ORMAT°111 

June 13, 2014 

Submitted To: 

Steve Page, Director 

Office of Air Quality Planning and Standards 

Office of Air and Radiation 

U.S. Environmental Protection Agency 

Oilandgas.whitepapers@epa.gov 

Re: Comments on White Papers on Methane and VOC Emissions in the Oil and Natural Gas 

Sector: Oil and Natural Gas Sector Compressors 

Submitted by: 

Ormat Technologies Inc. 

6225 Neil Road 

Reno, NV 89511-1136 

Contact: Bob Sullivan. bsullivan@ormat.com / (775) 356-9029 Ext. 32240 

Dear Director Page and staff, 

Ormat Technologies Inc. appreciates the opportunity to submit comments on the EPA technical 

white papers on VOC and Methane leak sources, released April 15, 2014. In particular our 

comments pertain to the white paper on Oil and Natural Gas Sector Compressors. 

About Ormat 

Ormat Technologies Inc. is headquartered in Reno, Nevada and has over four decades of 

experience in the development of state-of-the-art, environmentally sound alternative energy 

power plants. Ormat has pioneered the use of organic fluids as the power system's motive fluid, 

generally refened to as Organic Rankine Cycle (ORC) systems. These ORC systems can be used 

to convert low to moderate temperature heat sources to fuel and emission-free electricity. 

Ormat's ORC application for Waste Heat Recovery, which we call Recovered Energy 

Generation (REG) units, has been applied successfully on 19 natural gas pipeline compressor 

stations in North America alone. 

We believe that waste heat recovery on natural gas transmission pipelines is an important 

mechanism for reducing the Wm/de climate impact of the natural gas supply chain. 

We commend EPA and the Administration for recognizing the climate impacts of an inefficient 

natural gas delivery system and for beginning to scope out methods for improvement. Should 

EPA prepare a rulemaking on methane leaks and flaring, we also recommend that technology 

solutions like Ormat's REG units should be eligible as one compliance pathway. 
Ormat comments on Methane White Papers 

Description of Pipeline Compressor Control Technology 

Ormat's REG units use a power-generation technology based on the classic Rankine Power 

Cycle.' First, the exhaust heat from an industrial process is recovered using a heat exchanger on 

the exhaust stack, utilizing a thermal oil to recover the heat. The thermal oil then circulates to 

another heat exchanger, where heat is transferred to a working fluid (pentane) in a closed-loop 

vaporizer system. As the working fluid is heated, it vaporizes and expands in volume, which 

turns a turbine, driving an electric generator to create electricity. The turbines in the REG unit 

operate at a very high aerodynamic turbine efficiency of 88 to 91 percent. (See Figure on page 

3). 

Ormat has installed the majority of its REG units at natural transmission gas pipelines. On large 

interstate gas pipelines, compressor stations are installed roughly every 100 miles. These 

compressors are essentially jet engines that compress and move the pipeline contents. Because 

this is a high-energy and high-pressure operation, compressors expel heat at about 900° F. 

Ormat's REG units capture and convert this waste heat into electricity — usually about 5 to 6 

megawatts per unit — that can then deliver electricity back to the electric grid of the local 

operating utility. Ormat has REG solutions in place at 19 gas pipeline compressor stations in 

North America alone. 2Together, these stations provide over 100 megawatts of clean generation. 

The U.S. Energy Information Administration (EIA) notes that in the United States alone, there 

are over 1,400 compressors on gas-transmission pipelines. 3Most of these stations would be 

candidates for waste heat recovery installations. 

The installation of waste heat recovery on compressor stations creates many economic benefits. 

For a typical REG installation, the business arrangement includes a waste heat host agreement 

between the pipeline owner and the REG owner. The compressor station owner would receive a 

royalty or waste heat host fee for the usage of the heat produced by the compressor station in the 

REG process. The operations of the pipeline and compressor station on which the REG facility is 

installed are not impacted by the operation of the REG facility. In some cases, the gas pipeline 

will retain ownership of the REG unit, thereby retaining ownership of the energy produced and 

any other attributes associated with the project. The owner of the energy that is generated from 

the REG facility can sell that back to the local utility. 

Waste heat capture as a regulatory compliance mechanism 

Ormat supports inclusion of technology solutions that reduce the lifecycle GHG impact of the 

natural gas supply chain in any pending rulemaking on methane. 

See Figure A 

2 See Figure B 

3 See Figure C. EIA citation here: 

http://www.eia.goy/pub/oil gas/natural gas/analysis publications/ngpipeline/index.html. 

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Ormat comments on Methane White Papers 

In a new proposed regulation on methane leaks, EPA could develop minimum performance 

standard for pipeline owners/operators that is a function of methane wa§ted versus energy 

productivity. One potential metric for minimum performance on pipelines could be: 

I

MMBtu of methane leaks / MMBtu of methane delivered I 

This approach would be similar to the compliance model for EPA's newly proposed New Source 

Performance Standards (NSPS) for carbon emissions. A single source would be required to limit 

its overall emissions as a function of energy productivity (i.e. tons of CO2/MWh of power 

produced). EPA does not prescribe specific control technologies with this NSPS proposal. 

Instead, individual CO2 sources have pursue a number of pathways to achieve the minimum 

performance. 

Taking another page from the NSPS model, these performance standards could be applied across 

the entire pipeline, allowing leak controls and technology solutions applied at one portion of the 

pipeline to be averaged in with the rest of the structure, compensating for lesser-performing 

components along the supply chain. This model is in accordance with EPA's well-established 

"bubble concept" for NSPS compliance. 

To fit in with the suggested performance metric above, technology solutions like Ormat's REG 

unit could be afforded an "MMBtu rnethaneequivalent" to help pipeline owners/operators achieve 

minimum compliance for methane leaks. This would be similar to the metrics currently used to 

compare energy contents of alternative fuels to gasoline, the gallon of gasoline equivalent. 

Alternatively, there are several well-established protocols for converting all greenhouse gases 

into CO2 equivalents according to their global warming potential. EPA could use these protocols 

make an "apples to apples" comparison of avoided CO2 emissions, enabled by REG and other 

technology solutions, and translate them to some value in avoided methane emissions. An 

example of a method Ormat suggests for calculating the value of carbon emission offsets created 

from the operation of REG facilities is shown below. Utilizing the emission comparison values 

created by the US Energy Information Administration (EIA) or Idaho National Engineering and 

Environmental Laboratory (INEEL), values for CO2 emissions from coal fossil fuel power 

generating plants range from 2.08 to 2.18 lbs CO2/kw-hr and energy generated. See 

http://www.eia.gov/tools/faqs/faq.cfm?id=74&t=11 and 

http://www.inl.gov/technicalpublications/Documents/33 14491 .pdf 

Using the lowest of these emission levels for comparison purposes, for each MWh generated 

from a REG facility will avoid the generation of 2,080 lbs annually. A typical REG facility rate 

6MW will avoid the generation of approximately 50,000 tons of CO2 annually. This calculation 

can be used as a direct conelation between REG output and CO2 off set amounts. 

Waste heat capture as a pathway to recognition under Natural Gas STAR 

The Natural Gas STAR Program works to help companies implement cost-effective technologies 

that reduce methane emissions, but it is up to each partner to determine which technologies and 

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Ormat comments on Methane White Papers 

practices it will implement. Ormat proposes that as a corollary to our proposal for REG as a 

compliance pathway, Ormat proposes that technical solutions like REG should be one pathway 

for natural gas delivery agents to achieve recognition under the Natural Gas STAR program. 

EPA should offer technical information on waste heat recovery to Natural Gas STAR partner 

companies as one proven cost-effective methane mitigation technology. EPA should also include 

waste heat recovery vendor companies, like Ormat, in peer-to-peer networking and technology 

transfer workshops offered by the Natural Gas STAR program. 

In May 2014, EPA proposed new protocols for companies to achieve Gas STAR Gold. 4Ormat 

proposes that waste heat technologies should be an allowable pathway for a facility to achieve 

Gold status. Implementation of waste heat recovery could earn gas companies a "bonus" 

recognition for reducing the lifecycle greenhouse gas impact of the natural gas supply chain. 

Waste heat recovery could also provide sufficient "credit" for a given gas facility where other 

types of methane control technologies are comparatively expensive or difficult to delivery. 

General Cominents 

By classifying waste heat recovery as a pathway to mitigation of the impacts of methane leaks 

and flaring, EPA can provide the natural gas supply chain with greater flexibility to achieving 

measurable improvements. While Ormat has introduced a type of waste heat technology directly 

applicable to pipelines, there are many other potential applications for waste heat recovery across 

the gas supply chain, including on gas processing plants, natural gas engines, flare gas and LNG 

import/export facilities. 

Ormat looks forward to working with EPA to quantify in greater detail how waste heat 

technologies can reduce the lifecycle greenhouse gas impact of the natural gas supply chain. We 

also look forward to working together if EPA does elect to promulgate a rulemaking on methane. 

Thank you for your consideration and please direct any questions to bsullivan@ormat.com . 

Sincer9ly, 

I 

Bob Sullivan 

Vice President of Business Development 

Ormat Technologies 

Attachments 

• Figure A: Schematic of an Ormat Recovered Energy Generation (REG) waste heat 

capture system 

• Figure B: Photo of a 22 MW REG Unit on a Compressor Station in North Dakota 

4See here: http://www.epa.gov/gasstar/documents/Gas STAR Gold proposedframework.pdf#page=9. 

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Ormat comments on Methane White Papers 

• Figure C: Illustration of U.S. Natural Gas Pipeline Compressors, U.S. Energy 

Information Admithstration, 2008 

5 
Condenser 

Heat 

Transfer 

Fluid Pump 

Air-Cooled ORMATo ENERGY CONVERTER (OEC) 

Exhaust 

Stack 

By Pass 

Stack 

Heat 

— Recovery Unit 

Hot 

Gases 

Recuperator 

1 

itot Exhaust Gases 

Heat Transfer Fluid 

Motive Fluid (Liquid) 

Motive Fluid (Vapor) 

Storage / Expansion Tank 

Motive Fluid Pump 

Ormat comments on Methane White Papers 

FIGURE A: Schematic of a Recovered Energy Generation (REG) System 

Recovered Energy Generation (REG) System 

FIGURE B: 22 MW REG Unit on a Compressor Station in North Dakota 

6 
Legend 

= Interstate Pipeline 

- = Intrastate Pipeline 

isi = Compressor Station 

Ormat comments on Methane White Papers 

FIGURE C: Illustration of U.S. Natural Gas Pipeline Compressors, U.S. Energy Information Administration, 2008 

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