1. HIGH CONCENTRATION PHOTOVOLTAIC
(HCPV) TECHNOLOGY
Making It Work In Kenya
Charlene Maina
MD, Plexus Energy Limited

2. • What is it
• Why talk About it
• Case Study –
current project
• Some analytics

3. Concentrated Photovoltaic (CPV):
Uses optics such as lenses or curved
mirrors to concentrate a large amount
of sunlight onto a small area of solar
photovoltaic (PV) cells to generate
electricity.
High Concentration Photovoltaic
(HCPV):
Systems employ concentrating optics
consisting of dish reflectors or fresnel
lenses that concentrate sunlight to
intensities of 1000 suns or more.

4. • Customer with singular
objective
– Reduction of power bills
• Multiple challenges in
approaching the solution
– MW power required
– Both lighting and Thermal
solutions
– Space Restrictions
– Financial Viability

5. Address the most
pressing concern
- Biggest expense
- Boiler ( heating the
transfer fluid in the
boiler system)

6. Linear Fresnel
Solar Collector

7. THE PRINCIPAL
Flat Mirrors concentrate sunlight on absorber tube
Mirrors track the sun over the day
Heat transfer fluid circulates to transfer energy to
process

8. THE REASONING
– Large temperature range 100 – 400°C
– Easy to integrate (thermal & structural)
– Easy to operate
– Space Economics

9. THE INTEGRATION

11. ATTRACTIVE RETURNS

12. THE MONEY QUESTION

13. CLIENT ANALYTICS

14. EVEN BETTER
• Carbon Credits
– Initial assessment showed that client is in a position
to claim carbon credits based on reduction of
emissions further reducing time to break even point

15. THANK YOU
Contact me: charlene.maina@plexus-energy.co.ke
Telephone: 0754-405-552 or 0754-405-055

17. WHERE CAN YOU USE IT?

18. MULTIPLE USES
Solar process heat
Solar cooling
Solar thermal power generation
Solar desalination
Solar poly-generation

19. Length: modular in steps of 4m
Total width: 7.5m
Aperture width: 5.5m
Height: 4m
Weight: 27 kg/m²
Peak power: 560 W/m²

20. approx. 100 m
approx. 135 m
One collector unit
(approx. 65 x 8 m)
352 m² / 176 kW peak
Collector field layout with 7040 m²
aperture area for a thermal peak power
of 4 MW
Typical industrial roof top layout

21. Facts & Figures
• Heat transfer fluid
– Pressurized water
– Steam
– Thermal oil
• Receiver SCHOTT PTR® 70
– Maximum pressure
up to 120 bar (different versions 40, 60, 120 bar)
– Maximum temperature
up to 380 °C with thermal oil
up to 330 °C with saturated steam or pressurized
water
– Thermal loss per m² of primary reflector
u1 = 0.00043 W/(m²K²) (according to DLR)

22. Advantages I
Thermal Fresnel PTC Fresnel vs. PTC
Peak Power Ground
Area
Ground Area Ground Usage
Factor Ratio
88 kWth 264 m2 458 m2 1,73
176 kWth 528 m2 869 m2 1,65
500 kWth 1.500 m2 2.462 m2 1,64
1.0 MWth 3.000 m2 4.923 m2 1,64
10.0 MWth 30.000 m2 48.574 m2 1,62

23. • Low wind load
• Good weight-spread
• High ground usage factor
• No north-south alignment necessary
• Stationary receiver, no flexible connections
• Concentrated sunlight hits absorber
tube always from below
Rooftop
installation
Industry
Steam
Summary Advantages
• Easy cleaning (flat glass / good access)
• Low water demand for cleaning
• Reliable components (mirror/tube/drives)
Low O&M
• Primary mirrors made of flat glass vs. aluminum
(durability, reflectivity)
• Precise temperature and power control
• Less absorber tube per m² allows high quality
70 mm vacuum absorber tube (industrial standard)
• Remote control and monitoring via
LAN and internet