These science-based infographics from Tabletop Whale are terrific. The author is a designer and molecular biology major and composer of interesting animated gifs. She posts a new one every couple weeks. Bookmarked.
The Green World
The Lightning, Atmospheric Electricity and High Voltage Research Group on the Terrassa Campus of the UPC (Polytechnic University of Catalonia) has found a direct relationship between wind turbine movement and lightning discharges.
Given the right atmospheric conditions, any elevated structure can generate upward lightning flashes–especially where movement is involved. Industrial wind turbine blades are natural candidates for this phenomenon, but until recently no one had studied and demonstrated their association with electrical discharges.
Through its lightning mapping array located in the Terres de l’Ebre region of Tarragona, the UPC’s Lightning, Atmospheric Electricity and High Voltage Research Group (LRG) has detected electrical discharges from wind turbines that are repeated periodically. The duration of these discharges ranges from a few minutes to over an hour, depending on the storm conditions.
Researchers have made high-speed video recordings of lightning flashes caused by wind turbines on the Rubió wind farm. The LRG, which is a European benchmark in lightning studies, has recorded several upward lightning flashes caused by rotating wind turbines under clouds. These recordings were made at a distance of one kilometre from the wind turbine, with the camera set at a speed of 6668 frames per second and a resolution time of 150 microseconds.
Video images of lightning on the Rubió wind farm:
Given that the earth is struck by lightning an average of 100 times per second, this is important research. Lightning damage and damage prevention methods cost companies millions each year.
Read more: UPC
Build It Solar has a great DIY article about an easy solar hot water heater (a thermosyphon system) made by a resident of Costa Rica named Peter. Peter wanted to build a simple, rugged, inexpensive system to provide hot water for showers:
Like most houses in Costa Rica, our casita in Monteverde had no hot water. Our two showers were fitted with electric shower heads. At best, these take a little of the chill off the water. Sometimes it is difficult to know if they are even working, yet they use a great deal of electricity to do even that modest job. Further, having electrical wires attached to the shower head does not inspire confidence. Solar hot water seemed to present a great opportunity to generate more and hotter water at minimal cost, while being safer and more ecologically sound. Since solar is not commonly used locally, I also wanted to build something that could serve as a model for others, using readily available, inexpensive parts and simple construction.
Peter writes that because he lives in a remote community, the design needed to use readily available materials, few tools and his limited plumbing skills. His collector panels use galvanized steel roofing and chlorinated polyvinyl chloride (CPVC) pipe. The unit is located on a south-facing, 10° pitched roof (his latitude is fortunately also 10°) and painted with black roofing paint. The thermal rating for CPVC is close to the operating temperature for thermosyphon heaters, so Peter modified his design to provide extra ventilation and prevent overheating.
About 300 USD in all new materials were used. The result?
It was a smashing success from the beginning.
We love it. For more photos and information, see: A Simple DIY Thermosyphon Solar Hot Water Heater for the Tropics.
After looking at A Tediously Accurate Map of the Solar System the other day, I was reminded of a much bigger model of the same system. It’s found in Sweden, and it makes perfect sense when you see Globen – the building in Stockholm chosen to represent the sun.
The official name for is Ericsson Globe, and the original name was Stockholm Globe Arena, but the popular name has always been Globen. Globen is the largest spherical building in the world, and to plasma physicist Nils Brenning and astronomer Gösta Gahm the symbolism was obvious: – let Globen represent the sun, and use it to create a scale model of the solar system that spans the country of Sweden.
That’s Globen pictured above. Here’s a map of the Sweden Solar System (SSS), linked to a full size image:
Because Globen is 110 m (328 feet) in diameter, Mercury becomes a 25 cm (9.8 inches) sphere located at the Stockholm City Museum, located 2,900 meters (9,514 feet) from Globen. Pluto ends up in Delsbo, 300 km (186.4 miles) from Globen. The sizes of the planets (and objects) and the distances between them are at a scale of 1:20 million.
The SSS actually extends the entire length of Sweden, as it also contains several minor planets and comets. I’ve seen a number of the planet models and can confirm that this is Sweden at its best: playful, irreverent and smart, educating through a palatable combination of culture and science.
It’s sounds like a utopian idea – walk around, dance, or simply convert the mechanical action of rainfall into electric current. A Phys.org article asks the question: Tribo-electric, the buzzword of the future?
It is an alluring goal of clean, reliable power free from geo-political risks—and scientists in the United States said Tuesday it lies within reach, thanks to a smart way to harvest energy called tribo-electricity.
What is triboelectricity? (We’re going with the unhyphenated version of this word – like piezoelectric.) Science Daily has a good description:
In its simplest form, the triboelectric generator uses two sheets of dissimilar materials, one an electron donor, the other an electron acceptor. When the materials are in contact, electrons flow from one material to the other. If the sheets are then separated, one sheet holds an electrical charge isolated by the gap between them. If an electrical load is then connected to two electrodes placed at the outer edges of the two surfaces, a small current will flow to equalize the charges. By continuously repeating the process, an alternating current can be produced.
It sounds simple enough, but the energy source is unpredictable, and scientists have found it difficult to harness the sporadic bursts of energy.
Zhong Lin Wang, a professor of materials science and engineering, has a new invention he describes as breakthrough. Wang and his team have built a small, prototype device about 10 cm (four inches) wide that captures ambient energy:
Inside are two circular sheets of material, one an electron “donor” and the other an electron “receiver,” brought together through rotary movement. If the sheets are separated, one then holds an electrical charge isolated by the gap between them. Sandwiched between the two discs is a third disc with electrodes, which bridges the gap and helps a small current to flow. At a top speed of 3,000 revolutions per minute, the device generated 1.5 watts.
Energy efficiency of the triboelectric device was about 24 percent, which makes it as efficient as magnetic-induction turbine generators, and more than three times greater than piezoelectric generators.
Wang and his team actually discovered the principle of their device by accident. After noticing that the output from one piezoelectric device was much greater than expected, they realized the cause was a loose assembly that let two polymer surfaces rub together. Six months later (in 2012), they published their first journal paper on their triboelectric generator.
Everybody has seen this effect, but we have been able to find practical applications for it, said Wang. It’s very simple, and there is much more we can do with this. (Science Daily)
See more at: Tribo-electric, the buzzword of the future?
We’ve been looking at a lot of maps recently (probably because of the amazing wind maps we linked to), and we came across an old favorite from a few years ago.
Kai Krause, German software and graphical user interface designer, has invented a word for the lack of sufficient geographical knowledge. He calls it immappacy:
In addition to the well known social issues of illiteracy and innumeracy, there also should be such a concept as “immappacy,” meaning insufficient geographical knowledge. A survey of random American schoolkids let them guess the population and land area of their country. Not entirely unexpected, but still rather unsettling, the majority chose “1-2 billion” and “largest in the world,” respectively. Even with Asian and European college students, geographical estimates were often off by factors of 2-3. This is partly due to the highly distored nature of the predominantly used mapping projections (such as Mercator). A particularly extreme example is the worldwide misjudgment of the true size of Africa. This single image tries to embody the massive scale, which is larger than the USA, China, India, Japan, and all of Europe … combined!
Most maps use the Mercator projection to display the world (Google maps, for example, use a variant of the Mercator projection). The Mercator projection is an easy-to-read cylindrical map projection first proposed in 1569 by Flemish geographer and cartographer Gerardus Mercator.
All map projections distort the actual layout of the Earth to some degree, and the Mercator projection is no exception – Gerardus Mercator created this projection to aid navigation, and its use in world maps leads to significant distortion. The Mercator projection distorts both the size and shape of large objects, and the scale of the distortion increases between the Equator and the poles.
Here’s an example of Mercator projection:
And here’s an illustration of the distortion inherent in the Mercator projection using Tissot’s indicatrix (first presented by French mathematician Nicolas Auguste Tissot in 1859):
Notice how the distortion appears to dramatically increase around Greenland? This is why Greenland appears to be so large on standard Mercator projection maps, when really Australia is over 3.5 times larger!
Back to Kai Krause’s map – this is a clever way to illustrate the vastness of the African continent as well as show the comparative size of other countries. I learned geography at an early age from a Mercator projection map, and I can never quite wrap my head around the idea that Africa is so enormous (not to mention Australia). Here’s Krause’s complete image linked to the high-res version:
The one true map
Now we know the true area of Africa, right? Well…not really. While Krause’s map illustrates the size of the continent, there are other ways we can view its shape. During the late 20th century, a controversial projection was proposed as a replacement for the poorly implemented Mercator projection world maps. This is now known as the Gall–Peters projection:
So! This must be the perfect map, and that’s the real shape of Africa, right?
Nope. The history of the Gall–Peters projection is worthy of a soap opera, filled with social & political agendas, and false claims of provenance and accuracy. It’s like I wrote above – all map projections distort the actual layout of the Earth to some degree. It’s just not possible to display the spherical, three-dimensional Earth on a flat surface. Expecting 100% accuracy from a map projection is like trying to build a house with a single tool. What we really need is a complete toolbox, and fortunately there are a number of tools to choose and learn from.
- National Atlas is a good place to start
- The Future Mapping Company gives a brief history of the Robinson projection (a superior projection to the Mercator and the Gall-Peters projections)
- NASA’s G.Projector is free software to display a large number of projections
- Wikipedia also has a list of several map projection models
Finally, there’s the fabulous Dymaxion map by Buckminster Fuller, which has no right side up. It folds into a 3D icosahedron:
Fuller’s map is only for representations of the entire globe. Like the others, it’s not perfectly accurate, but it has a generosity of spirit that makes it by far my favorite view of the world – a unified view, where we all seem to share one big island.
The isle of Eigg is located off the northwest coast of Scotland in the Hebrides archipelago. Eigg is not tied to the national grid, and for many years, diesel generators supplied the few hours of electricity available to residents each day. In February 2008, the community switched on a local, renewable-powered electricity grid, and today solar panels, wind turbines, and hydro generators have largely replaced their diesel generators.
Eigg Island already gets over 85% of its energy from renewable sources, and the 100-person strong community will soon achieve self-sufficiency.
Eigg’s power systems
- One 100 kW hydro generator
- Two 5–6 kW hydro generators
- Four small wind turbines: 24 kW output
- Solar panels: 30 kW
- Total generating capacity = 164 kW
Electricity on Eigg is rationed – private residents are allowed to use up to 5 kilowatts at a time, and businesses are allowed 10 kilowatts. How much is 5 kilowatts? As they write on their site Island(s) Going Green: Enough for an electric kettle and washing machine, or fifty 100w light bulbs. Residents use energy monitors to manage their electricity needs, a practice proven to help reduce energy needs.
The local power company is Eigg Electric Ltd., a community-owned organization that maintains the renewable systems, 11 km (7 miles) of buried electric cable, transformers, inverters, and battery backup. Two diesel generators provide emergency backup in case the batteries fall below 50%.
Surplus energy goes to the community at large in the form of free heat:
We have heaters in all the public spaces on the island, the two churches, the community centre, the shop and café down at the pier. So we put free heating into these buildings to keep the island’s costs down and to keep the infrastructure of the buildings dry. (Eddie Scott, Eigg Electric maintenance team)
Eddie Scott never previously worked as a technician – like the rest of the team, he learned to maintain the renewable system when it was installed.
The more you learn about this community the more remarkable it appears. Like their electric company, Eigg is itself is owned by the community. A much smaller Eigg community purchased the island in the mid–90s after years of suffering under Keith Schellenberg, the owner of the island and operator of a feudal landlord system. The Guardian described Schellenberg this way:
A onetime bobsleigh champion, he took to crossing the windswept isle in a Rolls-Royce. Unfortunately, he was also Eigg’s owner, a position that gave him a staggering amount of power over its long-term residents. As the feudal laird, he owned everything, and decided everything: jobs, housing, transport, upkeep. Technically, you couldn’t even eat the seaweed without his say-so.
It’s an inspiring story with a happy ending, and the people of Eigg are eager to spread the word of their success. Read more about the egregious feudal laird at The Guardian, and follow the vibrant Eigg community at The Isle of Eigg (a small island with a big reputation), Eiggbox (their new cultural center), and Island(s) Going Green, where they detail life in their community and work to motivate a thousand more green islands like their own.
How times change: oil-rich countries in the Middle East are building massive solar facilities.
Last year, the first large-scale solar power plant in Dubai started up. Kuwait and Oman have planned their own solar power plants, and in the article Solar Achieves Grid Parity in Saudi Arabia – Significant Developments Expected, industry analyst Michael Deaves claims that large scale solar costs less in Saudi Arabia than electricity from oil-fired plants:
Since Saudi Arabia relies so heavily on oil for electricity production, measuring solar grid parity in Saudi Arabia is best done by comparing the cost of solar electricity generation with the opportunity cost of burning oil for electricity rather than export. According to ClearSky Advisors’ analysis, solar energy in Saudi Arabia is currently cost competitive with oil fired power plants. The analysis states that with currently available technologies and cost structures, large-scale solar PV costs less than $0.15/kWh, while the opportunity cost of burning oil for electricity costs the Kingdom between $0.127-$0.174/kWh.
Following a trend seen in other key emerging markets, most notably Chile, solar power in Saudi Arabia has achieved grid parity. In addition, the costs of solar PV are expected to decrease further as the industry within Saudi Arabia develops, making solar power even more attractive within the region; of course the same cannot be said for the global price of crude oil.
Deaves reports that electricity production in Saudi Arabia has increased 124% in the past 11 years.
Interestingly, oil and water consumption in Gulf countries are directly connected. Water is subsidized and provided at a low cost, which has helped lead to some of the highest water consumption rates in the world. Saudi Arabia has reached peak water; their water source is seawater from the Persian Gulf. Because desalinating seawater requires large amounts of energy, the more water is wasted, the more oil is needed to burn for electricity.
Ivanpah Solar Electric Generating System is a solar thermal power plant located close to Las Vegas in the California Mojave Desert. 173,500 heliostats reflect the sun’s rays at three solar power towers. Each tower features a water-filled receiver that generates high temperature steam when heated by the reflected energy. The farm has a planned capacity of 392 megawatts (MW).
BrightSource Energy and Bechtel developed Ivanpah Solar Electric Generating System at a cost of $2.2 billion. Google invested a significant amount in the project; the largest investor was NRG Energy based in Princeton, N.J. The United States Department of Energy provided a $1.6 billion loan.
For more information, see our article Controversial Ivanpoh Solar switches on.
There are only four days left on his Kickstarter campaign, but Jerry Callahan of ISI Technology isn’t worried. His project has already raised over three times the amount it needs to achieve funding. At the moment, 1,279 backers have pledged $399,989 of the $125,000 goal.
It’s heartening to see the public enthusiasm for practical devices like this: the tankless electric water heater Heatworks Model 1 solves the design problems of other heaters and allows users to save a lot of water and energy — up to 40% on energy, and 10% on water, says Callahan.
Every single time you turn on the hot water tap you save between 1 and 2 gallons per minute. At an average of 20 hot water draws per day per house, that’s 20 to 40 gallons of water every single day. (Jerry Callahan)
There are several ways you can use the device. Instead of running hot water pipes from a distant source such as a furnace room or basement, you can run a cold water pipe + electrical wiring and place a Heatworks unit at the point where you want hot water. If you’ve ever lived in a big house with an old hot water system, you know how much water can be wasted while waiting at the tap.
You can also install the device on hot water piping. The Heatworks Model 1’s advanced temperature control system works with preheated water, and would complement many solar hot water designs.
The device also betters other tankless water heaters by using graphite electrodes instead of standard heating coils:
Electricity passes through a heating coil which is heated to over 1000°F (538 °C) which then heats the water. This process means that a tremendous strain is placed on the coil which frequently burns out or breaks in as little as 12 months. Most units also contain a flow switch, which is inherently unreliable technology. The flow switch creates a “flutter” of alternating hot and cold water at low flow rates, which is frustrating and uncomfortable, but also unsafe due to excessive heating of water which can cause scalding. Heatworks Model 1’s graphite electrodes use the resistance of the water to heat it, and so they never get hotter than the surrounding water. This ensures a long life while heating the water reliably and consistently, even at low flow rates.
Even when they work well, says Callahan, other electric tankless units take a minimum of 30 seconds to generate hot water, which means more water wasted.
Another problem with competing tankless heaters is the sheer number and variety of units available. A typical tankless water heater must be chosen specifically for the electrical system where it will be used, but because the Heatworks Model 1 automatically senses voltage and current, the unit is nearly universal. No specific device is needed – the Heatworks Model 1 fits nearly all situations.
This is how quality design works. Strange ideas are often heard when you try to do something green (If everyone drives electric cars we won’t have enough electricity, or, If we only grow organic food we won’t have enough food to feed the planet), but there’s little room for argument when you reduce the complexity of green choices. We need more good alternatives like this that can simplify our lives.
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