Energy Efficiency and Renewable EnergyEnergy Efficiency and Renewable Energy

Brian KaestnerBrian Kaestner

Thanks to Miller and ClementsThanks to Miller and Clements

The Importance of Improving Energy EfficiencyThe Importance of Improving Energy Efficiency

Net useful energy Net useful energy

Life cycle cost Life cycle cost

Least EfficientLeast Efficient Incandescent lights Incandescent lights Internal combustion

engine

Internal combustion engine

Nuclear power plants Nuclear power plants

Energy InputsEnergy Inputs SystemSystem OutputsOutputs

U.S.economy

andlifestyles

84%

7%

5%4%

9%

7%

41%

43%

Nonrenewable fossil Nonrenewable fossil fuelsfuels

Nonrenewable nuclearNonrenewable nuclear

Hydropower, geothermal,Hydropower, geothermal,wind, solarwind, solarBiomassBiomass

Useful energyUseful energy

PetrochemicalsPetrochemicals

Unavoidable energy Unavoidable energy wastewasteUnnecessary energy Unnecessary energy wastewaste

Ways to Improve Energy EfficiencyWays to Improve Energy Efficiency

InsulationInsulationElimination of air leaksElimination of air leaksAir to air heat exchangersAir to air heat exchangersCogenerationCogenerationEfficient electric motorsEfficient electric motorsHigh-efficiency lightingHigh-efficiency lightingIncreasing fuel economyIncreasing fuel economy

Uranium100%

95% 54% 17% 14% 14%

Wasteheat

Wasteheat

Wasteheat

Wasteheat

Electricity from Nuclear Power Plant

Uraniummining(95%)

Uranium processingand transportation

(57%)

Power plant(31%)

Transmissionof electricity

(85%)

Resistanceheating(100%)

Passive Solar

Wasteheat

Sunlight100%

90%

Windowtransmission

(90%)

Prolongs fossilfuel supplies

Reduces oil imports

Very high netenergy

Low cost

Reduces pollutionand environmentaldegradation

Buys time to phase in renewable energy

Less need formilitary protectionof Middle East oilresources

Improves localeconomy by reducing flow ofmoney out to pay for energy

Creates local jobs

Hybrid VehiclesHybrid Vehicles

Rechargeable battery systems Rechargeable battery systems Hybrid electric-internal combustion engine Hybrid electric-internal combustion engine

ElectricityFuel

Combustion engineA

Fuel tankB

Electric motorC

Battery bankD

RegulatorE

TransmissionF

A

B

C

D

E F

Using Solar Energy to Provide Heat and ElectricityUsing Solar Energy to Provide Heat and Electricity

Passive solar heatingPassive solar heatingActive solar heatingActive solar heating

PASSIVE

Stone floor and wallfor heat storage

Superwindow

Wintersun

Summersun

Heavyinsulation

Superwindow

HotWatertank

Pump

Heatexchanger

Super-window

Heat to house(radiators orforced air duct)

ACTIVE

Heavyinsulation

Direct GainCeiling and north wall heavily insulated

Hot air

Super insulated windows

Cool air

Warmair

Summersun

Wintersun

Earth tubes

Greenhouse, Sunspace, orAttached Solarium

Summer cooling vent

Warm air

Cool air

Insulatedwindows

Earth Sheltered

Earth Triple-paned or superwindows

Flagstone floorfor heat storage

Reinforced concrete,carefully waterproofedwalls and roof

Using Solar Energy to Provide High-Temperature Heat and ElectricityUsing Solar Energy to Provide High-Temperature Heat and Electricity

Photovoltaic (PV) cells Photovoltaic (PV) cells

Single Solar CellBoron-enrichedsilicon

Junction

Sunlight

Cell

Phosphorus-enriched silicon

DC electricity

Solar Power Tower

Solar Thermal Plant

Advantages Disadvantages

Moderate netenergy Moderateenvironmental impact No CO2 emissions

Fast construction(1–2 years) Costs reduced with natural gas turbine backup

Low efficiency

High costs

Needs backup or storage system

Need access to sun most of the time

High land use

May disturb desert areas

Producing Electricity from Moving WaterProducing Electricity from Moving Water

Large-scale hydropower Large-scale hydropower

Small-scale hydropower Small-scale hydropower

Tidal power plant Tidal power plant Wave power plant Wave power plant

Basin side

Bulb unit impeller Sea side

Tide outtwice aday

Tide intwicea day

Tidal Power PlantTidal Power Plant Wave Power PlantWave Power Plant

Floatingturbogenerator VaneVane

Pump

Producing Electricity from WindProducing Electricity from Wind

Wind TurbineWind Turbine

Power cable

Electricalgenerator

Gearbox

Fig. 15.29, p. 381

Existing projects

Planned projects

Normal windsModerate windsGood windsExcellent winds

Advantages Disadvantages

Moderate to highnet energy High efficiency

Moderatecapital cost

Low electricitycost (and falling)

Very low environ-mental impact

No CO2 emissions

Quick construction Easily expanded

Steady winds needed

Backup systems when neededwinds are low

High land use for wind farm

Visual pollution

Noise whenlocated nearpopulated areas

May interfere inflights of migratorybirds and kill birds of prey

Producing Energy from BiomassProducing Energy from Biomass

BiofuelsBiofuels

Crop residuesCrop residues

Animal manureAnimal manure

Ethanol Ethanol

Solid Biomass FuelsWood logs and pellets

CharcoalAgricultural waste (stalks and other

plant debris)Timbering wastes (branches, treetops,

and wood chips)Animal wastes (dung)

Aquatic plants (kelp and water hyacinths)

Urban wastes (paper, cardboard, and other combustible materials)

Direct burning

Conversion to gaseous and

liquid biofuels

Gaseous BiofuelsSynthetic natural

gas(biogas)Wood gas

LiquidBiofuelsEthanol

MethanolGasohol

Geothermal EnergyGeothermal EnergyElectric power

Generator

Condenser

Coolingtower

SteamSeparator

Turbine

Warm brine

Steam and hot water

Cooled water

PumpPumpImpermeableImpermeable

rockrock

InjectionInjectionwellwell

PermeablePermeablerockrock

Cooled brineCooled brine

ProductionProductionwellwell

Hotbrine

Geothermal ReservoirsGeothermal Reservoirs

Entering the Age of Decentralized MicropowerEntering the Age of Decentralized Micropower

Centralized power systemsCentralized power systems

Decentralized power systemsDecentralized power systems

Micropower systemsMicropower systemsCentral power plants

Residential

Industrial

Commercial

TransmissionTransmissionand distributionand distribution

systemsystem

Bioenergy power plants Wind farm Small solar cellpower plants

Fuel cells

Solar cellrooftopsystems

Commercial

MicroturbinesIndustrial

TransmissionTransmissionand distributionand distribution

systemsystem

Residential

Small windturbineFuel cells

Rooftop solarcell arrays

Fig. 15.39, p. 389 Fig. 15.40, p. 390

Solutions: A Sustainable Energy StrategySolutions: A Sustainable Energy Strategy

Improve Energy Efficiency

Increase fuel-efficiencystandards for vehicles,buildings, and appliances

Mandate governmentpurchases of efficient vehicles and other devices

Provide tax credits for buying efficient cars, houses, and appliances

Offer tax credits for investments in efficiency

Reward utilities forreducing demand

Encourage independentpower producers

Increase efficiencyresearch and development

More Renewable Energy

Increase renewable energy to 40% by 2020

Provide subsidies and tax credits for renewable energy

Use full-cost accounting and least-cost analysis for com-paring all energy alternatives

Encourage government purchase of renewable energy devices

Increase renewable energyresearch and development

Reduce Pollution andHealth Risk

Cut coal use 50% by 2020

Phase out coal subsidies

Levy taxes on coal and oil use

Phase out nuclear power or put it on hold until 2020

Phase out nuclear power subsidies