Division of Energy Systems

1. Division of Energy Systemsat Linköping University, SWEDENProfessor Baharm MoshfeghChairmanof Division

2. Division of Energy Systems • Established in 1980 • Belong to the Department of Management and Engineering • 25 Employees • 16 Active PhD students are registered today • 55 Academic theses • >400 Scientific articles in journals and proceedings of international conferences • >100 Master theses • Thousands of students have read the division's courses

3. Definition of Energy 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.

4. 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.

5. Energy SystemsInterplay, analysis and optimisation of energy supply, use and conservation

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

7. Enhanced coal utilisation • Increasing energy demand makes coal more valuable. • Better coal use 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 demandLower CO2 emissions caused by satisfying energy demandIncomes from electricity and heat sales, which may reduce electricity price

8. Condensing power plantandCombinedHeatandPowerplant

9. CombinedHeatandPowerplant Electricity CHP plant Absorption process Domestic hot water District heating Space cooling District cooling Space heating Process cooling for industry Steam for industry

10. 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

11. District heating supply Electricity market Electricity grid Gas CHP Heat pump Combined heat andpower production Waste CHP DH network Heat demand Wood Heat-only boilers Oil Industrial waste heat DH system in Göteborg (Gothenburg)

12. District heating and cooling systems • Networks for hot and cold water are builtfrom 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 ofelectricity, heat, steam and cooling

13. Absorption vsvapour compression process Compression process Electricity grid Condensed power plant Compression process Fuel Cooling Electricity Absorption process Electricity grid Electricity CHP plant Fuel Heat Absorption process District cooling District heating

14. Condensed power plant Compressor process Cooling=100 MWh Fuel El El CHP plant Fuel Heat Absorption process District cooling=100MWh Absorption vsvapour compression process Condensed power plant+Compressor cooling machine El grid= 85MWh 355 MWh 135 MWh 50 MWh Combined heat and power plant+Absorption chiller Et grid=85 MWh 87 MWh 255 MWh 2 MWh 143 MWh

15. Absorption cooling – Heat driven cooling • Efficiency • Absorption cooling machine 0.7 • Compressor cooling machine 3-4

16. Boiler Steam turbine Generator Fuel Electricity Condenser District heating system District cooling system Pump CHP system that generates district heating and cooling as well as electricity

17. K Komp SV Boiler Steam turbine Generator F Fuel Electricity Condenser Avgivet värme Pump Condensed power plant+heat pump is it a good idea! 100 kWh 33,3 kWh 100 kWh 33,3 kWh

18. Heat recovery Heat can be recoveredfor repeated useat different temperaturesin industryand finally forlow-temperaturespace heating. Industrial processes Steam Hot water District heating network Buildings Space heating Domestic hot water

19. Influencing demand • Energy conservation • reduces energy demand • Load management reduces capacity demand • Energy carrier switching e g from electricity to fuel or district heating

20. Demand [ kW ] 9250 9000 8750 8500 8250 8000 6 12 18 24 Time [ hours ] Foundry Load Duration Curve, top 24 hours STEP: 60 (MIN) DURATION DIAGRAM

21. Foundry Load Duration Curves 10 Original load curve ”A” 8 ”B” 6 Demand (MW) 4 2 1 2 3 4 5 6 7 8 9 10 11 12 Time (months)

22. Demand-side measures Energy conservation Electricity supply Electricity demand Load management Energy carrier switching

23. 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.

24. 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 demandWhich combinations of energy sources, conversion plants and energy conservation measures are most beneficial? Energy demand Energy supply Energy conservation

25. MODESTan energy system optimisation modelModel for Optimisation ofDynamic Energy Systems withTime dependent componentsand boundary conditions • MODEST calculates how energy demandshould be satisfied at lowest possible cost. • MODEST can handle many kinds of energysources, forms, plants and demand • MODEST has been used for50 Swedish district heating systems,regional biofuel supply and use andnational electricity supply and conservation

26. Swedish electricity supply and conservation Business

27. Electricity supply without and with electricity conservation MODEST optimisation result

28. Swedish electricity supply during one year Weekday spring autumn daytime Condensing power Weekday summer daytime Marginal cost Weekday winter daytime Nights and weekends Hydro Hydro CHP CHP Wind power CHP Nuclear Kärnkraft of which is export h/year h/år seltv69

29. Electricity supply and conservation in Sweden during one year Condensing power Weekday spring autumn daytime Weekday summer daytime Nights and weekends Weekday winter daytime Electricity supply Hydro Wind power CHP CHP Nuclear of which is export Energy conservation Energy carrier switching Effektivisering Demand-side measures - Megawatts Elhushållning h/year

30. Supply curve for Swedish electricity Marginal cost Gas turbines Condensing power CHP Average marginal cost Demand now, after conservation Nuclear Hydro Wind power Waste-fired CHP TWh/year

31. CO2 emissions due toSwedish electricity demand Mton/year Sweden Sweden Without electricity conservation With electricity conservation Seltv 69,91

32. Assemblies of energy systems between the energy companies and industries give big financial and environmental benefits RESO Regional Energy System Optimatization

33. Project idea RESO is a project that examines and highlights the conditions forRegional cooperation between different actors by creating a common HEAT MARKET where several businesses can buy and sell heat.

34. RESO, Studied region Heat demand aprox.7 TWh/year

35. Heat market

36. Solution with the highest saving compared to BAU • 240 MSEK/year cost reduction which can be used for investment for measures • Process integration (Skutskär och Korsnäs) • New CHP plant (KEAB) • Increasing the heating market (Sandvik) • District heating will be increased by 600 GWh/year • Electricity production will be increased by 1150 GWh/year

37. Research Competence BasisEnergy Systems, Linköping university • Customer energy systems analysis • Reducing energy costs • Energy efficiency measures • Analyzing temporal patterns • Customer solutions • Communicated load management • Demand Side Management in a Systems Perspective • The proactive End User • Local, regional (and larger) energy systems analysis • CHP, bio-fuels, cooperation between manufacturing industry and energy suppliers

38. Continued • Influence of Deregulated Energy Markets on Demand Side Management and Local Generation • Local Distribution, Generation and End Use • Business Perspectives • Customer Behavior in a ”small scale” system • Communication Perspectives • Environmental Perspectives • Requirements for IT solutions

39. Continued • System related issues: • Energy users as alternative energy suppliers through their own generation capacity or through their capability to reduce energy demand • Competition between generation and energy end use measures • IT solutions for communication of the energy end use measures and their availability in parallel with the supply measures

40. Concluding benefits ofenergy systems analysis • Systems analysis can considerinterplay among energy supply, use and conservation andimproves understandingof complex energy systems • An optimisation model can consider many parameters that influence energy supply:Energy prices Environmental impact Time fluctuationsand presents the best system design and operation considering present and possible plants,available resources etc.

41. Dimensions of Energy Systems • Energy systems can be treated from different aspects or crossing points • User • Knowledge, norms, behavior etc • Formal and informal regulations • Policy and economy • Actors, driving forces, taxes etc • Technical conditions

42. Study of 20 low-energy houses in Sweden • Well insulated construction • Energy efficient windows • Passive solar architecture • Air-to-air heat exchanger (integrated heater) • Solar heating for DHW • Mechanical ventilation system

44. Annual energy demand Totally 8020 kWh/annually

45. Monitored annual energy demand , Lindås

46. Energy demand and indoor climate in low-energy buildings • The building sector stands for about 40% of the energy demand in the world • People spend more than 80% of their time inside buildings • Indoor climate and the energy issue are essential issues for achieving sustainability

47. Definition of low-energy buildings • Low-energy building is “a building that is built according to a design criteria aimed at minimizing the operating energy” • Passive buildings – a kind of low-energy building using mainly passive techniques • Plus energy buildings – a low-energy building using solar energy by means of both passive and active technologies and supply electricity to the grid • Yesterdays low-energy buildings are today's energy-efficient buildings

48. Activetechniques Passive techniques • Well-insulated envelope • Minimized amounts of thermal bridges • Airtight construction • Energy efficient windows (3- or 4-panes) • Air-to-air heat exchanger, • Heat exchange of waste water by heat pump and heat exchanger • Passive solar gains • Thermal mass • Pre-heating of ventilation air by buried pipes • Exhaust air heat pump • Ground source heat pump • Solar heating and PV • Fuel cells • Small-scale CHP using biomass

49. Some data

50. CO2-emissions