What are SLVWD's sources of greenhouse gas emissions?
The three primary sources of the District's GHG emissions over the years 2006-2017 are listed below:
- Mobile combustion (District vehicle fleet)
- Stationary combustion (generators and natural gas)
- Purchased electricity (water pumping and building use)
Using established protocols, SLVWD has assessed and reported its greenhouse gas emissions (GHG) for the years:
- 2017 Greenhouse Gas Emissions Report
- 2010 Greenhouse Gas Emissions Report
- 2009 Greenhouse Gas Emissions Report
- 2008 Greenhouse Gas Emissions Report
- 2007 Greenhouse Gas Emissions Report
- 2006 Greenhouse Gas Emissions Report
Reports for all years have been certified by CCAR and CAR, with SLVWD consistently recognized as a "Climate Action Leader."
Comparing SLVWD Greenhouse Gas Emissions from 2006 - 2017
As the chart above shows, the District's largest overall source of GHG emissions are electricity, which is used mostly to operate its deep-water wells and booster pumps. The District previously purchased its electricity from PG&E, which included both fossil-fuel and alternative energy sources in its mix.
In March 2017 Monterey Bay Community Power was formed and the District has started to purchase its electricity through the Community Choice Energy (CCE) model. The CCE model enables communities to choose clean-source power at a cost equivalent to PG&E while retaining PG&E’s role in maintaining power lines and providing customer service. MBCP procures carbon-free and renewable energy to support the electricity needs of their customers. They source their electricity from carbon-free energy sources such as solar, wind, and hydroelectric – they do not use any energy derived from nuclear or fossil-fuel based sources. Purchasing electricity through Monterey Bay Community Power will help the District reduce its GHG emissions.
The District’s mobile combustion emissions are generated by its vehicle fleet. Note that mobile combustion from SLVWD’s vehicle fleet increased with the addition of the Felton system in 2008 and the Lompico system in 2015. This was primarily due to increased driving to service the Felton and Lompico areas. Since 2008, SLVWD has replaced several old vehicles with more fuel-efficient ones, which caused GHGs to drop slightly. It should also be noted the vehicle fleet has grown as the District has expanded taking on new water systems and with new District hires.
The District's emissions from stationary combustion are generated by natural gas and other fossil fuels to run generators. Most generators are only used during power outages or other emergencies.
The large majority of the District's electricity powers groundwater pumping and booster bumps. In wet years’ groundwater pumping starts relatively late in the season and demand for water is generally lower. In dry years, groundwater pumping starts earlier in the season, and demand for water is generally higher.
As the charts above show, the District's GHG emissions from purchased electricity generally increases with the number of kwh used in every year, but it also depends on our electricity provider’s mix of fuel sources (starting in 2017 the District will be purchasing all carbon-free energy).
For example, compared to 2007, in 2008 PG&E's energy portfolio was more fossil fuel intensive. One of the alternative fuel sources that PG&E reduced in 2008 was hydropower, due to the statewide drought. In 2009, even though the District's kwh increased slightly, its GHG emissions dropped somewhat, which reflects a subsequent change in PG&E's mix of fuel sources.
2011 was a wetter year, PG&E had more alternative fuels in its energy portfolio, and, perhaps most significantly, the solar panel installation at Lyon and Felton treatments plants began producing electricity in July 2011. To learn more about our solar panel energy production, visit this page.
With each successive year of reporting, the District has gained valuable new information to assist it in assessing levels and identifying sources of its GHG emissions. Because the District cannot control droughts or influence the choice of energy sources by PG&E, the District increased its own use of alternative and renewable sources of electricity. In 2011, the District invested in a substantial solar project, which contributed to a significant reduction that year in both kwh of purchased electricity and GHG emissions. As the way purchased energy changes with options such as purchasing from Monterey Bay Community Power, the District expects GHG emissions to drop significantly in the coming years.