Read more: Out of the ashes, aeon magazine. Related: The bright future of solar thermal factories, Firewood in the fuel tank: woodgas vehicles, Medieval smokestacks: fossil fuels in pre-industrial times.

Katrin Puetz saw the potential of biogas for rural communities while doing her master’s thesis at a university in Germany. She wondered how to do the “last mile” of distribution from a central digester site to someone’s home. She came up with the biogas “backpack” — a sturdy bag to transport the gas.

Since then, she’s created a full line of products for villages to use biogas locally. First there’s a 2 x 5 meter bio-digester “system” for 44 pounds of cow dung a day. It’s a tank with an outer tent covering. Then, there are the packs which hold 1.2 cubic meters of biogas at a time (6 kilowatt-hours of energy or enough for four hours of cooking). And there’s a simple stove and several other parts.

The bag has a valve that attaches to the stove with a hose. Villagers place a rock or plank of wood on top of the bag to push the gas out. The bag presents no explosion risk because it is isn’t pressurized, Puetz says. “You can put the bag on an open fire and it will take 15 to 20 seconds to even melt the material. It is a very heavy duty material. And even after you’ve melted a hole the gas will come out and slowly flare off, because biogas needs to be mixed with air to be flammable,” she assures us.

Read more at Co.EXIST: These hilarious inflated backpacks are actually delivering cheap local energy to the rural poor. Picture: (B)energy. Previously: Gas Bag Vehicles.

Assasin’s Creed IV: Black Flag

“This research investigates the carbon footprint of the lifecycle of console games, using the example of PlayStation 3 distribution in the UK. We estimate total carbon equivalent emissions for an average 8.8-gigabyte game based on data for 2010. Two delivery scenarios are compared: the first examines Blu-ray discs delivered by retail stores, and the second, games files downloaded over broadband internet.”

“Contrary to current consensus that downloaded data will result in lower carbon emissions than distribution by disc, producing and distributing an average-sized game by Blu-ray disc in 2010 resulted in approximately 50 to 90% less emissions than downloading. The estimated carbon emissions from downloading only fall below that of Blu-ray discs for games smaller than 1.3 gigabyte. The study findings serve to illustrate why it is not always true that digital distribution of media will have lower carbon emissions than distribution by physical means when file sizes are large.”

“As internet efficiency and speeds increase, the carbon emissions of downloading versus Blu-ray discs may fall. This must, however, be considered against the trend for increasing game file sizes on next generation consoles. In October 2013, file sizes of the top ten selling games in Europe range between 1.3 and 24 gigabyte per game, with an average of 11 gigabyte. This average is larger than the average for 2010 of 8.8 gigabyte. The data capacity of optical discs has increased exponentially over the last two decades, and the energy required to produce different types of optical discs with different capacities has remained approximately the same at any point in time. Multilayer Blu-ray discs are now available that can store up to 100 gigabyte, and holographic technology that could store up to 1,000 gigabyte per disc is now available.”

Increases in disc capacity. BD = Blu-ray disc; DVD = digital video disc; CS = compact disc; GB = gigabyte.

“All Blu-ray discs distributed within Europe are manufactured in Salzburg, Austria. Discs are then distributed by truck and shipped to a central warehouse in Northampton, UK and subsequently to retailers’ warehouses ready for distribution to outlets and sold to customers. The study assumes that shoppers will travel by car to retail outlets and will buy a game along with nine other items. The carbon emissions of games distributed by Blu-ray discs are highly sensitive to the energy used by consumers traveling to shops.”

“If consumers purchase games along with many other items during a major shopping trip (e.g., 100 items), or use public transport to travel to the shops, the carbon emissions of Blu-ray disc production and distribution are between one quarter and one third lower. On the other hand, if consumers drive to the store specifically to buy a game (e.g., following a new game launch), then emissions for Blu-ray discs fall between lower and upper estimates for downloading. To put this in context, games of 5.4 to 19 gigabyte purchased as a sole item during a shopping trip would have carbon emissions in the same range as that for a download.”

“Carbon equivalent emissions of compact disc production and distribution in the United States is almost 3 times that of PS3 Blu-ray disc production in Europe. The higher emissions for optical disc production in the United States are mainly the result of the differences in transport and also differences in the carbon intensity of energy production and fuel use. Assuming Blu-ray disc production would be similar to CD’s, carbon equivalent emissions for Blu-ray discs in 2010 would only fall categorically below downloading for files above 11 gigabyte in the United States. The study findings can be considered broadly representative of PS3 games distributed within the EU and for larger-than-average files in the United States.”

Quoted from The Carbon Footprint of Games Distribution, Kieren Mayers, Jonathan Koomey, Rebecca Hall, Maria Bauer, Chris France, and Amanda Webb, in Journal of Industrial Ecology, September 2014. Via Yale Environment 360. Previously: Truckloads of Hard Discs: Imagine you put a portable hard disk of 500 gigabytes in your backpack and start walking. In which cases are you faster than your internet connection?

Promotional photo of BEI-Teesside, a planned biomass power plant in the UK. The volcanoe shape is well chosen if you consider the pollution that is produced by biomass power plants.

But this first-ever detailed analysis of the bioenergy industry reveals that the rebooted industry is still a major polluter. Comparison of permits from modern coal, biomass, and gas plants shows that a even the “cleanest” biomass plants can emit > 150% the nitrogen oxides, > 600 % the volatile organic compounds, > 190% the particulate matter, and > 125% the carbon monoxide of a coal plant per megawatt-hour, although coal produces more sulfur dioxide (SO2). Emissions from a biomass plant exceed those from a natural gas plant by more than 800% for every major pollutant.

Biomass power plants are also a danger to the climate, emitting nearly 50 percent more CO2 per megawatt generated than the next biggest carbon polluter, coal. Emissions of CO2 from biomass burning can theoretically be offset over time, but such offsets typically take decades to fully compensate for the CO2 rapidly injected into the atmosphere during plant operation.”

Read the report: Trees, Trash, and Toxics: How Biomass Energy Has Become the New Coal (PDF), Mary S. Booth, Partnership for Policy Integrity, April 2, 2014. Via biofuelwatch.

“Graining cereal crops is a basic, century old business and it will continue to be as important as ever before for centuries to come. Before the age of oil grain milling was entirely based on renewable energy. It was either done by wind energy, hydropower, animals or manpower. For the last century the traditional grain milling has been mainly replaced by electricity and fuel driven milling.”

“The Solar PV Grain Mill works to the same principle like any conventional, electrically driven mill. The mill has a very efficient 3-phase AC motor which is directly coupled to the graining system. The main invention of the system is, and that makes it unique among PV systems, that it is a “direct drive system” without the need of batteries. The Solar PV generator converts solar radiation into electricity, and the generated electricity is directly feeding the motor drive. There are no additional conversion losses, such as energy storage losses in batteries, battery maintenance or replacement costs, which are a common problem in conventional Solar PV off-grid systems.”

Read More: Solar Milling. Via Engineering for Change.

I would like to add that the direct drive system also eliminates the high energy use caused by the production of the batteries, which can make solar PV off-grid systems everything but sustainable. Therefore, storing work instead of energy — the solar mill only operates when the sun shines — is a very interesting strategy in sunny regions.

Related:

• The Bright Future of Solar Thermal Powered Factories
• Back to Basics: Direct Hydropower
• Wind Powered Factories: History (and Future) of Industrial Windmills
• Pedal Powered Farms and Factories: The Forgotten Future of the Stationary Bicycle

Gasification, in which dense biomass smoldering — but not combusting — in a low-oxygen environment is converted to hydrogen gas, is nothing new. Price said that ancient cultures used it to enrich their soils, and during World War II, a million vehicles utilized the technology. But after the war, it more or less vanished from the planet, for reasons unknown.

All Power Labs has taken gasification and combined it with two of the
Bay Area’s most valuable commodities — a rich maker culture and
cutting-edge programming skills — to produce what are called
PowerPallets. Feed a bunch of walnut shells or wood chips into these
$27,000 machines and you get fully clean energy at less than 10 cents a
kilowatt hour, a fraction of what other green power sources can cost.

Because there’s no combustion in All Power Labs’ gasification process, the carbon isn’t released into the air.
Rather, it is pulled from the biomass and converted into charcoal. Thanks to gasification and the fact that that charcoal can be put back into the ground, the process of releasing carbon is reversed, Price argued.”

Read more: Carbon-negative energy source a reality, and cheap too. Via Slashdot.

Solar Fire is currently testing a larger version of its low-tech solar concentrator; the Solar Fire P90. Just like its smaller predecessor the Solar Fire P32 (which we covered before), the machine can produce heat, electricity and direct mechanical energy, making it suitable to manufacture almost anything on your roof or in the garden.

The Solar Fire P90 delivers up to 5 kW of electricity and 40 kW of thermal energy, is built using simple, abundant and non-toxic materials, and requires no foundation in the ground. The frame size is 11.5 x 11.5 metres and the machine requires an area of 16 x 16 metres for revolving.

Tracking is done by hand using a simple but ingenious system — one person can operate up to five of these solar concentrators at the same time. The Solar Fire P90 is an open source design, but it can also be bought for about $ 12,000, excluding transport costs.

A video of the tests can be found here. For more information on the workings and applications of these kinds of machines, see the article “The bright future of solar thermal powered factories“.

Picture: Solar Fire.

• “Optimizing greenhouse gas mitigation strategies to suppress energy cannibalism“, J.M. Pearce, 2nd Climate Change Technology Conference, Hamilton, Ontario, Canada, May 12-15, 2009. (PDF).
• “Energy payback for energy systems ensembles during growth“, Timothy Gutowski, International Symposium on Sustainable Systems and Technologies, Washington D.C., May 16-19, 2010. (PDF)
• “Toward real energy economics: energy policy driven by life-cycle carbon emission“, R. Kenny, C. Law, J.M. Pearce, Energy Policy 38, pp. 1969-1978, 2010. (PDF)
• “Thermodynamic limitations to nuclear energy deployment as a greenhouse gas mitigation technology“, Joshua M. Pearce, Int. J. Nuclear Governance, Economy and Ecology, Vol. 2, No. 1., pp.113-130, 2008. (PDF)

Previously: Can renewables power consumer societies? The negative case.

“A modern, comfortable lifestyle relies on a variety of efficient Industrial Machines. If you eat bread, you rely on an Agricultural Combine. If you live in a wood house, you rely on a Sawmill. Each of these machines relies on other machines in order for it to exist. If you distill this complex web of interdependent machines into a reproduceable, simple, closed-loop system, you get these 50 machines.”

The GVCS is a work-in-progress. See the wiki, the blog and (the best introduction) the movie.

Related: How to make everything ourselves: open modular hardware.

Read more: “Can renewables solve the greenhouse problem? The negative case” (pdf), Ted Trainer, Energy Policy, March 2010. Also check out the author’s website, where you can find similar papers, like this one.

Read more: three inventors who tried to bottle the ocean’s power. Hat tip to Klaas Van Gorp.

Jatropha does not guarantee high returns

Jatropha: money doesn’t grow on trees (.pdf), a report by Friends of the Earth. Via Energy Bulletin. Previously.

“The digital billboards use more efficient LED (Light Emitting Diode) lighting than traditional signs, but deploy so many of the LED bulbs on each billboard that energy use is high; traditional billboards use just one or two large bulbs to illuminate signs. In addition, digital billboards are illuminated day and night, and require cooling systems that use more energy.”

Source: Yale Environment 360.

Previously: Viva Las Vegas – LEDs and the energy efficiency paradox.

Standby power use is the electricity consumed by appliances and other equipment when they are switched off or not performing their primary purpose. It is responsible for 3 to 12 percent of residential electricity use worldwide (source, pdf). Freelance journalist Robert Buzink has a low-tech solution for this – all you need is a pair of scissors and a screwdriver. The text is in Dutch but the pictures speak for themselves.

Following the intriguing but oversimplified graphic on materials scarcity published by New Scientist (a graphic that turns out to be 2 years old, by the way), this in-depth article at the Oil Drum Europe (original article here) gives a well founded look at the problem of metal minerals scarcity. Especially interesting is the link between energy and minerals:

“In case of unlimited energy supply, metal minerals extraction would only be limited by the total amount of mineral resources. However, due to the scarcity of energy, the extraction rates of most types of metal minerals will cease to follow demand. Probably the only acceptable long-term solution to avoid a global systemic collapse of industrial society, caused by these resource constraints, is a path towards managed austerity. Managed austerity will have to be a combination of changes in technology and changes in both individual and collective human behaviour.“

Related: Historical statistics for mineral and material commodities.