Organic Rankine Cycle (ORC) in Biomass CHP District Energy Systems

Organic Rankine Cycle (ORC) in Biomass CHP District Energy Systems

A Few Questions to Start With Why distributed biomass-fueled CHP? What is Organic Rankine Cycle (ORC)? What are the advantages of ORC? How is ORC applied in biomass district energy? Where is ORC already used in biomass CHP? What to condsider for ORC in biomass CHP? 2

Why Distributed Biomass-Fueled CHP? sustainable & renewable: CO2 neutral and re-growing fuel local energy source: no dependence on volatile global fossil fuel markets local base load electric power: relief for congested transmission lines impact on economy: uses a local supply chain and keeps energy dollars local clean technology: small plants - easier permitting Graph source: Der biologische geschlossene Kreislauf www.biomasseverband.it (April 2010) 3

Biomass Energy: Centralized El. Power optimized electric efficiency low total energy efficiency (< 40%; no use of heat) higher biomass transport cost & transmission losses Graph source: Neil Harrison: Wood burns: an urban myth? Presentation held at International Biomass Conference, Portland, OR, 2009 4

Biomass Energy: Distributed CHP very high total energy efficiency (CHP) higher specific investment cost low biomass transport cost & low transmission losses Graph source: Neil Harrison: Wood burns: an urban myth? Presentation held at International Biomass Conference, Portland, OR, 2009 5

What is Organic Rankine Cycle (ORC)? ORC is an outstanding technology for distributed generation of combined heat and power (CHP) from various renewable energy sources with plant sizes typically below 5 MWe ORC utilizes a high molecular mass organic fluid instead of water / steam standard size turbogenerators for biomass and waste heat recovery: from 500 kwe to 4 MWe customized ORC units for low temperature heat sources: up to 10 MWe 6

How does an ORC unit look like? Condenser- Recuperator Electric generator Electric cubicles ORC turbine Preheater Evaporator Feed Pump 1 MWe modular ORC unit ORC heat input (thermal oil) ORC heat output (hot water) 7

The Thermodynamic Principle: The ORC Cycle THERMAL OIL Generator TEMPERATURE THERMAL OIL Evaporator Regenerator WATER ENTROPY Pump WATER Condenser The turbogenerator uses the hot temperature thermal oil to pre-heat and vaporize a suitable organic working fluid in the evaporator (8 3 4). The organic fluid vapor powers the turbine (4 5), which is directly coupled to the electric generator through an elastic coupling. The exhaust vapor flows through the regenerator (5 9) where it heats the organic liquid (2 8). The vapor is then condensed in the condenser (cooled by the water flow) (9 6 1). The organic fluid liquid is finally pumped (1 2) to the regenerator and then to the evaporator, thus completing the sequence of operations in the closed-loop circuit. 8

What are the Advantages of ORC Turbogenerators? Technical advantages. low mechanical stress due to moderate temperature and pressure in the cycle high turbine efficiency (up to 85%), high cycle efficiency at moderate temperatures no corrosion, no turbine blade erosion, no water treatment system due to absence of water translate into operational (=client) advantages automatic, safe and continuous operation, no operator attendance needed very high reliability (e.g. Admont, AUT: operation since 1998, availability > 98%) low O&M requirements (3-5 hours/week), equipment life time 20 years+ remote monitoring & assistance services by Turboden Advantages vs. steam turbines ease of operation, no steam boiler operator requirements wide flexibility, 10:1 turndown ratio, high efficiency at partial load 9

Biomass How is ORC applied in biomass CHP? ORC plant in co-generation from Biomass 10

Biomass ORC Plants Perfomances 100 % Thermal power from thermal oil 78% Thermal power to heat users 20 % 2 % Net electric power Thermal losses (insulation and generator losses) Net electric efficiency: nearly 20% Overall energy efficiency: 98% 11

Biomass Biomass Fuel Types & CHP Applications Fuels Wood biomass: forestry residues, woodchips, bark, sawdust, treated wood Other biomass: dried sewage sludge, straw, green cuttings, rice husk, etc. Heat Consumers District Heating networks Timber drying in sawmills Saw dust drying in wood pellet factories Trigeneration Waste material Air pre-heating in MDF industry Greenhouses 12

Biomass CHP District Heating Networks WITHOUT ORC Applications BIOMASS BIOMASS POWERED BOILER hot water cold water HEAT USER Community district heat Universities & colleges Hospitals Airports Swimming pools / Spas WITH ORC Electric power BIOMASS BIOMASS POWERED BOILER Thermal oil hot water ORC cold water HEAT USER 13

Biomass Turboden ORC units for CHP Standard Size Modules and Typical Performances INPUT - Thermal oil TURBODEN 6 CHP TURBODEN 7 CHP TURBODEN 10 CHP TURBODEN 14 CHP TURBODEN 18 CHP TURBODEN 22 CHP Nominal temperature (in/out) C 300 / 240 300 / 240 300 / 240 300 / 240 300 / 240 300 / 240 Thermal power input kw 3240 3815 5140 6715 9790 12020 OUTPUT - Cooling water Nominal temperature (in/out) C 60 / 80 60 / 80 60 / 80 60 / 80 60 / 90 60 / 90 Thermal power to cooling water kw 2569 3040 4087 5318 7842 9601 PERFORMANCE Gross electric power kw 641 738 1016 1339 1863 2304 Gross electric efficiency 19,8% 19,3% 19,8% 19,9% 19,0% 19,2% Captive power consumption kw 30 35 48 58 79 97 Net active electric power output kw 611 703 968 1281 1784 2207 Net electric efficiency * 18,9% 18,4% 18,8% 19,1% 18,2% 18,4% (*) Ratio between Net active power output and Thermal power input from thermal oil 14

The PureCycle Power System Heat to Electricity Power Generation 280 kw Gross Power Free fuel Zero emissions Renewable baseload power generation 196ºF 300ºF* resource range Modular and scalable for larger plants Short lead times 24/7/365 remote monitoring High availability *91ºC 149ºC 15

Where has ORC been applied with biomass? 30 years of ORC experience - World leader in ORC for biomass CHP applications recent order: waste heat recovery ORC plant in Albany, NY 16

Fortune 50 corporation $58.7B in 2008 sales 180 countries 225,000 employees Turboden A Pratt & Whitney Power Systems Company UTC Power UTC Hamilton Carrier Research Sikorsky Otis Fire & Security Sundstrand Center Pratt & Whitney Large Engines Small Engines After market Marine Mobile Power Heat to Electricity PWPS - Turboden: Wide industrial ORC experience and strong presence in North-America A flexible partner ready to work out optimized ORC solutions for the client 17

Biomass CHP District Heating in Vipiteno (Italy) District heating network length 45 km with 750 connections (municipalities Vipiteno, Prati, Casateia ~ 8000 inhabitants) Regular winter heat demand: 12-14 MW with peaks up to 22 MW thermal Baseload installations: Biomass thermal oil boiler (7 MW thermal) Turboden ORC unit: electric capacity: 1,2 MWe hot water capacity: 5,5 MW at 80 C Additional peaking installations: 8,6 MW biomass water boiler 8 MW hot water storage Back-up boiler 9 MW fuel oil boiler 18

Case study District heating application in Tirano (Italy) Customer: T.C.V.V.V. Spa Location: Tirano (SO) Italy Start up: June 2003 ORC unit: Turboden 14 CHP 1.1 Mwe electrical output Thermal Power to the cooling water circuit: 4.8 MW at 60 C/80 C ORC in/out (140 F/~180 F) 30,6 km of piping network 664 connected users 19

The District Heating Model in Central Europe Small and medium-size communities (typically 2000-10000 inhabitants) in the area of the Alps Starting point: main heat users like community buildings, school/college campus, hospital, large commercial & industrial users Small residential users can follow Strong regional policy support for sustainable development: Investment incentives/grants for district heating infrastructure (differing with region) Long-term feed-in rates for electricity from biomass Financial/Investment schemes: Local utilities Co-ops with local farmers, forest owners & municipalities Local private long-term thinking investors 20

District Energy with Hot Water vs Steam In Europe hot-water district heating systems are state- of the art technology Hot water systems are much easier to control no 24/7 attendance needed (no high pressure equipment): operator can take care of other activities The operation of old steam systems often means considerable energy losses in the distribution system modern insulated water pipes minimize heat losses, can be directly burried and have life time 50 years Conversion of old steam systems to hot water should be considered! 21

CHP with ORC in North America? Brief Feasibility Study: District Heating Assumptions: Installation cost of biomass CHP plant with capacity 1200 kwe net and 18 MMBtu/hr = 5,3 MWth hot water 190 F: estimated 4,800 USD per kwe annual O&M cost: 130,000 USD biomass fuel cost: 30-40 USD per green met.ton (50% m.c.) Electricity price: 12.5 c/kwh (Vermont feed-in rate) Thermal energy price: subsituted wholesale price heating oil in Northeast US: 2 USD/gal (winter 2009/10 average, source: EIA) Full-load equivalent of 5840 hrs (66,7% of time) Results: biomass consumption: 21,000 met.tons (3.6 met.tons/hr) electricity generation: 6,870 MWh / yr thermal energy generation: 110,000 MMBtu / yr Payback time 4 4.5 years (6% discount rate) 22

What to Consider? - Summary Find a good heat load: in CHP applications ORC works heat-driven ORC in distributed biomass CHP is not about the lowest price per kwe possible, but about Micro view: savings in fuel cost & O&M Macro view: benefits for environment & local economy Energy investments by their nature in many cases have rather a 4/5-year than a 2/3-year pay back time Use of different fuel types in the same boiler low-grade wood with varying moisture content in large commerical / industrial applications Energy prices and PPA with utility Good example: Ontario feed-in rate 13,8 CAc/kWh BC Hydro program: revision under way Generally high thermal energy prices in areas without natural gas grid 23

Thank you very much for your attention! Please visit our website to see ORC related articles and presentations: www.turboden.it Daniel Theuer Business Development daniel.theuer@turboden.it Turboden, a Pratt & Whitney Power Systems company Turboden s.r.l. Via Cernaia, 10-25124 Brescia, Italia tel +390303552001 - fax +390303552011 info@turboden.it www.turboden.it C.F./P.I. IT02582620981 capitale sociale 1.800.000 i.v. R.I.: C.C.I.A.A. di Brescia 02582620981 REA 461817