Technical Requirements for Building Integrated Photovoltaic Systems Dipl.Ing. Udo Siegfriedt , Paris

Transcription

1 Technical Requirements for Building Integrated Photovoltaic Systems Dipl.Ing. Udo Siegfriedt , Paris

2 Content Introduction Building related mounting methods for PV systems Safety Summary Building Integrated Photovoltaic Systems Page 2

3 Introduction DGS Germanys first non profit association aiming a renewable and environmental friendly energy supply. Founded in1975 Aims: to foster the usage of renewable energies and energy efficiency to establish a sustainable energy supply by means of information, education and political influence Approx members incl. 350 companies National agency of International Solar Energy Society (ISES) Magazine SONNENENERGIE, four times per year Weekly Newsletter Building Integrated Photovoltaic Systems Page 3

4 Expert Services Technical Due Diligence Plant acceptances Technical consulting Expert opinions for courts and insurances Yield studies Internal consumption calculations for the industry Review of operation data / resimulation Short term Performance Ratio acceptance tests Reflection and shading analysis DGS Manual Planning and Installing Photovoltaic Systems Building Integrated Photovoltaic Systems Page 4

5 SolarSchool Training courses for engineers, architects and craftsmen since 1996 more than participants VDE/DGS Fachkraft Photovoltaik Solar(fach)berater Photovoltaik One day courses: i.e. simulation, off-grid systems, marketing Courses on Renewables world wide Development and coordination of a country wide network of DGS SolarSchools Building Integrated Photovoltaic Systems Page 5

6 PV vs. Nuclear Power Building Integrated Photovoltaic Systems Page 6

7 Levilized cost of electricity in Germany Building Integrated Photovoltaic Systems Page 7

8 Global Horizontal Irradiation, France vs. Germany Building Integrated Photovoltaic Systems Page 8

9 Normal building views in the near future Building Integrated Photovoltaic Systems Page 9

10 Building related mounting methods for PV For roof mounted PV installations a distinction is made between normal on-roof systems and integrated systems PV for facades or as shading are mostly considered as integrated systems Source: DGS-Berlin Building Integrated Photovoltaic Systems Page 10

11 Technical requirements Grid Codes Structural design Fire safety Lightning protection Electrical safety Building Integrated Photovoltaic Systems Page 11

12 On-Roof System vs. Roof-Integrated System Source: DGS-Berlin Visual differences sometimes neglectable, especially for high roof filling factors In the end, there are most often no real benefits through roof-integrated systems Source: DGS-Berlin Building Integrated Photovoltaic Systems Page 12

13 PV integrated in facades Usually unused areas can produce energy Additional benefits as shading Visible! Interesting from an architectural point of view Source: DGS-Berlin Source: DGS-Berlin Building Integrated Photovoltaic Systems Page 13

14 Roof integration of PV: pros and cons Pros Homogeneous optical appearance Replacement of normal roof cladding (costs savings) No time shift in aging of roof cladding and PV system Only module surface is exposed directly to environmentally conditions as sun, rain, wind Cons Special modules and/or special mounting structure (cost increase) Replacement in case of malfunctions can be a problem if module type is not produced any more Higher safety requirements for both modules and installation Building Integrated Photovoltaic Systems Page 14

15 True and false roof integration False integration Water bearing layer below the modules Water tightness is provided by an additional layer True integration Modules are the water bearing layer Water tightness is provided by modules Water Water Source: DGS-Berlin Building Integrated Photovoltaic Systems Page 15

16 True and false roof integration False integration: Most often use of standard modules Additional layer must be fire retardant, but not necessarily the modules Cabling is not inside the building but between modules and the additional layer Low fire risk similar to on roof systems True integration: Most often use of special modules Modules must be fire retardant Cabling is inside the building, most often close to inflammable material Increased fire risk, therefore higher demands on installation quality Building Integrated Photovoltaic Systems Page 16

17 Alternating Current / Direct Current Voltage Current (with phase shift) Sine curve of voltage and current Periodic crossing of the origin Arcs (due to switching) are quenched at the next origin crossing Possibly phase shift between voltage and current Voltage Current No crossing of the origin Arcs will not quench automatically High risk of fire due to arcing Source: DGS-Berlin Building Integrated Photovoltaic Systems Page 17

18 Cabling requirements Earth and short circuit safe installation Use of suitable cable (solar cable with type designation H1Z2Z2-K) Avoid sharp edges to protect cable isolation Consider bending radius Only one type of suitable plugs, no third party manufacturer Protection of the cable against unnecessary impacts (animal bites, heat, humidity ) Cabling is most often not assessable for maintenance In case of failure messages of an isolation measurement (implemented in most inverters) an immediate repair must be carried out Building Integrated Photovoltaic Systems Page 18

19 Fire Prevention / Fire Fighting Main protection goals No touchable hazardous DC-voltage inside a building in case of fire Safe fire fighting and rescue of people Building Integrated Photovoltaic Systems Page 19

20 Measures to reach the given protective goal Organizational measures Information sign located at the house connection box or the main distribution board General plan for fire fighters Supplements to existing ground plan for fire brigade use Structural measures Fire resistant laying of DC cables DC cables outside the building Inverter mounted outside or at the outer wall Technical measures Remote DC isolator (fire switch) (Module integrated isolator) (Protective extra low voltage) Building Integrated Photovoltaic Systems Page 20

21 Structural and technical measures DC disconnector (fire brigade switch, module orientated solutions as optimizers) Fire safe cable laying (conduits, cable trays out or reach) Components outside the building Extra low voltage (A.Häring, SMA) Fire resistant conduit Adolf Würth GmbH & Co. KG Building Integrated Photovoltaic Systems Page 21

22 Typical problems of the possible measures Fire brigade switch: safe behaviour for expected life-time questionable, activation for firefighters not traceable Module orientated solutions: expensive, therefore only reasonable if other benefits are requested (reduction of shading losses) Fire safe cable laying: depends on the respective installation, often the best solution Components outside: sometimes not possible especially for integrated PV Extra low voltage: no longer common due to increased cable losses and more complex installation Not recommended! If suitable If suitable If suitable Not suitable Building Integrated Photovoltaic Systems Page 22

23 Another important topic: shading effects Shading cannot be avoided in total especially for building related PV systems Yield losses can be reduced with intelligent layout and with technical solutions Especially in facades shading can be a very complex problem Building Integrated Photovoltaic Systems Page 23

24 Conclusion The number of PV systems in France will increase significantly in the next few years Beside open space and on-roof systems, many systems will be building-integrated Safe operation of a PV system requires high component quality, proper planning, professional installation and qualified operation and maintenance For on-roof systems a fire safe installation is easier as most often the roof cladding is performed as hard top roof Integrated PV uses the same safety measures, but at an even higher quality level Fire safety is one of the most important topics for building related PV-systems Building Integrated Photovoltaic Systems Page 24

25 Thank you for your attention German Society for Solar Energy (DGS-Berlin) Udo Siegfriedt Sonnenenergie-eV / (Schweizer AG) Building Integrated Photovoltaic Systems Page 25