TECHNOLOGIES AND PERSPECTIVES OF

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1 Energy TECHNOLOGIES AND PERSPECTIVES OF LARGE SOLAR THERMAL SYSTEMS Gerhard Stryi-Hipp Group Leader, Fraunhofer Institute for Solar Energy Systems ISE President, European Technology Platform on Renewable Heating & Cooling Lisboa, Portugal, 23 October

2 Fraunhofer Institute for Solar Energy Systems ISE Applied research on Renewable Energies since 1981 Largest Solar Research Institute in Europe 1100 employees incl. 300 PhD and diploma students Director: Prof. Eicke R. Weber Part of the Fraunhofer Society with 60 institutes and employees, largest applied research network Energy Efficient Buildings Applied Optics, Functional Surfaces Solar Thermal Technology Silicon Photovoltaics Alternative PV Technologies Renewable Power Supply Hydrogen Technology

3 Relevance of the Heating and Cooling Market Heating & cooling has the largest share on final energy demand Oil and natural gas price is growing continuously Dependency on fossil fuels import is growing In future, energy policy must focus equally on electricity, transport AND heating & cooling Final energy EU 27 Heating without heat by electricity 42% 41,2 Solid Fuels 82,6 Electricity 25% Transport 33% 60,3 53,1 Oil Gas All Fuels Oil price development Import Production Energy import of EU 27 in 2007

4 Demand and Potential of Solar Process Heat 20 % of the final energy consumption in Europe is industrial process heat; this is 44 % of the heat demand. A significant share can be provided at temperatures below 150 C (e.g. 27 % in Germany [1]). Huge potential Germany ca. 16 TWh/a (3,1 % of industrial heat demand) [1] EU 27 ca. 111 TWh/a = 250 Mio. m 2 [2] (overall installed collector area in Europe in 2010: ca. 51 Mio. m 2 [3]) above 250 C 69 % C 4 % C 6 % below 100 C 21 % Industrial heat demand per temperature range (Germany) [1] [1] C. Lauterbach et al., 2011: Potential Sol. Prozessw. in Deutschl. Kassel University [2] C. Vannoni et al., 2008: Potential for Solar Process Heat in Ind. Processes, CIEMAT [3] W. Weiss et al., 2012: Solar Heat Worldwide Report AEE INTEC

5 Important Part of the Solution: RHC-Technologies RHC = Renewable Heating and Cooling Heating & cooling demand can be reduced significantly and satisfied increasingly by RHC. Until 2040 we can reach 100% RES for heating & cooling Heating and cooling demand and RHC-potential in EU 27 Benefits of RHC-technologies Mitigation of climate change Reducing import dependencies High security of supply Protection against oil price increase (social aspects) Local added value, creating jobs Heating & cooling demand (RDP-Scenario) Renewable heating & cooling potential Source: EHC-platform, Common vision for the RHC-sector, 2011 RDP-Scenario = Full Research, development and policy scenario

6 Solar Thermal Energy - Characteristics MARKET 2010 (EU-27 + Switzerland) Newly Installed: 3.7 Mio m 2 / 2.6 GW th Total installed: 34 Mio m 2 / 24 GW th Heat produced: 1.5 Mtoe / 17 TWh CHARACTERISTICS Solar radiation: for free and everywhere Daily and seasonal solar variation Storage and auxiliary heating source needed CHALLENGES Increase the solar fraction per building From hot water to Solar-Active-Houses Enlarge the type of applications Large systems, district heating, process heat, higher temperature, solar assisted cooling Reduction of costs APPLICATIONS Domestic hot water & space heating One/two/multi family homes Hotels, hospitals, residential homes, District heating systems Multifunctional façades PV-Thermal (PV-T) hybrid collectors Process heat Low up to 100 C Medium up to 250 C Solar assisted cooling and refrigeration

7 Solar Thermal Energy: Underestimated Source of Power Source: IEA-SHC Solar Heat Worldwide, Edition 2012,

8 Solar Thermal World Market largest markets Installed capacity in Japan 2010 Unglazed: 0 MWth (0 m 2 ) ETC: 3.4 MWth (4,794 m 2 ) FPC: MWth (158,716 m 2 ) Total: MWth (163,510 m 2 ) Evacuated tube collector Flat plate collector Source: IEA SHC, Solar Heat Worldwide, Edition 2012

9 Solar Domestic Hot Water System forced circulation Solar radiation Hot drinking water outlet Typical system in Germany (4 person household): Forced circulation 5-6 m² collector area 300 liter storage tank Glazed solar collector Flat plate collector or Evacuated tube collector Pumped solar circuit - Anti freeze heat transfer fluid - Controller - Pump - Safety (pressure) valves Solar heat store with two heat exchangers Cold drinking water inlet Auxiliary heating via natural gas, oil, wood, district heating, electricity,

10 Thermosiphon Solar Domestic Hot Water Systems are mainly used in southern countries Typical system for Southern Europe: Thermosiphon system 2-4 m² collector area liter storage tank Natural circulation Natural convection: The solar heat expands the heat transfer fluid, becomes lighter and rises to the storage tank above. Source: Schueco

11 Typical Solar Thermal Combi-System for domestic hot water and space heating Typical system in Germany: m² collector area liter storage tank % solar fraction Main store contains heating water (buffer) Domestic hot water tank contains drinking water Space heating circuit (water system) Combi-store

12 Typical Large Solar Thermal Systems Collector Loop freeze protected Solar Heat Store buffer water Domestic Hot Water supply Collector inlet temperature must be as low as possible (store stratification!) -> high collector efficiency Charge and discharge devices and strategy must lead to a good temperature stratification Cold water supply must cool down the bottom of the buffer store via heat exchanger for a high solar collector efficiency

13 Structure Solar Thermal is part of the European Technology Platform on Renewable Heating & Cooling RHC-Platform is supported by the European Commission

14 Solar Thermal Technology Platform Support of technological development in Europe and Germany Objective: accelerate the technological development Politicians Solar Thermal Vision 2030 Role of solar thermal energy in 2030, which technologies will be used? Researcher Solar Thermal Research Agenda published: Industry Strategic Research Agenda Which R&D is necessary to let the vision become reality? Implementation Stimulation of new R&D programs, political advice, lobbying,

15 Solar Thermal Vision 2030 of the Solar Thermal Technology Panel of the European Technology Platform on RHC New buildings: Active Solar House 100% solar heated buildings will be the building standard Existing building stock: Solar Refurbishment Solar refurbished buildings will be the most cost effective way to refurbish the building stock (solar fraction > 50%) Source: Solifer Source: Schüco Industrial + Agricultural Solar Applications Solar thermal systems will cover process heating and cooling demands Solar district heating and cooling networks will be widely solar assisted Overall goal: ca. 50% of the low temperature needs (up to 250 C) will be provided by solar thermal Source: Solvis

16 Large Solar Thermal Systems For multi family homes, hotels, hospitals, nursing homes Crucial: management of the different heat sources Image: Solvis Image: Wagner & Co

17 Source: Viessmann Source: Fraunhofer ISE Promising Technology Solar Assisted Cooling (Solar) thermally driven cooling machines Cooling demand and solar supply patterns match well There are already more than 400 pilot systems installed in Europe Small systems are under development Adsorption cooling machine Building: Governmental Press Office Berlin Building: IHK Freiburg

18 Solites Solites Promising Application Solar District Heating - will play a big role in the future Semi-detached houses in Neckarsulm, Germany Solar District Heating, Marstal, Denmark collector area 17,000 m² Arcon 12,000 m³ seasonal storage, Friedrichshafen, Germany

19 Current Status and Barriers for Market Deployment of Solar Thermal Process Heat Systems Current Status Only a few hundred systems installed worldwide Remarkable growth rates e.g. in India Deployment is promising but challenging Barriers High financial expectations (payback < 5 years required) Priority of energy efficiency measures Source: Sotec Solar, Germany Complex system integration, high planning effort, lack of planning tools and standardized solar thermal system designs, missing links between industrial process planners, energy consultants and solar companies

20 Solar Heat Integration: Process- or Supply Level? Solar heat can be integrated into the heat distribution network (steam or hot water) or into the different processes Supply level Make-up water 20 C Boiler house Process steam 140 C, 4 bar Condensate return 90 C Process level Process 1 50 C Process 2 80 C Process C

21 Supply Level All processes connected to heat network can be supported: make-up water pre-heating return flow boost or direct steam generation (not shown in picture)

22 Process Level Often lower temperatures than supply level => higher solar gains possible Examples: Heating of cleaning or process water, heating of galvanic baths, heating of drying air High dependency on changes in the process

23 Suitable Processes Pre-heating of raw materials Cleaning and washing Pasteurization, sterilization Surface treatment Drying Boiler feed water Supply of hot water or steam Source: Uni Kassel

24 Process Heat Collector Development for working temperatures from 80 C to 150 C Objectives Decrease specific heat losses by: Second transparent cover Application of external reflectors (concentration) Highly efficient at temperatures between 80 and 150 C Avoid tracking (stationary) Low costs and efficient use of roof area Visualisation of the RefleC-concept

25 Pilot Plant: Laundry Laguna, Marburg Impressions of laundry processes (left) and the steam boiler (right)

26 Collector Field Reference flat-plate collectors (glass-foil, front) and newly developed RefleC-collectors (back) Fluid connection collector field View into the RefleC-trough from the east

27 Innovative Solar Thermal System Increased temperatures for solar loop and storage Support of the steam network (feed-water and make-up water) Monitoring and system optimization, variation of control concepts Planning / Monitoring: Wagner & Co. Fraunhofer ISE 2010 RefleC 2 x 20.3 m² Glass-foil flatplate collector 16.2 m² T max = 130 C p sys = 6 bar Air heat exchanger 1000 l storage 120 C 3 bar Primary 2x1000l stora 110 ge C 3 bar Secondary 300l 80 C Feed water 90 C C 4.5 m³ / d Additional make-up water 20 C - 90 C 3.5 m³ / d Soft water washing machines 20 C - 80 C 1m³ / d Simplified system concept of the pilot plant

28 a) Heating of water for washing or cleaning Exemplary system concept for pre-heating of water

29 b) System concept: heating of make-up water feed water 90 C Exemplary system concept for pre-heating the make-up water of a steam process High solar gains because of low temperature level System concept very similar to conventional systems Only applicable for (partly) open steam networks Heat recovery has to be analyzed and can increase available temperature

30 c) Heating of baths and vessels Exemplary system concept for the solar heating of an industrial (galvanic) bath. Direct heating of the bath possible by bypassing the storage. The electrical heater is used for temperature control. Closed process: Economics highly depend on the bath temperature Heat recovery from baths with higher temperatures checked? Regular refill favorable Small buffer storage volume possible (bath can act as a storage)

31 d) Convective drying with hot air Exemplary system concept of an open drying process. The open air collector system is serially supported by a boiler (solar fan left, conventional fan right) No storage necessary Continuous heat demand favorable Efficiency of air collectors decreases with decreasing mass flow

32 Brewery Hofmühl, Eichstätt Private brewery, founded in1492 Beer production of m 3 /year, 2/3 of that within summer Implementation of a energy saving brewing process (savings up to 60%) Primary energy demand for heat generation: 2,2 GWh/year (Oil) Solar thermal system: 736 m 2 vacuum-tube collectors 2 x 55 m 3 buffer storage Brewing water pre-heating, bottle washing and heating of production site Source: M. Wutzler, TU Chemnitz - Planning / Installation: Solarbayer Stainless steel storages outside Insulation 500 mm mineral wool Serially connected

33 Brewery and malt house Lammsbräu, Neumarkt Pre-heating of ambient air for drying of malt (up to 60 C) 72 m 2 air collectors, no storage, low temperature level Planning / Installation: Grammer Solar, 2000 Quelle: R. Ettl, Grammer Solar

34 Design Guidelines Results of the EU project SO-PRO Solar heating concepts for specific industrial applications and sectors: heating of make-up water washing and cleaning heating of baths / vessels solar drying Promotion of best practise approaches Training of professionals on national and international level More Information: So-Pro Design Guide for four specific industrial applications

35 Process Heat Collector Testing For serious planning the process heat collectors must be characterized. Fraunhofer ISE TestLab Solar Thermal Systems offers Process heat collector tests up to 200 C and 20 bar Air collector test stand Hailstone testing System test facility Quality labelling of solar thermal collectors (Solar Keymark, SRCC Fig.: Thermal efficiency curve determination of the RefleC collector at Fraunhofer ISE

36 Conclusions Solar thermal energy can cover up to 50% of the overall energy demand for heating and cooling in Germany and Europe The potential for solar thermal process heat is very high especially in south European countries There are several barriers to overcome to deploy solar thermal process heat systems - identification of attractive applications - standardization of system technologies - know-how transfer and capacity building on designing, planning, installing, operating and monitoring of solar process heat systems Source: Industrial Solar Source: Pro Solar Source: Genersys

37 Thank you very much for your attention!