Is it a bird? Is it a plane? No, it’s Mythbuster Woman, joining you for a second installment of Debunking Energy Myths. I’ve taken a few moments out of my busy schedule of leaping tall buildings (in a single bound, of course) to answer those of you who challenged me with more myths.

We heard from many of you following my past post regarding energy-related myths. I’ve taken a crack at answering a few of your questions.

Myth #1: Is it true turning your computer on and off decreases its lifespan?
Answer to the Myth: True…with a catch.

While turning your computer on and off does decrease the lifespan of your computer (as well as many other appliances), the reality is that the effect is minimal. Fact is, you’ll probably need to replace or upgrade your computer well before any of the adverse affects would be noticed.

As we’ve said many times before, it’s always a good idea to turn off non-essential appliances, when possible. The energy savings you’ll achieve by hitting the off button far outweighs any wear-and-tear you’d experience.

What’s more, leaving your PC on can actually have a negative effect. When powered on, a PC produces heat, which builds up fairly quickly and both the heat and the cooling mechanism effort increase the wear and tear on your computer. Unless you’re like my dad who still has his Compaq Presario from 1994 (and I’m not judging!), your short-term energy bill is more significant than your long-term computer life.

Myth #2: I’ve heard you should leave your air conditioning on and windows closed when there is a short-term drop in outside air temperature, as it takes more energy to cool your house down again when the weather warms. Is this true?

Answer to the Myth: Not true! says George Spargo, one of the many Energy Efficiency Engineers/Superhero Friends here at Xcel Energy. According to George, short-term dips during the summer months do not have a dramatic affect on your energy bill. So when the temperature drops outside, it is best to turn your AC off and use the free cooling from Mother Nature.

Thanks, George! Now, if I could just find a tip that would turn my Chevy Gremlin into an energy efficient Invisible Plane?

Myth #3: This one comes to us from Fred C., who wrote “One of my favorite (myths) is, ‘Fill your ice cube trays with hot water, it will freeze faster.’”

Answer to the Myth: You’re right, Fred! In some circumstances, warm water actually does freeze faster than cold water. How do we know this? Well, Erasto Mpemba first documented the phenomenon in 1969. Today, it’s known as the Mpemba Effect.

Unfortunately, this little factoid doesn’t exactly save energy because 1) it doesn’t always work and 2) the amount of energy used to heat the water makes up for energy saved in cooling it faster.

I hope you’ve all enjoy my encore performance as Mythbuster Woman. Keep your comments coming, and I will dedicate myself to debunking energy hoaxes, thwarting scams and educating energy users everywhere. (Cue patriotic music)

Article by Mary LaLone, appearing courtesy Xcel Energy Blog.

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Abu Dhabi is commissioning a new set of nuclear plants for the first time in 2018, that will generate 25% of its power. I find this a bit hard to understand, since it’s happening just as countries like Germany and Italy are decommissioning their nuclear power. Also, Abu Dhabi has huge peaks; their ratio of peak to average load is one of the largest on Earth, due largely to air conditioning, which represents 85% of load — even more surprising for a country that has huge energy needs for water desalination and the petrochemical industry.

Making matters worse, they don’t seem to be able to handling these peak loads too elegantly. It’s not uncommon for transformers to burst into flame, turning people out into the streets to sleep where it’s much cooler when the A/C goes out. This, in turn, negatively affects production, when people can’t get a good night’s sleep.

Holy cow.

So, I asked the speaker: “Why on Earth do they want nuclear (that doesn’t scale up and down according to load)?”

“They like ‘big,’” he answered. “They want to make one deal and have a solution – large enough to make it possible for them to crank up their air conditioning so they can show off their furs.”

Wow. I thought we had idiotic extravagances here. It’s quite a world.

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Two of the most interesting and efficient air conditioners arriving on the market this cooling season have come to us, not from the world of mainstream air conditioner manufacturers, but from renewable energy companies.

The first of them is the SplitCool DC18 solar air conditioner from Solar Panels Plus. This is a 48 volt DC air conditioning unit that employs a variable speed compressor. According to the company, their engineers started with Mitsubishi High-SEER brushless DC inverter compressor and re-engineered it in cooperation with the factory, removing the rectifier and configuring it to function on 48 volt DC power input.

There is no inverter needed or used on the inside or outside of the unit. This is important to solar energy users, because not using a AC-DC inverter avoids the power loss experienced when running a AC powered appliance on solar power. Since solar power is always native DC and 15 to 20% of the power is lost during the AC-DC conversion process, avoiding the inverter, by itself, makes this air conditioner far more efficient that a high-SEER AC unit connected to solar through an inverter.

From HotSpot Energy, another renewable energy company operating in the area of waste heat recovery, comes a new AC product called the ACWH18 Air Conditioner Water Heater. Like the solar air conditioner mentioned above, it is a 18,000 BTU ductless mini-split heat pump, but the HotSpot air conditioner-water heater runs on normal 220v AC power.

The ACWH is a SEER 18 EnergyStar certified unit that includes an integrated heat recovery circuit allowing it to make hot water as a free byproduct of running the AC.The heat recovery circuit recovers the heat that would normally be thrown away, and recycles it to make hot water at temperatures up to 140F.

The HotSpot air conditioner-water heater system installs like a normal mini-split, and then the outdoor unit is connected by insulated water lines to the customers hot water tank, using a special tank adapter. According to HotSpot engineers, it can make about 100 gallons of hot water per day, give or take, depending on its duty cycle and the entering water temperature.

The company says that a typical user with a seven month cooling season will save over $1,000 per year in combined electrical and water heating savings, compared to a customer running a SEER 13 unit and using a standard water heater, with users in southern areas like Florida able to achieve double that amount of savings. And it qualifies for a federal tax credit.

Article by Jason Burns, appearing courtesy EnergyRefuge.

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Where do you begin with the benefits of green roofs? Over time, green roof owners, from residential to corporate, have testified to the numerous benefits they have received since installing green roofs on their homes and office buildings. Along with drastic cuts in electric and energy bills, they’ve also experienced longer-lasting durability and an improved aesthetic appeal while helping defend against increased air pollution. Read below to see how green roofing can benefit you, your home and business:

1. Economic benefits (energy costs, tax incentives)
Probably the biggest incentive for installing green roofing is its financial. Converting to green roofing has been found to cut as much as 25% in air-conditioning costs during the summer through a mere 10 centimeters of grass installed onto the roof. This is usually seen over a long-term range, however, as the initial cost of installing green roofing can be quite staggering. Green roofing installation generally comes with a $15 to $20 price tag per square foot as opposed to standard asphalt which is priced at almost $80 per 100 square feet. The best way to think about it is to consider it an investment for future energy costs, as recent economic hardships have shown us that energy resources are finite and rapidly on the decline.

Many states also offer tax breaks or credits for business and home owners who employ green roofing techniques. Homeowners in New York, for example, are eligible to receive a federal tax credit of up to $1,500 for green roofing installation and through the state’s tax abatement program, which also includes solar-paneled roofs.

2. Improved insulation, from sound and temperature regulation
Ever feel like you get home or arrive at the office with the sounds of the outside world trailing behind you? With green roofing, you add another layer of insulation to help keep out the excess noise pollution. This is quite practical for urban areas that experience high volumes of noise throughout the day. Suburban or rural locations can also benefit from green roofing noise reduction against heavy rain and neighborhood traffic.

Green roofing can also help regulate indoor temperatures. Homeowners with green roofs have noticed significant drops in heat during the summer and have found themselves turning on the air conditioner less frequently and at not-as-low temperatures. This can help lower the cost of energy bills significantly and prevent further consumption of toxic coolants and chemicals used to produce and maintain air conditioning.

3. Improved air quality
One of the greatest benefits of having a green roof is its role in improving the overall quality of air. Urban areas that experience several forms of air pollutants (ex. car exhaust, restaurant smoke, cigarette fumes) in a condensed space will especially benefit from having the plants on green roofing constantly supplying fresh oxygen. They are able to do this due to their natural cooling abilities, as cooler temperatures hinder air pollution from accelerating and spreading. One square meter of grass roof can eliminate around 4 pounds of air particles through a natural filtering process.

4. Aesthetics
Looks aren’t everything, but they do count. If the technicalities of green roofing go way over your head, take a look at some examples to better visualize how your home or office could possibly look with a green roof. Modern architecture has found itself pairing green roofs with glassy, mirrored buildings in order to mesh contemporary and natural elements. There are also plenty of options when selecting the plants and flowers to include on your roof. Plants like grass, shrubs, and sedum plants work particularly well on green roofs due to their shallow roots and low maintenance. They are also relatively inexpensive and come in a wide assortment to help you design your green roof to your desires.

5. Food production (for garden roofs)
As if reducing energy costs and noise pollution weren’t enough, green roofing is also a viable location to start a small garden. Granted, not all roofs are suited for garden growing. Flat roofs are obviously the easiest for the gardener to access and tend to the garden, but roofs with a slight slope are not out of the question. Also, not every type of food can be produced on roofs. Seeds that expand into deep roots will be difficult to maintain as they quickly consume resources and take over the soil space. There is also the issue of weight; fruits trees and the other types of arboreal plants which deep, heavy roots will add pressure to the water membrane separating the roof from the soil, causing cracking and leaking. For the maximum benefits of food production on green roofs, stick to smaller produce, such as tomatoes, herbs, and squash.

Article by Lola Pak, a writer from Atlanta, GA, where she enjoys writing about the topic of green roofing.

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Mitsubishi and Nippon Fruehauf, a light metals manufacturer, have developed an “idling-stop” solar-powered air conditioning unit that cools the truck cabin when the engine is not running.

Called the “i-Cool Solar,” the solar-powered, 900 W (maximum) AC system uses a series of Mitsubishi Chemical Corp. solar photovoltaic (PV) thin-film cells on a Nippon Fruehauf mount attached to the top of the trailer, behind the cabin or tractor. A battery stores the electricity for use when the truck is at a standstill or the engine is not running.

The addition of solar cells insures that the battery is kept fully charged, allowing for the stable operation of truck tailgates and wings. The solar cells also make possible a one-percent fuel savings per year, as well as a savings of about 1.8 liters (1.90 quarts) of light hour per hour. For a 10-ton truck, this is the equivalent of 1,500 liters (396 gallons) of light oil not used each year.

According to Mitsubishi Chemical, if all the trucks in Japan used the i-Cool Solar, the country’s carbon dioxide emissions would fall by 1.65 million tons. The companies are also planning a smaller version of the i-Cool for use in cars.

The solar AC unit should be commercially available in the spring of 2012. The current “i-Cool,” was released on May 24 and consists of a battery that stores electricity while the truck is moving and makes it available when the engine is not operating. Nippon Fruehauf also makes trailer bodies.

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You wouldn’t expect that energy from sunlight, which is very hot, could power air-conditioning units to cool things down. But that’s precisely the latest breakthrough from China-based Shandong Vicot Air Conditioning Co.

Debuting its solar-powered people-cooler at the 2010 World Solar-Powered Air Conditioning Development Forum in Dezhou, China, Shandong demonstrated that the idea is not only feasible, but practicable.

The unit achieves an optimal 85-percent thermal cooling conversion efficiency, and is 27 times more efficient at converting solar insolation to cool air than even the average solar water heater. Since passive and flat-plate solar water heaters are among the most efficient ways to convert solar insolation to usable hot water, this is amazing. More amazing is the fact that the unit is a direct-from-solar cooling device, rather than air conditioning that runs off the electricity generated by solar panels.

According to Shandong Vicot President Li Wen, the A/C unit is the culmination of three years of pioneering solar research efforts by Chinese and American scientists, who collaborated to achieve this cutting-edge technology, which is not only low-carbon but low cost. That is, the unit will recoup its initial investment in 3.5 years, and the entire investment in 6.7 years.

Industry experts were almost unanimous in their opinion that the Shandong Vicot offering is an innovation worthy of China’s increasingly dominant solar technology sector. It also represents an arrow in time for the industry’s future development, particularly as the world is replete with solar technologies to extract electricity from sunlight, but heretofore has no method for converting solar insolation to cooler air.

If, as predicted, 2060 sees the Earth exhausted of its traditional sources of energy like coal, oil and gas, the advent of clean energy technologies like solar, which can be tweaked to produce light, heat and cooling, will be a literal lifesaver.

For China, the world’s largest producer and consumer of solar power, the invention is a milestone. The Chinese people have taken to solar-powered water heating in a big way, and the industry itself reached 4.2 million square meters production capacity in 2009, or an annual growth rate of 35.4 percent.

China now produces 40 percent of the world’s solar cells. In spite of that, most of China’s solar-related production is destined for export, even though last year China rose to be the world’s biggest energy user in 2009 – a record formerly held by the U.S.

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It sits in the middle of a harsh, barren desert, sweltering in searing heat. It has no clean water, its sea is polluted and there is no topsoil, just a covering of sand. It is also the biggest per capita consumer of fuel, massively reliant on cars, power-hungry desalination and air-conditioning. And with all this, can the United Arab Emirate state of Abu Dhabi really succeed in building a new “green city” in the Middle East?

If you can believe visionary people like architect Gerard Evenden (his words above), from the British architectural firm Foster & Partners, yes it can. Billions of dollars are riding on the assumption

Masdar City is the project Evenden is referring to. Masdar City is a $22 billion USD project being financed by the  Abu Dhabi Future Energy Company and is largely designed and planned by Foster & Partners.

So how is this so-called totally green city going to work in one of the hottest and driest regions on earth? According to Evenden, this futuristic project of 6 million square meters will eventually house around 50,000 people and will be completely environmentally sustainable – in every possible way.

As he noted in a recent Financial Times article The Greening of Arabia, by Edwin Heathcote :

“if you can make it work here, you can make it work anywhere.”

In one of Green Prophet’s previous articles on Masdar City it was noted that: “the project will be one in which commercial and residential entities will blend with each other to create a totally harmonious and ‘zero carbon’ environment, where all lighting and air conditioning systems will be powered by a 40 to 60 megawatt solar power plant, a 20 megawatt wind farm, and geo-thermal and hydrogen based power.”

The construction itself will be such as to shelter the inhabitants from the blistering Arabian sun and will include specially constructed walls, screens and meshes to allow breezes to enter and keep sunlight out as much as possible.

All this sounds absolutely wonderful and almost too good to be true. But as we pointed out earlier, Masdar City could either be a practical community innovation or expensive showcase.

The project has one big drawback – the construction itself.  Any true environmentalist knows that a significant construction project, such as the many that have been going on in various locations of the UAE, can in themselves be very damaging to an environment that is very fragile, to say the least.

Anyone visiting these locations must sometimes wonder at what expense to the environment these projects will cause, including island projects like Abu Dhabi’s planned $27 billion USD Saadiyat Island commercial, residential and leisure time project currently under construction, and mooted to become Abu Dhabi’s cultural center.

But once completed, Masdar City will hopefully prove to be as green and sustainable as its planners and developers say it will;  and will not be just a “showcase” project as Saadiyat Island looks to be by many.

What do you think? Voice your opinion below in our comments.

Article by Maurice Picow appearing courtesy of Green Prophet

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The explosive growth of modern refrigerants, originally developed to replace ozone-destroying chemicals, could become a significant cause of global warming if they are not soon replaced by a new class of coolants, according to Dutch and U.S. researchers.

Reporting in the Proceedings of the National Academy of Sciences, the scientists said that hydrofluorocarbons (HFCs) – now used in most air conditioning in cars and buildings – are a potent greenhouse gas whose heat-trapping effects currently equal less than one percent of all CO2 emissions worldwide. But booming economic growth in the developing world and the rapid spread of air conditioning mean that by 2050 HFCs could cause at least 25 percent of human-induced global warming, the study said.

HFCs came into widespread use when they replaced ozone-depleting chlorofluorocarbons two decades ago. The good news is that industry is now developing a new class of more benign refrigerants, and researchers and policy makers are calling on the global community to phase out HFCs, much as chlorofluorocarbons were eliminated under the 1989 Montreal Protocol.

This article originally appeared on Yale Environment 360 at http://e360.yale.edu

[photo credit: niallkennedy]

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