General Energy Use & Conservation Measures

Transcription

1 General Energy Use & Conservation Measures

2 What is Energy? The ability to do work (create motion or change matter) Ways to Measure Energy Joule (J) BTU British Thermal Unit amount of energy needed to heat 1 lb of water by 1 F. Calorie amount of energy needed to heat 1 kg of water by 1 C Kilowatt-hour (kwh)

3 Commonly Used Forms of Energy Energy Forms Used to Generate Electricity in US Natural Gas 32% Coal 30% Nuclear 20% Renewables 17% Petroleum 1% Energy Forms Used in Total Energy Use in US Petroleum 37% Natural Gas 29% Coal 14% Renewables 11% Nuclear 9% Recent Trends Natural gas has overtaken coal as primary means of making electricity and overall energy use Renewables use has increased across energy use sectors

4 Energy Categories Renewable Energy any source of energy that can be replaced as fast as it is used Examples: wind, hydroelectric, biofuels, solar, geothermal, biogas Nonrenewable Energy any source of energy that is used faster than it is replaced Examples: coal, oil, natural gas, nuclear

5 Energy Conservation & Efficiency Using energy more efficiently is considered a critical contributor to increasing national energy security What is Efficiency? The measure of how much of given energy to a device is used to actually run the device for its intended purpose. Example: Incandescent Light Bulbs are 5% efficient. This means that 5% of energy given to it creates light. The rest is used in other ways (mainly heat)

6 Energy Inefficiencies 84% of energy in U.S. is wasted. About half of that waste is unnecessary, due to inefficient uses of it Big Energy Wasters Light Bulbs Incandescent Light Bulbs 95% inefficient Compact Fluorescent Bulbs -- 80% inefficient LEDs (Light Emitting Diodes) least inefficient Internal Combustion Engine 94% inefficient Nuclear Power Plants around 90% inefficient Coal Power Plants 67% inefficient in coal burning

7 Ways To Save Energy Cogeneration using waste energy of one function for another function Example: Steam is produced as byproduct of nuclear power generation. This waste steam is pumped into nearby buildings for heating Increase use of efficient devices Switch to more efficient appliances like Energy Star rated appliances that have been assessed for efficiency by the government Switch to CFL or LED light bulbs Replace energy-wasting electric motors to newer models

8 Ways to Save Energy Design energy efficient and environmentally-friendly buildings by: Making them super-insulated Orienting the house south to get winter sun for heating Planting trees on west side of house. These shade the house in the summer to reduce air conditioning costs Using energy efficient windows Plugging leaks and insulate them Having efficient furnaces & heaters Reusing prior construction materials Buildings with high efficiency and green design can become LEED-certified (Leadership in Energy Efficiency and Design).

9 Energy Efficiency and Cars Car efficiency is rated by gas mileage. Why has the US struggled to increase gas mileage over time? SUVs are popular in the US The US government has created artificially low gas prices by subsidizing gas to lower its price. Thus, less need to pursue fuel efficiency The US government has not regularly raised the Corporate Average Fuel Economy (CAFE) standards These are requirements for car makers to make cars that meet a minimum gas mileage standard. The US kept them stable. In 2009, they were raised from 25 mpg to 35 mpg but have stalled out around this level Most nations have higher fuel efficiency requirements than the U.S. I HATE YOU, CAR OF THE DEVIL!!!!

10 Types of Cars Internal Combustion Engines (ICE) car that uses only gas to run it Hybrid Cars combo using gas and electric engine to run the vehicle The car runs off gas at high speeds. During braking, kinetic energy of the moving car is used to pump/charge a battery in the car. The battery energy helps start the car and run it at low speeds. Some are plug-ins car can charge the battery also by plugging in Battery Electric Vehicles (BEVs) Car will run fully on a charged electrical motor that is plugged in for recharging May have a gas tank for use only when the electric charge runs out

11 Vehicular Pros & Cons ICE Pros: Technology is well understood Gas stations already set up for these cars Maintenance on these are less complex and costly ICE Cons: Higher cost for buying fuel More nonpoint source air pollution More fossil fuel use more dependence on foreign oil Hybrid & BEVs Pros: Run quiet Low to no use of fuel Lower nonpoint air pollution Improves local air quality Incentives given to buy such cars (tax rebates, etc) Hybrid & BEVs Cons: BEVs need regular charging Less access to charging Air pollution will just move from cars to power plants (still need to create electricity to charge car) Cost more for initial purchase Time to recharge can be long

12 Hydrogen Energy and Cars What is a Hydrogen Car? Hydrogen fuel cells store H 2 and burn it for energy. Water is created as waste. H 2 + O 2 H 2 O + energy In theory, only water is made and there s no carbon emissions Problems with Hydrogen Cars: It takes energy/electricity to make H 2 for the fuel cell more energy than what you get when burned. Hydrogen cells are expensive Making hydrogen actually does require fuel use and creates greenhouse gases Switching to hydrogen cars would require a massive investment in hydrogen fuel gas stations across the country this would cost billions of dollars Iceland is the only country with some hydrogen cars and economy in existence (although progress is slow and stalled)