Division of Energy Systems at Linköping University, SWEDEN Professor Baharm Moshfegh Chairman of Division

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 >400Scientific articles in journals and proceedings of international conferences >100 Master theses Thousands of students have read the division's courses

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.

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.

Energy Systems Energy Systems Interplay, analysis and optimisation of energy supply, use and conservation

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

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 demand Lower CO 2 emissions caused by satisfying energy demand Incomes from electricity and heat sales, which may reduce electricity price

Condensing power plant and Combined Heat and Power plant

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

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

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

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 otherwise might be wasted, e.g. industrial waste heat, municipal waste Cogeneration of electricity, heat, steam and cooling District heating and cooling systems

Absorption vs vapour compression process Electricity grid District cooling Heat Electricity Absorption process District heating CHP plant Fuel Cooling Electricity Electricity grid Compression process Condensed power plant Fuel Absorption process

2 MWh 50 MWh135 MWh 255 MWh 355 MWh Fuel Condensed power plant El grid= 85MWh Condensed power plant+Compressor cooling machine Cooling=100 MWh Compressor process El Et grid=85 MWh Combined heat and power plant+Absorption chiller El District cooling=100MWh Absorption process Heat 143 MWh 87 MWh Fuel CHP plant Absorption vs vapour compression process

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

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

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

Buildings Heat recovery Space heating District heating network Industrial processes Steam Hot water Domestic hot water Heat can be recovered for repeated use at different temperatures in industry and finally for low-temperature space heating.

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

Foundry Load Duration Curve, top 24 hours Demand [ kW ] Time [ hours ] STEP:60 (MIN) DURATION DIAGRAM

Foundry Load Duration Curves Time (months) Demand (MW) Original load curve ”A” ”B”

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

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

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

MODEST an energy system optimisation model Model for 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 50 Swedish district heating systems, regional biofuel supply and use and national electricity supply and conservation

Swedish electricity supply and conservation Business

Electricity supply without and with electricity conservation MODEST optimisation result

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

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

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

CO 2 emissions due to Swedish electricity demand Seltv 69,91 Without electricity conservation With electricity conservation Sweden Mton/year

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

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

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

Heat market

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

Research Competence Basis Energy 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

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 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 Continued

Concluding benefits of energy systems analysis Systems analysis can consider interplay among energy supply, use and conservation and improves understanding of complex energy systems An optimisation model can consider many parameters that influence energy supply: Energy prices Environmental impact Time fluctuations and presents the best system design and operation considering present and possible plants, available resources etc.

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

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

Annual energy demand Totally 8020 kWh/annually

Monitored annual energy demand, Lindås

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

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

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 Active techniques Exhaust air heat pump Ground source heat pump Solar heating and PV Fuel cells Small-scale CHP using biomass

Some data

CO 2 -emissions

Embodied and operational energy