I attended first the GreenNet conference today and it was packed. In fact, there was standing room only. Gavin Newsome kicked off the conference with a spectacular keynote given seemingly off the cuff where he reviewed all the progress that San Francisco has made towards reducing carbon foot prints. One of the most exciting things was the ability to use your mobile to check for free parking spots. Also, I learned a few interesting factoids at the conference that impressed me and had interesting implications.


Data centers and electricity use

presented by Jonathan Koomey of Stanford

  • Global data center use represents 1-2% of all electricity use in the world and is equivalent to all the electricity used by Mexico, a country of 90M people, on an annual basis.
  • Over time, as data centers become more powerful, 35-45% of the cost of running a data center will be electrical and cooling related
  • Computing cycles per unit electricity (computing efficiency) is increasing at a much faster rate than total electrical consumption. This means our chips are getting more efficient at a faster growth rate than total compute demand.

These are impressive points. Datacenters are using ever more electricity and with the rise of online video and IPTV, this will only increase. Looking to Japan, the 1Gbps connections delivered over fiber to the home provide this bandwidth today; there’s no reason for a similar pattern not to develop in the US. Additionally, as the dominant cost of running a data center shifts to energy, this implies a shift in the pricing of data centers from paying per square foot of data center to paying per kilowatt. 

presented by Andrew Tang, PG&E

  • 5% of PG&E’s capacity is used only 2 days per year*
  • 25% of generating capacity is used fewer than 30 days per year
  • Peak load is 2x greater than non-peak
  • 50% of total solar PV installations in the US are in the PG&E service area

The difference in peak and off peak load is staggering and has continued to bethe challenge in maintaining the power grid for the past 100 years. In fact, failure of this type of demand management was the root cause of the 2002 black out on the east coast. The main demand management problem is supplying enough electricity produced by power plants to meet demand.

As we evolve this hundred year old system pioneered by Edison, there’s a consequent and concomitant increase in complexity. Today’s utilities manage a small number, perhaps several hundred, very large powerplants producing power at a steady rate. In 20 years, utilities will need to manage millions of power generators. Those millions of power generators are the solar cells, the wind turbines and other power generation sources installed by the people whom the utilities serve.

Because of the increase in the number of generators and because the renewable sources of energy have no consistency in power generation, electrical storage and predictive optimization becomes critical. Electrical storage enables power produced during peak wind and solar times to be stored for later. This is why two-way communication on the grid is essential. To manage this system, utilities will need to develop core competencies in more sophisticated network management systems.

On another note

The most successful hardware solutions will be ones that can be installed once and can be upgraded remotely. It’s an obvious point, but one that PG&E stressed during the meeting.