RELINK explains why PV micro inverters are 2 times better than string inverters

1. Benefits of PV micro
inverter systems
Vins di Gennaro

2. 2
RELINK - the company
✓ Founded 2013 in Malta to develop an innovative range of Energy
Storage systems combined with Micro Inverters co-developed
with a primary technology provider of PV conversion.
✓ RELINK relies on the wide and strong skills of its founders in the
Energy and Renewables segments, in photovoltaic since 2007.
✓ RELINK has offices in:
✓ Malta
✓ Germany
✓ Melbourne foreseen in 2016

3. 3
RELINK - micro inverter technology
✓ The unique RELINK technology has been developed with a
partnership with a world leader of Energy Conversion and
the former R&D manager of a PV inverter leader.
✓ The RELINK micro inverters optimize the energy output of
a PV module converting in the most efficient way the DC
power in AC power available to the electric grid.
✓ The RELINK micro inverters offer an impressive value
proposition for the PV systems.

4. 4
RELINK - a complete system
Gateway
Monitoring
Micro Inverter

5. 5
RELINK - microinverter benefits
✓ Longer life time and reliability
o eliminates components that represent main reason of
failure getting a life time of 25 years.
✓ The best output power
o Optimizes power for each module / stable over wide
temperature range.
✓ Increased safety
o Low voltage AC current, no high DC voltages, significant
reduction of fire hazard
✓ Simplified design and installation
o Easy design due to independence of each/couple of
modules, minumum shade impact. No DC cables.
✓ Advanced monitoring systems
o Accessible via Web, smart phone and tablet.
RELINK
Converts each module
MAXIMUM ENERGY

6. 6
String vs. Micro inverter
When PV modules is shaded, with string
inverter, each module connected in
series, domino effect reduces ower
output of entire PV system.
RELINK micro inverters, with
modules connected in parallel,
eliminate the domino effect,
provide maximum power output.
The problem The Solution

7. 7
String inverter layout
PV strings - DC side Inverter - AC side

8. 8
Micro inverter layout
1 or 2 PV modules - DC side Micro Inverter - AC side

9. 9
RELINK - the best convertion system
Components with limited reliability, short life used in string inverters:
✓ Electrolytic Capacitors and opto-isolators.
o the best electrolytic capacitors have an operational duration of about
7.000 hours @ 105°C.
✓ String inverter expeted life time 8 to 10 years.
The RELINK technology has superior performances:
✓ Does not use components with limited life time.
✓ Improves the stability and the Maximum Power Point Tracking (MPPT).
✓ The life time of a RELINK micro inverter is more than 25 years.
o Uses innovative capacitors with operational duration of about 21.000
hours @ 105°C. (3 times more than string inverter)

10. 10
RELINK benefit - more output power
String Inverters Micro Inverter RELINK
Micro Inverters eliminate DOMINO effect and
performance mismatch of PV modules

11. 11
RELINK benefit - more output power
What causes modules mismatch
Dust & Debris Defects & Degradation
Different temperature Shade & obstacles

12. 12
RELINK - benefit higher reliability
Test duration: 24 months
Number of inverters
✓ Micro: 10.360
✓ String: 3.373
Defects
✓ Micro: 0,21%
✓ String: 9,43%
Field reliability
45x
Field reliability test

13. 13
RELINK - benefit higher reliability
RELINK
✓ PV system architecture
o A single event cannot stop all
the system
o The field interventions are dine
only on a small portion of the
system
o Service is less urgent
PV systen availabilty
> 99,4 %
String
Time
Time

14. 14
RELINK - outstanding safety
No high voltage DC cables
✓ The maximum Dc voltage is lower than 60V. DC-AC conversion is done
at module level. No electrical archs risk.
The micro inverter automatically switches off if:
✓ grid is off (no AC present)
✓ temperature is too high (thermal switching)
Significant reduction of folgoration and fire hazards
✓ Increased safety for installers and firemen.
✓ Improved asset protection and better risk management.

15. 15
RELINK - real case in Australia 2,2kWp
✓ Difficult roof for string inverters
due to double shade.
✓ Professional PV installer should
not install a string inverter in
this situation.
✓ RELINK micro inverters offer
best solution by reducing shade
impact and maximising energy
output

16. 16
RELINK - real case in Australia 2,2kWp
✓ The increased PV
system energy
production ranges from:
✓ Min + 5% w/o shade
o more MPPT
o no mismatch
✓ Up to + 30% with shade
Shaded modules have no impact on
overall performance of the system

17. 17
RELINK - real case in Australia 2,2kWp
MICRO
Increased productivity

18. 18
Energy Sharing Mode in Offices

19. 19
RELINK - micro inverter conclusions
MICRO RELINK STRING
Productivity Precise and constant
(from +5 to +30%)
Variable
Reliability System availability 99,4%
Defects < 0,5%
System availability 85%
Defects > 4%
Duration >25 years 8-10 years
Easiness Completely AC
Integrated cabling
Complex Design
Safety Low DC voltages
Switches off at high temp.
DC archs risk
Fire hazard
Life time cost of micro inverter 50% lower than string