Last week, after an overview of lighting history, we examined incandescent lighting--the lamp technology invented by Thomas Edison. Until the mid-1900s incandescent lighting dominated both commercial and residential lighting applications, indoors and outdoors.

I'm not usually all that comfortable in front of a camera, but I had fun walking the Greenbuild 2008 Expo floor with a video crew from CNNMoney.com and Fortune magazine. We focused on four or five technologies in our tour, only two of which made it into the final two minute video (after a nice lead-in by Scot Horst of 7group). The CNN crew were looking for photogenic presentations, while I was looking for products I believe in to talk about.

You find the darndest things on YouTube sometimes. Southwest Windpower, the maker of the Skystream 3.7 small-scale wind turbine, brought this video (and others like it) to my attention.

In 1997, humorist Dave Barry wrote a newspaper piece titled "The Toilet Police," about those newly mandated 1.6-gallon low-flow toilets that honestly and truly deserved to be dumped on. The column is still floating around the internet, and clearly people are still moved by it. But, y'know, that was over a decade ago. There are still crappy toilets to be had, just like there are lousy products of all sorts readily available, but smart toilet makers have strained to get the kinks out to the point that a one-gallon flush can outperform some of those old three-and-a-half-gallon water-hogs.

Environmental Building News (where I work) reported on photoluminescent exit signs in 2006. With tens of millions of exit signs deployed in North America that use up to 350 kWh each annually (as much as a nicely efficient refrigerator), it's a big deal.

Light is one of our most important energy needs. Historically--before the advent of electric lighting--the need for illumination governed architecture. Buildings were designed to facilitate natural daylighting. My office is in one of the old Estey Organ buildings on Birge Street, built in the late 1800s; it's just 28 feet wide, allowing natural light from the windows to reach fully into the building.

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Greenbuild 2008 included the first ever Green Homebuilder's Day, a conference within the much larger overall conference. Homebuilder's Day welcomed old hands and newcomers to the field of green building, and the sessions were full. BuildingGreen organized the event, which coincided with the announcement of our soon-to-be-available, residentially oriented Green Building Advisor. That this day of educational sessions took place at all is a good sign for the future of houses in America and for softening their environmental impact.