Posts Tagged ‘energy’
Beyond Food Miles: Some Types Of Food Take More Energy
Posted in Research by Kate Archdeacon on March 17th, 2011
Source: PostCarbon Institute
Image: renatamiyagusku via flickr CC
From “Beyond Food Miles” by Michael Bomford:
NOTE: The following article is concerned strictly with the energy equation of the food system and is intended to stimulate questions about how best to grow, transport, store and prepare (ideally local) foods. There are many reasons to favor local food, including supporting local economies and building local food security.
A locavore is “a person who endeavors to eat only locally produced food.”[1] What better diet could there be for an energy constrained world? After all, feeding Americans accounts for about 15% of US energy use,[2] and the average food item travels more than 5,000 miles from farm to fork.[3] It seems obvious that eating locally will go a long way to reducing food system energy use. Yet cracking the case of America’s energy-intensive food system demands that we look beyond the obvious.
A local diet can reduce energy use somewhat, but there are even more effective ways to tackle the problem. Single-minded pursuit of local food, without consideration of the bigger picture, can actually make things worse from an energy perspective.[4]
If you realize you’re spending too much money, the first thing to do is figure out where it’s going. Cutting back on pizza won’t make much difference if you’re spending most of your money on beer. Similarly, the first step in reducing food system energy use is to figure out where all the energy is going. That’s what a team of economists working for the United States Department of Agriculture (USDA) did last year, in a report called “Energy Use in the US Food System“.
The report contains some surprises. Transportation is the smallest piece of the food system energy pie. Even farming isn’t a particularly big contributor. The big energy users turn out to be food processing, packaging, selling, and preparation. Our kitchens command the biggest slice of the pie, using twice as much energy as the farms that grew the food in the first place.
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Read the full article by Michael Bomford at the Post-Carbon Institute for more information and access to the end-notes included above.
Animation: 300 Years of Fossil Fuels in 300 Seconds
Posted in Movements by Kate Archdeacon on March 16th, 2011
Source: PostCarbon Institute
THE ULTIMATE ROLLER COASTER RIDE: A Brief History of Fossil Fuels
Fossil fuels have powered human growth and ingenuity for centuries. Now that we’re reaching the end of oil and coal supplies, we’re in for an exciting ride. While there’s a damned good chance we’ll fall off a cliff, there’s still time to control our transition to a post-carbon future.
Watch it on the Post Carbon Institute or on You Tube.
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Burning Wood: Not So Carbon Neutral?
Posted in Models, Opinion, Research by Kate Archdeacon on March 1st, 2011
Source: The Ecologist
Image: Shandchem via flickr CC
From Turning our Victorian Terrace into an Eco-Home part seven – Heating by Sue Wheat:
Sue Wheat thought a wood-burning stove was the greenest way to heat her house until a chat with authors, Nick Grant and Alan Clarke, made her think again. The biggest crisis of her eco-refurb so far? You bet it was!
With the cold weather closing in, it was time to think about green ways to heat our home. We chose a Stovax multi-fuel stove, which we were lucky enough to get from friends.
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In a city where every other house seems to be having its kitchen or bathroom ripped out, there is vast amounts of burnable scrap wood lying around waiting to go to the dump, which could instead be heating your house. Paying for wood to burn seems positively stupid when you can pick up a week’s supply from neighbours, most of whom are all too willing to let you have it. I can’t see the logic in buying wood that’s been transported hundreds of miles either, so I’ve become something of an eagle-eyed wood-spotting obsessive. We look for wood that’s unvarnished, unpainted and untreated, and either carry it home, or rope in friends with cars or vans to pick it up for us. I’ve also got a few friendly builders who drop off scrap wood to us (thus saving them dumping fees), and a supply of off-cuts from a furniture repair workshop. To build up next year’s wood store, which we made from scrap wooden pallets covered with tarpaulin, we’re planning to buy some logs from a local tree surgeon and season them for a year, by which time the excitement of dragging wood out of skips and yards may well have worn off.
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As I basked rather smugly in the warm glow of our pretty, near zero-carbon heating system, for a good few weeks I was unaware that things were about to get tricky. Then with one click on the mouse, I stumbled across a website which catapulted me into my biggest eco-refurbishment crisis yet. It seems, according to some of the eminent researchers at the Association of Environmentally Conscious Builders [AECB] that burning wood is not carbon neutral after all. I was gutted, to say the least. I emailed the AECB in a panic, who put me onto the authors of Biomass: A Burning Issue, Nick Grant and Alan Clarke. Their paper concludes that while it’s true that trees do absorb carbon dioxide when they grow, it doesn’t mean that the best use for the wood biomass is burning it. Burning, say Grant and Clarke, produces more carbon emissions than burning gas. Disaster.
Instead, they argue that timber should be left unburnt, thus imprisoning the carbon, and put to other uses; for example, as structural timber, insulation material or furniture. As owners of low-energy houses fuelled by wood burning stoves, they are both gutted too. ‘We don’t want people to hate us,’ Nick told me. ‘Please don’t shoot the messenger.’ The unfortunate result of assuming that wood-burning is carbon neutral is that it has been promoted by just about everyone, which has meant, as they point out, that wood is now being burnt faster than it’s grown, leading to rising prices and unsustainable burning practices to start.
Read the full article by Sue Wheat, and check out the comments section which has some useful links posted by the author.
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Refining Technology: Bio-Digester for an Ice Cream Factory
Posted in Models by Kate Archdeacon on January 28th, 2011
Source: FoodMag
Image courtesy of Paques
From Unilever to build bio-digester at Dutch ice cream factory:
Unilever and biotechnology company Paques have started the construction of a bio-digester at the food giant’s Ben & Jerry’s ice cream factory in Hellendoorn, the Netherlands. Paques’ BIOPAQ AFR bio-digester, which will convert waste products from the production of ice cream into clean energy, will cover 40 per cent of the ice cream factory’s green energy requirements.
According to Paques, this bio-digester has been built specifically for applications where the purification of fat-containing wastewater is required. Unlike conventional systems, the bio-digester treats wastewater containing fat and oil in a single compact reactor, together with degradable particles. The installation of the bio-digester is a part of Unilever’s Sustainable Living Plan, which aims at reducing the production of waste and the consumption of water and energy. The bio-digester is expected to become operational mid year.
Source: FoodMag
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This is cool – Passivhaus NYC
Posted in Models by Kate Archdeacon on January 17th, 2011
by Lloyd Alter via Treehugger
Image by Loadingdock5
Sustainable design techniques and high tech photography merge to give us a great insight into advanced architectural practice through this piece on Treehugger.
“Really, one could go on for hours explaining the benefits of Passivhaus design, but it is all right here in this thermogram (thermograph?) of Loadingdock5′s 174 Grand Street in New York City. It’s neighbours just glow with red, representing lost heat; the building in the middle barely registers. In fact the high performance windows are even darker than the building itself.”
Read the rest to see a larger photo and visit Loadingdock5′s site to see detailed information about the project.
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Zeer Pot Fridge: Low-energy technology
Posted in Models by Kate Archdeacon on December 9th, 2010
Source: Nourishing the Planet: Worldwatch Institute
Practical Action’s Zeer Pot Refrigerator:
In the heat of Sudan, food doesn’t stay fresh for long. Tomatoes go off in just two days. After four days carrots and okra are rotten. For poor families in North Darfur and Blue Nile State, without any means of preserving their crops, this can lead to hunger and even starvation. The situation is especially grave for those most vulnerable like children and elderly family members.
One ingenious solution is the zeer pot: a simple fridge made of local materials. It consists of one earthenware pot set inside another, with a layer of wet sand in between. As the moisture evaporates, it cools the inner pot, keeping up 12kg of produce fresh for up to three weeks.
Fruit, vegetables, water. The zeer pot keeps them all fresher for longer – providing much needed help to starving families.
You can see from the table below the incredible difference that a zeer pot makes to food preservation in Sudan. For many families, it can mean the difference between potential starvation and having enough food to feed themselves.
Visit the website for more details on the Zeer Pot Fridge, including how to make one, and basic information on evaporative cooling. http://practicalaction.org/our-work/ourwork_zeerpotfridge
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What if we didn’t use electricity to store all of our fresh food? Our energy-hungry fridges could be much smaller if we used more passive technology. For other fridge designs, check out these VEIL student works: “Circular“, “Tower of Power” and “Split Fridge“ -KA
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Retrofitting Apartments with Smart Meters
Posted in Models by Kate Archdeacon on December 2nd, 2010
Source: EcoVoice
From “Brisbane residential high-rise leads the way with advanced smart metering system“:
Brisbane ‘cleantech’ company, networkGreen, has signed a 10 year contract with Felix Apartments to retrofit the latest in embedded smart meter technology and manage the on-supply of electricity, hot water, and gas. Daniel Filmer, Managing Director of networkGreen, said that this was a significant milestone in the evolution of sustainable living by bringing meaningful electricity, water, gas consumption data to the individual user.
“High-rise buildings are one of the largest contributors to carbon pollution, we wanted to allow residents to see what they were using in real-time, so they had the opportunity to reduce waste and create a more sustainable way of living .” he said. Felix Apartments comprises of 253 residential apartments over 39 levels and will undergo a retrofit program to install the embedded smart-meter technology, which will allow each occupant individual access to their electricity, water and gas consumption by logging into their secure web portal for their apartment.
networkGreen smart meter systems use the latest technology to capture accurate electricity, water and gas usage information and display this information to the end user through a secure and easy to use online web portal and iPhone application.
Read the full article on Eco-Voice.
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Bluebonnet Energy Co-Op: via Mexico City
Posted in Models by Kate Archdeacon on November 21st, 2010
Sustainable Cities Net: Posting from the UCLG Congress in Mexico City 18-25 November
Bluebonnet Electric Co-op is an example of a Smart Grid installation in the Dome here in Mexico City. The Co-op has installed smart meters in its members’ homes after an education and engagement process designed to avoid the criticisms leveled at smart meters – namely that they don’t deliver behaviour change. Ensuring that the Co-op members have access to tools such as Net Energy Management, pictured here, increases their capacity for observing and responding to their energy consumption data and the related costs. The smart meters allow the energy supplier to moderate how much electricity they produce, and the related software allows the customer to choose what they use and when. Smart meters, packaged with appropriate tools by an interested company for an interested market, are a great example of the consumption reduction that ICT can deliver. An additional benefit, briefly touched on in the Dome presentation, is that the meters no longer need to be physically visited by the company’s readers. While this saves 30% of the company overheads (it’s unclear what the former meter readers do now), it also eliminates hours of driving from one property to another, and the associated GHG emissions – moving into the territory of sustainable & efficient logistics.
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Introducing the Smart Grid! via Mexico City
Posted in Movements, Research by Kate Archdeacon on November 19th, 2010
Sustainable Cities Net: Posting from the UCLG Congress in Mexico City 18-25 November
A Smart Grid, described by Siemens as the “intelligent network infrastructure” that supports the “systematic optimization of the energy system”, would allow energy production and consumption to become more aligned, reducing waste in energy production and increasing consumption awareness through smart meters, tariffs and smart appliances.
Siemens have erected their Smart Grid Dome in the Plaza Santo Domingo, here in Mexico City. The interior dome acts as a projection screen for a multimedia introduction to Smart Grid Solutions, while touchscreens around the walls divide the information into (roughly) Grid Management and ICT, Renewable Energy, and Scales of Application (Industrial, Commercial, Residential). The information is a mixture of technical specifications, background information, current research, case studies and proposals.
While it may seem like shifting to smart appliances and meters does not reduce the need for “stuff” (and what we do with all the “non-smart” stuff when it’s not wanted anymore), there are opportunities to combine Sharing Services and Product Service Systems (PSS) with smart grids. For example, a smart grid might encourage people to set their smart washing machine to run during off-peak supply for wind power – say at 3 in the morning. In this model, everyone still owns a washing machine. But what if your local laundry service did the same thing – using less resources and energy while creating a central point for water-saving infrastructure? (Local Laundry Service?? Check out this pedal-powered laundry service in Buenos Aires.)
More to come on this…
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To follow the posts from the Summit follow or bookmark this link, http://www.sustainablecitiesnet.com/tag/mexico-city/.
Could urban heat islands produce geothermal power?
Posted in Research, Sustainable Cities by Kate Archdeacon on November 3rd, 2010
Via Environmental Research Web
Image: dustinphillips via flickr CC license
From Hot water to get cities out of energy trouble? by Liz Kalaugher
Cities are generally warmer than the rural land surrounding them, in a phenomenon known as the urban heat-island effect. It’s not just above-ground temperatures that rise – the soil beneath also experiences several degrees of warming. Now, researchers have found that the extra heat stored in groundwater beneath cities around the world could provide enough geothermal energy to heat urban homes.
“In most cities, with a variety of populations and climates, the large amount of geothermal energy stored in the urban local subsurface is capable of fulfilling the annual space-heating demand for years and potentially decades,” Ke Zhu of the University of Tübingen, Germany toldenvironmentalresearchweb.
Together with colleagues from Karlsruhe Institute of Technology, Germany, St Francis Xavier University, Canada, and ETH Zürich, Switzerland, Zhu measured groundwater temperatures in Cologne, Germany, and Winnipeg, Canada. Both cities had extensive underground warming, with temperatures 3–5°C higher than surrounding rural areas. Similarly, the subsurface beneath urban green spaces was cooler than that below business districts.
The urban heat-island effect arises because of factors such as buildings preventing heat from leaving the ground at night, changes in the properties of the ground surface and the absence of plants that provide cooling by evapotranspiration.
“Urban aquifers with elevated temperature are attractive shallow geothermal-energy reservoirs, and meanwhile there is high energy demand just above,” said Zhu. “In our opinion, it is important to study the geothermal potential of urban heat islands before planning large geothermal projects.”