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CHP for Buildings
CHP for Buildings
CHP for Buildings
What Is CHP for
Buildings?
CHP is an integrated energy system that:
• Is located at or near a building
• Generates electrical
• Recovers waste heat for
heating,
cooling
dehumidification
• Can utilize a variety of technologies and fuels
What Is CHP for Buildings?
Fuel Utilization for Electric Production by U.S. Utility Sector
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Source: http://www1.eere.energy.gov/manufacturing/distributedenergy/pdfs/chp_report_12-08.pdf
Fuel 100 units
CHP 75% efficiency
Total Efficiency ~ 75%
CHP Recaptures Much of that Heat, Increasing Overall Efficiency of Energy Services……
Fuel
Fuel
30 units
Power Plant 32% efficiency (Including T&D)
Onsite Boiler 80% efficiency
45 units
Electricity
Heat
Total Efficiency ~ 50%
94 units
56 units
150 units
100 units
75 units
…..and Reducing Greenhouse Gas Emissions
Fuel 100 units
CHP 75% efficiency
Total Efficiency ~ 75%
Fuel
Fuel
30 units
Power Plant 32% efficiency (Including T&D)
Onsite Boiler 80% efficiency
45 units
Electricity
Heat
Total Efficiency ~ 50%
94 units
56 units
30 to 55% less greenhouse gas emissions
Defining Combined Heat & Power (CHP) The on-site simultaneous generation of two forms of energy
(heat and electricity) from a single fuel/energy source
Conventional CHP (also referred to as Topping Cycle CHP or Direct Fired CHP)
Separate Energy Delivery:
• Electric generation – 33%
• Thermal generation - 80%
• Combined efficiency – 45% to 55%
CHP Energy Efficiency (combined heat and power)
70% to 85%
o CHP is more efficient than separate generation of electricity and heat
o Higher efficiency translates to lower operating cost, (but requires capital investment)
o Higher efficiency reduces emissions of all pollutants
o CHP can also increase energy reliability and enhance power quality
o On-site electric generation reduces grid congestion and avoids distribution costs
What Are the Benefits of CHP?
Source: DOE/CHP Installation Database, 2012 Data
• 82.4 GW of installed CHP over 4,200 facilities (2012)
• 71% of capacity is natural gas
• Avoids more than 1.8 quadrillion Btus of fuel consumption annually
• Avoids 241 million metric tons of CO2 compared to separate production
CHP Today
Source: DOE/CHP Installation Database, 2012 Data
•Today - 87% is Industrial Uses
•Buildings is an Emerging Market
CHP – The Opportunity
Why are Buildings So Important?
Bring the Efficiency of CHP Systems to the
Building Sector is Important – But Not Easy
Attractive CHP for Buildings
Markets
Commercial o Data centers
o Hotels and casinos
o Multi-family housing
o Apartments
o Office buildings
o Restaurants
o Supermarkets
o Green buildings
o Hospitals
o Schools (K – 12)
o Universities & colleges
o Residential confinement
CHP for Buildings
Technologies
Prime Mover Reciprocating Engines
Combustion Turbines
Microturbines
Steam Turbines
Fuel Cells
Electricity On-Site Consumption
Sold to Utility
Fuel Natural Gas
Propane
Biogas
Landfill Gas
Coal
Steam
Waste Products
Others
Generator
Heat Exchanger
Thermal Steam
Hot Water
Space Heating
Space Cooling
Refrigeration
Dehumidification
Topping Cycle
Prime Mover: Gas Turbine
o Size Range: 500 kW to 250 MW
o Advantages
– High reliability
– Low emissions
– High grade heat available
o Disadvantages
– Poor efficiency at low loading
– Require high pressure gas or in-house gas compressor
– Output falls as ambient temperature rises
o Typical Applications: hospitals, universities, campus
and district heating and cooling, military bases
Prime Mover: Reciprocating Engines
o Size Range: < 5MW in DG application
o Advantages
– Fast start-up
– Relatively lower cost
– High efficiency at part-load
o Disadvantages
– High maintenance costs
– Lower temperature heat applications
– Relatively high emissions
– High levels of low frequency noise
o Typical Applications: office buildings, multifamily,
nursing homes, hospitals, schools, universities.
Prime Mover: Microturbines
o Size Range: 30 kW to 250 kW
o Advantages
– Small number of moving parts
– Compact size and light weight
o Disadvantages
– High costs
– Lower mechanical efficiency
– Limited to lower temperature cogeneration applications
o Applications: multifamily, nursing homes
Prime Mover: Fuel Cells o Size Range: 5 kW to 2 MW
o Advantages
– Low emissions
– Low noise
– High efficiency
o Disadvantages
– High costs to date
– Low durability to date
– May require fuel processing
o Typical Applications: data centers, hotels
office buildings, waste water treatment
Heat Recovery Steam Generator
(HRSG)
o Recover exhaust heat
generated by:
o Gas turbine and engines
o Transfers exhaust gas into
useful heat (e.g., steam) for
downstream applications
o Heat recovery steam
generator (HRSG) the most
common
Heat Exchangers
Capturing Heat
• Use “waste” heat to
chill water for A/C
ABSORPTION
CHILLERS
• Use exhaust gas, hot
water, or steam to
produce chilled water
for air conditioning
• Range: 500-1500 tons
Heat-Driven Chillers (Absorption) Using Heat
• Use “waste” heat to
chill water for A/C
TURBINE CHILLERS
• Use exhaust heat
steam to produce
chilled water for air
conditioning
• Range: 1500-5000 tons
Heat-Driven Chillers (Turbine) Using Heat
o Separates
Latent from
Sensible Load
o Reduces
Humidity
and Reduces
AC Load
Desiccant
Dehumidifiers
Using Heat
71% Natural Gas
2% Reciprocating Engine
50% Combined Cycle
12% Combustion Turbine
35% Boiler/ Steam Turbine
Source: DOE/CHP Installation Database
Existing CHP Capacity by
Technology
71% Natural Gas
24% Boiler/ Steam Turbine
7% Combined Cycle
12% Combustion Turbine
48% Reciprocating
Engine
Existing CHP Sites by Technology 11% Other
CHP Technologies by Site
Source: DOE/CHP Installation Database
71% Natural Gas
Coal 15%
Oil 1%
Waste 9%
Wood 2%
Other 1%
Biomass 1%
Existing CHP Capacity by Fuel
Source: DOE/CHP Installation Database
Natural Gas is the Preferred Fuel for
Existing CHP
CHP for Buildings
Challenges
o Issues in Analysis
– Coincident Needs for Power & Thermal
Energy in the Building
– Economics of Buying Electric Power from the
Grid Relative to the Cost of Fuel
– Installed Cost Differential Between a
Conventional and a CHP System Including
Contributor Benefits
Need Good Analysis for CHP
Opportunities
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Barriers To CHP Implementation
o Natural Gas Price Volatility
o Electric Utility Resistance:
– Excessive Grid Interconnect Requirements
– High Standby and Backup Tariffs
– Both Improving with Deregulation
o Lack of Engineering Familiarity with CHP
o Assessing CHP Value
o Stakeholder Apathy (lack of incentive for facility
manager / engineering firms to try something
different)
o CHP for Buildings
– Need Greater Awareness and Analysis
Capability Among A/E and HVAC Design
Firms (ASHRAE Core Membership)
– Analysis is Not Simple – Effectiveness of CHP
Depends on the Load Dynamics of the
Building
Lack of Engineering Familiarity with CHP
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Analysis Capability for A/E Firms Within Standard Building Simulation Models
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Buildings Need Heating and Cooling
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Thermally Driven Cooling Make the Need
for Capable Modeling More Essential
CHP for Buildings
Case Studies
o CHP is not always sold on economics alone
o Other drivers exist for CHP projects
o Case study series explores other drivers
o Case Studies (Project Profiles) located at http://www1.eere.energy.gov/manufacturing/distributede
nergy/projects_sector.html#healthcare
CHP Case Studies
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Case Studies: Addressing Coal Emissions
Kent State University
Kent, OH
Capacity: 12 MW
Fuel: Natural Gas
Prime Mover: Comb. Turbines
(1 x 5MW and 1 x 7MW)
Installed: 2003, 2005
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Case Studies: Partnership w/ Municipality
U.S. Energy Partners,
LLC & City of Russell
Russell, KS
Capacity: 15 MW
Fuel: Natural Gas
Prime Mover: Comb Turbine
Installed: 2002
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Source: http://www.midwestcleanenergy.org/profiles/ProjectProfiles/USEnergyPartners.pdf
U.S Energy Partners & City of Russell – 15.0 MW
o 2 – 15 MW Gas
Combustion Turbine
o 65,000 lbs./hr. of high
pressure steam
o City of Russell needed to
replace 13.2 MW of electric
generating capacity – City owns turbine
– Ethanol plant owns HRSG
Source: http://www.midwestcleanenergy.org/profiles/ProjectProfiles/Utilimaster.pdf
Utilimaster Corporation
Wakarusa, IN
Capacity: 70 kW
Fuel: Natural Gas
Prime Mover: Microturbine
Installed: 2004
Case Studies: Industrial Dehumidification
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Lake Forest Hospital – 3.2 MW
o Campus Operation –
District Energy System
o 4 – 820 kW Engines
o Natural Gas Fueled
o Recaptures 3,600 Lbs./hr.
– 65 psi steam
o 525 tons of Absorption
Cooling
o Annual Instantaneous
Power Outages –
reduced from 50 to 2
Presbyterian Homes – 2.4 MW o Nursing Home Facility
o 3 – 800 kW Engines
o Natural Gas Fueled
o Recaptures 8,000 lbs./hr. –
low pressure steam
o 225 tons of Absorption
Cooling
o Ice storm 1998 knocked
out power for 9 hours.
– 600 senior residents
transferred to safety
– CHP installed to avoid
future outages
“The environment we provide to elderly adults had everything to do with our decision to pursue power
generation. Loss of power isn’t an option. Lives depend on it.”
- Keith Stohlgren, V/P Operations
“We had no power for nine hours one cold, winter day during an ice storm. The loss of power forced us to take immediate, aggressive measures to ensure the comfort
and safety of our residents.”
– Nancy Heald Tolan, Director of Facilities Management
Beloit Memorial Hospital – 3.0MW
o Campus Operation –
District Energy System
o 2 – 1.5 MW Engines
o Dual Fueled (diesel &
natural gas)
o 434 tons of Absorption
Cooling
o CHP system serves
both day-to-day and
emergency power
Advocate South Suburban Hospital – 2.0
MW
o 3 – 300 kW CAT Engines
o 1 – 1,050 kW Waukesha
Engine
o Natural Gas Fired
o Absorption Cooling
o When hospital opened its
doors in 1971, electric utility
could not supply 450 volts
electricity… stand alone
CHP initially installed
o 1993… because hospital was
located at end of electric
utility’s feeder, many
frequent brown outs were
experienced
Northwest Community Hospital – 4.6 MW
o 4 – 1.1 MW Recip.
Engines
o Natural Gas Fired
o CHP system installed
during facility expansion
and due to aging HVAC
Equipment
"We said, ‘Well, if we're going to centralize it all, doesn't it make sense to do a CHP—and
generate our own electricity, to reduce our demand load, and then capture the heat of
those engines and utilize all that for heating and/or cooling?' "
Charlie Stevenson, Director of Plant Operations
Northwest Community Hospital
"The beauty of this CHP to him was not simply the return for the cogen system, but the
fact that these savings would pay for the central energy plant too.”
Joe Sinclair
Dell Children’s Medical of Central Texas
o Combustion Turbine (4.6 MW)
o Thermal applications: steam,
double-effect absorption
chiller, thermal storage
o First healthcare facility in the
world to achieve a LEED
Platinum certification by the
U.S. Green Building Council
(USGBC)… early 2009
Mississippi Baptist Medical Center
o Jackson, MS
o 1 - 4.0 MW NG-fired turbine
o Hurricane Katrina
– 302,000 homes destroyed
– Approximately $125-250B in
damages
– 1,323 deaths
– 2.7M customers without
power
MBMC Response
- Connection to
MPG Restored
57 hr.
-Main Power Grid (MPG) Failed
-Alternate Power Grid Enabled
-City Water Lost
1 hr.
-MPG Restored, but Unstable
-Load Shed Performed (1.2 MW Disconnected)
-Pumping Trucks Supply Water to Physical Plant
3 hr.
-Power Reliability Problems
-Switched to CHP Operation Only
-Elevators on Emergency Generators
-Restricted Use of MRI Equipment
5 hr.
- 52 hrs. of 100% operation on CHP
- Only Hospital in the Jackson Metro Area
to be Nearly 100% Operational!!
August 29, 2005
Hurricane Katrina
Hits Jackson, MS
o Remained open and treated a high volume of patients
o Provided clothing, food, and housing for displaced patients during the first night of the disaster
o Opened a round-the-clock day care to allow employees to focus on patient care
Value of CHP at MBMC
Naval Station Great Lakes –
14MW o Campus Operation -
District Energy System
o 2 – 5.5MW Natural Gas
Turbines
o 2 – 1.5MW Back
Pressure Steam Turbines
o 100,000 lbs./hr. @ 350psi
steam
o Stand alone system
Laclede Gas – Office Building
– 4.3MW o 4 – 800kW and
2 – 550 kW
Engines
o Island Mode –
Independent of
Grid
o 25,200 lbs./hr.
Low Pressure
Steam
Breeden YMCA – 120 kW
o 2 – 60kW Micro-turbines
o Natural Gas Fueled
o 750,000 Btu/hr. @ 1900F
Hot Water
o Installation Cost -
$177,000
o No Cooling
o Thermal Used for
Showers & Potable Water
First National Bank of Omaha
o Four (4) 200 kW PC25 Fuel
Cells
o Hot water heat recovery
utilized for:
– Winter: space heating
and snow melting
– Summer:
dehumidification
o 99.99999% reliability factor
o No downtime due to power
failure since 6/1999
Antioch Community High School – 360 kW
o Landfill ½ mile away
supplies fuel
o 12 – 30 kW
microturbines
o Gas clean up required
University of Iowa – 24.9 MW
o Campus Operation –
District Energy System
o 4 Water Tube Boilers
producing 540,000 lbs./hr.
Steam
o 3 Steam Turbines
o Coal Boilers co-fired with
Biomass (Oat Hulls) 50%
co-fired
UW Cogeneration Plant
o On Line: 2005
o 150 MW for for City
Power
o HRSG Steam to
Campus Heating
o HRSG to Turbines for Summer
Cooling or Combined Cycle
Operation
o Owned by Gas & Electric Utility
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UW Cogeneration Plant
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