Cooler Planet

Could we someday have a fabric that could power our cell phones and MP3 players?  Scientists from the Georgia Institute of Technology hope so.  Yong Qin, Xudong Wang and Zhong Lin Wang are developing a fabric embedded with piezoelectric zinc oxide nanowires to create a nanogenerator within our clothes.  These minute generators could create electricity from our own body movements. 

Their article, published in the February 13 edition of the journal Nature, describes how by coating half of the zinc oxide wires with gold the fabric’s embedded wires can then convert physical movement into electricity.  Evidently, the gold plating enables the microscopic wires to act as an electrode so that when the “charged” wires contact the non-gold plated wire an electric current can run through the fabric.  Their research has also demonstrated that the microscopic wires must be arranged similar to a bottle-brush as opposed to another type of alignment. 

All is not perfect, however.  Though the scientists have added a polymer layer to prevent the zinc oxide from wearing away, the research team must still figure out how prevent the zinc oxide from degrading when wet.  It wouldn’t do to power your cell phone in clothes that cannot be laundered. 

A lamp’s “color temperature” describes how warm or cool a light appears to our eye.  Traditional incandescent light bulbs emit a warm (or reddish colored) light.  Scientists measure color temperature in degrees Kelvin (K).  On a bright sunny day, the scientists would say the color temperature equaled 5,500 K, whereas candlelight would register at 1,500 K.  Incandescent lights equal 3,000 K.

The other component of a light’s quality is its color rendering index (CRI) which measures how accurately the light reflects color.  The CRI is measured on a scale of 1 to 100 and daylight and incandescent light bulbs set the standard for 100.

So the incandescent light bulb has ruled our world, setting the standard for light color since Thomas Edison mastered his invention oh so long ago.

Fluorescent lights were invented in 1976 but hadn’t made a dent in the market until recently.  Today, fluorescent light bulbs are close to par with the incandescent standard.  When shopping for a compact fluorescent bulb (CFL), look for a CRI at 82 +.  Many have a color temperature of 3,000 K.

Since CFLs use 30 to 50% less energy than incandescent bulbs, using the modern CFLs available today makes more and more sense just from a comparable color standpoint.  So go for it, rather than looking pasty in the mirror you’ll look warm and bright.  It will be our planet that stays cooler instead.

Have you ever wondered how solar electric or solar thermal systems work?  Cooler Planet has just published a couple of pages that go into depth about how each of the systems work and save you money.  From talking about solar panels vs building integrated photovoltaic products to solar hot water systems and solar pool heating systems, the pages give you a good run down on them. Just another way to help make this a cooler planet.

These days, there are seemingly endless amounts of “green labels” out there.  What do they all mean?   

In the world of green building there are a variety of green building rating systems.  Some take a holistic approach and evaluate all the various systems inside and outside your home; others examine a narrower band of categories such as indoor air quality or energy efficiency.  Complicating matters further, different – yet similar – names are used within different regions (or even smaller jurisdictions) throughout the country.  Take, for example, this dizzying sampling of names:  Built Green, Build Green, Earth Advantage, Earth Craft Home, Green Home Choice, I-Built, EcoBUILD. 

Generally, to achieve certification in any of these green building rating systems designers produce designs and specifications that incorporate the required goals and then builders incorporate requirements into their construction practices.   What generates confusion for home owners and buyers is trying to understand the myriad of different goals and check-list requirements applied to each prospective home.  Green labels wouldn’t do much good if consumers did not understand them and what they are trying to achieve. 

Understanding and appreciating the design, engineering and finishing choices builders include can help prospective home buyers differentiate between homes beyond an aesthetic appeal.  Builders often tout a home’s “green features.”  However, until a single building standard is adopted what is called “built green” may differ between programs.

So how do you distinguish between green building certifications?  Let’s start at the national level.  Both the National Home Builders Association (NAHB) and the U.S. Green Building Council (USGBC) have developed rating systems for residential construction.  The NAHB calls it guidelines, the Green Home Building Program; the USGBC who created the Leadership in Energy and Environmental Design (LEED) certification system, calls its system:  LEED for Homes.  Both of these rating systems include a wide-range of protocol for how to build a green home. 

At first glance, both the NAHB Green Home Building Program and the USGBC LEED for Homes look similar.  They are.  Both organizations have published lengthy checklists and guidelines that define categories such as Energy Efficiency, Water Conservation, and Indoor Environmental Quality.  Both describe criteria and objectives to meet in order to obtain points toward a rating.  And each rating system has different levels – the Green Home Building Program has 3-levels:  Bronze, Silver, and Gold; LEED for Homes has 4-levels:  Certified, Silver, Gold, and Platinum.  The higher the level, the more green features a home has incorporated.  Both rating systems aspire to design and build homes that are energy efficient, use water wisely, are well placed on a site, and incorporate building materials and best construction management practices that tread lightly on the earth.

The differences between the programs are subtle.  Many of the variances relate to how the homes are rated, how the programs are executed, and plain old competition for brand name recognition and dominance.   The USGBC rating system relies on third-party certification to determine how many points to award each house.  The NAHB allows local builders and jurisdictions to establish their own certification process.  For example, the local home builders’ chapter in King and Snohomish counties, two counties in Washington State, has established a rigorous green building rating system that requires third-party certification to achieve its highest green building levels whereas the lower-point levels are based on the builder’s self-verification. 

In future posts I’ll explain the actual differences between other types of green building certifications, labels, and standards. 

The Energy Star label identifies products that deliver comparable or superior performance but save a whole lot of energy.  A government and industry partnership between the EPA, the U.S. Department of Energy, and numerous private industries, Energy Star has become a respected label to help consumers identify high efficiency products.  Today, Energy Star encompasses more than 50 different types of products including heating and cooling systems, appliances, office equipment, consumer electronics, and lighting.  Products with an Energy Star logo meet energy efficiency criteria set by the EPA and the Department of Energy. 

The Energy Star website provides a dearth of information about how products are selected.  You can also download a comprehensive list of current products that meet and exceed Energy Star criteria at www.energystar.gov.

Take computers, for example.  In June 2007, Energy Star strengthened its energy-efficiency requirements for computers.  Recognizing that computers are used for more hours throughout a day than ever before, qualifying computers must meet energy use thresholds in each of three operating modes:  while in use, in standby, and when in sleep.  As a result, Energy Star rated computers use 70 percent less electricity than models that lack these power management features. 

During the winter months you may notice how well, or not so well, your windows work.  If your home feels drafty or you continually see condensation build on your windows, you may own single-paned windows.  Replacing single-paned windows with double-paned glass can do wonders for increasing energy efficiency in your home, not to mention moderating the indoor temperature better.

Look for double-paned windows with a low “U-value.” U-value measures the amount of heat lost through a material.  Another factor to consider is “E-value” – the reflective value of a window to help prevent heat from escaping.  Double-paned windows are rated for both U- and E-values.  A low U-value (around 0.20) prevents loss through a window; and ideal low E- and U-value is rated around 0.35.  Minding your Es and Us can help you moderate the temperature inside your home.

Wouldn’t it be nice to not have to flick a light switch during the day to light up a dark area in your house?  Whether your home is brand new or heritage, there always seem to be a room less well lit than others.  Solar tube skylights can turn a dim space bright.

Solar tubes are similar to a skylight but not as space consuming.  In your home, they look more like a recessed ceiling light fixture instead of like a skylight.  Solar tubes guide light from outside through a reflective tube to an interior ceiling mounted light diffuser.  (In fact, some even come with an internal light fixture so that they double as a regular light fixture during the night time.)  Solar tubes are relatively inexpensive – many models start at about $150.  

Exactly how the solar light tube originated isn’t exactly clear, it’s likely someone once had an epiphany while installing a metal chimney for a wood stove.  The hole was cut in the roof, the stove pipe inserted, and in an instant the space went from dark to bright!

Solar tube lighting is manufactured by a number of different companies; from major skylight manufacturers to specialty firms.  Generally, all solar tube products come with roof components (a light collector and roof flashing), a reflective tube to direct the light, and a ceiling fitting (comprised of a trim ring and a light diffuser).  

The easiest time to install a solar tube is when a house is being built or is being re-roofed; however, professional installers can retrofit solar tubes into a home as well.  Be sure to consider the characteristics of the side of the roof where you plan to place the solar tube.  You want to capture the light, but not place it in on the roof in a place that might make it prone to leak.  

So next time you flick on a light, think about whether a solar tube might do the trick instead.  Cooling our planet one flick at a time . . .

Have you ever wondered how solar photovoltaic (pv) cells work?  How they are able to create electricity without burning fuel and without any moving parts?  Check out our Photovoltaic Cells page for information and an animation on how electricity is created using solar energy.