Origins of the Electrical Grid (1882)

• Thomas Edison built world's first central power station on Pearl Street, Manhattan in 1882
• Station contained 6 generators, each producing 100 kW
• Powered 1,200 light bulbs per generator (7,200 total)
• Light bulbs lasted ~1,200 hours, needed regular replacement
• Initial cost: $300,000 ($20 million in today's money)
• Project ran operating loss for first 2 years
• New York Times became early customer, published positive review describing light as "soft, mellow, and graceful to the eye without a flicker"

Technical Limitations of Early DC System

• Generated low voltage direct current
• Couldn't scale economically without installing more power stations nearby
• Power loss equation: Power loss = Current² × Wire resistance
• To reduce power loss, need to minimize current by increasing transmission voltage
• DC couldn't be efficiently transformed from low to high voltage

AC vs DC Battle

• Edison's approach: Many smaller generators near population centers
• Nikola Tesla's approach: One large efficient engine far from population centers
• AC's advantage: Can be transformed from low to high voltage much more efficiently than DC
• Tesla's approach won - today hundreds of gigantic power stations generate gigawatts far from population centers

Current US Power Grid Infrastructure

• Contains enough high voltage wiring to wrap around Earth 6 times
• Built in little over 100 years
• Power generation by region:
  • High rainfall areas (Washington State, Alabama): Hydro power
  • Central America: Wind turbines (highest wind speeds)
  • California, Arizona: Solar power (most sun)
  • Nuclear plants: Located where water is plentiful (for steam turbines and cooling)
  • Coal plants: Close to coal mines (heavy fuel)
  • Natural gas: Largest percentage of US energy (cleanest fossil fuel)

Power Transmission Process

• Electricity exits power plant through step-up transformer
• Delivered across high voltage power lines
• Fed into local step-down transformers for neighborhood distribution
• Stepped down again by transformer drums/poles outside houses
• Consumption measured by meters at each house

Grid Management Challenges

• Base load plants (coal, nuclear) maintain constant power during low demand
• Rolling blackouts occur when power stations fail and demand can't be met
• 2003 northeastern blackout: Left 50 million people without electricity
• Modern countries need redundant power sources and excellent communication
• Renewable sources (wind, solar) create micromanagement difficulties
• Cannot command weather to make renewables work harder when needed
• Sometimes must shut down renewables generating unneeded energy to prevent system overload

Energy Storage Solutions

• Hydroelectricity: 80% of worldwide energy storage
• Denmark example: Exports excess wind energy to Norway
• Norway uses mountainous terrain to pump water uphill with cheap excess power
• Water released to power hydroelectric turbines when needed
• Some power loss occurs but better than shutting down wind turbines at peak performance

Future of Power Grid

• Tesla's power wall integral for widespread home solar power
• Must store excess solar energy generated during day for nighttime use
• Without storage, still dependent on base load fossil fuel/nuclear plants
• Solar panel manufacturing costs decreasing
• Large fossil fuel AC power plants becoming outdated
• Will be decommissioned over next couple decades
• Moving toward Edison's vision: Many local low-voltage DC generators
• Modern twist: Powered by renewable energy sources