integration of solid oxide fuel cells and ... - Ea Energianalyse

A. MARKET INVESTIGATION
A.4 DG appendix
In order to see whether there was a match between SOFC waste heat,
absorption cooling heat demand and hot water heat demand, the Gas
consumption and the electricity consumption was obtained for a typical
18.000m 2 Hotel with 230 rooms in three different American states [13].
This data did however not specify how much of the gas was used
for space heating and how much for hot water heating. And neither
did it specify how much of the electricity was used for electrical air
conditioning and how much for lighting etc. So the fraction for these
things was approximated by using data for the energy consumption of
the total hotel and lodging industry in the US [13].
This meant that 65% of the gas use is assumed to be for space heating,
and 35% for hot water, while 27% of the electricity is for Air conditioning
and 73% is for other equipment (including refrigeration). The cooling
demand is then estimated by assuming a COP of 4 for the electrical air
conditioning and multiplying this with the electricity use for air conditioning.
These numbers now represent what in this report is called ”normal climate”.
A hot climate has then been approximated by assuming that the
cooling demand (kWh/y) is twice that of the normal climate (since air
condition will run all year), and that no energy is needed for space heating
anymore, whereas the hot water heating consumes the same power
as in the normal climate.
Somewhere in the report the annuity has been used, elsewhere NPV is
used. This is because of the following:
The annuity is preferable for the so called chain investments which is
when a new identical unit is bought as soon as the old one is worn down.
Imagine you have the following two options: A) will give a total NPV of
1mio DKK during a lifespan on 1 year, whereas B) will give a total NPV
of 3 mil. DKK during a life span of 6 years. Option B will have the highest
NPV, but if a new unit is purchased each time the old one is worn up,
option A will give 1 mil. DKK per year, whereas option B will only give
0,5mio DKK per year (both continuing year after year). So option A is to
prefer although option B has the highest NPV per investment cycle.
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The problem with the annuity is that it can not be calculated for 0