Cogeneration FacilityOverview

History

   Joshua Walker Gore (1852-1908) and Gore Building at Cogeneration Facility

• Came to Chapel Hill in 1882, taught philosophy, physics and engineering• Designed 1st campus steam plant in 1895

•Located near old Venable Hall•Burned coal and wood•Started cogeneration using a small steam turbine in 1901

•New plant built on same site around 1920

Original Cameron Avenue plant• Constructed in 1941• Commitment to coal, 2 pulverized coal boilers

1978

Cameron Avenue Plant in 1974• Open coal pile• Bag houses to address stack emissions

Cameron Avenue Plant in 2005

District Energy System

1880 1900 1920 1940 1960 1980 1997 2008

U.S. Average Generating Efficiencies

100%

80%

60%

40%

20%

0%

UNC Cogen •

• Traditional thermal electric plant• 65% of energy goes to a cooling tower, lake, etc.

Steam Distribution System

Plant Operation

Plant Operation• Built to utility standards, complete redundancy

throughout• 2 circulating fluidized bed boilers, 250,000

lbs/hour– Only boilers capable of operating the turbine

generator– Lower temperature than pulverized coal or gas,

inhibits NOx– Limestone injection limits SO2 but creates CO2

– 40 minutes before pressure incident if tripped• 1 natural gas/oil boiler, 250,000 lbs/hour

– Fuel and boiler diversity to increase reliability– 10 minutes before pressure incident if tripped

Circulating Fluidized Bed System

NSPS 40CFR60, Subpart DbConstituent Permit Limit Typical

Operation

Sulfur Dioxide

90% reduction1.2 lbs/MMBtu

92% reduction0.2 lbs/MMBtu

Nitrogen Oxide

0.6 lbs/MMBtu 0.4 lbs/MMBtu

Mercury 0.000003 lbs/ MMBtu

0.00000075 lbs/MMBtu

Hydrogen Chloride

435 lbs/hour 4.4 lbs/hour

Particulate 0.5 lbs/MMBtu 0.01 lbs/MMBtu

Opacity 20% 3%

Finances

How Expenses Are Paid

Type of Cost Carolina Other Schools

Capital Projects Debt retired by utility revenues*

State appropriated capital project

Renewal and Replacement

Debt retired by utility revenues

State appropriated R&R allocation

Operations and Maintenance

Utility revenues State appropriated building operating reserve

Fuel costs or direct purchases of power

Utility revenues State utility operating budget

Revenue Sources

Major Rate Components

• Debt Principal and Interest– 34% of total budget– $94 million remaining on debt to construct plant, paid

in 2022• Fixed Costs

– Do not vary with amount of steam produced– Examples: labor, maintenance

• Variable Costs– Fuel is 30% of total budget – Natural gas is purchased at the interruptible rate

State of NC Requires Lowest Cost Operation

All-in cost includes limestone and ash disposal, and adjusted for lower efficiency of natural gas

State Recaptures Any Savings

• Office of State Budget and Management– Determines increase factor– Adds to prior year’s actual expenditures

• Example– Assume state appropriated utility budget is $100

million– Assume actual expenditures are $95 million– Assume OSBM increase factor is 10%– Increase = $9.5 million (calculated on $95 million)– $95 million + $9.5 million = $104.5 million new budget– Appropriated utility budget increased by $4.5 million

State Inadvertently Recaptures Energy Budgets for New Buildings

• When a new building comes on line mid-year– Partial year’s funding received for the 1st year– Funding for remainder of full year ‘s cost provided

in 2nd year• If the first year’s partial funding is not spent, then it is

recaptured in the increase procedure and permanently lost

• Partial year funds normally are not spent because– Utility costs are transferred from the contractor

when the building is accepted and move-in occurs later so usage is low

– Consumption is not uniform, may miss a summer or winter peak

– No debt service or fixed cost components in the utility rates in the first year of a building’s operation

Alternative Energy

Climate Action Plan

• UNC was an early adopter of the American College and University Presidents Climate Commitment

• Pledged climate neutrality by 2050• Climate Action Plan adopted by

University in September 2009• Alternative Energy Study, looked at

alternatives to coal, began 2 years before Climate Action Plan issued

Transportation

Conservation

Energy

Green Building

BehaviorSupply

Chain

Offsets

LevelizedCost(Savings)perMTCDE

Near-TermPortfolioA B C

DF G

H I JK

L

MNOP

E

$0

$100

>$150

$50

($50)

($100)

($150)

<($200)

Scale

100,000MTCDEA. Biomass Gasification at Carolina North (CN)

B. 100% Coal SubstituteC. 50% Coal SubstituteD. Plasma Gasification of MSW - SyngasE. Shops and Informal Contract RecyclingF. 50% Natural Gas, 50% Coal SubstituteG. Plasma Gasification of MSW: Syngas + Natural GasH. 50% Natural Gas

I. Biomass Gasification w/ Biochar Production (CN)J.Energy Conservation (Mid-High Investment)K. Large Scale BiomassL. Biomass Gasification at CN (Phase II)M.Solar Thermal (CN)N. Solar Thermal to Electricity (Troughs) (CN)O. Solar Thermal to Electricity (Dish Sterling) (CN)P. Demo Scale Concentrating Solar PV (CN)

LevelizedCost(Savings)perMTCDE

Near-TermPortfolioA B C

DF G

H I JK

L

MNOP

E

$0

$100

>$150

$50

($50)

($100)

($150)

<($200)

LevelizedCostUnder CarbonCapandTrade

Scale

100,000MTCDEA. Biomass Gasification at Carolina North (CN)

B. 100% Coal SubstituteC. 50% Coal SubstituteD. Plasma Gasification of MSW - SyngasE. Shops and Informal Contract RecyclingF. 50% Natural Gas, 50% Coal SubstituteG. Plasma Gasification of MSW: Syngas + Natural GasH. 50% Natural Gas

I. Biomass Gasification w/ Biochar Production (CN)J.Energy Conservation (Mid-High Investment)K. Large Scale BiomassL. Biomass Gasification at CN (Phase II)M.Solar Thermal (CN)N. Solar Thermal to Electricity (Troughs) (CN)O. Solar Thermal to Electricity (Dish Sterling) (CN)P. Demo Scale Concentrating Solar PV (CN)

50% Natural Gas50% Coal Substitute

100% Coal Substitute

Large Scale BiomassPlasma Gasification

Near-Term Portfolio Long-Term Common

Long-Term Alternative

LFG Banked Offsets

Additional Projects

Biomass Issues• Fuel supply chain and cost• Front end fuel handling

– Storage– Feed systems

• Impact on combustion and heat transfer surface

• Baghouse impacts• Ash disposal impacts

Biomass Plan• Test protocols – February 2010• Dried wood pellets tests – Spring

2010• Torrified wood tests – Fall to Winter

2010/2011• Evaluation and implementation plan

development – 2010/2011• Burn 2012 – Dependent upon fuel

supply reliability and extent of required modifications

Questions