Sustainability and why dimming your lights may not save...

I ran across a series of interesting articles on "sustainability" today. I'm trying to figure out if people are finally joining the sustainability movement because it's becoming more mainstream, or if they really think it's a good idea. Perhaps the higher cost of energy (recently) has been pushing people to save money. Maybe the economic downturn is hitting people so they're trying to save money everywhere they can.

In any case, the ILLUMRA philosophy still applies: saving energy (for any reason) by automating and controlling devices that use energy. Decades ago it only mattered that the lights worked, the cost of operating them was small in comparison with the light bulb itself (or so everyone assumed). Of course most of the products sold by ILLUMRA (the company, as opposed to this, the blog) involve energy harvesting in one way or another, which ultimately saves wiring, batteries, or both.

In any case, here are links to the articles:
Survey: Americans favor Sustainable Engineering and Manufacturing
Energy cost savings through load shedding (and load balancing)

The power factor issue in the second item will be, I believe, a bigger issue in the future. I've been recently working over ideas for large-scale (building-wide) LED lighting systems. It's critical that the power supplies (ballasts) for the LED lights include power factor correction, and therefore act as "nice" loads on the grid. This will avoid the kinds of noise-induced power quality issues that often occur in large manufacturing environments. Years ago, power supplies in all PCs were not power factor corrected, and contributed to power quality problems (including neutral heating) in office buildings. If someone goes a "too-cheap" route when converting their lighting, they could create as many problems as they solve.

One reason this is so important: Dimmable fluorescents are a nice way to introduce some energy savings (and load-shed capacity) to a building. However, if you use ballasts that support phase-cut dimming on their line inputs (as opposed to 0-10V low voltage control dimming) then the effective power factor will degrade. If a whole office building used this technique to load-shed during a high-demand time-of-day, the net effect may actually increase the electric bill of the facility (because of the power factor and demand charges outlined in the second article above). It's important that while phase-cut dimming is a nice feature on a dimmable ballast (fluorescent or LED) it's not a good way to control a large number of ballasts. A 0-10V solution (wired or wireless) is the best way to go.