Course chp

Slide1: 

Clean Energy Project Analysis Course © Minister of Natural Resources Canada 2001 – 2005. Combined Heat and Power Project Analysis Photo Credit: Warren Gretz, DOE/NREL PIX Power Plant

Objectives: 

Objectives Review basics of Combined Heat and Power (CHP) Systems Illustrate key considerations for CHP project analysis Introduce RETScreen® CHP Project Model

What do Combined Heat and Power (CHP) systems provide?: 

Electricity Heat Buildings Communities Industrial processes …but also… Increased energy efficiency Reduced waste & emissions Reduced T&D losses An opportunity to use district energy system Cooling What do Combined Heat and Power (CHP) systems provide? Photo Credit: Andrew Carlin, Tracy Operators/NREL PIX Biomass Fired Power Plant, USA

CHP System Motivation: 

CHP System Motivation Traditional central power system is inefficient One-half to two-thirds of energy is wasted as heat This heat, otherwise lost, can be used for industrial processes, space and water heating, cooling, etc. Electricity is typically more valuable than heat Adapted from World Alliance for Decentralized Energy; Units in TWh

The CHP Concept: 

The CHP Concept Simultaneous production of two or more types of usable energy from a single energy source (also called “Cogeneration”) Use of waste heat from power generation equipment

CHP DescriptionEquipment & Technologies: 

CHP Description Equipment & Technologies Power equipment Gas turbine Steam turbine Gas turbine-combined cycle Reciprocating engine Fuel cell, etc. Heating equipment Waste heat recovery Boiler / Furnace / Heater Heat pump, etc. Cooling equipment Compressor Absorption chiller Heat pump, etc. Photo Credit: Rolls-Royce plc Gas Turbine Photo Credit: Urban Ziegler, NRCan Cooling Equipment

CHP Description (cont.)Fuel Types: 

CHP Description (cont.) Fuel Types Fossil fuels Natural gas Diesel (#2 oil) Coal, etc. Renewable fuels Wood residue Biogas Agricultural byproducts Purpose-grown crops, etc. Bagasse Landfill gas (LFG) Geothermal energy Hydrogen, etc.

Slide8: 

CHP Description (cont.) Applications Single buildings Commercial and industrial Multiple buildings District energy systems (e.g. communities) Industrial processes LFG CHP for district heating system, Sweden Photo Credit: Urban Ziegler, NRCan

District Energy Systems: 

Heat from a CHP plant can be distributed to multiple nearby buildings for heating and cooling Insulated steel pipes are buried 0.6 to 0.8 m underground Advantages compared to each building having own plant: Higher efficiency Emissions controls on single plant Safety Comfort Operating convenience Initial costs typically higher District Energy Systems Photo Credit: SweHeat Photo Credit: SweHeat

CHP System Costs: 

CHP System Costs Costs highly variable Initial costs Power generation equipment Heating equipment Cooling equipment Electrical interconnection Access roads District energy piping Recurring costs Fuel Operation & maintenance Equipment replacement & repair

CHP Project Considerations: 

CHP Project Considerations Reliable, long-term supply of fuel Capital costs must be kept under control Need “customer” for both heat and power Must negotiate sale of electricity onto grid if not all consumed on-site Typically plant is sized for heating base load (i.e. minimum heating load under normal operating conditions) Heat output typically equal to 100% to 200% of the electricity output Heat can be used for cooling through absorption chillers Risk associated with uncertainty of future electricity / natural gas (“spark”) price spread

Example: CanadaSingle Buildings: 

Example: Canada Single Buildings Buildings requiring heating, cooling, and a reliable power supply Hospitals, schools, commercial buildings, agricultural buildings, etc. Reciprocating Engine Photo Credit: GE Jenbacher Exhaust Heat Recovery Steam Boiler Photo Credit: GE Jenbacher Hospital, Ontario, Canada Photo Credit: GE Jenbacher

Examples: Sweden and USAMultiple Buildings: 

Examples: Sweden and USA Multiple Buildings Groups of buildings served by a central heating/cooling power plant Universities, commercial complexes, communities, hospitals, industrial complexes, etc. District energy system Turbine used at MIT, Cambridge, Mass. USA Photo Credit: SweHeat District Energy Plant

Example: Brazil Industrial Processes: 

Example: Brazil Industrial Processes Industries with a high, constant heating or cooling demand are good candidates for CHP Photo Credit: Ralph Overend/ NREL Pix Also applicable to industries that produce waste material which can then be used to generate heat and power

Examples: Canada and SwedenLandfill Gas: 

LFG CHP for district heating system, Sweden Examples: Canada and Sweden Landfill Gas Landfills produce methane as waste decomposes This can be used as the fuel for cooling, heating or power projects Photo Credit: Urban Ziegler, NRCan Photo Credit: Gaz Metropolitan

RETScreen® CHP Project Model: 

RETScreen® CHP Project Model World-wide analysis of energy production, life-cycle costs and greenhouse gas emissions reductions Cooling, heating, power, and all combinations thereof Gas or steam turbines, reciprocating engines, fuel cells, boilers, compressors, etc. Vast range of fuels, ranging from fossil fuels to biomass & geothermal Variety of operating strategies Landfill gas tool District energy systems Also includes: Multiple languages and currencies, unit switch, and user tools

RETScreen® CHP Project Model (cont.): 

RETScreen® CHP Project Model (cont.) Capabilities for various type of projects Heating only Power only Cooling only Combined heating & power Combined cooling & power Combined heating & cooling Combined cooling, heating & power

RETScreen® CHP Project Model Heating Systems: 

RETScreen® CHP Project Model Heating Systems

RETScreen® CHP Project Model Cooling Systems: 

RETScreen® CHP Project Model Cooling Systems

RETScreen® CHP Project Model Power Systems: 

RETScreen® CHP Project Model Power Systems

RETScreen®CHP Energy Calculation: 

RETScreen® CHP Energy Calculation See e-Textbook Clean Energy Project Analysis: RETScreen® Engineering and Cases Combined Heat and Power Project Analysis Chapter Simplified CHP Energy Model Flowchart

Example Validation of the RETScreen® CHP Project Model: 

Example Validation of the RETScreen® CHP Project Model Overall validation by independent consultant (FVB Energy Inc.) and by numerous beta testers from industry, utilities, government and academia Compared with several other models and/or measured data, with excellent results (e.g. steam turbine performance calculations compared with GE Energy process simulation software called GateCycle) Kpph = 1000 lbs/hr Steam Turbine Performance Calculation Comparison

Conclusions: 

Conclusions Combined Heat and Power (CHP) systems make efficient use of heat that would otherwise be wasted RETScreen calculates demand and load duration curves, energy delivered, and fuel consumption for various combinations of heating, cooling and/or power systems using minimal input data RETScreen provides significant preliminary feasibility study cost savings

Questions?: 

Questions? www.retscreen.net For further information please visit the RETScreen Website at Combined Heat and Power Project Analysis Module RETScreen® International Clean Energy Project Analysis Course