D yogi goswami, frank kreith handbook of energy efficiency and renewable energy

Atthe same time, the availability of nonrenewable sources, particularly liquid fuels, is rapidly shrinking.Therefore, there is general agreement that to avoid an energy crisis, the amoun

The International System of Units,

Fundamental Constants, and Conversion FactorsNitin Goel

Intel Technology India Pvt Ltd.

The International system of units (SI) is based on seven base units Other derived units can be related tothese base units through governing equations The base units with the recommended symbols are listed

inTable A1.1 Derived units of interest in solar engineering are given inTable A1.2

Standard prefixes can be used in the SI system to designate multiples of the basic units and therebyconserve space The standard prefixes are listed inTable A1.3

Table A1.4lists some physical constants that are frequently used in solar engineering, together withtheir values in the SI system of units

Conversion factors between the SI and English systems for commonly used quantities are given inTable A1.5

A1-1

TABLE A1.2 SI Derived Units

Dynamic viscosity Newton-second per square meter N s/m2

TABLE A1.3 English Prefixes

TABLE A1.4 Physical Constants in SI Units

First radiation constant C1Z2phC2 3.741844!10 K16 W m 2

Second radiation constant C2Zhc/k 1.438833!10K2m K

The International System of Units, Fundamental Constants, and Conversion Factors A1-3

TABLE A1.5 Conversion Factors

Internal energy or enthalpy e or h 1 Btu/lbmZ2326.0 J/kg

1 cal/gZ4184 J/kg

T(8F)Z[T(8C)](9/5)C32 T(8F)Z[T(K)K273.15](9/5)C32

1 barrelZ42 gal (U.S.)

1 gal (U.S liq.)Z3.785 L

FIGURE A2.1 Description of method for calculating true solar time, together with accompanying meteorological charts, for computing solar-altitude and azimuth angles, (a) Description of method; (b) chart, 258N latitude; (c) chart, 308N latitude; (d) chart, 358N latitude; (e) chart, 408N latitude; (f) chart, 458N latitude; (g) chart, 508N latitude Description and charts reproduced from the “Smithsonian Meteorological Tables” with permission from the Smithsonian Institute, Washington, D.C.

20 30

S O L A

I ME

S O L A

I

M E

(b)

210 220

10

20 30

210 220

70 60 50 40 30 20 10 0

S

O

L A

210 220

80 70 60 50 40 30 20 10 0

3 p m.

+23.27 ° +20 °

60 80

50 40 30 20 10 0

S

O

L A

I M E

S

O

L A

I M E

3 p m.

2 p.m.

1 p.m. Noon 11 a.m.10 a.m.

9 a.m.

8 a.m 7 a.m.

6 a.m.

5 a.m

+23.27 ° +20 °

20 30 40 50

(f)

210 220

80 70 60 50 40 30 20 10 0

3 p m.

2 p.m.

9 a.m.

8 a m.

TABLE A2.1 Solar Irradiance for Different Air Masses

Air Mass; aZ0.66; bZ0.085 a Wavelength

TABLE A2.1 (Continued)

Air Mass; aZ0.66; bZ0.085aWavelength

TABLE A2.1 (Continued)

Air Mass; aZ0.66; bZ0.085aWavelength

TABLE A2.1 (Continued)

Air Mass; aZ0.66; bZ0.085aWavelength

Source: From Thekaekara, M P 1974 The Energy Crisis and Energy from the Sun Institute for Environmental Sciences.

TABLE A2.2 Monthly Averaged, Daily Extraterrestrial Insolation on a Horizontal Surface (Units: Wh/m2)

TABLE A2.3a Worldwide Global Horizontal Average Solar Radiation (Units: MJ/sq.m-day)

Position Lat Long January February March April May June July August September October November December Argentina

TABLE A2.3a (Continued)

Position Lat Long January February March April May June July August September October November December

Accra 5.60 N 0.17 W 14.82 16.26 18.27 16.73 18.15 13.96 13.86 13.49 15.32 19.14 18.16 14.23 Great Britain

TABLE A2.3a (Continued)

Position Lat Long January February March April May June July August September October November December Lithuania

Islamabad 33.62 N 73.10 E 10.38 12.42 16.98 22.65 — 25.49 20.64 18.91 14.20 15.30 10.64 8.30 Peru

TABLE A2.3a (Continued)

Position Lat Long January February March April May June July August September October November December Switzerland

Note: Data for 872 locations is available from these sources in 68 countries.

TABLE A2.3b Average Daily Solar Radiation on a Horizontal Surface in U.S.A (Units: MJ/sq m-day)

TABLE A2.3b (Continued)

Baltimore 7.38 10.33 13.97 17.60 20.21 22.15 21.69 19.19 15.79 11.92 8.06 6.36 14.54 Massachusetts

TABLE A2.3b (Continued)

TABLE A2.4 Reflectivity Values for Characteristic Surfaces (Integrated Over Solar Spectrum

and Angle of Incidence)

Water surfaces (relatively large incidence angles) 0.07

Building surfaces, dark (red brick, dark paints, etc.) 0.27

Building surfaces, light (light brick, light paints, etc.) 0.60

Source: From Hunn, B D and Calafell, D O 1977 Solar Energy, Vol 19, p 87; see also List, R J.

1949 Smithsonian Meteorological Tables, 6th Ed., pp 442–443 Smithsonian Institution Press.

Properties of Gases, Vapors, Liquids and

SolidsNitin Goel

Intel Technology India Pvt Ltd.

A3-1

TABLE A3.1 Properties of Dry Air at Atmospheric Pressures between 250 and 1000 K

Source: From Natl Bureau Standards (U.S.) Circ 564, 1955.

TABLE A3.2 Properties of Water (Saturated Liquid) between 273 and 533 K

TABLE A3.3 Emittances and Absorptances of Materials

Absorptance

Long-Wave Emittance

a 3

Class I substances: Absorptance to emittance ratios less than 0.5

Class II substances: Absorptance to emittance ratios between 0.5 and 0.9

Earth surface as a whole (land and sea, no clouds) 0.83 10 10 –

Class III substances: Absorptance to emittance ratios between 0.8 and 1.0

Small hole in large box, furnace, or enclosure 0.99 0.99 1.0

Class IV substances: Absorptance to emittance ratios greater than 1.0

(continued)

TABLE A3.3 (Continued)

Absorptance

Long-Wave Emittance

High ratios, but absorptances less than 0.80

Deposited silver (optical reflector) untarnished 0.07 0.01

Class V substances: Selective surfacesa

Plated metals:b

Black cupric oxide on sheet aluminum 0.08–0.93 0.09–0.21

Copper (5!10w5cm thick) on nickel or silver-plated metal

Cobalt oxide on platinum

Particulate coatings:

Lampblack on metal

Black iron oxide, 47 mm grain size, on aluminum

Geometrically enhanced surfaces: c

a Selective surfaces absorb most of the solar radiation between 0.3 and 1.9 mm, and emit very little in the 5–15 mm range– the infrared.

b For a discussion of plated selective surfaces, see Daniels, Direct Use of the Sun’s Energy, especially chapter 12.

c For a discussion of how surface selectivity can be enhanced through surface geometry, see K G T Hollands, July 1963 Directional selectivity emittance and absorptance properties of vee corrugated specular surfaces, J Sol Energy Sci Eng, vol 3 Source: From Anderson, B 1977 Solar Energy, McGraw-Hill Book Company With permission.

TABLE A3.4 Thermal Properties of Metals and Alloys

Material k, Btu/(hr)(ft.)(8F) c, Btu/(lbm)(8F) r, lbm/ft 3 a, ft 2 /hr

Source: From Kreith, F 1997 Principles of Heat Transfer, PWS Publishing Co., Boston.

TABLE A3.5 Thermal Properties of Some Insulating and Building Materials

Temperature, 8F

k, Btu/(hr)(ft.) (8F)

c, Btu/(lbm) (8F)

Source: From Kreith, R 1997 Principles of Heat Transfer, PWS Publishing Co.

TABLE A3.6 Saturated Steam and Water–SI Units

Subscripts: f refers to a property of liquid in equilibrium with vapor; g refers to a property of vapor in equilibrium with liquid; fg refers to a change by evaporation Table from Bolz, R E and

G L Tuve, eds 1973 CRC Handbook of Tables for Applied Engineering Science, 2nd Ed., Chemical Rubber Co., Cleveland, Ohio.

TABLE A3.7 Superheated Steam–SI Units

Source: From Bolz, R E and G L Tuve, Eds 1973 CRC Handbook of Tables for Applied Engineering Science, 2nd Ed., Chemical Rubber Co., Cleveland, Ohio.

Ultimate Analysis of

Biomass FuelsNitin Goel

Intel Technology India Pvt Ltd.

Thermophysical

Properties of RefrigerantsNitin Goel

Intel Technology India Pvt Ltd.

of production by January 1, 2030

These refrigerants are being replaced by HFC refrigerants which have zero ozone depletion potential.Common HFC refrigerants are R-32, R-125, 134a, and R-143a and their mixtures, such as, R-404A,R-407C, and R-410A

This appendix gives thermophysical properties of these HFC refrigerants and ammonia water andwater–lithium bromide mixtures which are used in absorption refrigeration systems Properties of R-22are given to serve as a reference (Figure A5.1throughFigure A5.8)

A5-1

4.0

6.0

10 15

20 30 40

600 700 800 900

1000 1050

1100 1150 1200

1250 1300

Satur

ated liquid 0.1 0.2 0.3 0.5 0.6 0.7 0.8 0.9

Satur ated V apor

20 20

10 8 6 4

2

1 0.8 0.6 0.4

0.2

0.1 0.08 0.06 0.04

–20 –30

–40

–50

–60

400 300 200 150 100 80 60 40 30 20 15 10 8.0 6.0 4.0 3.0 2.0 1.5 1.0 0.80 0.60 0.40

ted liq

uid

Satur ated V apor

0.4 0.6 0.8 1.0 2.0 4.0 6.0 8.0 10.0 20.0 40.0 60.0 80.0 100.0

0.010 0.015 0.020 0.030 0.040 0.050 0.060 0.080 0.10 0.15 0.20

0.30 0.40

0.70 1.0

1.5 2.0

0.00105

220 230240

60 50

FIGURE A5.3 Pressure–enthalpy diagram for refrigerant R-404A.

100 150 200 250 300 350 400 450 500 550 600

100

Satu rated liqui d

300

Enthalpy (kJ/kg) 350

0.50

0.70

0.40 0.30 0.20 0.15 0.10 0.080 0.060 0.050

0.040 0.030 0.020 0.015 0.010 0.0060 0.0050 0.0040

0.0030 0.0025

0.0018 0.0016 0.0014 0.0013 0.0012 0.0015 0.00200.0011

0.0010 0.00095 0.00090 0.00085

0.00080 0.00075 0.00070

20.0

10.0

6.0 8.0

100 150 200 250 300 350

60 50 40 30 20 10

100

Satu rated liqui d

Satu rated

0.060 0.050 0.040 0.030 0.020 0.015 0.010 0.008 0.006

0.004 0.005

Volume = 0.50 π Y/kg

600 Enthalpy (kJ/kg)

Enthalpy (kJ/kg) 6

2

1

0.08 0.1

0.06 0.04

0.02

0.01 0.008 0.006

0.8 0.6

210 Saturation pressure, kPa

Enthalpy of saturated vapor, kJ/kg vapor

Enthalpy of saturated liquid, kJ/kg liquid

2000 2200 2500

0.300 0.500 0.600 0.700 0.750 0.800 0.850

0.900 0.920 0.940 0.960

0.980

0.990

0.995 0.997

0.999

0

100 1350

1400 1450 1500

1600 1700

600

10000 8900

7800 6800 5800 4800 3800

3400 4300 5300 6300 7300 8300

9400

3100 2500 2200

1800 1450 1150 900 700 600 450 400 350 300 250 225 200 175 150 125 100 75 50 40 30 1225 1250 1275

FIGURE A5.7 Enthalpy–concentration diagram for water/lithium bromide solutions.

20 30 40 50

100 150 200

20

30 40 50 60 70 80 90 100 110 120

Refr iger ant temper

Purpose

The goal of this handbook is to provide information necessary for engineers, energy professionals, andpolicy makers to plan a secure energy future The time horizon of the handbook is limited toapproximately 25 years because environmental conditions vary, new technologies emerge, and priorities

of society continuously change It is therefore not possible to make reliable projections beyond thatperiod Given this time horizon, the book deals only with technologies that are currently available or areexpected to be ready for implementation in the near future

Overview

Energy is a mainstay of an industrial society As the population of the world increases and people strivefor a higher standard of living, the amount of energy necessary to sustain our society is ever increasing Atthe same time, the availability of nonrenewable sources, particularly liquid fuels, is rapidly shrinking.Therefore, there is general agreement that to avoid an energy crisis, the amount of energy needed

to sustain society will have to be contained and, to the extent possible, renewable sources will have to

be used As a consequence, conservation and renewable energy technologies are going to increase inimportance and reliable, up-to-date information about their availability, efficiency, and cost is necessaryfor planning a secure energy future

The timing of this handbook also coincides with a new impetus for the use of renewable energy Thisimpetus comes from the emergence of renewable portfolio standards [RPS] in many states of the U.S andrenewable energy policies in Europe, Japan, Israel, China, Brazil, and India An RPS requires that a certainpercentage of energy used be derived from renewable resources RPSs and other incentives for renewableenergy are currently in place in 20 of the 50 states of the U.S and more states are expected to soon follow.The details of the RPS for renewable energy and conservation instituted by state governments vary, but all

of them essentially offer an opportunity for industry to compete for the new markets Thus, to besuccessful, renewable technologies will have to become more efficient and cost-effective Although RPSsare a relatively new development, it has already been demonstrated that they can reduce market barriersand stimulate the development of renewable energy Use of conservation and renewable energy can helpmeet critical national goals for fuel diversity, price stability, economic development, environmentalprotection, and energy security, and thereby play a vital role in national energy policy

The expected growth rate of renewable energy from portfolio standards and other stimulants in the U.S

is impressive If current policies continue to be implemented, by the year 2017 almost 26,000 megawatts ofnew renewable energy will be in place in the U.S alone In 2005, photovoltaic production in the world hasalready topped 1000 MW per year and is increasing at a rate of over 30% In Germany, the electricity feed-inlaws that value electricity produced from renewable energy resources much higher than that fromconventional resources, have created demand for photovoltaic and wind power As a result, over the lastthree years the photovoltaic power has grown at a rate of more than 51% per year and wind power hasgrown at a rate of more than 37% in Germany Recently, a number of other European countries have

adopted feed-in laws similar to Germany In fact, growth of both photovoltaic and wind powerhas averaged in the range of 35% in European countries Similar policy initiatives in Japan indicate thatrenewable energy technologies will play an increasingly important role in fulfilling future energy needs.

Organization and Layout

The book is essentially divided into three parts:

† General overviews and economics

† Energy conservation

† Energy generation technologies

The first chapter is a survey of current and future worldwide energy issues The current status of energypolicies and stimulants for conservation and renewable energy is treated inChapter 2for the U.S as well

as several other countries Economic assessment methods for conservation and generation technologiesare covered inChapter 3, and the environmental costs of various energy generation technologies arediscussed in Chapter 4 Use of renewables and conservation will initiate a paradigm shift towardsdistributed generation and demand-side management procedures that are covered inChapter 5.Although renewables, once in place, produce energy from natural resources and cause very littleenvironmental damage, energy is required in their initial construction One measure of the energyeffectiveness of a renewable technology is the length of time required, after the system begins operation,

to repay the energy used in its construction, called the energy payback period Another measure is theenergy return on energy investment ratio The larger the amount of energy a renewable technologydelivers during its lifetime compared to the amount of energy necessary for its construction, the morefavorable its economic return on the investment will be and the less its adverse environmental impact.But during the transition to renewable sources a robust energy production and transmission systemfrom fossil and nuclear technologies is required to build the systems Moreover, because there is a limit

to how much of our total energy needs can be met economically in the near future, renewables willhave to coexist with fossil and nuclear fuels for some time Futhermore, the supply of all fossil andnuclear fuel sources is finite and their efficient use in meeting our energy needs should be a part of anenergy and CO2 reduction strategy Therefore, Chapter 6 gives a perspective on the efficiencies,economics, and environmental costs of the key fossil and nuclear technologies Finally, Chapter 7provides projections for energy supply, demand, and prices of energy through the year 2025.The U.S transportation system relies 97% on oil and more than 60% of it is imported Petroleumengineers predict that worldwide oil production will reach its peak within the next 10 years and thenbegin to decline At the same time, demand for liquid fuel by an ever-increasing number of vehicles,particularly in China and India, is expected to increase significantly As a result, gasoline prices willincrease precipitously unless we reduce gasoline consumption by increasing the mileage of the vehiclefleet, reducing the number of vehicles on the road by using mass transport, and producing syntheticfuels from biomass and coal The options to prevent an energy crisis in transportation include: plug-inhybrid vehicles, biofuels, diesel engines, city planning, and mass-transport systems These are treated inChapter 8; biofuels and fuel cells are treated inChapter 24andChapter 27, respectively

It is an unfortunate fact of life that the security of the energy supply and transmission system hasrecently been placed in jeopardy from various sources, including natural disasters and worldwideterrorism Consequently, energy infrastructure security and risk analysis are an important aspect ofplanning future energy transmission and storage systems, and these topics are covered inChapter 9.Energy efficiency is defined as the ratio of energy required to perform a specific task or service to theamount of energy used for the process Improving energy efficiency increases the productivity of basicenergy resources by providing the needs of society with less energy Improving the efficiency across allsectors of the economy is therefore an important objective The least expensive and most efficientmeans in this endeavor is energy conservation, rather than more energy production Moreover, energyconservation is also the best way to protect the environment and reduce global warming