Combined Micro-Systems - Design for Micro-Combined Cooling, Heating and Power Systems - page 72

2 Comparative Analysis of Cogeneration Technologies
in mCHP Systems

A variety of types of cogeneration systems are available, or under research and
development, for single- and multifamily residential buildings and small scale
commercial applications. These technologies could replace or supplement the
conventional boiler in a dwelling and provide both electricity and heating to the
dwelling, possibly with the surplus electricity exported to the local grid and surplus
heat stored in a thermal storage device.
A review of existing residential cogeneration systems performance assessments
and evaluation can be found in [ 16 ] and the main advantages and disadvantages of
each of the prime mover options for cogeneration can be found in [ 17 ]. A summary
of typical cost and performance characteristics by CHP technology type [ 18 ]is
presented in Table 6 . Data represent illustrative values for typically available

systems.

Table 6 Typical cost and performance characteristics by CHP technology type [ 18 ]
Technology Steam

turbine

Diesel
engine

Nat. gas
engine

Gas turbine Microturbine Fuel cell

Power
efficiency
(HHV)

15 - 38 % 27 - 45 % 22 - 40 % 22 - 36 % 18 - 27 % 30 - 63 %

Overall
ef

70 - 80 % 70 - 80 % 70 - 75 % 65 - 75 % 65 - 80 %

80 %

ciency

Typical
capacity
(MW e )

0.2 - 800 0.03 - 5 0.03 - 5 1 - 500 0.03 - 0.35 0.01 - 2

Typical
power to
heat ratio

0.1 - 0.3 0.5 - 1 0.5 - 1 0.5 - 2 0.4 - 0.7 1 - 2

CHP
Installed
costs
($/kW e )

300 - 900 900 - 1,500 900 - 1,500 800 - 1,800 1,300 - 2,500 2,700 - 5,300

Availability near

100 %

90 - 95 % 92 - 97 % 90 - 98 % 90 - 98 %

>95 %

Hours to
overhauls

25,000 -
30,000

24,000 -
60,000

30,000 -
50,000

5,000 -
40,000

10,000 -
40,000

>50,000

Start-up
time

1h - 1 day 10 s 10 s 10 min - 1 h 60 s 3 h - 2 day

Fuels all Diesel,

residual
oil

Gas,
biogas,
propane,
landfill
gas

Natural
gas,
biogas,
propane,
oil

Natural gas,
biogas,
propane, oil

Hydrogen,
natural gas,
propane,
methanol

Uses for
thermal
output

LP-HP
steam

Hot water,
LP steam

Hot water,
LP steam

Hot water,
LP

Heat, hot
water, LP
steam

Hot water,
LP HP

steam

- HP

steam

-