Tracking California Renewable Energy

As I write this post at mid-day on July 23, I can see online that the California electric grid is absorbing over 9,600 Megawatts of renewable energy, meeting 29% of current energy demand.  That's equivalent to the output of about nine major power plants.

July 23, 2015

Source:  California Independent System Operator

I know this because a little known agency, the California Independent System Operator (ISO), posts near-instantaneous data about California electric supply and demand (here).  The ISO manages the flow of electricity over long-distance transmission lines for about 80% of California.  The numbers are lower than actual California renewable output since they don't include rooftop solar or some local renewable power generation.  As you'd expect, solar provides a substantial amount of electricity between 10 a.m. and 6 p.m. on a typical summer day:

Wednesday, July 22, 2015
Source:  California Independent System Operator

As more California renewables go online, ISO is regularly reporting new record amounts of solar production.  On June 19, they reported a peak amount of 6,217 MW of solar.  Less than a month later, on July 16, they reported a peak solar output of 6,329 MW.

Incorporating increasing amounts of renewables into the electric grid presents some interesting challenges, as I noted in my post about California 2030 renewable energy goals (here).  Assuring the maximum use of renewables in the future will require better coordination of energy supplies across the western U.S., more flexibility to curtail non-renewable power plants, and increased use of energy storage.  Below is a chart showing the amount of energy delivered from various sources on Wednesday, July 22.  Daily summary reports from the ISO on day-before and historical renewable output are available here.

Wednesday, July 22, 2015
Source:  California Independent System Operator

An interesting and innovative initiative of the ISO is to move towards allowing aggregation and grid-deployment of distributed generation sources such as rooftop solar and energy stored in electric vehicle or other batteries.  “With the rapidly evolving grid and quantum growth in distributed generation, this framework for integrating smaller renewable resources onto the high voltage grid demonstrates a significant step in re-designing our energy future with lower carbon emissions and helping California meet its clean energy goals,” said ISO President and CEO Steve Berberich. “This proposal encourages innovation and entrepreneurs to explore opportunities within the wholesale market by combining resources that individually would be too small to participate on their own.”  More information here and here.

If you want to see these sorts of cool graphs and data while out and about .. ISO has an app for that, ISO Today for Apple or Google Play.  I have to admit, I'm captivated by the information on my phone, including a map of renewable energy generation facilities.