ch 20-Sustainable Energy Notes

Learning Impact: Sustainable energy education impacts our approach to energy consumption and environmental stewardship.

Green Buildings: Incorporate insulation and efficient windows, leading to significant energy cost reduction.
- Example: Super insulated houses can use 90% less energy than conventional homes.
Vampire Currents: Unplugging appliances helps reduce standby energy consumption, which can account for 25% of monthly electric bills.

Automobile Emissions: Cars and light trucks represent 40% of U.S. oil consumption.
- Historical Improvement: Average gas mileage in the U.S. increased from 13.3 mpg in 1973 to 25.9 mpg in 1988 with targets set for 54.5 mpg by 2025.
Efficient Transport Solutions: Promote electric vehicles (EVs) and hybrids for reduced emissions and reliance on fossil fuels.
Active Transportation Trends: Increasing popularity of electric-assist bikes and bike-share programs as alternatives to short car trips.

Energy Resource Potential: Solar energy reaching Earth is significantly greater than global energy consumption.
- Solar collectors can either be:
- Passive: Use structures without moving parts (e.g., greenhouses).
- Active: Involve systems that pump heat-absorbing mediums through collectors.
Concentrating Solar Power (CSP): Utilizes parabolic mirrors to collect sunlight and generate electricity through steam turbines.
Photovoltaic Cells: Convert sunlight to electricity, with efficiency improvements from under 1% to over 20% in commercial applications.

Production and Efficiency: Modern wind turbines can achieve operational efficiency of about 35%.
- Wind energy provides no fuel costs or emissions, yet presents challenges such as intermittency and infrastructure requirements.
Offshore Wind Trend: Growing interest in offshore wind facilities due to higher efficiency potential compared to onshore.

Global Production: Historically accounts for a substantial share of global electricity, though its share has declined due to rising fossil fuel use.
Environmental Concerns: Dams can lead to significant ecological impacts, including habitat loss and water quality issues.
- Alternatives include low-head hydropower systems that minimize disruption to ecosystems.

Resource Utilization: Biomass can harness substantial solar energy stored in organic matter, though the process can lead to habitat destruction.
Methane Production: Captured from organic waste (such as livestock and landfills) can serve as a clean energy source, often used in anaerobic digesters for electricity generation.
Ethanol and Biofuels: Employed as alternatives to fossil fuels, with significant production in Brazil and the U.S., though with environmental trade-offs regarding land use.

Heat from Earth's Core: Geothermal energy is derived from hot springs and geysers for heating and electricity generation. Well-designed systems can drastically lower energy costs.

Comprehensive Change: Transitioning from fossil fuels involves not only technology but also policy adjustments and infrastructure investment.
Grid Management: Integration of smart grid technologies allows better support for renewable energy distributions, especially from remote generating locations to urban centers.

Operation Mechanism: Electrochemical reactions in fuel cells produce electricity, water, and heat with high efficiency compared to conventional systems.
- Fuel cells are scalable and sustainable alternatives to traditional batteries.