Energy Conservation

A Major Part of the Solution to Energy Generation and

Global WarmingDennis Silverman

U. C. Irvine Physics and Astronomy

Why Us (U.S.)?

With 5% of the world’s population, the U.S. uses 26% of the world’s energy.

A U.S. resident consumes 12,000 kWh of electricity a year, nine times the world’s avg.

The average American household emits 23,000 pounds of CO2 annually.

Two billion people in the world do not have electricity.

Using just using off the shelf technology we could cut the cost of heating, cooling, and lighting our homes and workplaces by up to 80%.

Scientists in Energy

James Joule

First Law of

Thermodynamics

Sadi Carnot

Second Law of

Thermodynamics

Carnot Cycle

Thomas Edison

Light Bulb, etc.

Alexander

Graham Bell

Telephone

Scientists in Energy

Albert Einstein

E=mc²

Enrico Fermi

First Nuclear

Reactor

William Shockley

Transistor

Bill Gates

Computers

Electric Energy Conservation in the Home

Some of the following slides are from a talk by John Wilson, Advisor to Commissioner Art Rosenfeld of the California Energy Commission

Annual Electricity Use Per California

Household (5,914 kWh per household)

Total Electricity Use, per capita, 1960 - 2001

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U.S.

kWh

Average Energy Use per Refrigerator, 1947 to 2009

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Refrigerator kWh per Unit

1978 Cal Standard

1990 Federal Standard

1987 Cal Standard

1980 Cal Standard

1993 Federal Standard 2001 Federal

Standard

Estimated Standby kWh (per house)

Conservation Economic Savings If California electricity use had kept growing at

the US rate, kWh/person would have been 50% higher

California electric bill in 2004 ~$32 Billion… so we’ve avoided ~$16 B/yr of electricity bills. Net saving (accounting for cost of conservation

measures and programs) is ~$12 B/year, or about $1,000/family/yr.

Avoids 18 million tons per year of Carbon Appliance standards save ~$3B/year (1/4)

Lighting

Compact Fluorescents or Long Fluorescents using plasma discharges use only 1/3 of the energy and heat of incandescent lights, which derive their light from heating filaments hot enough to emit visible light.

If every home changed their five most used lights, they would save $60 per year in costs.

This would also be equal to 21 power plants. The fluorescents also last up to 10 times as long. Replacing one bulb means 1,000 pounds less CO2

emitted over the compact fluorescent’s lifetime. Traffic signal LEDs use 90% less energy and last 10

years rather than 2 years.

Household Energy Use for Entertainment Electronics

0 200 400 600

Plasma HDTV

DVD/VCR

HD set top box

Analog CRT

DVD/VCR

Digital cable set top box

Annual Energy Use (kWh)

Primary TV

Secondary TV

Combined energy use~ 1200 kWh per year

NRDC, "Tuning in to Energy Efficiency: Prospects for Saving Energy in Televisions," January 2005. 

“Zero energy” new homes

Goals: 70% less electricity => down to ~2,000 kWh/yr 1 kW on peak

Electronics are a problem! 1,200 kWh/ yr for TVs, etc. 100-200 W for standby

TV Power Plasma TV (50”) 400 W Rear Projection TV (60”) 200 W Large CRT (34”) 200 W LCD (32”) 100 W

Information Technology in the Home Imagine the following conversations in the near future: Household Info System: I detect you are now in the

living room but left all of the lights on in six other rooms. I am turning them all off now, okay? OK

HIS: There is an electricity shortage due to the high demand for air conditioning in this heat. I cannot run the dishwasher until 10 pm. Overriding this will cost 10 times the average rate.

HIS: Your kids are playing computer games past their bedtimes. I am shutting them off now, okay? OK

HIS: I detect that you have put an old fashioned incandescent bulb in the bathroom. How dare you! I am cutting off all power for fifteen minutes as punishment. Change that bulb now!

(Interval meters and hourly px pricing)

Home Energy Conservation

Department of Energy: Energy Efficiency and Renewable Energy

Central resource for the following slides on home energy technology

We only select some topics of interest Other sources

California Consumer Energy Center California “Flex Your Power”

Heating and Cooling in the Home

Accounts for 45% of energy bill or $1,000 per year

HVAC – Heating, Ventilating and Air Conditioning

SEER efficiency rating of AC Before 1992, typically 6.0 After 1992 required 10.0 Jan. 2006, required minimum 13.0

Annual Usage of Air Conditioning in New Homes in California

Annual drop averages 4% per year

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Source: CEC Demand Analysis Office

1992 Federal Appliance Standard

California Title 20 Appliance Standards1976-1982

Initial California Title 24 Building Standards

Estimated Impact of 2006 SEER 13 Standards

100%

33%

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Refrigerators

Central A/C

Gas Furnaces

Impact of Standards on Efficiency of 3 Appliances

Source: S. Nadel, ACEEE, in ECEEE 2003 Summer Study, www.eceee.org

75%

60%

25%

Setback Thermostats

Program to lower temperature setting at night and if gone on weekdays.

Required in California Winter suggested: 55° at night, 68° when at

home Summer suggested: 85° when gone, 78°

when at home 20 to 75% energy savings

Solar Water Heating

Water heating uses 14-25% of energy use Solar water heating replaces the need for 2/3 of conventional water

heating. Virtually all homes in Greece and Israel (700,000) use solar water

heating. Japan has over 4 million units. The US over a million, with most systems in Florida and California,

and Hawaii has 80,000. Each saves 1.5 to 2.5 tons of CO2 a year. Typical cost is $3,000 for 50 square feet. DOE is trying to lower this to $1,000 to $1500. Energy saved would be about 3,000 kWh per year per household DOE would like to have 3 million new units by 2030. Current payback is 10-13 years (solar lobby says 4-8 years),

whereas for 50% market penetration, 5-6 years is needed.

Tankless Water Heaters

These heat water on demand with gas or electricity. With gas heating their energy efficiency is 0.69 to

0.84, compared to gas tank heaters that range from 0.55 to 0.86.

However, they require a start up time. They also have a limited volume flow compared to a

tank. And they may require larger gas lines to do more

heating in a short time.

Heat Insulation

Heat flow is proportional to the temperature difference across a material of thermal resistance R

Q / t = A ΔT / R Analogous to current I = Voltage / Relectrical

R is also the sum of all R’s in a series of materials Current FHA requirements:

Ceiling R38 Walls R19 Floors R22

Recommended Insulation

Building energy efficiency

Structural Insulated Panels are 4-8 inches thick and are foam filled. They can be faced with drywall and plywood. They give R-4 to R-8 per inch of thickness.

Insulation includes batts and rolls, loose fill (blown in), rigid and reflective.

Cool Roofs: white reflective roofs on a summer’s day lower roof temperature from 150-190° F to 100-120° F. Saves 20% on air conditioning costs.

Estimated savings for a typical home from

replacing single pane with ENERGY STAR qualified windows are significant in all regions of the country, ranging from $125 to $340 a year.

Window Ratings

Ratings include solar heat gain coefficient or SHGC which is the fraction transmitted, from 0 to 1.

U-value (which indicates how well the window insulates) is inverse of R value, so lower is better.

and visible transmittance (which indicates how well light passes through the window), lower means more shading, from 0 to 1.

High-tech efficiency options include windows with argon between the window panes and low-emissivity (low-e) coatings.

Reflective coatings and outside shades are also effective at less cost.

Additional Advantages of Energy Conservation (Moralizing)

Less need to secure oil overseas with attendant military and civilian casualties while costing hundreds of billions of dollars

Fewer power plants and liquid natural gas ports are needed

Less air pollution Less drilling for oil in Alaska and near national parks Less global warming and attendant environmental

destruction

Conclusions on Energy Conservation Energy conservation has saved the need for many power plants

and fuel imports. It has also avoided CO2 and environmental pollution. Energy conservation research is only funded at $306 million this

year at DOE, which is low considering the massive amounts of energy production that are being saved by conservation.

Regulations on efficiency work, but voluntary efforts lag far behind.

Much has been done, but much more can be done In this new era of global warming and high energy costs and

energy shortages, the public must be informed and politicians sought who are sensitive to these issues.