California's three large IOUs collectively served 12.7% of their 2007 retail electricity sales with renewable power.

– Pacific Gas and Electric (PG&E) - 11.4% – Southern California Edison (SCE) - 15.7% – San Diego Gas & Electric (SDG&E) - 5.2%

IOU is an Investor owned Utility Co. (not a city or county or company owned by the public)

The California Legislature has set a target of using 20% renewable energy by 2010

2

California’s RPS is the most Aggressive in the Country

Source: Black andVeatch

Geothermal - 47.93% Wind - 19.04% Biomass - 14.32% Small Hydro - 11.12% Biogas - 4.73% Solar - 2.86%

http://www.cpuc.ca.gov/PUC/energy/electric/RenewableEnergy/

Renewable Energy Sources used in California in 2007

California Renewable Generation Mix 2007

Geothermal48%

Wind19%

Biomass14%

Small Hydro11%

Biogas5%

Solar3%

GeothermalGeothermal

• Using the earth’s heat energy to Using the earth’s heat energy to produce electricity.produce electricity.

• California’s Geyser facility is the California’s Geyser facility is the largest geothermal electricity largest geothermal electricity producer in the world producer in the world

• Need to locate a “hot spot”Need to locate a “hot spot”• 50X fewer emissions that fossil 50X fewer emissions that fossil

fuel powered plants.fuel powered plants.• Geothermal accounts forGeothermal accounts for

2,800 MW of capacity in the 2,800 MW of capacity in the United States United States Geysers plant Near Sonoma

850 megawatts capacity

Generation costs of renewable technologies

Solar Energy – Using sun’s radiation to Solar Energy – Using sun’s radiation to heat water and air.heat water and air.

• Most readily Most readily available source available source of energyof energy

• Use sun’s Use sun’s radiation to radiation to heat a fluid.heat a fluid.

Using sunlight to create electricity Using sunlight to create electricity using photovoltaics (PV):using photovoltaics (PV):

• Sunlight hits a Sunlight hits a sandwich of doped sandwich of doped silicon. Electrons are silicon. Electrons are knocked out of their knocked out of their orbits. orbits.

• The electron flow The electron flow provides the provides the currentcurrent of electricity .of electricity .

PV was developedIn the 1950’s for PoweringSatellites.

Just at the junction the electrons and holes mix, creating a an electric field (voltage) separating the two sides. This voltage allows electrons to flow up but not down.

The solar cell is acting like a diode; current flows in one direction only.

http://www.specmat.com/pn%20junction.jpg

http://www.specmat.com/Solar%20Cell%20Description.jpg

http://www.specmat.com

A – glass coating

B – contact grid

C – Antireflective coating

D – N-type Si

E – P-type Si

http://www.wcubed.com/solar/solar_photovoltaics.htm

PV System with Batteries

It is for the safety of line-workers that PV system inverters are engineered to shut down when they do not receive input of matching voltage from the grid.

This system can be taken off the grid.

Where can PV be installed?

• On any portable device• On a rooftop• On a car• On the ground• In space

Cal State LA Solar Eagle Vehicle

Net Metering

• Offers electric energy savings to individuals• Everyone can generate their own electric

power• Distributed generation of power• Helps meet electricity demands during peak

times• Reduces demands on transmission lines

California Public Utility CommissionSelf-Generation Incentive Program

Customers who install small solar, wind, biogas, and fuel cell generation facilities (1 MW or less) to serve all or a portion of onsite electricity needs are eligible for the state's net metering program. The customer receives a financial credit for power generated by their onsite system and fed back to the utility. The credit is used to offset the customer's electricity bill. The utility does not pay for power above the amount of electricity the customer consumes from the utility.

Self Generated Power in CA

– Thermal cogeneration systems (fuel cells, engines, and turbines) provided over 80 percent of the electricity.

– PV projects supplied the next largest amount (17 percent).