Solar Desalination Skylight

“You hand pump seawater or polluted water into a bowl. Throughout the day the energy from the sun heats up this water and, instead of evaporating into the atmosphere, it gets trapped in the top section. All the fresh water will then trickle down into this bottom basin and all the impurities of the salt and polluted water stay behind. You’re going to have a left-over salt brine which is going to be a waste resource, but instead of throwing it away, this salt brine goes into the series of seawater batteries around the perimeter that can light a LED strip during the night. At night you can turn on the light and you get an energy source through the salt batteries. And during the day, this is like a skylight, bringing natural light to the interiors.”

“The power of the sun is amazing, and I was trying to copy this hydrological cycle. It can kill 99% of dangerous pathogens, remove salt brine and reduce the need of having to boil your water. I am not necessarily reinventing the wheel; solar distillers have been around for a long time, but a lot of these systems are heavy, expensive to make and with very complicated designs. I wanted to think about one which could potentially be portable and simple to construct, made out of local materials and able to Achieve a higher yield of water.”

“This new design was exactly the same but at a large scale. We created a recipe book that is a step-by-step guide on how you can create this same design using bamboo and local work. It could be flat packed into a bag and deployed very simply and quickly and then attached to a bamboo structure which allows structural rigidity but also a community shaded spot, where you can produce around 18 liters of purified water everyday.”

Read more: Low-Tech Solutions for Complex Demands: An Interview with Architect Henry Glogau, ArchDaily. Image by Henry Glogau. Hat tip to Michael.

Off-grid solar e-waste in the Global South

“There has been a boom in the sale of small-scale off-grid solar products across the Global South over the past decade. A substantial portion of this boom has been driven by international investment in off-grid solar start-up companies, and a formalized off-grid solar sector has been established, with the Global Off-Grid Lighting Association acting as a key representative body.”

“Although this boom has aided in extending electricity access to many energy-poor households and businesses, an emerging concern is the short (three to four years) working life that these off-grid solar products typically have. This has led to a growing issue of solar e-waste. Here we examine how the structure of the off-grid solar sector results in substantial barriers to addressing solar e-waste in the Global South. We consider how practices of repair might contribute to addressing the issue, and set out a research agenda to facilitate new approaches to the issues of solar e-waste.”

Read more: Munro, Paul G., et al. “Towards a repair research agenda for off-grid solar e-waste in the Global South.” Nature Energy (2022): 1-6.

Solar Metal Smelter

Jelle Seegers set out to design a production line that drastically lowers our footprint, using nothing but the sun, wind, or muscle power as its energy source. The ‘Solar Metal Smelter’ is his pièce the résistance: this huge magnifying glass creates a powerful focal point that, on a sunny day, makes metal melt. Cast in a sand mould, the hot substance is transformed into machine parts for a foot-driven grinder in an off-grid practice.

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Solar Concentration for Craft Practice

“This research indicates the technical capabilities of using a 40 cm2 Fresnel lens to heat, melt and vitrify a variety of materials and suggests future applications of this technology including the ability to digitise the process. This material processing technique offers an alternative to heat matter and is significant in geographical locations with ample sunlight, offering a cost-effective option to traditional heating methods and allows directional heating, which local craftspeople can exploit to their creative advantage.” [Read more…]

Solar Powered Website: Uptime for 2020

In 2020, our solar powered website obtained an uptime of 95%, meaning that it was offline for 444 hours or 20 days. Unsurprisingly, most of the downtime is concentrated in the winter months.

The graph above (click to enlarge) shows battery storage capacity in relation to the weather in Barcelona from January to December 2020. Yellow is sunny, grey is cloudy, blue is rain. From May to November, we were online without interruption for almost 6 months.

The data were collected and visualised by Roel Roscam Abbing and David Benqué.

Scaling of Greenhouse Crop Production During Nuclear Winter

During a global catastrophe such as a nuclear winter, in which sunlight and temperatures are reduced across every latitude, to maintain global agricultural output it is necessary to grow some crops under structures. [Read more…]