A combined heat and power solar concentrating collector Joe Coventry Centre for Sustainable Energy Systems Australian National University

The CHAPS collector  Combined Heat And Power Solar Collector  Generation of DC electricity AND Generation of hot water  Applications: DHW, HHW and electricity Commercial buildings Light industrial buildings Residential colleges (eg. Bruce Hall 300m 2 system)

CHAPS system components  CHAPS troughs 24 m long x 1.6 m wide rows 37x geometric concentration ratio Modular system  Solar cells 20% efficient under 30suns and 25°C Low series resistance Manufactured at ANU

CHAPS system components Receivers Aluminium extrusion Series connected solar cells Finned fluid conduit Glasswool insulation Anti-freeze, anti-corrosive heat transfer fluid Assembled at ANU  Mirrors Glass-on-metal laminate mirrors Silver backed mirror Stamped tab ribs Manufactured at ANU

Efficiency tests  Measured on a custom built outdoor test rig at ANU with: 1.25 m wide trough 27 solar cell receiver Steady state conditions Maximum power point electrical load Range of input temperatures Constant low flow conditions  Efficiency results include: Losses due to receiver shading Losses due to hydraulic connections

Efficiency Results

Flux profile across a cell  Illumination profile measured using videographic flux mapping techniques Peaks exceeding 100 suns Significant temperature variation across cells

Cells & Modules – testing  Range of cell and module tests UV testing High temperature testing Humidity testing Thermal cycling On sun!  Challenges Differential expansion Corrosion Water ingress

Receiver design  Domestic system Mechanical bond Adhesives Intermetalic bond Electroplating  Commercial system Closed circuit

Attaching the cells  Thermal tape  Alumina based substrates  Anodising  Plasma coating

Interconnections  Tabs  Tab connections Braid Shim Spot welding

Optical system  GOML mirror  Low iron glass  Silicone  Textured cells

Conclusions  Significant work on reliability, longevity  CHAPS systems beginning to be commercialised