THIS PAGE WILL SOON BE REVISED, given that the City Council voted in March 2013 for Palo Alto to pursue only carbon-neutral electric resources! Meanwhile, the basic information below is generally correct and can be used to get an idea of how the portfolio standards work and where Palo Alto stood prior to this recent Council decision.
The City has adopted a Renewable Portfolio Standard (RPS) requiring that 33% of the City’s retail electric sales be supplied by eligible renewable energy resources by 2015, providing that goal can be reached without causing rates to rise by more than a half a cent per kilowatt-hour (kWh). The City continues to ramp up its purchases of renewable energy (and, through efficiency measures, ratchet down its total consumption), so that in 2012 about 21% of the City’s electricity sales were supplied by renewable power. As shown below, contracts are in place for projects that are expected to provide renewable supplies for about 35% of total sales by 2015. The City is pursuing additional renewable energy supplies to meet its RPS needs for future years (when some of older renewable power contracts begin to expire), while also pursuing increased energy efficiency to reduce or eliminate increases in electricity demand. Our power content labels show how renewable Palo Alto's electric supply has been.
Carbon free portfolio:
The City’s electric supply portfolio contains resources that are considered to be "eligible renewable energy resources." This means that these resources can be counted as renewable and included in the Renewable Portfolio Standard (RPS) target. In addition, the City receives electricity from large hydroelectric resources that provide a carbon-free supply, but under California’s renewable energy eligibility criteria do not count towards the RPS target. This chart shows that, depending upon hydrologic year, roughly three-quarters of the City’s electric supplies are carbon-neutral. Recently, the City Council approved a plan to make Palo Alto's entire electric supply portfolio carbon-neutral.
2012 pie chart:
This chart shows the breakdown of the City’s electric supplies for calendar year 2012. As shown, over 60% of the supplies were carbon-neutral, with hydro supplying almost half of the City’s needs. Power purchases from the market meet the balance of the City’s needs. (In an average hydrologic year, hydroelectric resources supply about an additional 10% more power, and market power would provide about 10% less power.) As more of the City’s renewable projects are completed, the percentage of power purchased from the market is expected to decline. The Power Content label provides additional information.
Another way to illustrate the “carbon content” of the electric supply portfolio is to show the amount of carbon dioxide equivalent (CO2e) greenhouse gas emissions generated for each megawatt-hour (MWh) of electricity delivered. This chart shows the downward trend of the carbon content of the portfolio since 2005. This is largely due to the increasing purchases of renewable power supplies. This downward trend is expected to continue in the future as more renewable supplies are added to the portfolio.
The chart also shows the carbon content of the portfolio adjusted for an average hydrologic year, since some years are wet (resulting in more hydroelectric generation) and some are dry (resulting in less hydroelectric generation). For example, 2006 was a very wet year, so market purchases of electricity were minimal. On the other hand, 2007 through 2009 were relatively dry years, requiring more market purchases.