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

2. MARKET INVESTIGATION
2.3.2 Micro CHP - Refrigerators
The refrigerators used in hotel rooms are of the absorption type, but
they use the Platen cycle, which means that the COP is only around 0,25
In addition the heat must be supplied at relatively high temperatures
- in the range of 120-180 ◦ C [18]. In hotels the driving heat is typically
provided by an electric heating element which gives quite a high energy
consumption, but this is tolerated since the refrigerator is very quiet. For
other applications like mobil homes LPG is used as energy source.
In theory there might be a potential in combining a SOFC with an
absorption refrigerator for private homes. There is enough waste heat,
since the average waste heat consumption would be in the order of 200W
for the absorption refrigerator (see calculations in Appendix A.3 on page
196).
Assumptions
The following assumptions have been used to calculate the cost (Net
Present Value and annuity) of an electrical and an absorption refrigerator
(all seen from the consumer view point - including taxes and VAT):
• Compressor refrigerator price = 4,000DKK 5 [8]
• Absorption refrigerator price = 11,000DKK 6 [1]
• Compressor refrigerator electricity consumption = 208kWh/y
• Electricity price 2 DKK/kWh (Danish prices)
After 10 years, the annuity cost is 1420 DKK for the absorption and
930DKK for the electrical unit including investment and electricity but
no extra piping or heat exchanger for transferring the SOFC waste heat.
So with a lifespan of 10 years, the absorption unit is estimated to be
about 50% more expensive than the conventional refrigerator including
electricity consumption and purchase price but no piping. The pay back
time will be around 50 years strongly dependent on the discount factor,
which is assumed to be 5%. The full calculations can be seen in appendix
A.3 page 196.
5 Bosch KGV 36X27 225 liter refrigerator and 91 liter freezer.
6 RGE 400 from Åbybro camping og fritid 224 liter refrigerator + 76 liter freezer.
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