Hicon PV Project: Developing Advanced High Concentration Photovoltaic Power Systems

1. Hicon PV Project Overview

2. 1. The Hicon PV Project Project Name: High Concentration Photovoltaic Power System Project Acronym: Hicon PV Contract Number: SES6-CT-2003-502626 Total budget: 4.899.616 €. EC contribution: 2.699.924 € Project duration: 36 months. Start date: 01/01/2004. End date:31/12/2006

3. 2. The Consortium 9 Partners:

4. 3. Aim of the Project Develop, set up and test a new high concentration (1000x) PV system with a large-area III-V receiver. …by integrating two technology fields: • The high concentration of the sunlight will be obtained using technologies experienced in solar thermal systems like parabolic dishes or tower systems. • The receiver is based on the III-V solar cell technology.

5. 4. Project Objectives • Develop, set up and test a new high concentration PV system with a large-area III-V-receiver (1000x) • Single-junction GaAssolar cells for highly concentrating applications • Reach 20% efficiency for the full MIM (Monolithic Integrated Module) • 3 Compact Concentrator Modules (CCM) as prototypes for field-testing, each around 2 kWp from a module area of about 100 cm² • High-efficient concentrating photovoltaic system cost goal of 1 €/Wp by 2015 • Cost goal for the concentrator is 100 €/m2 • Cost goal: 200’000 €/m2 for solar modules including heat sink, taking into account the future improvements with multi-junction cells

6. 5. The receiver III–V solar cell concept • Silicon Cells: • Restricted to a concentration factor of less than 500x and to a module efficiencies of about 20% • III-V GaAs Cells: • Allow higher concentration ratios and much higher efficiencies • Traditionally used in space applications

7. 1 cm2 chip 1 cm 3.9 cm2 MIM chip 1.6 cm 2.4 cm The monolithic interconnected modules (MIMs) • Very high current densities under 1000x concentrated sunlight • 28 A / cm2  2800 A on 10 x10 cm2 • Small solar cells required to reduce current • Large chips are required for the interconnection in CCM • Solution: MIMs

8. The compact concentrator module (CCM) • Assembly • MIMs mounted on: • - ceramic strips • - directly on ceramic heat sink • Water cooling system • Highly silver loaded adhesive • 24 MIMs in 6 rows • C = 1000X • VOC 120 V per row  up to 720 V per receiver

9. The compact concentrator module (CCM) Performance • MIMs • Average efficiency:18.3 %@ C=1000 • Complete Receiver • Projected efficiencyC = 1000, T=25°Ch = 16.0 %

10. 6. The concentrator Two options: • Solar tower systems - Problems with the cosine effect factor and with flux variability during the year - Spillage losses • Parabolic dishes - Stable flux during year but problems with flux gradients • Solution - Spherical dish with flux homogenizer

11. Flux Distribution Spherical Dish with homogeneizer Parabolic Dish

12. Construction of the prototype

13. The prototype

14. 7. Tests. PSA solar furnace Results • MIMs characterization tests

15. 7. Tests. PSA solar furnace Results • CCM characterization tests

16. 8. The Concentrator. Last steps in the project. 1. Flux Measurement(From December) • Flux characterization in the receiver with the flux former • Flux characterization with shadowing of mirrors

17. The Tailored Concentrator + CCM 2. Concentrator and Receiver Integration

18. The Hicon PV Concentrator. Further Improvements • CCM: • After second CCM design, with single junction MIMs… Further options: • Reducing series resistance losses • Reducing the width of the grid fingers and bus bars • Reducing or sacrificing the bypass diode • Development of a frameless heat sink and a mounting procedure with narrow gaps • Next generation MIM CCM, with tandem MIMs… better efficiency at lower currents

19. The Hicon PV Concentrator. Further Improvements • Concentrator From hexagonal and small mirrors To Square and big mirrors

20. The Hicon PV Concentrator. Further Improvements • Concentrator • From glass to plastic30€/m2 • To the 120m2 heliostat concept