California's Renewable Energy Progress

• Climate stabilization plans require power sector net zero CO2 by 2050
• Coal construction dropped 70% since 2015 due to economic pressures, not just climate concerns
• Solar/wind getting cheaper driving fossil fuel plant closures
• California energy mix transformation 2010-2018:
  • Solar rose from minimal to 19% in 8 years
  • Wind doubled to 6.5%
  • Natural gas, hydro, nuclear, geothermal percentages all dropped
• California set 100% renewable energy goal by 2045
• State on track but transition becoming more expensive/difficult

Moss Landing Power Plant Case Study

• Natural gas plant operational since 1950
• Original capacity: 613 MW, expanded to 2,560 MW by 2002 (largest in California)
• 2019 announcement: 567 MW battery storage facility (world's largest)
• Battery designed to replace peaker station role
• Takes over surge energy provision to grid when needed

Daily Energy Demand Analysis (May 24, 2018)

• Nuclear provides steady 2,280 MW base load (~90% capacity)
  • Diablo Canyon power plant output remains flat
  • Takes tremendous time to vary load
• Renewable energy spike starts 6 AM (sunrise)
• 34.5% of electricity from renewables that day
  • 51% of renewables from solar
• Solar drops off at 5 PM as population leaves work
• Peak demand at 8:30 PM (4.5 hours after solar peak)
• California ramps up natural gas stations for demand surges
• Imports significant energy from other states:
  • Wind/hydro from Pacific Northwest
  • Nuclear/coal/natural gas from Nevada

Battery Storage Cost Analysis

• Calculated storage needed to replace natural gas peaking power May 24, 2018
• Assumed 4,220 MW steady natural gas base load (10% drop from that day)
• Required battery storage: 11,200 MWh
• Tesla Hornsdale facility: 129 MWh for $56 million
• Extrapolated cost for 11,200 MWh battery: $4.86 billion
• Comparison: Diablo Canyon (5x daily energy output) cost $13.8 billion to construct
• Batteries don't generate energy - need renewable surplus to charge

California's Curtailed Energy Problem

• California already curtails significant renewable energy daily
• April 2019 record: 190,000 MWh wasted
• May 7, 2019: 8,369 MWh curtailed (nearly enough to charge massive battery)
• May 15, 2019: Only 193 MWh curtailed
• Renewable resources highly variable and unreliable even in summer

Winter Solar Generation Challenges

• Topaz solar farm analysis over 4 years
• Energy generation drops significantly in winter:
  • June peak: 4,388 MWh average daily
  • January low: 2,637 MWh average daily
• To charge 11,200 MWh battery in winter: need solar farm 4.25x bigger than Topaz
• Topaz cost: $2.4 billion
• Scaled winter solar farm cost: $10.2 billion
• Summer excess generation: 7,437 MWh daily average
• Additional storage for excess summer energy: $3.2 billion
• Total estimated cost: $18.26 billion ($4.6 billion more than Diablo Canyon)

Long-term Storage Requirements

• Clean Air Task Force/MIT estimates:
  • 80% renewable: 9.6 million MWh storage needed
  • 100% renewable: 36.3 million MWh storage needed
  • Equivalent to 12 days and 45 days energy storage respectively
• Lithium-ion batteries unsuitable for long-term storage (gradual charge loss)
• At $100/kWh future price: 36.3 million MWh = $3.63 trillion
• Exceeds California's $3 trillion GDP (2018)

January 2019 Detailed Analysis

• Solar generated average 8.2% of total generation
• Range: 2.1% (Jan 4) to 12.7% (Jan 27)
• Consecutive bad solar days Jan 14-17: 2.1%, 2.2%, 5.2%, 3%
• Wind generation higher on cloudy/stormy days, compensating for low solar
• Combined renewables (solar + wind + geothermal + biofuels + small hydro): 20% average
• Large hydro not counted in renewable totals despite being renewable
• Adding large hydro smooths output, reduces battery/excess power reliance

Strategic Recommendations

• California over-relying on solar, needs diversification
• Wind more expensive but vital for renewable portfolio diversity
• Continue building lithium-ion batteries for natural gas peaking replacement
• Batteries not panacea for renewable energy challenges
• Need breakthrough in low-cost long-term energy storage

Future Storage Technology Development

• ARPA-E invested $30 million in 10 startups for long-term storage
• Technologies include:
  • Thermal batteries
  • Thermochemical storage
  • Form Energy sulfur-based battery (largest funding share)
• Goal: store summer excess power for year-round use
• Could enable smaller, more efficient renewable grid

Grid Optimization Requirements

• Every country needs intelligent grid optimization for renewables
• Requires careful historical data analysis
• Statistical likelihood calculations for demand fulfillment
• Python programming and statistics knowledge needed for comprehensive analysis