$1-20$ Why are the SI units simpler and preferred over English units? Explain.

$1-21$ What are the units of mass, length, time, energy, and power in the SI system and the English

system?

$1-22$ What is the difference between kW and kWh units? Show that $1kWh=3600kJ.$

$1-23$ Show that $1kJ=1$kPa$*m^3.$

$1-24$ Show that $1k\frac{J}{k}g=1000\frac{m^2}{s^2}.$

$1-25$ Total world delivered oil consumption by end$-$use sectors in $2017$ was $188\mathrm{.}8$ Quad, while the

renewable consumption was $19\mathrm{.}4$ Quad. Express these consumptions in Btu, GJ$,$ and kWh$.$

$1-26$ Ton of oil equivalent $($toe$)$ is commonly used to express large amounts of energy. It represents

the amount of energy released by burning $1$ ton $(1000$ kg $)$ of crude oil. One toe is equal to $41\mathrm{.}868$ GJ $,$

sometimes rounded to $42$ GJ $.$ Total world delivered energy consumption in $2010$ by fuel was $523\mathrm{.}9$

Quad, while that by end$-$use sector was $382\mathrm{.}0$ Quad. Express these values in toe units.

$1-27$ In $2013,21\mathrm{.}7$ percent of global electricity was generated from natural gas$-$burning power

plants. Total electricity generation in that year was $23,332$ terawatt$-$hours $($TWh$)$ and it is estimated

that $45$ Quad natural gas was consumed to generate electricity. Determine the overall thermal effi$-$

ciency of natural gas$-$burning power plants in $2013.$

$1-28$ According to a $2007$ report, $19,028$ TWh electricity was produced in the world in $2006,$ and

$55\mathrm{.}3$ percent of this production took place in OECD countries. The report also indicates that the

average efficiency of thermal power plants in OECD countries in $2006$ was $38$ percent. Determine the

amount of energy consumed in OECD countries in TWh$,$ Quad, and toe.

$1-29$ The average annual electricity consumption by a household refrigerator has decreased from

$1800$ kWh in $1974$ to $450$ kWh today. Consider a country with $10$ million households with a market

penetration of $100$ percent for modern refrigerators. If the refrigerators in this country were to con$-$

tinue to consume electric power at the $1974$ levels, how much additional installed power would be

needed to meet this extra demand? Assume that the load factor $($average fraction of installed power

load that is actually produced$)$ of the power plants is $0\mathrm{.}8$ and the power plants operate $90$ percent of

the time on an annual basis.

$1-30$ A utility company decides to use kWh instead of therm for billing natural consumption of

users. If the price of natural gas is $$\frac{1\mathrm{.}5}{?}$ therm, express the natural gas price in $\frac{\text{\$}}{k}Wh.$

$1-31$ A $4-$kW resistance heater in a water heater runs for $3$ hours to raise the water temperature to

the desired level. Determine the amount of electric energy used in both kWh and kJ $.$

$1-32$ The global wind power capacity was $743$ GW in $2020.$ This was $6$ percent of the global power

capacity. The offshore wind power capacity increased by $15$ percent in $2020$ and reached $31\mathrm{.}9$ GW $.$

$($a$)$ Using unity conversion ratios, express the wind power capacity in the world in $kW,M\frac{J}{h},$ and

toe$/$h$.$

$($b$)$ Determine the percentage of offshore wind capacity with respect to total power capacity in the

world.

$($c$)$ What is the approximate total power capacity in the world?

$1-33$ The global hydropower capacity reached $1\mathrm{.}34$ terawatt $($TW$)$ in $2021.$ On the other hand, the

hydropower generation in the world in $2021$ was $4370$ terawatt hours $($TWh$).$