Chicago, Illinois, USA January 18-20, Professor Bahram Moshfegh Chairman of Division of Energy Systems Linköping University Sweden

Transcription

1 EIGHTH GOVERNMENT BUILDING ENERGY EFFICIENT TECHNOLOGY WORKSHOP Chicago, Illinois, USA January 18-20, 2012 Energy Systems Optimization Tool with Linköping University Swedish case studies Professor Bahram Moshfegh Chairman of Division of Energy Systems Linköping University Sweden

2 Definition ofenergy Systems Energy systems consist of technical artefacts and processes as well as actors, organizations and institutions which are linked together in the conversion, transmission, management and utilization of energy. The view of energy as a Socio-technical system implies that also knowledge, practices and values must be taken into account to understand the on-going operations and processes of change in such systems.

3 Levels of the Energy Systems Global energy systems National energy systems Regional energy systems Local energy systems Industrial energy systems Building as an energy system Sources, transport, resources, distribution, history-future, policy, rules, etc.

4 Energy Systems Analysis Interplay and optimisation of energy supply, use and conservation

5 Many possibilities to satisfy energy Global fuel market Coal Natural gas Waste Biofuel Hydropower Nuclear power Wind power Solar cells Condensing power plants Combined Heat and Power plants demand Wasted heat Electricity distribution District heating network Energy demand Electricity required Lighting Electric appliances etc Industrial manufacturing Electricity / fuel / heat possible Space heating, hot tap water Industrial heating Space cooling Waste heat from industries Utilised heat Absorption refrigeration District cooling network

6 Enhanced coal utilisation Increasing energy demand makes coal more valuable. Better to use coal in an efficient CHP plant that uses the heat than in a condensing plant that wastes the heat If the heat is used: Less coal needed to satisfy energy demand Lower CO 2 emissions caused by satisfying energy demand Incomes from electricity and heat sales, which may reduce electricity price

7 Condensing power plant and Combined Heat and Power (CHP) plant Losses Utilised heat Electricity Coal Condensing power plant CHP plant

8 Sustainable electricity utilisation Electricity is valuable Minimised electricity consumption Heat can be used instead of electricity in many cases, e.g. for heating and cooling. Heat from combined heat and power (CHP) plants or boilers that produce only heat

9 District heating and cooling systems Networks for hot and cold water are built from plants to industrial premises, commercial centres, houses etc when a district is built. Convenient for inhabitants District heating enables Utilisation of resources that otherwisemight be wasted, e.g. industrial waste heat, municipal waste Cogeneration of electricity, heat, steam and cooling

10 District heating supply η tot = 92.5% Electricity grid Electricity market Gas CHP Combined heat and power production Heat pump Waste CHP DH network Heat demand Wood Heat-only boilers Oil Industrial waste heat DH system in Gothenburg

11 Absorption vsvapour vapour compression process Condense power plant + Ccoling compression process Electricity Fuel Condensed power plant Electricity Compression process Cooling CHP plant+absorption process Electricity Fuel CHP plant Electricity Heat Absorption process District cooling District heating

12 Absorption vsvapour vapour compression process Condense power plant + Ccoling compression process Electricity 85MWh Fuel Condensed power plant 355 MWh 135 MWh 50 MWh Electricity Compression process ηel = 38% COP = 2 Cooling 100 MWh CHP plant+absorption process Electricity 85 MWh 255 MWh Fuel CHP plant η tot = 90% η el = 34% α = 0,61 Electricity Heat 87 MWh 2 MWh 143 MWh Absorption process COP el = 50 = 0.7 COP heat District cooling District heating 100MWh

13 Combined Heat and Power plant CHP plant Electricity Space cooling Absorption process District cooling District heating Domestic hot water Space heating Process cooling for industry Steam for industry

14 Demand-side measures Energy conservation reduces energy demand Load management reduces capacity demand Energy carrier switching e g from electricity to fuel or district heating

15 Many possibilities to satisfy energy demand Global fuel market Coal Natural gas Waste Biofuel Hydropower Nuclear power Wind power Solar cells Condensing power plants Combined Heat and Power plants Wasted heat Electricity distribution Utilised steam District heating network Energy demand Electricity required Lighting Electric appliances etc Industrial manufacturing Electricity / fuel / heat / steam possible Industrial steam Industrial heating Space heating, hot tap water Space cooling Waste heat from industries Utilised heat Absorption refrigeration District cooling network

16 System analysis Energy system System boundary Management Aim: Supply energy at low cost Components: Available capacity Resources: Limited supplies Boundary conditions Fuel prices, Laws, Demand? How to use components and resources to achieve aim best? Use a model that describes important properties of the system.

17 Energy system optimisation model Country, region, municipality, district-heating system Electricity and heat production Short and long-term variations Cost minimisation Optimisation method: Linear programming Investments in new plants: type, size, occasion Given energy service demand Energy supply Energy demand Energy conservation Energy carrier switching Load management

18 MODEST an energy system optimisation model Modelfor Optimisation of Dynamic Energy Systems with Time dependent components and boundary conditions MODEST calculates how energy demand should be satisfied at lowest possible cost. MODEST can handle many kinds of energy sources, forms, plants and demand MODEST has been used for more than 50 Swedish district heating systems, regional biofuel supply and use and national electricity supply and conservation

19 MODEST Information flow Input data Time division Energy demand Plants and equipment Supply Conservation Costs and other properties Documentation Optimisation Result Total cost Investments Operation Marginal costs Emissions Graphs

20 MODEST Some of the parameters that can be defined Available capacity for plants Max & Min / fix energy per year, season Efficiency Power to heat ratio for CHP plants Storage capacity Energy demand Sales Emission coefficients and limits Energy costs Investments costs Electricity prices, fuel prices Depreciation time Taxes and policy instruments

21 Hydro Nuclear Wind Electricity trade Other electricity demand Swedish electricity supply and conservation Condensing Gas turbines CHP Electricity distribution Electricity demand industry Business Bransch 1, 2, Process a, b, Conservation Oil, gas boilers Oil, wood boilers District heating Energy carrier switching Wood boilers

22 Swedish electricity supply and conservation VA water IM Nordic EX Nordic PU Import Export Buyers SV continental PE continental UY MG main grid VK hydropower GL local grids MODEST model AL non-industrial PC coal, peat AF waste NG natural gas CK CP CA CG CB CU NP nuclear VB wind power CH CT condensing EC lighting, ventilation, compressed air EG other TR idling Energy conservation TZ supply DM other industry TL supply LM studied industry Demand UL Oil UT US WF wood MB industrial MI industrial CHP plants CC new CF new GB gas turbines DH Boilers GP OL BL District heating KG processes KO processes KB heating Energy-carrier switching KD manufacturing processes District-heating boilers CI FL KF heating KH manufacturing processes CL KK cooling

23 Electricity capacity demand MW January July Monday Tuesday Wednesday Thursday Friday Saturday Sunday Sweden 2000

24 Season Diurnal period i j Days Hours Hours a year t ij 1 1 Weekdays November March Weekend Peak days Weekdays April September 3 Weekend October Weekdays May - August Weekend

25 Electricity supply without and with electricity conservation Energy-carrier switching of which is export Hydropower Nuclear power Biofuel CHP Wind power Fossil CHP Import Energy conservation TWh / year MODEST optimisation result

26 Electricity supply and conservation in Sweden during one year Effekt MW Condensing Kondenskraft power vardag Weekday dag winter vinter daytime Weekday vardag spring dag autumn vår höst daytime Hydro Vattenkraft vardag Weekday dag sommar summer daytime nätter o helger Nights and weekends Electricity Elproduktion supply CHP KV Vindkraft Wind power Import Import CHP KV Kärnkraft Nuclear Energy Konvertering conservation varav export of which is export Effektivisering Energy carrier switching Demand-side Elhushållning measures - Negawatts h/year MODEST optimisation result - Duration graph

27 Mton/year 15 CO 2 emissions due to Swedish electricity demand Import Import 0-5 Sweden Sverige Export Netto 0-5 Sverige Sweden Export Netto Without electricity conservation With electricity conservation

28 Regional Energy System Optimisation Potential for a local heat market

29 Project idea Is to investigate and analyze the economical potential for regional collaboration in the energy field between different companies by means of establishing a joint heat market where several companies can buy and sell heat

30 RESO -Studied region Sandviken Sandvik Gävle Korsnäs Sweden StoraEnso Skutskär Distance is about 50 km 40 km Heat demand is about 7 TWh/year

31 Aim of the project Connecting the district heat systems Use of excess heat from industries Possibilities, difficulties, influences Optimal design of the energy systems Win-Win benefits How the present and new utilities should be used? How the energy demand should be provided? How the results will be influenced by the fluctuations in electricity fuel prices CO2-tax electricity certificates trading emission rights trading

32 Schematic representation of the modeled system Approach System perspective Optimization Peat Wood chips Wood powder Oil LPG Bark Wood Chips Waste Biogas Oil Steam boiler Heat-only boilers SEAB Steam boiler Waste incineration Heat-only boilers GEAB Steam turbine DH grid DH demand Steam turbine DH grid DH demand Heat mar rket Steam grid Demand DH Steam Demand Heat pump Heat-only boilers Evaporation plant Steam grid Steam demand Steam boilers SANDVIK Steam boilers Steam turbine New bark boiler New turbine Electricity Oil Electricity Oil Black liqour Bark KEAB & KORSNÄS Oil Heat-only boiler DH grid Steam grid Steam turbine Bark Black liqour ÄFAB DH demand Electricity production Steam demand Steam boilers SKUTSKÄR Oil

33 Possible investments and changes 30 cases: Usage of excess heat Process integration within the system Waste incineration plant New bio-fuel CHP plant Upgrading the turbines Increasing the district heating demand

34 Possible reduction in costs compared to ref. Scenario MSEK K/år Scenario

35 Solution with the highest revenue, compared to the present system 270 MSEK/year saving which can be used for the investment Investments in the following measures Process integration New bio-fuel CHP plant Increasing the capacity of the heat market District heating market 770 GWh/year Electricity production 980 GWh/year

36 Results with highest revenue compared to the ref. scenario(gwh) Gävle Energy Sandviken Energy Älvkarleby Fjärrvärme Heat market Korsnäs Karskär Energy Sandvik StoraEnso Skutskär

37 Heat production Oil boiler (KEAB and GEAB ) KEA B (Heat pump) SEA B (Heat boiler) GEAB (waste incineration) GW Wh Korsnäs (Back pressure evaporation plant) Sandvik steam boiler (oil) Sandvik steam boiler (electrical) KEA B (new and existing) Steam (live and excess) Skutskär (sewage) KEA B (flue gas heat recovery) SEA B (CHP) Scenario GEAB (CHP)

38 Electricity production GWh h/year SEAB GEAB Skutskär KEAB Scenario

39 CO 2 emissions, compared with the ref. scenario (kton CO2) Scenario 5 Scenario 10 Scenario 14 Scenario 18 Scenario 21 Scenario 24 Scenario 25 Scenario 26 Scenario 28 0 Marginal Coal Marginal NGCC Average Swedish -200

40 Influence on each actor, compared with the ref. scenario MSEK/ye year Scenario 5 Scenario 10 Scenario 14 Scenario 18 Scenario 21 Scenario 24 Scenario 25 Scenario 26 Scenario GEAB SEAB SAB KEAB Korsnäs Skutskär/ÄFAB

41 Common component types and energy flows for a local Swedish utility that supplies electricity and district heating Power supplier ELECTRICITY Wind power Hydropower Electricity grid Electricity demand Biomass CHP plant Electric boiler Heat pump FUEL Oil Boilers District-heating network District-heating demand Heat supplier Hot-water storage HEAT Dag Henning Optensys ENERGIANALYS

42 Issues for a local utility that can be analysed with MODEST Which kind and how large CHP plant should be built? What is the benefit of connecting separate district-heating networks? Which CO 2 emissions are caused by a solution? What is the marginal cost for heat and electricity supply at various occasions? Which impact has energy prices and policy instruments on investments and operations? Dag Henning Optensys ENERGIANALYS

43 District heating production in Linköping GWh värme heat Månad Month Elpanna Electric boiler Oil Olja Fat Fett Oil CHP Olja KV Kol, gummi, trä KV Coal, rubber, wood CHP Wood, Trä, plast plastic KVCHP Avfall Waste MODEST optimisation result

44 Marginal cost for district heating production SEK/MWh Manual method MODEST method Martes method Actual tariff (excl VAT) 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec -100 Linköping Sjödin Henning 2004

45 Possible district-heating supply in a Swedish town during a year Cold winter days Duration curve for district-heating demand winter spring & autumn summer MODEST optimisation result Örnsköldsvik

46 Possibilities to increase heat demand Värmebehov and utilisation time for CHP production Oil-fired boilers Combined Heat and Power plant Steam supply to industry Absorption cooling Waste heat from industries & Heat supply to industries vinter winter spring vår och & höst autumn sommar summer

47 GWh/year GWh/år Long-term district-heating Old CHP plant Grundfall supply for a Swedish city Heat pump Old biofuel boiler Oil-fired boilers Electric boilers New biofuel boiler Waste AFA VP KVV HVC Ny gaskombi Nytt kraftvärmeverk Ny hetvattenpanna Elpannor Oljepannor Uppsala MODEST optimisation result Mattias Wuopio

48 Absorption Cooling in CHP systems Old technique with new opportunities

49 Windows of opportunity for AC in Sweden Heat demand The need for cooling is growing Rising electricity prices Possibilities to further electricity production in CHP systems A surplus of heat in summer Electricity production Cooling demand

50 Aim The aim of this study is to analyse the economic and environmental impacts of introducing absorption chillers into a CHP system in a Swedish municipality.

51 Case study Local energy utility owned by one of the largest energy suppliers in Sweden The studied energy utility produces annually 450 GWh of electricity 1090 GWh of district heating 13 GWh of district cooling Future investments plans New CHP plant for mix waste incineration New compression chillers(cc) or new absorptions chillers (AC)

52 System-optimal production of cooling Eu. el prices Future cooling demand ACM GWh Existing system Eu. el prices CC Free cooling 0 Without out ACM With ACM Without out ACM With ACM Without out ACM With AC ACM Scenario 1 Scenario 2 Scenario 3

53 Extra electricity generation when introducing AC Scenario Description Electricity surplus [GWh/year] 1 Existing system European electricity prices European electricity prices and cooling demand 13.4

54 Effects on system cost when introducing AC Thuosand euro/year Scenarios 1 Existing energy system 2 European electricity prices 3 European electricity prices, higher cooling demand

55 Effects on global CO 2 emission when introducing AC tonnes/ye ear Existing energy system 2 European electricity prices 3 European electricity prices, higher cooling demand

56 Modelling of a Swedish Biogas System Ph. D. Student Shahnaz Amiri Department of Management and Engineering, Division of Energy Systems, Linköping University Department of Engineering and Environment, Division of Energy Technology, University of Gävle

57 Objectives The objectives of this study are: to present a model for a biogas system in order to achieve a cost-efficient system, and to analyse the conditions for connecting a combined heat and power (CHP) plant to the biogas system.

58 Biogas System in Linköping, Sweden The material is mixed into homogeneous slurry in a reception tank. After which it is pasteurised for 1 hr at 70 C by heating, in order to kill bacteria After cooling, the material is pumped into a digester to be broken down by different types of micro-organisms in an anaerobic environment at about 38 C. The material remaining after the digestion process is transported back to farmers and used as bio-fertiliser Simplified view of biogas process at the biogas plant (Åby) in Linköping

59 Simplified view of biogas production in Linköping District heating Electricity Gas-boiler Heat Slurry Nykvarn plant Gas External electricity Gas accumulator Sludge Waste Torching Compressor Gas demand District heating Electricity Åby plant Gas LNG Upgrading Biological fertilister External electricity

60 VF CC Sold heat Electricity Heat VV KF External heat Electricity and heat Nykvarn plant GP Gas boiler Gas LNG, gas Sludge PS SL NK MN LN RS Sludge EM Gas F1 Torch External electricity SS Compression External electricity SS WW Upgrading SS R2 OO HT External heat Organic waste AV KF MA EN AB Torch F2 JJ UR HH Gas accumualtor Gumpekulla BG Biological fertilister Åby plant BB Gas demand, buses TA Gas demand, cars Components, as well as material, gas and other energy-carrier flows in the MODEST model of the biogas system in Linköping

61 Biogas production for Present and Base case in Linköping

62 Results: Flow characteristics (U j /U c = 6.50/1.73) End! Stagnation point Horseshoe vortex Thank you! Down-wash vortices Questions / Comments? Up-wash flow Up-wash vortices B