Green Roof Resource

In yesterday’s NYT, John Markoff reported that Google is pushing for more efficient power supplies for PCs. I haven’t been able to track down the white paper, which was presented on Tuesday at Intel’s Developer Forum, but based on the public information, I can do a little investigating of my own to see how much environmental benefit standardizing power supplies to 12-volts would really be.

The white paper argues that deploying a new 12-v standard to 100 million desktops would reduce energy consumption by 40 billion kilowatt-hours over three years (13.3 billion kWh annually). While it’s interesting that this could save “$5 billion at California’s energy rates,” what does it mean environmentally?

First a few facts. The EIA states that 52% of the electricity generated in the US is generated by coal-fired power plants. Assuming that on average, this form of generation emits 0.5 kg/kWh of carbon dioxide, standardization of the power supply would result in 7.2 million metric tons of CO2 (MMTCO2) not being emitted into the atmosphere. For comparison, the EIA reports that 2361 MMTCO2 were emitted by the electric power sector in 2005 (changing the power supply of 100 million desktop computers would reduce emissions by 0.3%). That’s may seem small, but when you realize that it is a calculable effect due to modifying the power supply of desktop computers, significant gains can be made from small steps.

Technorati Tags: efficiency, energy, google

It may be nearly October, but if you haven’t seen it, check out the September issue of Metropolis. The focus is on greening cities, specifically with green roofs. Several articles assess the industry within the US paying particular attention to Chicago, the green roof mecca in the US.

Additional articles include a timeline of the green roof industry (beginning in Germany in 1961 with Reinhard Bornkamm), and a map of the US showing number of projects and regional coverage of rooftop vegetation. In addition to the map, Michael Silverberg and Sierra Gonzalez summarize relevant statistics. For instance, on a 95 degree-F day, a green roof membrane is on average 80 degree-F cooler than a conventional roof membrane. They also provide some interesting statistics on expected population growth - currently, about 50 percent of the population lives in cities and that will increase to 60 percent by 2030. All in all, a great collection of facts on my favorite verdant concept.