1 of 20

Feasibility of Wind Power

in North Georgia

Jose Marte

Keith Dowsett

Krissie Haddon

Santiago Juarez

Shannon Chen

Tom Cihota

ISYE 6701

SPRING 2022

2 of 20

Introduction

Questions our analysis seeks to answer:

What is Georgia’s present approach to investing in sustainable energy?
To what extent can wind power be implement in (North) Georgia?
What is the practicality and cost of replacing fossil fuels with Georgia wind?
What are the best ways of approaching this implementation?

3 of 20

Existing Wind Power

Georgia currently has NO wind power installed or under construction
Current energy source mix consists of:

Electric Mix in Georgia (Source: https://windexchange.energy.gov/states/ga)

4 of 20

Challenges to Wind Deployment

RES or RPS are legislative mandates and more impactful than voluntary mandates

Georgia currently has 0 RPS/RES goals

RPS or Voluntary Targets by State (Source: State Renewable Portfolio Standards and Goals (ncsl.org).

The NREL states that challenges to wind deployment include

Lack of constant policies
Issues regarding regulatory process
Issues concerning integration
Lack of skilled labor

According to the National Renewable Energy Laboratory, there are several challenges to wind deployment. This includes lack of consistent policies, issues with the regulatory process, issues with integration and lack of skilled labor. Renewable portfolio standards or renewable energy standards are policies which require electricity suppliers to generate a portion of the electricity they provide. Since these standards are legislative mandates, they have a greater impact than voluntary mandates. As shown in the figure on the right, the dark green states represent states with active renewable portfolio standards as of 2018, which includes California, Texas and New York. The light green states have voluntary standards or targets. The yellow states have expired standards or goals and the grey currently have no renewable standards or targets. We can see that as of 2018, Georgia has no renewable standards or targets.

5 of 20

Existing Policies in Georgia

According to DSIRE, there are 18 regulatory policies and financial incentives that support renewable energy generation, but 14 are federal

4 policies and incentives specific to Georgia (chronologically):

Net Metering (2001)
Interconnection Guidelines (2003)
City of Atlanta - Sustainable Development Design Standards (2003)
City of Chamblee - LEED Requirement for Public and Commercial Buildings (2008).

LEED-certified Chamblee Public Safety Building (Source: https://chambleega.com)

The Database of State Incentives for Renewables and Efficiency notes that there are 18 regulatory and financial incentives that support renewable energy generation in Georgia. However, the majority of these standards are US policies and incentives. The remaining 4 incentives specific to Georgia were Net Metering, Interconnection Guidelines, City of Atlanta Sustainable Development Design Standards and the City of Chamblee LEED requirements for public and commercial buildings. The net metering policy requires Georgia Power to offer net metering to 5000 rooftop solar customers or until it reaches 32 MW of capacity. The Atlanta’s Design Standard is limited to funding building construction and renovation projects that utilize sustainable design. The interconnection guidelines allows residential and commercial solar, wind or fuel cells to connect to the grid. Lastly, the City of Chamblee LEED requirement requires that any new city building over 5000 sq ft or greater than $1 million dollars to be certified under LEED. However, none of these are specific policies to promote wind energy

6 of 20

Types of Policies

There are four different policies that can be used to promote renewable energy: market based incentives, command-and-control regulation, information and organization.

NREL Recommended Policy	GA Existing Policy	Year Established
RES Targets	None currently existing
Feed-in-Tariffs	None for wind in Georgia
Interconnection Standards	Interconnection Guidelines	2003
Net Metering	Net Metering	2001
Financial Support	None for wind in Georgia
Private Investment Support	None for wind in Georgia

There are 4 policies that government can use to promote renewable energy, which include market based incentive, command and control regulation, information and organization. Alone, these policies can not bring about significant change, but various policy pairing can be used to mutually benefit each other. Several of these pairings include benchmarking and energy codes, emission caps and regulatory authorities, energy audits and rebates and subsidies and R&D hubs. The National Renewable Energy Laboratory also recommends policies to promote wind energy. As shown in the table, Georgia only has 2 of the 6 recommended policies. In addition to the established interconnection standards and net metering, the government is encouraged to implement renewable energy standard targets, feed in tariffs, financial support and private investment support for wind energy.

7 of 20

Policy Recommendations

Creating an RES target for Georgia

Feed-in Tariffs for Wind Generation

Financial Incentive Programs to benefit large scale wind farms ( > 10 kW)

Low Interest Rates and Loan Guarantees to Private Investors

Based on the existing policies in place, the best recommendation for the government is to first create a mandatory renewable energy standard for Georgia. Currently, more than 60% of Georgia’s electricity is generated from fossil fuels. Implementing a renewable energy standard will not only promote renewable energy in general, but also promote wind energy in Georgia. Feed in tariffs are incentives that ensure that energy generators who connect to the grid receive a fixed price, which is typically above market value. Currently Georgia has the Georgia Power’s Advance Solar Initiative, which is a feed in tariff for small, medium and large scale solar generation. Economists typically favor these market based incentives because it can encourage polluters to find alternative ways to avoid polluting. By implementing a similar feed in tariff for wind technology, it can help encourage wind energy generation in Georgia. Lastly financial incentives programs are needed for large scale wind generation, as well as low interest rates and loan guarantees for private investors.

8 of 20

Technical Considerations: Turbine Selection

Newest on-shore product lines from market leaders
Goal: maximize capacity while considering ease of installation

Vendor	Model	Diameter (m)	Capacity (MW)	Hub Height (m)	Cut-in (m/s)	Cut-out (m/s)
GE	Cypress GE-158-6.1	164	6.1	112-167	3.0	25
Vestas	EnVentus V162-6.8	162	6.8	119-166	3.0	25
Siemens Gamesa	SG-6.6-155	155	6.6	90-165	4.0	25
Goldwind	GW165-5.6	165	5.6	100-165	3.0	25
Nordex	N163/6.X	163	6.5	<164	3.0	26

Largest cut-in speed eliminates Siemens Gamesa
Lowest capacity eliminates Goldwind
Split-rotor design makes GE a clear winner for transportation & installation

9 of 20

Technical Considerations: Turbine Selection

Transporting blades in two pieces means tighter corners can be rounded, shorter trucks.
Assembly performed on-site, reducing rigging requirements.
These are pivotal considerations in North Georgia

GE’s Modular Wind Turbine Blade (Source: https://ge.com)

GE specifications + equation below @ 10 m/s results in:

Wind power (P_wind) = 12.9 MW, but rated capacity is 6.1 MW.
If this design were to operate at Betz limit, capacity would be 6.95 MW
Cypress operates at 88% of the Betz (59.3% efficiency) limit ! √

10 of 20

Technical Considerations: Power & Efficiency

GE Cypress Model GE-158-6.1 (6.1 MW) turbine
10 m wind speed: approximately 4.7 m/s
Rated wind speed: approximately 10.1 m/s
Capacity Factor: 29.1%
MWh/year per wind turbine: 15,550
135 turbines to power 1% of residential load

GE’s Cypress Turbine (Source: https://ge.com)

For this technical consideration we chose the general electric model Cypress GE-158-6.1 which is a 6.1 MW wind turbine. The design point for this wind turbine consists of a 10 meter wind speed of 4.2 meters per second. Based on GE's Technical specifications, the rotor diameter is 164 meters in the hub height is 167 meters. We utilized an altitude of 400 meters to represent the hub height At which the turbine would operate as tall wind in north Georgia. At 400 meters we can assume that the air density is approximately 1.179 kilograms per meter squared in a sustained wind speed of 6.28 meters per second. This produces a rated wind speed of 10.19 meters per second. Assuming an availability of 98%, this wind turbine would produce 15,551 MW hours per year With a capacity factor of 29.1%.

In terms of efficiency, this wind turbine design can operate at greater than 80% efficiency when the generator output is at least 15% of the rated 6.1 megawatts. This is fairly significant considering that typical fossil fuel burning generators operate at much lower efficiencies. For example, a typical coal fired unit operates at approximately 30 to 35% efficiency at full load. and subsequently, as the coal fired unit decreases it's generator output the efficiency decreases exponentially. We utilize heat rate as a way to understand the efficiency of fossil fueled generators. Heat rate is simply the measurement of how many btus required to generate one kWh of electricity. Therefore, the same 15% output would equate to a 50% increase in unit heat rate or a decrease of unit efficiency by 50%.

Ultimately from this analysis, we can see a noticeable improvement in generator efficiencies across all load ranges compared to typical fossil fueled generators.

11 of 20

Technical Considerations: Power & Efficiency

Wind turbine efficiency 80%+ at low loads (15% rated load)
Fossil fuel generators operate at ~30-35% efficiency at full load
At 15% load (grid-side), a fossil generator can see a decrease in efficiency of 50+%

GE’s Cypress Turbine (Source: https://ge.com)

For this technical consideration we chose the general electric model Cypress GE-158-6.1 which is a 6.1 MW wind turbine. The design point for this wind turbine consists of a 10 meter wind speed of 4.2 meters per second. Based on GE's Technical specifications, the rotor diameter is 164 meters in the hub height is 167 meters. We utilized an altitude of 400 meters to represent the hub height At which the turbine would operate as tall wind in north Georgia. At 400 meters we can assume that the air density is approximately 1.179 kilograms per meter squared in a sustained wind speed of 6.28 meters per second. This produces a rated wind speed of 10.19 meters per second. Assuming an availability of 98%, this wind turbine would produce 15,551 MW hours per year With a capacity factor of 29.1%.

In terms of efficiency, this wind turbine design can operate at greater than 80% efficiency when the generator output is at least 15% of the rated 6.1 megawatts. This is fairly significant considering that typical fossil fuel burning generators operate at much lower efficiencies. For example, a typical coal fired unit operates at approximately 30 to 35% efficiency at full load. and subsequently, as the coal fired unit decreases it's generator output the efficiency decreases exponentially. We utilize heat rate as a way to understand the efficiency of fossil fueled generators. Heat rate is simply the measurement of how many btus required to generate one kWh of electricity. Therefore, the same 15% output would equate to a 50% increase in unit heat rate or a decrease of unit efficiency by 50%.

Ultimately from this analysis, we can see a noticeable improvement in generator efficiencies across all load ranges compared to typical fossil fueled generators.

12 of 20

Technical Considerations:�Intermittent Grid Infrastructure

Energy Storage approaches include

Batteries
Hydrogen
Compressed Air
Gravity

Compressed fluids energy storage (Source: https://researchgate.net)

”Tower of Power” concept (Source: https://power-technology.com)

Large scale battery depot (Source: https://pv-magazine-usa.com)

13 of 20

Economic Feasibility

	2022 USD
Fixed Charge Rate	6.50%
CapEx Rate [$/kW]	1593.96
OpEx Rate [$/MWh]	12.77

Cost estimates from NREL report

Parameter	Value	Unit
Annual Expected Power (Energy Capture)	15551.72	MWh/yr
Capacity Factor	29.1	%

GE Wind Turbine Performance Estimates for Georgia

Parameter	Cost
CapEx Estimate [$]	$ 9,722,973.00
OpEx Estimate [$]	$ 198,595.46

Calculated Expenditure Costs

GE Cypress Turbine estimated to have an LCOE of 53.40 $/MWh

14 of 20

Economic Feasibility

The installation of wind turbines for electrical generation in GA is economically viable. √

Estimated LCOE is comparable to EIA’s projections for onshore wind
Discrepancies driven by:

Expected year of installation
Estimation technique
Evaluated capacity factor

Wind Turbine in GA has competitive LCOE against other generation means

Onshore EIA Projection

Offshore EIA Projection

Combined Cycle

EIA Projection

Calculated

To see how our LCOE calculation fairs against other technologies and projections, data from the US energy information administration was brought into consideration. When comparing this reports calculated LCOE againstas EIA’s projection for onshore wind, the values are different by about 4 dollars per megawatt hour, and discrepancies between these numbers are due to the expected year of installation, where we assume we’re building wind turbine farm today, and EIA’s estimates builds by 2023. Additionally, the estimation technique itself and the capacity factor will also have an influence on the discrepancy, however our estimate is higher with lower wind capacity when compared to the capacity used by EIA of 37%, which show’s we’re in the right direction in terms of estimation.

Lastly, the wind turbine generation technologies are becoming more competitive against fossil fuel generation, where combined cycle power plants estimates of EIA would have an LCOE of 43 dollars per MWh, while wind turbine projections for onshore wind are already in the high 40s. As renewable technology continues to be researched, we can expect to see these renewable resources become even more competitive.

Having this said, wind turbine power generation is economically viable

35 seconds to 2 minutes and 11 seconds

15 of 20

How to Upscale Georgia Wind Power

Organize land purchases in Northern GA’s optimum 1000 mi² of high-wind territory
Oceanic surveying to determine minimum-LCOE offshore installation sites
Power Purchase Agreements (PPAs) with other wind-producing states

Offshore wind generation

Onshore wind generation

Blue Canyon (Oklahoma) PPA

Map of Georgia in the Southeast U.S. (Source: https://amcharts.com)

16 of 20

Emission Offset

Coal, petroleum and natural gas are traditionally the leading fuels that generate electric power

Each emit carbon at different rates

CO2e Emission Data from Georgia Electric Generation in 2020
Fuel	Coal	Natural Gas	Petroleum	Total
Electric Generation Emissions, billions of kg	18.64	26.77	0.904	46.314
Share of Electric Emissions, %	40.25	57.8	1.95	100.0
Emissions per unit energy, kgCO2 / kWh	1.356	0.5904	0.97 (nationally)

17 of 20

Emission Offset

offsetting the total output would require:

3,800 units
Hardware cost of ~ $37 billion

Georgia Electric Utility Generation by Energy Source in 2020
	Coal	Natural Gas	Petroleum	Utility Scale Solar	Hydro- electric	Biomass	Nuclear
TWh Produced	13.75	45.34	0.0047	3.78	4.63	5.86	32.83
% Total	12.94	42.7	0.0044	3.56	4.36	5.52	30.91

offsetting 1/6th of the output would require:

634 units
Hardware cost of ~ $6.17 billion

To offset the electric utility CO_2e output from natural gas and coal in Georgia using GE’s Cypress Wind Turbines…

GE’s Cypress Turbine (Source: https://wind-turbine-models.com)

18 of 20

Conclusions & Recommendations

Georgia should definitely implement wind power
Our analysis shows it is feasible to install onshore wind turbines in Northern Georgia

Offshore wind should be strongly considered

Using wind alone to completely offset natural gas and coal generation is not likely feasible
However, replacing 1/6^th of fossil fuel generation is very feasible

19 of 20

References

“State Energy Profile Data - EIA - independent statistics and analysis,” U.S. Energy Information Administration . [Online]. Available: https://www.eia.gov/state/data.php?sid=GA#ConsumptionExpenditures.

“Georgia - annual average wind speed at 80 m,” Wind Exchange. [Online]. Available: https://windexchange.energy.gov/files/u/visualization/pdf/ga_80m.pdf.

Cox, Sadie, et al. “Policies to Support Wind Power Deployment.” National Renewable Energy Laboratory, May 2015, https://www.nrel.gov/docs/fy15osti/64177.pdf.

“Economic Incentives.” EPA, https://www.epa.gov/environmental-economics/economic-incentives#:~:text=Market-based%20approaches%20or%20incentives%20provide%20continuous%20inducements%2C%20monetary,polluting%20entities%20to%20reduce%20releases%20of%20harmful%20pollutants.

“Programs.” DSIRE, https://programs.dsireusa.org/system/program/ga/wind.

“Coweta-Fayette EMC - SmartChoice Home Program.” DSIRE, https://programs.dsireusa.org/system/program/detail/5049/coweta-fayette-emc-smartchoice-home-program

“Georgia Interfaith Power and Light - Energy Improvement Grants.” DSIRE, https://programs.dsireusa.org/system/program/detail/4894/georgia-interfaith-power-and-light-energy-improvement-grants

“Walton EMC - HomePlus Loan Program.” DSIRE, https://programs.dsireusa.org/system/program/detail/2281/walton-emc-homeplus-loan-program

“Renewable Energy Explained.” U.S. Energy Information Administration (EIA), https://www.eia.gov/energyexplained/renewable-sources/portfolio-standards.php.

“Cypress onshore wind turbine platform,” Cypress Onshore Wind Turbine Platform | GE Renewable Energy. [Online]. Available: https://www.ge.com/renewableenergy/wind-energy/onshore-wind/cypress-platform.

“EnVentus Platform.” [Online]. Available: https://nozebra.ipapercms.dk/Vestas/Communication/Productbrochure/enventus/enventus/enventus-brochure-2021/.

“SG 6.6-155,” Onshore Wind Turbine SG 6.6-155. [Online]. Available: https://www.siemensgamesa.com/products-and-services/onshore/wind-turbine-sg-5-8-155. “GW 165-5.2 / 5.6MW,” Goldwind Americas. [Online]. Available: https://www.goldwindamericas.com/sites/default/files/Goldwind%20GW165-5.2-5.6MW-Product%20Brochure%20GWUSA.pdf.

20 of 20

References

“N163/6.X,” Nordex SE. [Online]. Available: https://www.nordex-online.com/en/product/n163-6-x/.

“Betz's law,” Wikipedia, 09-Feb-2022. [Online]. Available: https://en.wikipedia.org/wiki/Betz%27s_law.

J. Wirfs-Brock, “Lost in transmission: How much electricity disappears between a power plant and your plug?,” Inside Energy, 14-Jun-2017. [Online]. Available: http://insideenergy.org/2015/11/06/lost-in-transmission-how-much-electricity-disappears-between-a-power-plant-and-your-plug/.

“2019 cost of Wind Energy Review - NREL.” [Online]. Available: https://www.nrel.gov/docs/fy21osti/78471.pdf.

“Inflation calculator: Find US Dollar's value from 1913-2022,” US Inflation Calculator. [Online]. Available: https://www.usinflationcalculator.com/.

“Advantages and challenges of wind energy,” Energy.gov. [Online]. Available: https://www.energy.gov/eere/wind/advantages-and-challenges-wind-energy.

“Georgia - State Energy Profile Analysis - EIA - independent statistics and analysis,” U.S. Energy Information Administration (EIA). [Online]. Available: https://www.eia.gov/state/analysis.php?sid=GA#:~:text=Georgia%20does%20not%20have%20a,generation%2C%20and%20electric%20vehicle%20use.

E. Shao, “Solar Power Booms in Georgia, where it isn’t mandated,” 22-Aug-2021. [Online]. Available: https://www.wsj.com/articles/solar-power-booms-in-georgia-where-it-isnt-mandated-11629637200.

“Wind Generation.” [Online]. Available: https://www.georgiapower.com/company/energy-industry/energy-sources/wind.html.

“Levelized Costs of New Generation Resources in the Annual Energy Outlook 2021,” Feb-2021. [Online]. Available: https://www.eia.gov/outlooks/archive/aeo21/pdf/electricity_generation.pdf.

“State Electricity Profiles - EIA - independent statistics and analysis,” U.S. Energy Information Administration . [Online]. Available: https://www.eia.gov/electricity/state/.