Energy Sector ETAAC Meeting

July 2, 2007Sacramento, CA

Renewable Energy Technologies• CA RPS-eligible renewable resources:

– Wind– Solar (concentrating thermal and photovoltaic)– Small hydro (less than 30 MW w/o new diversion)– Geothermal– Biomass, biogas (landfill gas, digester)– Fuel cell using renewable fuel– Municipal solid waste conversion using a non-combustion

thermal process – Ocean wave, ocean thermal, tidal current

Biomass

Dairy Biogas-revisited• California has 1.7 million cows in 2,000 dairies

– 50% in the San Joaquin Valley• Dairies release methane and other reactive organic gases (ROGs)• Methane has 21 times the greenhouse gas (GHG) impact of CO2 • San Joaquin Valley is a non-attainment area for air quality, which is

affected by ozone created by ROGs• Biogas scrubbed/cleaned of CO2, H2S, etc.; pressurized gas injected

into pipeline• Total market size for energy is relatively small, but large GHG

reduction potential• Transporting to cleanest, most efficient plant, produces

flexible, RPS-eligible energy and GHG credits while improving local air quality

SUVSUV11 CO CO22 = 4.9 t/yr = 4.9 t/yrCowCow22 CO CO22e = 4.9 t/yre = 4.9 t/yr

1 12,000 mi/yr, 25 mpg (Toyota Highlander V-6)2 manure only

Biomass

Bioenergy Conversion Pathways

Source: Rob Williams, UC Davis, July 2006

Source: Rob Williams, UC Davis, July 2006

Landfill Gas• The energy sector and the industry sector both

identify landfill gas as an important issue.• Both groups will examine the benefits and

approaches to capturing landfill gas for energy supply.

• The sectors also plan to compare the benefits of landfill gas versus diverting organic compounds to composting, and capturing the methane gas for energy generation from the compost.

Source: Rob Williams, UC Davis, July 2006

Pyrolysis

• Convert materials into bio-oil through the chemical process of decomposition through heating.

• Liquids produced can be further processed into fuels, pharmaceuticals and food additives. Solid residues can be used as fertilizer.

• University of Western Ontario and Agri-Therm Limited are working on a fast pyrolysis machine.

BioChar

• A type of charcoal produced from biomass, employed most commonly as a soil amendment and is essentially a form of activated carbon. Biochar is largely inert, and microbial composting action leaves charcoal largely unaffected. It is highly porous, both retaining water and providing large surface area for microbes.

• Field experiments were started in Cali, Colombia, through Cornell to study soil nutrient availability in acid soils as affected by bio-char applications. Studies are ongoing and show significant yield increases of maize, improved pasture and native savanna.

• Other biochar activity is taking place in New South Wales, University of Western Ontario, University of Georgia, and Iowa State University.

Source: Cornell University

Renewable Energy Cost TrendsLevelized cost of energy in constant 2005$1

Source: NREL Energy Analysis Office (www.nrel.gov/analysis/docs/cost_curves_2005.ppt)1These graphs are reflections of historical cost trends NOT precise annual historical data.

Illustrative Energy Procurement Costs

New Build Energy Procurement Cost ($/MWh)

0 20 40 60 80 100 120 140 160 180

Combined Cycle

Combustion Turbine

Energy Efficiency

Wind

Geothermal

Biomass

Solar & Emerging

ETAAC Website