Project Green District Energy Feasibility Study - Partners in Project ...

TRCA Pearson Eco-Business Zone District Energy Feasibility Study 10 April 2012
Appendices
11.8 Definitions and Abbreviations
Btu – British thermal unit; the amount of energy required to raise 1 pound (lb) of water by 1°
Fahrenheit (F)
Base Load – that portion of energy demand required constantly; the DE industry uses a looser
definition that is essentially the energy demand economically served by high capital/low
operating cost resources such as CHP or biomass; best illustrated visually by a load duration
curve. In the example shown in the graph below, the peak system demand is close to 30 MWt,
but a resource with a capacity of 10 MWt could economically supply approximately 80% of the
thermal energy – the area below the curve and 10 MWt.
Peak Heating Load (MWt)
30
25
20
15
10
5
Typical
Heating Load Duration Curve
GTA
0
0 1000 2000 3000 4000
No. of hours
5000 6000 7000 8000 9000
BAU – Business as Usual, i.e. the default scenario if district energy is not implemented
Chiller – a machine for generating cooling energy in the form of chilled water used in air
conditioning, its efficiency is often expressed in terms of COP (see below).
CHP - Combined Heat and Power, also known as cogeneration, means simultaneous
generation of both useful heat and power in a single process.
Conversion from Degrees (°) Fahrenheit (F) to Celsius (C)– subtract 32 then divide by 1.8;
from °C to °F, do the opposite, i.e. multiply by 1.8 then add 32.
COP – Coefficient of Performance, the ratio of output divided by input; used to express the
efficiency of chillers or heat pumps
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