Wednesday, July 18, 2007

Demand Management

There has been quite a lot of controversy surrounding the proposed new Xcel towers at Ruby Hill. Does anyone realize this upgrade can be completely avoided with prudent Demand Side Management?

This from the Leonardo Energy website:
"Italy is currently undertaking a programme to install 30 million smart meters. It is estimated that demand-side management tariffs, which limit customers to 3KW of power during peak periods, have reduced peak demand by 5% for 3 hours, 10 days a year. This has removed the need to construct a power station with 2GW capacity to cover the peak demand."

Smart meter technology can also prevent all new powerline capacity upgrades.

Saturday, July 14, 2007

Passive Solar Heating is Simple

I found this European, scholarly, technical paper on Green Building.

Here's my favorite passage:

"3.1 Heating
3.1.1 Passive systems
General considerations The best way to reduce energy consumption is to take advantage of all available natural energy. This is the purpose of bioclimatic design, which is one path to a low energy house. The bioclimatic approach operates at two levels:
1. let the energy of the sun come in
2. do not let it out again"

It really doesn't get much more complicated than that. We've been in our near-zero energy home for 2.5 years now, and have discovered that not only are we saving energy and money, the comfort is amazing.

A relatively overlooked aspect of passive solar is that you want windows with high SHGC (solar heat gain coefficient) on the south side, preferably with overhangs. In the actual marketplace, I have as yet only found only one supplier of these windows, Hurd. Be sure to specify "hard coat" Lo E. In addition, don't "overglaze" the south side, you might get October overheating or need to wear sunglasses indoors.

Now, armed with that advice, find a building site where your neighbor can't block your sun.

Saturday, July 7, 2007

Xcel's "Time of Use" energy rates

Electric utilities are rightly concerned about peak electrical usage, and they spend some effort trying to smooth daily peaks and filling nighttime valleys.

In the 70's Colorado Public Service introduced "off-peak" rates, later called "Time-of-day" rates. This rate schedule was recently discontinued for lack of interest. Coincidentally, they recently offered a new pilot program called "time-of-use" pricing that also aims at that target. Once again, they have developed a rate structure that is too hard to understand and therefore too hard to take advantage of.