From a total cost of ownership (TCO) measure, LEDs have beat other lighting technologies for a while. Not surprising since solid state devices almost always win economically over time. Now LED prices are dropping to the point that they can compete with the purchase price of other lighting technologies.
An emerging idea is to use LED in streetlights and street signs. In the streetlight market, the energy winners are low power sodium and LED lights. However, because LEDs last 10-15 years, with the right timer controller, an LED streetlight requires no maintenance for at least 10 years. That gives LED streetlights the clear advantage over low power sodium lights.
The following table lists annual power consumption and operating costs for commercially available streetlights. It does not include initial cost and installation of the streetlight pole and light, but those costs differences are negligible over ten or twenty years of use. It makes many assumptions about energy and labor costs and typical bulb life. However, it is fair to say that, of all these lighting technologies, LEDs are dropping most quickly in price.
Energy Use and Cost for Residential Streetlights
Light
kW-hrs Per Year
Operating $ Per Year
Mercury Vapor
1,104
$108
Metal Halide
690
$94
High Power Sodium
460
$63
Low Power Sodium
345
$65
LED
376
$43
There are something on the order of 10 million streetlights in the United States. Add street signs (like the signs you see on the side of the freeway giving mileage to the next few exits), and the number of fixtures probably doubles.
As with traffic lights, where LED usage has reduced energy consumption and operating costs, expect to see LED streetlights and street signs near you soon.
Global Warming is Not a Crisis -- An Oxford-style debate that is provocative, intellectually rich, humorous, and dramatic. For each debate, three panelists argue for a motion and three argue against it, with a moderator controlling the proceedings. After the formal arguments, the debate is thrown open to the floor for questions. Each side attempts to persuade the audience to vote their way. Arguing for the motion are author and filmmaker Michael Crichton, Alfred P. Sloan Professor of Atmospheric Sciences at MIT Richard S. Lindzen, and emeritus professor and biogeographer from the University of London, Philip Stott. Arguing against the motion are Union of Concerned Scientists' national climate program representative Brenda Ekwurzel, NASA climate scientist Gavin Schmidt, and University of California-San Diego distinguished professor at Scripps Institution of Oceanography Richard C.J. Somerville. Moderator Brian Lehrer is host of the New York Public Radio program "The Brian Lehrer Show" and award-winning author and documentary producer. -- KQED Radio
At the beginning of the audience Q&A section, a New York Times reporter asked a couple of incisive questions. First he asked whether anyone on either side of the issue disagreed that humans were contributing to global warming. No panelist disagreed. Then he asked whether any panelist thought it was bad to reduce greenhouse gas emissions. Only one panelist disagreed, the rest thought it was good.
I turned off my radio.
Wow, I thought. I wasn't thinking of Microsoft Vista. I was thinking that the real global warming debate comes down to ROI. The panelists arguing so forcefully against investing in greenhouse gas reductions were just like atheists who say they are agnostic. If the insurance policy for purgatory is just to say that God might exist, why not? Likewise, if the insurance policy for global warming disasters is a set of investments in CO2 reduction that provide market ROI, why not?
An emerging idea is that if there is good business in greenhouse gas reduction, by all means reduce the greenhouse gases -- just don't ask anyone to give up their SUV.
I wrote previously about pricing problems related to global warming. Another economic problem revolves around entrenched industries. A good example of an investment that reduced greenhouse gases while providing good ROI? How about the recent replacement of traffic lights with LED lights? This government action reduced energy usage significantly, but it required administrators to evaluate infrastructure costs using total cost of ownership (TCO) rather than lowest bid (although LED lights costs are dropping enough to win bids on upfront costs in many cases).
If traffic lights have been replaced by LED lights, why not streetlights? Energy investments work very differently when evaluated on a TCO basis rather than an upfront cost basis. Until administrators change their evaluation methodology, inefficient solutions that generate lots more greenhouse gases will dominate markets.
Change may be on the way. SunEdison, for instance, is using financial contracts to encourage the use of solar energy. Industry and government can do much more, though, to encourage better use of financial contracts and TCO evaluations to reduce greenhouse gases. Industry can help define and market standards that make it easy for buyers to understand TCO. For instance, most electric devices provide specifications on power draw. A smart buyer can add up the costs of power over the life of a device (as well as maintenance, replacement costs, etc.), and calculate TCO for the device. But industry can make this easier. For instance, websites could help buyers make TCO calculations and trade-offs for devices deployed in specific environments and applications to determine the most cost-effective device over the life of the application.
Government can require TCO analysis before it lets contracts, and even weight energy savings more favorably to reduce CO2 emissions. It also can provide policy direction, identifying areas where TCO analysis will have the most impact on greenhouse emissions.
As I realized listening the global warming debate on the radio today, whether your stand on global warming is that we should do something about global warming or that spending money on global warming is a waste, no one can argue with economically rational investments. While the debate rages, industry and government can start today to take steps reducing greenhouse gas emissions without debate: evaluate TCO before buying energy consuming devices.
I took a walk around the new Federal building with my friend Jim, an architectural critic. If you walk around San Francisco, you can't miss the enormity of the City's most recent edifice. However, you might miss some of the environmental features of the building. Most prominent of the features: no air conditioning. What may be most notable about the absence of air conditioning at the new Federal Building is that it took so long to build a modern office building without air conditioning in a city known for its natural air conditioning system: fog.
To replace air conditioning, the building employees several emerging technologies. Many windows open automatically to cool off the building, especially at night. On the north side of the building (see photo), the decorative fins act as chimneys to vent hot air up the side of the building. The delicate building skirt on the south side provides a sunblock that reduces radiation absorption on the building's sunniest surface.
Removing the air conditioning also frees up space inside the building. Gone are the air conditioning machines, electrical panels, and ducts needed to cool most modern office buildings. Building maintenance costs change, too, with automatic window maintenance replacing air conditioning maintenance. Removing the air conditioning also requires more attention to building orientation, with as narrow a building as possible for natural air flow and lighting, and as little eastern and western exposure as possible for sun utilization.
Some of the energy saving features involve behavior modification of the building's occupants. The elevators, for instance, stop at every third floor rather than at every floor. In theory, these elevators deliver you to your desired floor more quickly when you take an elevator that goes to your desired floor because that elevator makes fewer stops on the way. Fewer elevator stops translates into more efficient use of elevator energy. It also gives occupants an incentive to use stairs to travel to floors only one or two levels away.
All-in-all, the building's designers estimate the building will use 50% less energy than a standard U.S. office building. Here's a comprehensive video on how the EPA built a sustainable building. It examines everything from site utilization to construction techniques to energy use.
It's difficult to pinpoint the start of modern architecture, but William LeBaron Jenney's innovate use of steel framing made possible the first skyscraper in 1885. By today's standards, the 10-story Home Insurance Building appears minuscule. When it was introduced, the clear advantage of skyscraper design was building more office space on a given plot of land. Since 1885, improvements in design, construction, material, and building technologies have provided the ability to build practically any office building imaginable. While architects cram more and more usable space onto a property with all these new technologies, they have not created particularly efficient buildings.
Given the economic advantages of building sustainable buildings, how did the commercial real estate market arrive at a point where sustainability is so rarely incorporated in building design? An emerging idea is that financial markets under-value total cost of ownership for a structure. Three factors cause the market to discount ongoing operating costs.
First, since buildings are easily razed and replaced, investors sometimes value a property for its potential cash flow rather than its current cash flow. As the expected life time for a building shrinks, so does the value of reducing a building's energy use.
Second, the risk of introducing a new sustainable technology may outweigh its potential cost savings. For example, if you build a commercial building with elevators that stop at every third floor, do you decrease the building's yield because fewer companies want to rent in the building? Give an investor a choice between a known design that creates a predictable cash flow and a new design that may save money, and the investor will chose the predictable cash flow every time.
Third, the increased liquidity of commercial real estate in today's capital markets gives builders an incentive to complete a building quickly with technology that its subcontractors have deployed rather than new technology that may slow down a project. Faster construction translates into quicker sales and lower construction financing costs. Liquidity increases with commoditization, too, and so an innovative building may take longer to sell.
What pushes the commercial real estate market towards sustainable building? Many of the sustainable buildings in the U.S. are government buildings. Since the government, a very large owner of office space, maintains buildings for long periods of time, it discounts sustainability differently than the commercial market and places a higher value lower operating costs. The good news is that taxpayers will be rewarded for the government's rational risk-taking. The better news is that the commercial markets will be able to model innovative sustainability technology accurately, thus reducing the risk of these technologies in the commercial market.
Other emerging ideas include better sustainability standards and different finance instruments. One simple sustainability standard would be a measure of energy use per usable area, analogous to the government's MPG mileage standards for cars. If buildings were rated for typical energy use in, say, BTUs per square meter, a tenant could compare office space with some idea how much of rent goes to pay the power company instead of building amenities. Such an energy use standard might have all the same problems as the MPG used for cars, but it has the potential to improve significantly the information flow in the real estate market.
Building financing could be split between short-, medium-, and long-term owners. Short-term owners would assume "start-up" risk, including design approval, project management of the construction, and commodity prices for materials. Long-term owners would assume "market" risks, including changes in local business activity, interest rates, and energy and labor costs. By segregating the risks, rewards could be tailored for categories of investors. As importantly, long-term owners would weigh-in on sustainability.
Unfortunately, plenty of inefficient buildings will stand with us for decades. That should give government and commercial building owners who care about sustainable architecture more incentive to fix the market soon.
Update: Jim's take on the new San Francisco Federal Building.
