Prof. dr. Marija Todorovic DERES - DIVISION FOR ENERGY EFFICIENCY AND RENEWABLE ENERGY SOURCES

1. E N E R G Y S U P P L Y MICRO AND DISTRIBUTED GENERATION AND TRIGENERATION I Prof. dr. Marija Todorovic DERES - DIVISION FOR ENERGY EFFICIENCY AND RENEWABLE ENERGY SOURCES Faculty of Agriculture, University of Belgrade, Serbia deresmt@EUnet.yu, deres@agrifaculty.bg.ac.yu www.rcub.bg.ac.yu/deres 2006 6th November

2. Introduction to the relevant definitions and aspects of the combined heat & power (CHP),micro and distributed generation and trigeneration for all UNESCO E-Learning target groups, Its aim is to provide an understanding of power generationtechnologies and to show how “waste” heat from electric­generation process can be used for: heating and/or coolingto increase systems integral energy efficiency, to reduce operating costs and the need for new electric utility construction, as well as to reduce the load on electric transmission systems. It is an introduction to the Fundamentals of CHP Systems, Engineering Issues, Benefits and Barriers to CHP’s broader utilisation, Micro and Distributed Generation – Cogeneration and Trigeneration, Examples of implementation AIM OF THIS LECTURE

3. ACRONYMS Combined Heat & Power (CHP) Buildings Cooling, Heating & Power (BCHP) CHP for Buildings (CHPB) Integrated Energy Systems (IES) Total Energy Systems (TES) Trigeneration Systems (Trigen) CHP for Industry Cogeneration

4. Micro - CHP Systems Technologies What is CHP - Cogeneration - HP Production Why Consider CHP What is Trigeneration CHP Characteristics of Good Applications CHP Barriers CHP Managing Overview & Services COMBINED HEAT & POWER (CHP) - MICRO AND DISTRIBUTED GENERATION AND TRIGENERATION Micro Combined Heat and Power or MicroCHP is an extension of the well established idea of COGENERATION to the single/multi family home or small office building

5. Exhaust Gas Natural Gas Exhaust Gas Heat Exchanger Air Kathalyst < 120 °C Peak Load Boiler 90 °C Final Heat User 84 °C 79 °C Electrical 82 °C Grid . . 70 °C Engine Cooling Waterr-/-Oil Heat Exchanger V = f(T) V = f(DP) Combined Heat and Power Productioon Lubricant Oil Thermostat

6. What is CHP Combined Heat and Power – Cooling, Heating & Power – Total energy systems – Cogeneration / trigeneration – Energy recycling It is an Integrated System that: – Supplies electrical or mechanical power – Uses thermal output for space or water heating, cooling, dehumidification, or process heat – Is located at or near user – Can serve a single facility or district energy system – Can range in size from a few kW to 100+MW

7. How CHP Saves Energy

8. Electrical efficiency Heat efficiency Overall efficiency (also called “Cogeneration efficiency or “Total efficiency)

9. Power-to-Heat Ratio Where is: Qe – Gross electrical output, kWe Qheat – Usefull heat output, kWth Qfuel – Fuel energy input (based on Net Caloric Value (Lower Heating Value: LHV)), kWth

10. Separate Production of Electricy and Heat POWER PLANTFuel100Electricity36 BOILERFuel100Heat80 Total Efficiency: 0,58 Cogeneration POWER and HEAT Fuel100 Electricity 30 and Heat 55 Total efficiency: 0,85

11. CHP System Sizes (Terminology)

12. TECHNOLOGIES Micro CHP systems are currently based on several different technologies Internal combustion engines Stirling engines Steam engines Microturbines Fuel cells

14. Exhaust Gas Natural Gas Exhaust Gas Heat Exchanger Air Kathalyst < 120 °C Peak Load Boiler 90 °C Final Heat User 84 °C 79 °C Electrical 82 °C Grid . . 70 °C Engine Cooling Waterr-/-Oil Heat Exchanger V = f(T) V = f(DP) Combined Heat and Power Productioon Lubricant Oil Thermostat

15. QK Condenser Compressor Power Expansion Evaporator Q0 Vapour compression cooling mashine

16. Wapor Steam Heat Trigen Block From back cooling dilute solution Concentrated Wasser pump Expans. Valve To back cooling Wasserdampf Air Conditioninig Plant Condenser Generator Abwärme Evaporator Absorber Absorptions refrigeration plant

17. Trigeneration Module Exhaust Gas Natural Gas 3-Way-catalyst Exhaust Gas- Heat Exchanger Air Cooling Absorptions- cooling plant Electricity CoolEnergy- Storage Heat- Storage Engine watercooling-/-oil Heat Exchanger TRIGENERATION Power-Heat-Cool-Coupling

18. 34 % Electricity Gas 100 % 100 % 53 % Heat 13% Losses Absorption Cooling Plant hel= 35 % 38 % Kälte zref = 71 % hth= 55 % POWER – HEAT – COOL - COUPLING 6 °C / 12 °C Absorption Cooling „fueled“ by the Heat

19. 38% Cooling hel= 36 % hel= 35 % 38% Cooling Primary energy 100 % hth= 55 % Separated Production Electricity 9 % Compression cooling- mashine Primary energy 121 % eKKM = 4 77 % 34 % Eliectricity Losses Power-Heat-Cooling-Coupling Absorbtion cooling plant Heating 53 % zAKA = 0,71 13 % 34 % Electricity Losses POWER – HEAT – COOL - COUPLING

20. Supermarket/ Office building/Hospital Back cooling Natural Gas Heating in Winter Electrical Grid Trigen Block Cool- Storage Heat Storage Safety cooling Absorber Electricity Power – Electr. Grid – Heat – Cooling - Coupling

21. Oil for heating Back Cooling Natural Gas Supply Supermarket/Office Building/Hospital Natural Gas Supply Electrical Grid Energy Supply and Saving Safety cooling Trigen Block Boiler Power – Electr. Grid – Heat – Cooling - Coupling

22. The environmental damage caused by the use of energy coupled with advances in technology has led to a change in the view of the building as an energy system. Technologies such as photovoltaic facades, fuel cells, ducted wind turbinesand cogeneration allow a building to produce clean energy for own needs – heating/cooling/electr. Raised best performance related issues, matching demand and supplied heat and power, optimization (design & control) of the interaction of the EG (DEG) with HVAC/technical systems in transient conditions. The answer to most of these questions requires some form of integrated building design and systems simulation. THE BUILT ENVIRONMENT MAJOR CONSUMER OF HEAT AND ELECTRICITY

23. MODELLING AND SIMULATION OF SMALLSCALE EMBEDDED GENERATION SYSTEMS Advances in heat and power production lead to a revolution in buildings perception as an energy system. The addition of heat and power production increases buildings complexity and new design issues must be addressed: integration of DEG with traditional systems; optimal demand and supply matching; demand side management and its impact on environmental performance; interaction of the DEG systemwith the local electricity network, etc.

24. Small-scale CHP installation analysis CHP contribution: - 30% electrical load - 23% heating load CHP benefits (Feb-May 05): - 7,000 kWh primary fuel savings - 1,450 kg CO2 savings Optimisation: - 2 units running simultaneously Sustainable Research Building Nottingham University 5.5 kW el, 12.5 kW th Max 83oC water out

26. ELECTRICAL POWER COOL USEFUL HEAT

27. TRIGENERATION STATE OF THE ART Existing installations: - medium to large-scale - Prime movers: Internal Conmbustion engines and turbines - Cooling: absorption chillers Challenges in small-scale applications - Cooling technology? - Costs? - Fuel and emissions?

28. TESTING, SIMULATION AND ANALYSIS OF A SMALL-SCALE TRIGENERATION Designers need simulation tools to help answer questions relating to building environmental performance. For the development of integrated EG schemes, building simulation tools must evolve to facilitate all aspects of DEG systems modeling: - EG components, electrical power flow, demand and supply control algorithms, etc. - To assess the interactions between an EG system and all other components of a building, modeling, must be undertaken in an integrated manner.

29. MODELING AND SIMULATION Simulation – modeling tools have evolved to assist in the design and assessment of building performance, particularly in: - low energy building design, - modeling of active and passive solar systems, - modeling natural ventilation systems - daylighting and effects of saving technologies - modeling of modern, building integrated heat and power sources such as photovoltaics and fuel cells.

30. Evaluation of benefits of CHP installation Optimisation: Interaction CHP/Building’s heating system Trigen Heat/Power/Cooling capacities ratios• Outcomes: Trigen offers Significant primary fuel savings CO2 emissions reductions However, payback period can be/very long! ? Future work: Improve component efficiencies - COP SUMMARY AND CONCLUSION MICRO SCALE DEG AND TRIGENERATION

31. CHP FOR INDUSTRY - THE CONCEPT THE IOWA ETHANOL INDUSTRY Improved Reliability Lower Energy Costs Better Power Quality Lower Emissions (including CO2) Conserve Natural Resources ResourcesResources Support Grid Infrastructure – Defer Costly Grid Upgrades – Price Stability Facilitates Deployment of New Clean Energy Technologies Enhances Competition

32. CHP FOR HIGH ENERGY USERS Example Ethanol Facility –Thermal »75–80% Energy Costs are Natural Gas - Steam Production - Dryers» » $10 Million/Year –Electrical »~ $2.5 Million/Year »3.5 to 4.5 MWe Load => 30 to 40 Million kWh/Yea –Process Can Use all the Thermal Produced »Expect Between 4,300 and 5,300 lbs/hour per Installed MWe

33. CHP AT AN ETHANOL FACILITY? Both Thermal and Electric Reliability Very Important –Lose Batch –Several Hours to Restart Electric Reliability –Grid Backs Up CHP System –CHP System Backs up Grid Thermal Reliability –CHP System Provides Part of Thermal Load –Boilers Sized to Provide All of Thermal Load Reliability In Design –Systems Need to be Designed to Do This!

34. CHP AT AN IDUSTRIAL FACILITY? Long Hours (7/24/365) Availability of Fuels Other than Natural Gas –Coal –Biofuels –Waste Water or Land Fill Gas Saves Energy –Efficiencies Upwards of 85% because of High Thermal Use and Value Reduces Energy Costs

35. TYPICAL INDUSTRIAL CHP SYSTEM

36. RELIABLE CHP TECHNOLOGIES Electric Generation Equipment Gas Turbines and Engines, Reciprocating Engines and Steam Turbines

37. RELIABLE CHP TECHNOLOGIES Heat Recovery Systems - Steam and Hot Water - Exhaust Gases

38. Absorption Chillers Desiccant Dehumidification

40. Northern Power supplied a hybrid solar PV / microturbinestandalone power system for a new PEMEX natural gas production platform. The Lankahuasa-1 platform, an innovative tripod design is the first offshore site deployed as part of PEMEX’s strategic gas initiative program, tapping the newly discovered gas reserves southeast of Tampico in Mexico.

41. High Energy Use Coincident Needs for Electrical and Thermal Energy Cost of Buying Electric Power from the Grid Relative to the Cost of Fuel Installed Cost Differential Between a Conventional System and a CHP System KEY FACTORS FOR CHP INDUSTRIAL ATTRACTIVENESS

42. WHY THE OPPORTUNITIES FOR DEG ARE IN GROWTH? • Aging Electric Transmission and Distribution Systems • – Difficult to Site New Lines • – Capacity Constrained • – Costly to Maintain • Rising Concerns Over • – Blackouts/Brownouts • – Power Supply Constraints • – Electricity Prices

43. MAIN IMPEDIMENTS TO CHP High First Cost Discourages Investment Despite Life Cycle Benefits Assessing CHP Value(Beyond Energy Cost Reduction) Hard to Identify, Quantify, and Allocate Among Parties Stakeholder Apathy Lack Lack of Incentive for Facility Managers and Engineering Firms to Try Something Different Too Few Case Studies Inconsistent, Hard to Find, and Often Incomplete in Financial Details Permitting Process Sometimes Long, Cumbersome, and Costly

44. Electric Utility Response / Interconnection Often Times Ambivalent at Best, Hostile at Worse - Inconsistent Standards, Complex Process, Network Issues and Unpredictable or High Costs Natural Gas Prices / Volatility Creates Uncertainty in Energy Costs Utility Tariffs Standby Charges and General Rate Design Lack of Familiarity With CHP Technologies, Concepts, and Environmental Benefits Electric Restructuring Creates Uncertainty and a “Wait and See” Attitude

45. Ultimately this should lead to creating an environment that enables DER to succeed.

46. DECENTTRALISED GENERATION

48. Central power station Photovoltaics power plant Transmission Network Storage Storage Flow Control Storage Power quality device Storage House Power quality device Distribution Network Local CHP plant Wind power plant House with domestic CHP Commercial building Factory Central power station Tomorrow: distributed/ on-site generation with fully integrated network management Yesterday CHP : cleaner, cheaper and competitive

49. DISTRIBUTED GENERATION WITH HIGH PENETRATION OF RENEWABLE ENERGY SOURCESDistributed Generation (DG) is growing in popularity to meet urban, rural, and diverse customer loads. Integrating the various Distributed Generation technologies into a power system in efforts to improve reliability vary for each application.

50. Distributed generation a new trend in the generation of heat and electricalpower, or Distributed Energy Resources (DER) concept permits "consumers" who are generating heat or electricity for their own needs (hydrogen station and microgeneration) to send surplus electrical power back into the power-grid so known as net metering - or share excess heat via a distributed heating grid. Distributed generation systems with (CHP) systems can be very efficient, using up to 90% of the potential energy in the fuel they consume. CHP can also save a lot of money and fuel. Estimates are that CHP has the potential to reduce the energy usage of the USA by up to 40%. A cluster of distributed generation installations is view as a Virtual power plant. Even if the term "distributed generation" is quite well established, terms like distributed power, distributed energy, distributed energy resources, embedded generation, decentralized power, dispersed generation, and onsite generation can also be found in the literature. Although some of those terms may be used with a different meaning, typically they exactly refer to distributed generation.