Category Archives: GREEN NEWS
The UN has new weapons to fight hunger, boost nutrition and reduce pollution, and they might be crawling or flying near you right now: edible insects.
The Food and Agriculture Organization on Monday hailed the likes of grasshoppers, ants and other members of the insect world as an underutilized food for people, livestock and pets.
A 200-page report, released at a news conference at the UN agency’s Rome headquarters, says 2 billion people worldwide already supplement their diets with insects, which are high in protein and minerals, and have environmental benefits.
Insects are ‘extremely efficient’ in converting feed into edible meat, the agency said. On average, they can convert 2 kilograms (4.4 pounds) of feed into 1 kilogram (2.2 pounds) of insect mass. In comparison, cattle require 8 kilograms (17.6 pounds) of feed to produce a kilo of meat.
Most insects are likely to produce fewer environmentally harmful greenhouse gases, and also feed on human and food waste, compost and animal slurry, with the products being used for agricultural feed, the agency said.
Currently, most edible insects are gathered in forests and what insect farming does take place is often family-run and serves niche markets. But the UN says mechanization can ratchet up insect farming production. The fish bait industry, for example, has long farmed insects.
Insect farming is “one of the many ways to address food and feed security,” the food agency said.
“Insects are everywhere and they reproduce quickly,” the agency said, adding they leave a “low environmental footprint.” They provide high-quality protein and nutrients when compared with meat and fish and are “particularly important as a food supplement for undernourished children,” it said.
Insects can also be rich in copper, iron, magnesium, manganese, phosphorus, selenium and zinc, and are a source of fiber.
The agency noted that its Edible Insect Program is also examining the potential of arachnids, such as spiders and scorpions, although they are not strictly speaking insects.
University biologists have analyzed the nutritional value of edible insects, and some of them, such as certain beetles, ants, crickets and grasshoppers, come close to lean red meat or broiled fish in terms of protein per gram (ounce).
But are they tasty?
The report noted that some caterpillars in southern Africa and weaver ant eggs in Southeast Asia are considered delicacies and command high prices.
And some people who might not entertain the thought of consuming insects might already be eating them. Many insects are ingested inadvertently.
Created by U.S. architectural firm Brooks + Scarpa, the recently completed Green Dot Animo Leadership High School in Inglewood, Los Angeles, wears its green heart very much on its sleeve. The new public school for 500 students is characterized by a large south facing façade covered with 650 solar panels, which not only help shield the building from the sun but also capture an estimated 75 percent of the energy needed to power the school.
According to Brooks + Scarpa the school’s combined sustainable strategies “will reduce carbon emissions by over 3 million pounds (1.36 million kilograms),” which translates to the equivalent of the annual emissions from more than 1000 cars.
In a design that also incorporates passive solar principles, the architects chose to move away from creating a traditional large block-like structure, instead choosing to build the school around a large internal courtyard. Benefiting from the Californian temperate climate, this landscape naturally makes its way into the school’s protected open-air lobby. This design helps to improve the amount of natural light and ventilation that can enter the structure, limiting the need for additional interior lighting and air conditioning.
Where the exterior is not covered with solar panels, ribbed screens have been installed which visually connects the school with its external environment and enable staff members to control how much light can enter the building.
The 53,500 square foot (4970 sq m) Green Dot school was completed at a cost of US$17.3 million.
A US school has cut a six-figure sum from its winter energy bill by replacing its oil-burning boiler with woodchip biomass ones. The switch has reduced the school’s carbon footprint by between 35 and 45 percent. The boilers are housed in a brand new green-roofed building which has become only the third LEED-certified power facility in the US.
Unlike the oil-fired boiler they have replaced, the biomass burners combust locally-sourced woodchip, which, though not a wholly clean source of energy, is cleaner than using oil. An electrostatic precipitator removes 95 percent of particulates from emissions before entering the atmosphere.
Because the woodchip comes from FSC-certified forests, it’s effectively a renewable source of energy as the forests are managed to maintain their stock. The International Panel on Climate Change goes so far as to argue that appropriately sourced woodchip is a carbon neutral fuel for this very reason. The carbon lost to the atmosphere when the woodchip is burned is gradually put back as replacement trees grow.
There are green roofs and there are green roofs. The former, best written in the sort of quotation marks that express dubiousness, are often little more than a thin shrubbery planted apologetically in the corner of a roof terrace. The latter are almost lush undulating meadows in comparison, and create the impression that the building has been slipped into the landscape like a letter into an envelope – when viewed from a favorable angle at least. It’s firmly in this category that the new biomass building at the Hotchkiss School in Connecticut belongs.
As one should expect from a green roof, this one serves more than aesthetic purposes. Bioswales, specially designed sloping channels, combine with rain gardens to slow and filter rainwater before it enters the ground.
The Hotchkiss School reports that between mid-October and the end of December, nearly half of the system’s winter operating period, the school slashed more than US$350,000 from its energy bill.
Lockheed Martin has been getting its feet wet in the renewable energy game for some time. In the 1970s it helped build the world’s first successful floating Ocean Thermal Energy Conversion (OTEC) system that generated net power, and in 2009 it was awarded a contract to develop an OTEC pilot plant in Hawaii. That project has apparently been canceled but the company has now shifted its OTEC sights westward by teaming up with Hong Kong-based Reignwood Group to co-develop a pilot plant that will be built off the coast of southern China.
OTEC uses the natural difference in temperatures between the cool deep water and warm surface water to produce electricity. There are different cycle types of OTEC systems, but the prototype plant is likely to be a closed-cycle system. This sees warm surface seawater pumped through a heat exchanger to vaporize a fluid with a low boiling point, such as ammonia. This expanding vapor is used to drive a turbine to generate electricity with cold seawater then used to condense the vapor so it can be recycled through the system.
Tropical regions are considered the only viable locations for OTEC plants due to the greater temperature differential between the shallow and deep water. Unlike wind and solar power, OTEC can produce electricity around the clock, 365 days a year to supply base load power. OTEC plants also produce cold water as a by-product that can be used for air conditioning and refrigeration at locations near the plant.
Despite such advantages, and even though demonstration plants were constructed as far back as the 1880s, there are still no large-scale commercial OTEC plants in operation. This is largely due to the costs associated with locating and maintaining the facility off shore and drawing the cold water from the ocean depths. But the time may finally be right.
With the shelving of the Hawaii OTEC pilot plant, the 10 MW prototype offshore plant will be the largest planned OTEC project to date. Like the Hawaii project, which was also to be a 10 MW facility, the China OTEC plant is designed to pave the way for higher capacity plants ranging from 10 to 100 MW.
The plant is to be built off the coast of southern China to supply 100 percent of the power needed for a large-scale green resort community being developed by Reignwood Group. The new resort is planned as Reignwood’s first net-zero community, with the company also currently developing two large-scale low-carbon resorts and others planned for key locations in China.
Lockheed Martin and Reignwood will begin concept design of the sea-based prototype plant this year with construction due to begin next year. Once it is up and running, the two companies plan to use the knowledge and experience gained over the course of the project to improve the design of additional commercial-scale plants.
The companies claim each 100 MW OTEC facility could produce the same amount of energy in a year as 1.3 million barrels of oil and decrease carbon emissions by half a million tons. Assuming oil trading at near US$100 a barrel, they estimate fuel savings from one plant could exceed $130 million a year.
The video below from Lockheed Martin describes the OTEC process.
Ordinarily seen as a waste product, the husks of sunflower seeds could be used to make concrete, according to research out of Turkey. Not only are the husks a sustainable source of aggregate, it’s claimed that the resulting concrete is more resistant to cracking during post-freeze thaws.
However, the researchers report that with greater concentrations of husk, the concrete would only be suitable for use as an insulating material. Lower husk density results in a lightweight concrete that could conceivably be used for construction purposes, though the researchers suggest this should be restricted to agriculture buildings a single story tall.
Having a high calorific value sunflower seed husks can also be formed into pellets for use as a biomass fuel.
The research was carried out by Can Burak Sisman and Erhan Gezer, engineers at Turkey’s Namik Kemal University. The research appeared in the International Journal of Environment and Waste Management.
While we wait for affordable multi-junction solar cells that are pushing past the 40 percent conversion efficiency mark to make it out of the lab and onto our roofs, we have to make do with standard commercial silicon cells that currently max out at around 19 percent. A team from the University of New South Wales (UNSW) in Australia has found a way to improve the quality of low-grade silicon, enabling higher efficiency solar cells to be produced from cheaper, low-grade silicon.
It’s been known for several decades that hydrogen atoms can be introduced to help correct the efficiency-reducing defects and contaminants found in lower-grade silicon. However, researchers have had limited success in controlling the hydrogen to maximize its benefits. The solution found by the UNSW team relates to controlling the charge state of the hydrogen atoms.
Hydrogen atoms can exist in a positive, negative or neutral charge state, which determines how well they can move around the silicon and their reactivity, which is important to help correct the defects. The researchers say that by controlling the charge state, it will be possible to achieve higher efficiencies using lower-cost, low-grade silicon.
“We have seen a 10,000 times improvement in the mobility of the hydrogen and we can control the hydrogen so it chemically bonds to things like defects and contaminants, making these inactive,” says Scientia Professor Stuart Wenham from the School of Photovoltaics and Renewable Energy Engineering at UNSW. “This process will allow lower-quality silicon to outperform solar cells made from better-quality materials.”
Wenham expects to achieve efficiencies of between 21 and 23 percent using this new technique, which was patented by the UNSW team earlier this year. The researchers have attracted the interest of industry partners interested in commercializing the technology, and they are working with manufacturing equipment companies to introduce it into solar cell manufacturing processes.
Source : UNSW
Three years after Mahindra group acquired Bangalore-based electric car maker Reva, the company launched its first electric car ‘e2o’ priced at Rs 5.96 lakh (on road Delhi, after state subsidy).
The group also said it has plans to extend the electric mobility technology to its two-wheelers, while seeking support from the central government for pushing eco-friendly vehicles.
The Mahindra e2o utilises Lithium ion batteries and offers a 100 km drive range to its owner which is a very feasible distance for urban use. In terms of recharging, the electric car can be re-charged through any 15 amp plug point along with the Sun2Car option that utilises solar power technology. While the e2o does not have active competition in the market, the upcoming Nissan Leaf may be able to give it a run for its money. Additionally, vehicles like Hyundai i10, Maruti Ritz and Swift will also offer competition to the e2o as they are a part of the growing B segment hatchback portfolio.
Commenting on the market expansion plans for the e2o, Mahindra & Mahindra President (Automotive and Farm Equipment Sectors) Pawan Goenka said: “We will be launching it in eight other cities over the next three to four weeks. The prices will vary as it would depend on how much subsidy state governments will give to the electric car.”
In Delhi, the government has given a total of 29 per cent subsidy on the electric car as a result of which the company has been able to sell it at an on-road price of Rs 5.96 lakh, he said, adding it would be more expensive in other cities.
The ‘e2o’ will also be launched in Mumbai, Bangalore, Pune, Ahmedabad, Hyderabad, Chandigarh, Pune and Kochi.