The Future of Heat Recovery: Combined Heat & Power

Transcription

1 The Future of Heat Recovery: Combined Heat & Power Carolyn Roos Energy Engineer Northwest CHP Technical Assistance Partnership Alaska Rural Energy Conference Fairbanks, Alaska April 11, 2018

2 Outline of Presentation US DOE s Combined Heat and Power (CHP) Technical Assistance Partnerships (TAPs) o Who we are and what we do Introduction to CHP Why CHP? The Multiple Benefits of CHP Finding the Best Candidates for CHP in Alaska o o o Characteristics of Attractive Sites Microgrids Common in Alaska and CHP Compatible Involving the Utility Developing CHP projects with CHP TAP resources 2

3 DOE CHP Technical Assistance Partnerships (CHP TAPs) DOE CHP Deployment Program Contacts Tarla T. Toomer, Ph.D. CHP Deployment Manager Office of Energy Efficiency and Renewable Energy U.S. Department of Energy Patti Garland DOE CHP TAP Coordinator [contractor] Office of Energy Efficiency and Renewable Energy U.S. Department of Energy Ted Bronson DOE CHP TAP Coordinator [contractor] Office of Energy Efficiency and Renewable Energy U.S. Department of Energy 3

4 DOE CHP Technical Assistance Partnerships (CHP TAPs) End User Engagement Partner with strategic End Users to advance technical solutions using CHP as a cost effective and resilient way to ensure American competitiveness, utilize local fuels and enhance energy security. CHP TAPs offer fact-based, nonbiased engineering support to manufacturing, commercial, institutional and federal facilities and campuses. Stakeholder Engagement Engage with strategic Stakeholders, including regulators, utilities, and policy makers, to identify and reduce the barriers to using CHP to advance regional efficiency, promote energy independence and enhance the nation s resilient grid. CHP TAPs provide fact-based, non-biased education to advance sound CHP programs and policies. Technical Services As leading experts in CHP (as well as microgrids, heat to power, and district energy) the CHP TAPs work with sites to screen for CHP opportunities as well as provide advanced services to maximize the economic impact and reduce the risk of CHP from initial CHP screening to installation. 4

5 CHP: A Key Part of Our Energy Future Form of Distributed Generation (DG) An integrated system Located at or near a building / facility Provides at least a portion of the electrical load and Uses thermal energy for: o Space Heating / Cooling o Process Heating / Cooling o Dehumidification CHP provides efficient, clean, reliable, affordable energy today and for the future. Source: 5

6 CHP System Schematic Fuel Natural Gas Propane Biogas Landfill Gas Coal Steam Waste Products Others Prime Mover Reciprocating Engines Combustion Turbines Microturbines Steam Turbines Fuel Cells ORC turbine Heat Exchanger Generator Electricity On-Site Consumption Sold to Utility or - Operated by Utility Thermal Steam Hot Water Space Heating Process Heating Space Cooling Process Cooling Refrigeration Dehumidification 6

7 CHP Recaptures Heat of Generation, Increasing Energy Efficiency, and Reducing GHGs 94 units 56 units Fuel Fuel Power Plant 32% efficiency (Including T&D) Onsite Boiler 80% efficiency 30 units Electricity Heat CHP 75% efficiency Fuel 100 units 45 units Total Efficiency ~ 50% Total Efficiency ~ 75% 30 to 55% less greenhouse gas emissions Separate Heat and Power Combined Heat and Power 7

8 What Are the Benefits of CHP? CHP is more efficient than separate generation of electricity and heating/cooling Higher efficiency translates to lower operating costs (but requires capital investment) Higher efficiency reduces emissions of all pollutants CHP can also increase energy reliability or resilience and enhance power quality 8

9 Beneficial Uses for Thermal Energy Recovered Space heating at a single facility, district or campus o District heating Domestic water heating Process hot water or steam at an industrial facility o Prime Alaska example: Seafood processing Hospitals: Steam for space & water heating, humidification and sterilization Pool or spa heating at hotels, schools, rec centers Absorption chilling for refrigeration 9

10 CHP Critical Infrastructure and Resiliency Benefits Critical infrastructure refers to those assets, systems, and networks that, if incapacitated, would have a substantial negative impact on national security, national economic security, or national public health and safety. Patriot Act of 2001 Section 1016 (e) Applications: Hospitals and healthcare centers Water / wastewater treatment plants Police, fire, and public safety Centers of refuge (often schools or universities) Military/National Security Food distribution facilities Telecom and data centers In Alaska, may include dwellings! CHP (if properly configured): Offers the opportunity to improve Critical Infrastructure (CI) resiliency Can continue to operate, providing uninterrupted supply of electricity and heating/cooling to the host facility 10

11 Finding the Best Candidates for CHP Some or All of These Characteristics High and constant thermal load Favorable spark spread o High electricity rates relative to fuel prices o Both expressed in $ per MMBtu Need for high reliability Concern over future electricity and/or heating prices Interest in reducing environmental impact Existing central plant Planned facility expansion or new construction; or equipment replacement within the next 3-5 years Other local or regional societal benefits 11

12 CHP Today in the United States 82.6 GW of installed CHP at nearly 4,400 industrial and commercial facilities 8% of U.S. Electric Generating Capacity; 14% of Manufacturing Avoids more than 1.8 quadrillion Btus of fuel consumption annually Avoids 241 million metric tons of CO 2 compared to separate production 12

13 CHP Opportunity Summary: Manilaq Health Center, Kotzebue, AK Constant Loads, Need for Reliability & Price Stability in a Critical Facility Problem $1.6M energy costs in 100,000 sf facility; 17 bed hospital / 18 nursing home beds $0.367/kWh for electricity, $4.18/gallon for No. 1 fuel oil in Fuel oil prices change dramatically. In 2016, price was $5.48 per gallon Proposed Solutions Consider 250-kW Reciprocating Engine or 200 kw Microturbine Thermal recovery for potable hot water and steam for health center applications Outcome of Screening and Technical Assessment Estimated payback years, depending on options chosen Improved reliability of a critical facility, Hedge against rising energy costs Strategy Utility integration to address load loss and integration with existing generation 13

14 CHP Opportunity Summary: Kotzebue Hospital Concept for a Kotzebue District Energy System 14

15 Combined Heat and Power: Generation of Power and Heat in an Integrated System Woody Biomass Powers and Heats School in Central Alaska Tok School Gateway Schools, Tok Junction, Alaska Application/Industry: School / Forest Management Capacity: 125kW Prime Mover: Elliot Steam Backpressure Turbine Fuel Type: Timberland thinning and forest slash for wildfire prevention Thermal Use: School and Greenhouses Installation Year: 2013 Highlights: The system heats the 80,000-square-foot local school and a greenhouse growing 20,000 lb. of fresh vegetables for the school district's food service program, while saving an estimated $125,000 per year on fuel. With savings from the biomass CHP project's, Tok School has been able to rehire three staff members for the school: a music teacher, counselor, and a boiler operator. "All of those BTUs, all of that energy, just went up in smoke. By the school using this material, it's saving me a minimum of $1,000 an acre." Jeff Hermanns (Tok area forester) 15

16 Alaska Has a Large Collection of Microgrids What is a Microgrid? A group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid CHP can be the centerpiece of or support element in a community microgrid Provide uninterruptable baseload power Supply thermal energy for cooling and heating Support integration of other resources, such as wind Can provide grid services (stabilizing) Source: Pace Energy and Climate Center, Community Microgrids: Smarter, Cleaner, Greener. 16

17 Involving the Electric Utility is Critical in Alaska: Local electric utilities are integral to interwoven remote communities What is different in Alaska o o In the lower 48, microgrids can connect and disconnect from the grid to enable them to operate in both grid-connected or island-mode In much of Alaska microgrids ARE the utility grids -- and many are cooperatives Utility engagement as cooperating partners is essential. o o Any loss of a major baseload (such as public buildings) has great impacts on small isolated utilities. So independent CHP development is likely a threat to them A major load loss also negatively impacts all end users in a microgrid by increasing costs to remaining end users. Identifying win/win solutions o Utilities co-locating their generating facilities at load centers to sell waste heat and power to customers o Construct district heating thermal distribution loops o Add waste heat recovery to existing reciprocating engines o Thermal uses can be as simple as de-icing or as complex as refrigeration 17

18 Current Situation: CHP Opportunity Summary: Trying to Find a Win-Win Municipal Utility With Potential Fish Processing Plant as Thermal Host Plant currently generates their own power using 1960 s era diesel gen-sets. Recovering waste heat only for domestic water heating and dock de-icing. Baseline electricity cost (self-generating) is $0.1943/kWh, with fuel oil cost of $2.32/gallon. In a preliminary screening, a utility CHP system was considered running on fuel oil with heat recovery to provide steam to the facility for cooking and fish meal drying. 18

19 CHP Opportunity Summary: Trying to Find a Win-Win Additional considerations for project development: Intermittent high peak loads that are not constant year round. Fish plant would size unit for base load and rely on utility backup power for peak loads > project must not destabilize microgrid There are some system configurations that may be cost effective for the plant, but not the utility Conditions that might favor a win-win Studied in Advanced Technical Assistance: Implement CHP when plant s gen-sets or boilers are at end-of-life or during a plant expansion Create public-private partnership between municipal utility and plant Consider supplying heat and power to nearby facilities in a district system Explore state and local incentive opportunities, etc. 19

20 How to Implement a CHP Project with the Help of the CHP TAP 20

21 CHP TAP Role: Technical Assistance 21

22 DOE TAP CHP Screening Analysis Annual Energy Consumption Base Case CHP Case High level assessment to determine if site shows potential for a CHP project Qualitative Analysis Energy Consumption & Costs Estimated Energy Savings & Payback CHP System Sizing Quantitative Analysis Understanding project drivers Understanding site peculiarities Purchased Electricty, kwh 88,250,160 5,534,150 Generated Electricity, kwh 0 82,716,010 On-site Thermal, MMBtu 426,000 18,872 CHP Thermal, MMBtu 0 407,128 Boiler Fuel, MMBtu 532,500 23,590 CHP Fuel, MMBtu 0 969,845 Total Fuel, MMBtu 532, ,435 Annual Operating Costs Purchased Electricity, $ $7,060,013 $1,104,460 Standby Power, $ $0 $0 On-site Thermal Fuel, $ $3,195,000 $141,539 CHP Fuel, $ $0 $5,819,071 Incremental O&M, $ $0 $744,444 Total Operating Costs, $ $10,255,013 $7,809,514 Simple Payback Annual Operating Savings, $ $2,445,499 Total Installed Costs, $/kw $1,400 Total Installed Costs, $/k $12,990,000 Simple Payback, Years 5.3 Operating Costs to Generate Fuel Costs, $/kwh $0.070 Thermal Credit, $/kwh ($0.037) Incremental O&M, $/kwh $0.009 Total Operating Costs to Generate, $/kwh $

23 DOE CHP TAP Advanced Technical Assistance: Where opportunity and end-user interest are high, the DOE NW CHP TAP can provide additional analyses customized to the site, end-user and their specific needs: Emissions Analysis Electrical load profiling Thermal load profiling Thermal use determination (what to do with the heat) Installation cost estimations Financial calculations Cost savings information compared to what your facility would pay if the CHP system were not installed Etc. 23

24 Next Steps Resources are available to assist in developing CHP Projects at your site. Contact the Northwest CHP TAP to: Perform CHP Qualification Screening for a particular facility Identify existing CHP sites for Project Profiles Additional Technical Assistance 24

25 Summary CHP is a proven technology providing energy savings, reduced emissions, and opportunities for resiliency CHP is particularly suited for application in Alaska, where both heat and local power generation are essential and usually colocated or quite close Emerging drivers are creating new opportunities to evaluate CHP and numerous examples exist to learn about facilities that have incorporated CHP Engage with the US DOE Northwest CHP TAP to learn more about the technical assistance offerings in evaluating CHP opportunities at your site! 25

26 For More Information Review the CHP Technology Fact Sheet Series at Visit the CHP Deployment Program at us at 26

27 Thank You! Questions & Contact Information: Northwest CHP Technical Assistance Partnership Washington State University Energy Program Dave Van Holde, PE, Director (360) Gil McCoy, PE, Senior Energy Engineer (360) Carolyn Roos, Ph.D., Energy Engineer (360)

28 Additional Slides: Common CHP Prime Movers 28

29 Prime Mover: Reciprocating Engines Size Range: 10 kw to 10 MW Characteristics Thermal can produce hot water, low pressure steam, and chilled water (through absorption chiller) High part-load operation efficiency Fast start-up Minimal auxiliary power requirements for black start. Example Applications: universities, hospitals, water treatment facilities, industrial facilities, commercial buildings, and multi-family dwellings 29

30 Prime Mover: Gas Turbines Size Range: 1 MW to 300 MW Characteristics Produces high quality, high temperature thermal that can include high pressure steam for industrial processes, and chilled water (with absorption chiller) Available in a wide range of capacities and configurations Best efficiency when operated at full load (part-load efficiency is often much lower than full load efficiency) Example Applications: hospitals, universities, chemical plants, refineries, food processing, paper, military bases 30

31 Prime Mover: Microturbines Size Range: 30 kw to 330 kw (modular packages exceeding 1 MW) Characteristics Thermal can produce hot water, steam, and chilled water (through absorption chiller) Compact size and light weight Inverter based generation can improve power quality Example Applications: multifamily housing, hotels, nursing homes, waste water treatment, gas & oil production 31

32 Prime Mover: Steam Turbines Size Range: 100 kw to over 250 MW Characteristics Requires a boiler or other steam source Can be mated to boilers firing a variety of gaseous, liquid or solid fuels (e.g., coal and biomass fuels such wood, waste products, and pellets). Mature technology with very high durability and reliability Can operated over a wide range of steam pressures Backpressure steam turbines can be used to produce power by replacing pressure reducing valves (PRVs) in existing steam systems Example Applications: Industrial applications, district heating and cooling systems, forest products, paper mills, chemicals, food processing, PRVs 32

33 Common CHP Technologies and Capacity Ranges Microturbines Gas/Steam Turbines Reciprocating Engines Fuel Cells 50 kw 100 kw 1 MW 10 MW 20 MW 33

34 Heat Recovery Heat Exchangers Recover exhaust gas from prime mover Transfers exhaust gas into useful heat (steam, hot water) for downstream applications Heat Recovery Steam Generators (HRSG) the most common Heat-Driven Chillers Absorption Chiller Use heat to chill water Chemical process (not mechanical) Steam Turbine Centrifugal Chiller Image Source: University of Calgary Image Source: DOE - EERE 34

35 Heat Recovery: Absorption Chillers Absorption chillers are heat operated refrigeration machines that operate on chemical and physical reactions to transfer heat. The absorption cycle substitutes a physiochemical process for the mechanical compressor used in common refrigeration systems. Absorption chillers can be driven with hot water, steam, or prime mover exhaust. Absorption chillers are available in sizes from 5 to 3,000 refrigeration tons. This capacity correlates to a CHP electric output of approximately 50 to 10,000 kw. For 40 F and higher chilling fluid temperatures (e.g., building air conditioning), a common refrigerant solution mixture is water (refrigerant) and lithium bromide (absorbent). For chilling fluid temperatures below 40 F (e.g., cold storage), a common refrigerant solution mixture is ammonia (refrigerant) and water (absorbent). A 200-ton single-stage absorption chiller integrated with three 600 kw reciprocating engines that also provide hot water for process and space heating. The system is located at a metal fabrication facility in Fitchburg, Massachusetts. Photo courtesy of Northeast CHP Technical Assistance Partnership (CHP TAP). 35