DOE-2 Reference Manual Version 2.1 - DOE2.com

ENCOP investment(first cost) + (replacement cost) for allcomponentsSubtracting from this the baseline first cost and baseline replacementcost gives the incremental investment.Incremental investment = (ENCOP investment) - (baseline first cost) -(baseline replacement cost)The cost savings is the difference between the life-cycle energy andoperations cost of the baseline and that of the ENCOP.Cost savings = (energy cost + operations cost)b~seline- (energy cost + operations costJENCOPThe energy use in DOE-2 is calculated both at the site (i.e., at thebuilding boundary) and at the source, and energy savings for both cases arecalculated in ECONOMICS.The savings-to-investment ratio (SIR) is just the cost savings divided bythe incremental investment.SIRcost savings~ incremental investmentAn SIR that is greater than 1.0 means that the ENCOP is cost effective. Thehigher the SIR, the more cost effective is the ENCOP.The energy-savin s-to-investment ratio gives the number of Btu's saved (overthe project lifetime per dollar invested.Energy-savings-to-investment ratioenergy savingsincremental investmentThe last quantity, discounted payback period, is the number of years ittakes the accumulated cost savings to equal the incremental investment. Forexample, if the present value of the cost savings in years 1 through 5 is$1000, $900, $800, $700, and $600, respectively, and the incremental investmentis $2700, then the payback period is 3.0 years.A cost-effective ENCOP has a payback period that is less than the projectlifetime. The shorter the payback period, the more cost-effective is theENCOP.3. Economics Description Language (EDL).A general discussion of Building Description Language (BDL), includingrules, syntax, notation, etc., can be found in Chap. II. The EconomicsDescription Language (EDLJ is that portion of BDL that is solely applicable tothe ECONOMICS program. Section B of this chapter describes the EDLinstructions (COMPONENT-COST, BASELINE, and ECONOMICS-REPORT).VI.4 (Revised 5/81)