North Carolina Solar Center

NC Combined Cooling, Heating and Power Program

Value of Renewable Energy Distributed Energy Resource for

MicroGrid Applications

Alex Hobbs, PhD, PEDirector, NC Solar Center

June 29, 2005


North Carolina Solar Center

• Operated by College of Engineering at NC State University

• Created in 1988 as a Clearinghouse for RE Information, Training, Technical Assistance and Applied Research

• Sponsored by the State Energy Office, NC Dept. of Administration

• Other Funding: Industry, Federal Labs, US DOE, USDA, IREC, Foundations, Other State Agencies & NGOs


An Inclusive Interest in Energy Efficiency and Renewable Energy

•Solar •photovoltaics•solar hot water•passive solar•daylighting

•Wind •Biomass

•animal & crop waste•landfill gas

•Biofuels •ethanol•biodiesel

•Green Buildings & Sustainable Design• Hydrogen & Fuel Cells •CHP & Distributed Generation•NC IOF Program

www.ncsc.ncsu.edu


Database of State Incentives for Renewable Energy

• The NC Solar Center hosts DSIRE - a comprehensive source of information on state, local, and utility incentives that promote renewables

• www.dsireusa.org


IREC Interconnection Project• The NC Solar Center

also hosts the IREC Interconnection Project - information on federal, state and utility net metering and interconnection programs

• www.irecusa.org/ connect


The Problem in the Southeast• Little Change = Little Opportunity

• No deregulation = no RPS, CAF, net metering, etc.

• No simplified interconnection or encouragement of independent power production – perceived generation supply glut

• Utilities have no reason to change – maintain the monopoly and get a guaranteed rate of return

• Have to fight the system to enter market – rules change at utility discretion to stop change from happening


Southeast has relatively cheap powerRisk of dying from coal fired power plant caused particulates

Source: Clean Air Task Force


Barriers facing Renewables Financing challenges

High first costs Uncertain long-term commitment to incentives Uncertainty in RE certificate markets

Unreasonable interconnect requirements High standby/back-up power costs RE environmental benefits / fossil &

nuclear environmental costs not valued Siting and permitting delays/uncertainties Non-core business investment for the

customer


Is There Hope in North Carolina?

• YES! Four Major Drivers – Politically strong Ag community wants to

promote biomass– Air Quality makes strange bedfellows (see

NC Clean Smokestacks – environmentalist tourism, health, etc)

– Rural jobs in NC rather than WV, KY or middle east

– Military Bases need to be sustainable


Key Policy Needs in North Carolina

• Portfolio Standards to encourage near market renewables (green power alone won’t cut it)

• Net Metering & Simplified Interconnection to support small scale DG, PV and Wind (underway at the NCUC)

• Public Building Requirements to raise awareness, supply GP and show state leadership

• Institutional Green Power Purchases to support market development

• Local Barrier Reforms in Zoning, Permitting, CC&Rs• Tax Credit Modifications to make the RE Credits

“tradable” • Public Benefit Funds to Support Market Emergence

and Development


Solar Energy


Myth: Solar Can Never be a Big Part of US Energy Supply

Solar can supply all electricity for the U.S. using a 100 by 100 mile area in the SW.

Solar from 1% of the Mojave Desert can provide the annual energy expected from ANWR.


Myth: Solar Energy is Only for the Desert

Portland, Maine receives 70% of the

solar energy that falls on Las Vegas, NV –

photovoltaics can and are used in every state in the United States,

including Alaska

Whr/m2/day1000 to 40004000 to 55005500 to 65006500 to 7500


Maturing an Energy Source = Time + Money

1900 1950 2000

Hydroelectric (more than $ 50 B)4

Nuclear ($ 25 – $ 50 B)3

Renewables (less than $ 13 B)1

1 Cumulative Federal renewable energy federal appropriations (1999$)

2 DOE PV Program Budget History since 1975

3 Range of cumulative appropriations based on 1998 Nuclear Energy Institute Federal Spending Analysis (1997$)

4 Federal appropriations since 1903 (1999$)

Myth: Investment in Solar Technology is Having no Effect

PV ($1.6B)2

* PV is a $2B per year industry growing over 25% per year


PV Increasingly Competitive

1980: $1.00/kWh

2000: ~$0.20 cents/kWh

2005: ~$0.12 cents/kWh

• Sacramento Municipal Utility District's (SMUD) 2-MW plant (2 acres)

• Enough power for 660 Sacramento-area homes

• Replaces some nuclear-generated power

Myth: Solar Energy is too Expensive


Myth: Solar Technologies take more energy to manufacture than the energy

they producePV Energy Payback

0

5

10

15

20

25

30

35

Worst Case Best Case

Yea

rs

Net EnergyProduction Period

Energy PaybackPeriod


Myth: Solar Technologies Also Pollute the

Environment Manufacturing• Small amounts of

hazardous materials used in manufacturing are completely contained -- no emissions

• PV’s are safe to produce

• Solar is silent • Low or no water use The Solar 2 Power Tower, which

includes integrated storage to provide baseload/intermediate generation.


Myth: Solar Energy is not Available When it is needed

Time of Day (EST): June 18, 1998

Me

as

ure

d E

lec

trica

l De

ma

nd

/Pro

du

ctio

n (W

atts

)

0 2 4 6 8 10 12 14 16 18 20 22 24-1000

-500

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000Control Home Net Load: 71.1 kWh

PVRES Net Demand: 15.2 kWh

PV Power to Grid: 15.6 kWh

Control and PV House Net Load on theElectric Grid, Summer Peak Day: June 18, 1998


The Value of Solar

• Flexible -- Either independent or “Grid-tied”• Sized, sited and installed faster • Avoids (or postpones) expensive

transmission and distribution upgrades• With storage, a premium power or remote

power solution• Provides energy savings and pollution

avoidance


Solar Potential• Fort Bragg is 251 sq. miles¹ • A photovoltaic (PV) array covering 1% of the

base would actually only be 0.42% of the total area due to spacing and tilt of the panels

• At 15% efficiency, this PV plant would produce 406 MW

• This PV array would almost quadruple the total PV production of the US (140 MW²) and would be 40% of the current world production (1050 MW²)

• It would cost $2 billion and would produce 500 million kWh/year, enough energy to run over 40,000 NC households a year

• Rules in NC give a 70% incentive, see DSIRE database

www.ncsc.ncsu.edu


Wind Energy


Wind Sizes and Applications Small (10 kW)• Homes (Grid connected)• Farms• Remote Applications

(e.g. battery changing, water pumping, telecom sites, icemaking)

Intermediate (10-500 kW)• Village Power• Hybrid Systems• Distributed Power

Large (500 kW – 6 MW)• Central Station Wind Farms

• Distributed Power• Offshore Wind Generation

Stations


Total Installed U.S. Wind Energy Capacity

TOTAL: 6,740 MW as of Jan 24, 2005


$0.00

$0.10

$0.20

$0.30

$0.40

1980 1984 1988 1991 1995 2000 2005

38 cents/kWh

Cost Nosedive Driving Wind’s Success

2.5-4.5 cents/kWh

Levelized cost at excellent wind sites in nominal dollars, not including tax credit


From the Mountains to the Sea Buffalo Mtn, Tn

Future view of main channel to NC Ports

NC Wind Working Group

•Western Wind Program•Appalachian State Energy Center•Dr. Dennis Scanlon

•Coastal Wind Program•NC State Solar Center•Ms. Beth Mast


Coastal wind

resourcesare large


Carteret County Opportunities•Open Ground Farms – 46,000 acres (72 square miles)•Class 4 or better winds

•Onshore Mainland 22,350 acres Barrier 20,923 acres

•Offshore Sound 1,132,078 acres State Ocean 530,883 acres

• 1.5 MW Turbine - Could install 36 turbines per square mile with 5x7 blade diameter separation

•At 30% capacity factor produce over 1,000 MWe equivalent year round output


Who might use this resource?


Biomass Energy

Power when you need it.


USDA/DOE Biomass Programs


•Rural Development•Climate Change Mitigation•Energy Security

How do we replace fossil fuel based energy and products with home grown biobased materials?

Policy Drivers


• 13th in nation in bioenergy generation

• 1.6 million MWh of electricity generated from biomass sources

• 1.3 % of electricity generation• Estimated potential: 16 million

MWh

Biomass Resources in NC

NREL biomass fact sheet for NC


Advantages of Biomass• Crude Oil => $40 / barrel• Natural Gas => $7 / 1000 cf Twice the price of• Woody Biomass => $50 / dry ton• On a BTU basis at these prices,

biomass resources are available for approximately half the cost of oil and gas

• Equivalent to low-sulfur coal cost


Disadvantages of Biomass

• Coal has an energy content of 950,000 BTU/ft3

• Wood has an energy content of 260,000 BTU/ft3

• A biomass fired generation plant would need to burn 3.7 times the volume of fuel that a comparable coal fired plant would require


Biomass Supply Database Do the study first, transportation will drive the project cost.

Resources Studied • Corn Stover• Wheat Straw• Switchgrass• Hybrid Poplar• Hardwood Logging Residues• Softwood Logging Residues• Hardwood Cull Residues• Softwood Cull Residues• Bark from Mills*• Fine Wood from Mills*• Coarse Wood from Mills*• Construction Waste*• Demolition Waste*• Renovation Waste*• Municipal Solid Waste*


Top 10 Counties - PotentialCounty Dry Tons (<$50)

Beaufort 322,439

Halifax 271,037

Bertie 257,011

Duplin 254,271

Northampton 251,302

Wake 225,099

Bladen 209,383

Robeson 205,341

Wilkes 194,787

Warren 188,901

Total 2,379,570


Potential 2039 Mwe Generation

at 25% efficiency

144, 7%

249, 12%

1188, 59%

81, 4%

79, 4%

111, 5%

187, 9%

AgriculturalWasteUrban WoodWasteForest and MillWasteEnergy Crops

Hog Waste

Poultry litter

Landfill Gas


Total Biomass Thermal Fuel Value 200x1012Btu/yr 6650 Mwt 1662 Mwe


Wood Biomass

Craven County Wood Energy (CCWE)


CCWE Biomass Emissions

0.009

2.89

7.3

3.28

11.85

5.22

0

2

4

6

8

10

12

lb /

mw

h

CCWE NC Average NC Coal

SO2

NOx

CO2

0

1293 2078


Landfill LocationsLandfill Gas Potential• Can draw from Fort Bragg

Landfill and nearby Cumberland County Landfill in Fayetteville

• Fort Bragg Landfill produces enough gas¹ to obtain 0.75 MWe² and 400 tons/hr of cooling²

• Cumberland County Landfill produces enough gas to obtain ~3 MWe and over 1500 tons/hr of cooling

• Combined potential resource of landfill gas totaling ~3.75 MWe and close to 2000 tons/hr of cooling

1. Landfill data from US EPA LMOP website and “Landfill Gas-to-Energy Project Opportunities: Landfill Profiles for the State of North Carolina” by US EPA LMOP

2. Values based on a 27% efficient gas turbine and a 50% efficient heating/cooling system


Ft. Bragg District Heating and Cooling

AMBIENT

AIR

GLYCOLCOOLING

PUMP

HEATEXCHANGER

HEAT RECOVERY CHILLER INLETDAMPER

IDFAN

EXHAUSTSTACK

DUCTBURNER

HEAT RECOVERY STEAM GENERATORDIVERTERDAMPER

SILENCER

EXHAUST STACK

EXHAUST STACK

SILENCER

ECONOMIZER

INLET AIR COOLER

GENERATOR GASTURBINE

GASCOMPRESSOR

HIGH

PRE

SSUR

E GA

S

CHILLED WATER

CHILLEDWATER

OPTIONAL

OPTIONAL OPTIONAL

STEAM

82nd Airborne CompoundNatural gas fired5 MW Solar gas turbine1000 Ton absorptive cooler28,000 PPH HRSG


Distributed Generationand MicroGrids


What is Distributed Energy?


Distributed Energy Resources


CHP Energy Savings


Generation Efficiencies

10kW 100kW 1 MW 10MW 100MW 1000MW 20%

30%

40%

50%

60%

70%

Micro Turbine

CHP

Fuel Cell

WithCHP

HybridFuel cell

ReciprocatingEngines

CCTGCCTG

GasTurbineGasTurbine

Oldsteam

1 MW


DER Market Scenarios• Back-up generation• Distribution system enhancement

– Feeder Relief– Transformer bank relief– Reactive support for the T&D Grid– Serve remote loads– Power Quality– Peak shaving– Energy needs (load growth) and Ancillary Services– Loss reduction– Transmission and distribution deferral– Improve grid asset utilization

• Local micro-grid• Interconnected local micro-grids• Interconnected local micro-grids and

utility distribution systems


Where Does CHP Fit With DER?

• High Thermal Loads High Thermal Loads– Cooling, Heating, or Dehumidification Cooling,

Heating, or Dehumidification– Steam, Hot Water, or Direct Heat Steam, Hot Water,

or Direct Heat

• High Electric Loads • Coincident Thermal and Electric Loads• Extended Operating Hours• Where the Rates and Regulatory Climate are

Favorable• Central HVAC System• Access to Fuels (Natural Gas or Byproducts)


MicroGrid pulls it togetherThe MicroGrid (The MicroGrid (An aggregation of micro-sources, loads and storage)– Presents itself as a single operating entity to the

grid– Customer centered; Key “value added” point– Can participate in markets (load management)– Recognizes combined heat and power

applications– No centralized fast control– Visualizes an appliance model: “Plug & Play”

model


Utility

Loads, micro-sources & storage

• Dispatchable load• Responds to real-

time pricing • Simple protection• Local voltage

control• UPS functions• Local redundancy• Digital power• Loss reduction• Use of waste heat

Customer

13.8 kV

5

8

M8

M5

MicroGrid ParadigmMicroGrid Paradigm


Do we have some questions?

Alex HobbsNC Solar Center

[email protected]

North Carolina Solar Center

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