climate change, habitat loss, natural disaster, and other threats is recognized as a worthwhile endeavor. Everyone knows good backup practice involves a copy of critical elements at a remote location, leading some to ask: why not the moon?

Not even the Svalbard global seed vault is out of the reach of climate change’s effects.

A biological sample repository already exists in the form of the Svalbard global seed vault, located in a mountain on a remote island in the Arctic circle. Even so, not even Svalbard is out of the reach of our changing Earth. In 2017, soaring temperatures in the Arctic melted permafrost in a way no one imagined would be possible, and water infiltrated the facility. Fortunately the flooding was handled by personnel and no damage was done to the vault’s contents, but it was a wake-up call.

An off-site backup that requires no staffing could provide some much-needed redundancy. Deep craters near the moon’s polar regions offer stable and ultra-cold locations that are never exposed to sunlight, and could offer staffing-free repositories if done right. The lunar biorepository proposal has the details, and is thought-provoking, at least.

The moon’s lack of an atmosphere is inconvenient for life, but otherwise pretty attractive for some applications. A backup seed vault is one, and putting a giant telescope in a lunar crater is another.

The Atomic Gardener Of Eastbourne

August 1, 2024 by Jenny List 8 Comments

Pity the video team at a large hacker camp, because they have a huge pile of interesting talks in the can but only the limited resources of volunteers to put them online. Thus we often see talks appearing from past camps, and such it is with one from Electromagnetic Field 2022. It’s from [Sarah Angliss], and as its subject it takes the extraordinary work of [Muriel Howorth], a mid-20th-century British proponent of irradiated seeds as a means to solve world hunger.

Today we are used to genetic modification in the context of plants, and while it remains a controversial subject, the science behind it is well known. In the period following the Second World War there was a different approach to improving crops by modifying their genetics: irradiating seeds in a scattergun approach to genetic modification, in the hope that among thousands of duds there might be a mutant with special properties.

To this came Muriel Howorth, at first charged with telling the story of atomic research for the general public. She took irradiated seeds from Oak Ridge in the USA, and turned them into a citizen science program, with an atomic gardening society who would test these seeds and hopefully, find the supercrops within. It’s a wonderfully eccentric tale that might otherwise be the plot of a Wallace and Gromit movie, and but for a few interested historians of popular science it might otherwise have slipped into obscurity. We’re sorry we didn’t catch this one live back when we attended the event.

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Spin Your Own Passive Cooling Fibres

July 31, 2024 by Jenny List 4 Comments

When the temperature climbs, it’s an eternal problem: how to stay cool. An exciting field of materials science lies in radiative cooling materials, things which reflect so much incoming heat that they can cool down from their own radiation rather than heating up in the sun. It’s something [NightHawkInLight] has been working on over a series, and he’s dropped a very long video we’ve placed below. It’s ostensibly about spinning radiative cooling fibers, but in fact provides a huge quantity of background as well as a bonus explanation of cotton candy machines.

These materials achieve their reflectivity by creating a surface full of microscopic bubbles. It’s the same process that makes snow so white and reflective, and in this case it’s achieved by dissolving a polymer in a mixture of two solvents. The lower boiling point solvent evaporates first leaving the polymer full of microscopic bubbles of the higher boiling point solvent, and once these evaporate they leave behind the tiny voids. In the video he’s using PLA, and we see him experimenting with different solvents and lubricants to achieve the desired result. The cotton candy machine comes in trying to create fibers by melting solid samples, something which doesn’t work as well as it could so instead he draws them by hand with a small rake.

When he tests his mat of fibers in bright sunlight the effect is almost magical if we didn’t already know the mechanism, they cool down by a few degrees compared to ambient temperature and the surrounding control materials. This is a fascinating material, and we hope we’ll see more experimenters working with it. You won’t be surprised to hear we’ve featured his work before.

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