DISTRICT HEATING:
AN OVERVIEW
PRESENTED BY:
NIELSEN SYSTEMS
APRIL 8, 2011
AGENDA
•
•
•
•
•
Introduction and Definition
Typical Heat Balance at a Landfill Gas Power Plant
Examples of District Heating Systems
Opportunities at West Carleton and Carp Road Region
Summary
Definition
• What is District Heating?
– Heating of a group of facilities within a geographic location from one
central source, as opposed to individual heating sources for each
facility
– Typically, district heating makes use of large centralized plants with
extensive piping distribution networks
– Recently the trend has been to use smaller, more efficient district
heating systems which incorporate cutting edge technologies to
recover and reuse otherwise wasted energy
Definition
• How does District Heating work?
– A centralized heat recovery or generation facility is connected to a
group of end users by a network of distribution piping
– The energy transported from the central facility to the end user may
be in the form of low temperature hot water, high temperature hot
water or steam
Definition
• Why does District Heating make sense?
– A district heating system which is driven by waste heat may potentially
result in lower energy costs to end users connected to the system
– Any system which is powered by waste heat is not subject to fuel cost
fluctuations
– The world’s most cost-effective untapped renewable energy source is
waste heat, and currently very little of heat by-products have been
resourced as a secondary energy
– A more advanced waste heat recovery/district heating system has the
opportunity to generate electricity, reducing electrical costs to the end
users while reducing greenhouse gas emissions
– Cost sharing and CO2 credits can help reduce the overall cost of waste
heat to power equipment
Typical Heat Balance: Landfill Gas Plant
WASTE, HEAT AND
MECHANICAL LOSSES
63.2%
ELECTRICITY
36.8%
FUEL IN 100%
THE PLANT ONLY EFFECTIVELY USES 36.8%
OF THE ENERGY GOING INTO IT!
Where does all the waste heat go?
EXHAUST GASES
32.8%
HEAT LOSS
3.6%
ELECTRICITY 36.8%
FUEL IN 100%
MECHANICAL LOSS
1.3%
JACKET WATER SYSTEM 25.5%
ATMOSPHERE
Where does all the waste heat go?
• There is an enormous opportunity for capture on the wasted
heat from the plant:
EXHAUST GAS
32.8%
JACKET WATER
25.5%
TOTAL ENERGY AVAILABLE TO
BE CAPTURED
58.3%
Typical Heat Balance with Heat Recovery
EXHAUST GAS LOSS
10%
HEAT LOSS
3.6%
FUEL IN 100%
HOT WATER OR STEAM
TO/FROM DISTRICT
HEATING SYSTEM
22.8%
ELECTRICITY 36.8%
MECHANICAL LOSS
JACKET WATER
HOT WATER TO/FROM DISTRICT HEATING SYSTEM 25.5%
1.3%
Typical Heat Balance with Heat Recovery
• With heat recovery measures in place, the balance of input
energy being used efficiently increases enormously:
ELECTRICITY
36.8%
JACKET WATER RECOVERY
25.5%
EXHAUST GAS RECOVERY
22.8%
TOTAL EFFICIENCY
85.1%
THAT’S AN INCREASE OF 48.3%!
DISTRICT HEATING SYSTEM EXAMPLES
District Heating Example: Vancouver
• In 2003, Maxim Power was chosen to provide a district
heating system to the city of Vancouver landfill which
included:
– Construction of compressors and condensate removal systems at the
Landfill blower/flare station
– Construction of a 2.5 kilometre pipeline from the Landfill to CanAgro's
greenhouses south of the Landfill
– Construction of a power station including 5.55 MW of generating
capacity using three Cat 3532 generators (reciprocating engines)
– Use of the hot water from the engines to provide 100,000 GJ per year
of heat to CanAgro's greenhouses
Case Study: Vancouver Landfill
District Heating Example using ORC turbine
technology
• A major energy developer has an innovative, industrial waste-heat
recovery system that is dramatically increasing the efficiency and output
of a 7.2 MW biogas power plant in the eastern Slovenian town of Lendava
• They use an Organic Rankine Cycle (ORC) waste-heat recovery system for
gas engines
• The extra thermal power is used to produce steam, which in turn
generates enough electricity to support 300 nearby European homes
without using additional fuel
• ORC systems like this one generally offer enhanced energy efficiency by
utilizing organic fluids that have lower boiling points than water to create
steam for electricity generation
West Carleton Landfill Opportunities
• Introduce a district heating system to increase efficiency on
energy inputs
• Provide heat to nearby commercial facilities which allows an
opportunity for end users to produce their own electricity
using processes such as Organic Rankin Cycle (ORC) turbines
• The energy recovered from waste heat streams could increase
net energy output for the existing landfill gas power plant
Carp Road Regional Opportunities
Summary
• Waste heat to power is an energy source with zero input fuel costs
• The advantages are electrical savings, but the process also displaces
fossil fuel electrical production, and hence, reduces CO2 emissions
• New technologies allow for use of low temperature hot water to
produce electricity for end users connected to a district heating
system
• End users on a district heating system making use of ORC turbine
technology can also recover enough heat to offset space heating
requirements in addition to generating their own electricity
QUESTIONS?