energy efficiency energy efficiency: percentage of the total energy input that does useful work and...

Energy Efficiency

Energy Efficiency: Percentage of the total energy input that does useful work and is not converted into LQE.

HQE = high-temperature heat and chemical energy in fossil and nuclear fuels - useful

LQE = low-temperature heat that is dispersed or diluted – mostly useless (generally through water vapor/steam)

Life Cycle Cost = initial cost + lifetime operating cost. Energy efficient appliances cost more initially, but cost less to maintain and therefore have lower life cycle costs.

ENERGY EFFICIENCY FACTS84% of all commercial energy used in the USA is wasted.

People in the USA unnecessarily waste as much energy as 2/3 of the world’s population consumes (more than $300 billion/year).

43% of the energy wasted is from using “energy inefficient” motor vehicles (especially SUV’s).

WHAT DOES THIS MEAN?

Energy Efficiency = Military, Economic, and Environmental Security

How do we achieve this?

LIFE STYLE CHANGES!

ENERGY EFFICIENCY IN COMMON ENERGY

CONVERSION DEVICES

Incandescent Light Bulb

5%

Fluorescent Light Bulb

22%

ENERGY EFFICIENCY CONTINUED

Gasoline Internal Combustion Engine

10%-30%

Steam Turbine – used in most power plants

45%

ENERGY EFFICIENCY CONTINUED

Coal Combustion = 30 % Efficient

ENERGY EFFICIENCY CONTINUED

Nuclear Power = 17 % Efficient

With externalities = 8% Efficient

Note: The greater the number of steps involved in energy conversion, the lower it’s net efficiency will be.

ENERGY EFFICIENCY IN APPLIANCES

Energy-efficient appliances typically cost more than than less efficient models.

Look for Energy Stars label.

Use appliances during off-peak hours:

winter – peak generating costs 4:00 – 8:00 pm

summer – peak generating costs 11:00 am – 8:00 pm

OVENS AND RANGES Gas – 60 % loss in energy,

but heat is distributed more evenly.

Electric – 40 % loss in energy.

Ovens that cycle on/off are more efficient.

Self-cleaning ovens have more insulation and retains heat very well - uses a LOT of energy

Comparison table of the energy costs of cooking the same meal by several methods

Appliance Temperature Time Energy Cost*

Electric oven 350ºF 1 hr. 2.0 kWh 16¢

Convection Oven 325ºF 45 min. 1.39 kWh 11¢

Gas oven 350ºF 1 hr. 0.112 therm 7¢

Cooktop/fryingpan 420ºF 1 hr. 0.9 kWh 7¢

Toaster oven 425ºF 50 min. 0.095 kWh 8¢

Crockpot 200ºF 7 hrs. 0.7 kWh 6¢

Microwave oven "High" 15 min. 0.36 kWh 3¢

*Cost assumes 8¢/kWh for electricity and 60¢/therm for gas

(Source: ACEEE, Consumer Guide to Home Energy Savings, 1999)

CLOTHES WASHERS A considerable amount of hot water is used for washing clothes. Use

a machine that uses the fewest gallons of water per pound of clothes and one with H,M & L settings for water level control.

Use appropriate volume of water for load. Use a low-warm water temperature for washing and cold cycle for

rinsing. Use during off-peak hours. Follow maintenance instructions and clean regularly.

WASHING MACHINES

CLOTHES DRYERSA dryer evaporates water from clothes and minimizes wrinkling by tumbling the clothes.

Water evaporation requires large amounts of heat.

Don’t over dry clothes!

Dry clothes outside on clothesline whenever possible.

Vacuum lint from motor housing 3-4 times per year.

CLOTHES DRYER

DISHWASHERS

Dishwashers use less hot water than washing dishes by hand, but requires the water to be 20 degrees F hotter.

Buy a dishwasher with an energy saving switch.

Wash only full loads during off-peak hours.

Clean filter screen regularly.

Follow maintenance instructions.

DISHWASHERS

Make sure dishes are rinsed thoroughly before running load!

REFIGERATOR-FREEZERS The larger the unit, the more

energy required to maintain desired temperature.

Refrigerator should be kept between 38-42 degrees F.

Manual defrost freezers use the least amount of energy, typically 55-60% less!

Buy a model with extra improved insulation.

Buy one with a seasonal energy-saving switch. Saves 15% of annual operating costs.

Top/bottom freezers are more energy efficient than side by side models.

CENTRAL AIR CONDITIONING

Central air conditioners (central ACs) are rated according to their seasonal energy efficiency ratio (SEER).

This is the ratio of cooling output to power input for a hypothetical average U.S. climate.

The higher the SEER, the more efficient the air conditioner. SEER standards requirements were raised to 13 in 2006 (from ~6-7)

WHAT CAN YOU DO AT HOME1. Look for Energy Stars labels.

2. Turn off the lights when you leave a room.

3. Buy compact fluorescent light bulbs.

4. Shut doors behind you so that heat does not escape.

5. Seal windows and doors to prevent air drafts.

6. Make sure your refrigerator is an energy star product because it uses the MOST electricity out of all appliances.

7. Use toaster oven or microwave instead of oven when possible.

WHAT ELSE CAN YOU DO?

Walk/bike for short, local trips.

Use mass transit (trains, bus, ferry)

Wear extra/less layers of clothing instead of turning up/down the thermostat.

Turn off lights when not needed.

REDUCING ENERGY WASTE IS IMPORTANT BECAUSE…

Decreases rate at which fossil fuels become economically depleted and allows extended time to phase in renewable energy resources.

Decreases dependency on foreign oil resources (probably not by drilling in ANWR)

Reduces local and global environmental damage.

Quickest and cheapest way to slow projected global warming.

Improves competitiveness in the International Marketplace.

Ways to improve energy efficiency

Power Utilities are the largest industry in USA – “regulated monopolies” – most utility companies make money by increasing the demand for electricity

Approximately 20 Utility Companies in the USA are promoting the “Negawatt Revolution” – utilities give customers cash rebates for improving energy efficiency in their houses

ONG – rebates for installing gas dryers/water heaters/heating systems

OG&E – “Smart Hours” to shift energy consumption way from 2-7pm

SAVING ENERGY IN TRANSPORTATION

Increase fuel efficiency in motor vehicles - in USA, fuel efficiency has decreased by 5% in the last 15 years

30 hybrid/electric models available at the beginning of 2011 in US – Toyota Prius is the most well-known, has the largest market share

Problem: Little interest in consumer market because of fuel subsidies that generally promote waste and prohibit conservation interest.

GREEN BUILDINGS SAVE ENERGY

Focus is on heating, cooling and lighting

South facing – maximize angle of insolation to capture solar energy (passive solar heating).

Energy-efficient lighting (passive lighting through south-facing windows and skylights)

Superinsulation & high efficiency natural gas burners. PROBLEM: air tight buildings negatively impact indoor air quality

LEED is “nationally recognized benchmark for green building”

GREEN BUILDINGS