Example:

An industrial plant needs $50\mathrm{.}000,000kW.$ hr of electrical energy a year with maximum demand of $10,000kW.$ These can be purchased from the local utility for $480,000$$ annually.

As an alternate scheme the industry considers installing a $10,000kW$ steam turbine plant.

The three following plants are proposed as tabulated:

$\backslash$table$[[,$Plant A$,$Plant B$,$Plant C$],[-$ Throttle steam conditions. Pressure, Psig,$200,400,900],[-$ Temp. $S,550,700,850],[-$ Station steam rate $($full load$)$ lb$/($kW$-$hr$),11\mathrm{.}8,10\mathrm{.}5,8\mathrm{.}5],[-$ Average station heat rate, Btu$/($kW$.$hr$),16,000,13,500,12,000],[$Unit installation costs:,,,$],[\backslash$table$[[-$ Steam generators & Auxiliaries $($ $$/($ lb$/$hr$)],[$capacity$)]],4\mathrm{.}08,4\mathrm{.}73,6\mathrm{.}45],[-$ Steam turbine & auxiliaries $($$$/$kW capacity$),38,42,51],[-$Electrical Equipment $($$$),200,000,200,000,200,000],[-$ Structures & Miscellaneous $($$$),200,000,200,000,200,000],[-$ Plant operators per shift,$4,4,4]]$

The station will run $24(hr{)}_{?}$ a day with operators working $8_{h}r$ per day and $5_{?}$ days a week.

Average annual salary for operators $$5,200.$

Repair cost estimated as $90$ cents$/$short ton of coal burnt.

From past experience, designers see that ultimate installed costs exceed original estimates by $20\%.$

General operating supplies are $$10,000$ annually.

Money earn $6\%$ in this business and plant life is $(15)$ years.

Taxes on real estate and property amount to $4\%$ and the various operating taxes add to $1\%$ of annual operating costs.

Annual insurance $0\mathrm{.}2\%$ of all equipment costs.

Fuel is coal at $$6\mathrm{.}50/$ short ton with a high heating value $($HHV$)$ of $14,200$ Btu$/$lb$.$

short ton $=2000lb.$

$***$ Determine which scheme is the most economic one, assuming all have equal reliability.