Combined Heat & Power (CHP)

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• Energy efficiency benefits

• Where is CHP being used?

• Case studies:• City of Saskatoon

Leisure Facilities

• Landfill Gas Project

• St. Paul’s Hospital

How Canadians Use Energy

Cogeneration (CHP)

• The simultaneous production of electrical and thermal energy from a single fuel

• Improvement in overall efficiency of 30 – 35%

• Overall efficiency can approach 85% for some systems

CHP System Types:

1. Gas turbines

2. Reciprocating engines

3. Microturbines

4. Fuel cells

5. Stirling engines

CHP versus Conventional Systems

CHP – Leisure Facilities

Lakewood Civic Centre

• 155 KWe, 230 KWth

• 55% of avg. KVA demand• 53% of electrical KWhr

• Capital Cost $600,000• Annual savings $31,000

Shaw Centre

• 265 KWe, 404 KWth

• 35% of avg. KVA demand• 32% of electrical KWhr

• Capital Cost $700,000• Annual savings $39,000

ENER-G

Lakewood CHP Unit

Heat Exchangers

Exhaust Gas Heat Exchanger Heat Exchanger in Boiler Plant

Landfill Gas Project$15 M Capital Cost, $1.2 M Annual Power Sales

Annual GHG Reduction of 50,000 tonnes CO2e

Landfill Gas Collection

Methane 50-55%

Carbon Dioxide 40-50%

Nitrogen 0-10%

Oxygen 0-1%

Energy Value 18 MJ/m3 (500 Btu/ft3)

Typical gas composition:

Project Layout

Gas Collection Facility

• The Gas Collection Facility draws gas from the wellfield, and flares the gas or removes moisture and particulates from the gas and sends the gas to the Power Generation Facility.

Power Generation Facility

• The Power Generation Facility combusts the landfill gas in two 815 KWe Landfill Gas Engine-Generator sets, generating electricity that is sold to SaskPower for approximately $1.2 million annually.

Power Generation Facility

• Two 815 KWe, 1175 KWth engine-generator sets

Power Generation Facility

• Each engine consumes approximately 230 cfm (9.4 E3M3D) of Landfill Gas when running at full output.

• LFG contains approximately 50-55% methane with energy content of 500 Btu/scf (18 GJ/E3M3)

Engine Exhaust Heat Recovery

Heat Rejection to Exhaust (LHV to 350°F):

24,766 Btu/min (435 KW)

Glycol/Water Loop Heater

Exhaust Stack Temperature: 847 °F

Engine Jacket Water Heat Recovery

Plate and Frame Heat Exchanger

Heat Rejection to Jacket:

42,129 Btu/min (740 KW)

EJW Outlet Temperature: 230 °F

St. Paul’s Hospital CHP Project

• 800 KWe, 900 KWth

• 40% of electrical KWhr

• Capital Cost $4 Million• Annual savings $250,000• 3,000 t CO2e reduction

Boiler Replacement

Steam / Utility Tunnel

No. 1 Boiler Installed in 1963$920,000 Replacement Cost

Heating Loop - Typical

Questions?

Powerhouse 1906 - Photograph LH-5281 by Peter McKenzie courtesy Saskatoon Public Library - Local History Room.