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2.3 Power Project Load and Energy Calculation
The calculation of load and energy for the power project is somewhat simpler than those for the heating and cooling projects, since twelve values of the average monthly power loads
p,1, p,2, ..., p,12 are specified directly by the user. The user also specifies the system peak electricity load over maximum monthly average:
The calculation of load and energy for the power project is somewhat simpler than those for the heating and cooling projects, since twelve values of the average monthly power loads
which enables the calculation of the peak electricity load Pp . The peak electricity load is assumed to happen for the duration of the peak period defined in section 2.1.5. The electricity use Qp,13 during the peak period is then given by:
and the electricity use Qp,i for each individual month i is given by:
where the n'i represent the modified number of hours in each month as per Table 4. Finally the total annual electricity use Qp is:
The use of electricity for non heating and cooling purposes also varies over the year. The variation can depend on more light being required during the winter period, or on activities and usage changes between the seasons. For existing systems it is recommended that the electricity bills be used to calculate a load profile. Note that if electricity is used for either heating or cooling, it should be included in the figures used for this calculation; the amount of electricity used for heating or cooling purposes is deducted on a monthly basis from the gross values entered by the user to calculate a net power monthly average. For example if an average power p→c,i is used by a compressor for space cooling for month i , and the gross average power load for the month specified by the user is p,i , then the net average power load for the month is only:
