In Conversation with Mr.Goutam Samanta Head- PV Technology Orange Renewable
How important is the selection of right modules for the solar projects?
Solar Module is the most important component of a solar power project. Module is defined as PV power generator as it directly converts sunlight to electricity. The rest of the system is to ensure that the DC electricity is converted to AC and is evacuated optimally (minimizing the transmission losses) to the grid. Solar Module accounts for nearly 60% of the total solar project costs and the power is to be delivered power for 25 years and more.Therefore, the choice of solar module selection is very difficult task as there are more than 800 module manufacturing companies available in the global market.Given the above fundamental and economic aspects, it is very important to scrutinize the technical parameters of module data sheet before purchasing solar module.The most important parameters to be considered are as follows:
- Light Induced Degradation (LID)
- Temperature co-efficient of power, current & voltage
- Potential Induced degradation (PID)
- Few critical parameters as per IEC 61215 standard
- Location of Plant
- Solar insolation at site
- PVSYST analysis with all major inputs of selected module
- Generation data
There are few more parameters need to be scrutinized
- Positive Power Tolerance
- Power Output (bins) for both for 60 & 72 cells family
- Module Efficiency
- System voltage
- Low light response
- Product warranty
- Performance warranty
- Busbars (BB)
- Class of JB
- Production Quality Control Plan
What are the recent technology trends seen in Solar module market?
Poly or Multi-crystalline silicon modules are dominating in the present global market with market share of 90%. Out of which ploy's share is almost 75% & balance 25% is mono. But the market share of mono-crystalline module is increasing in slow space. Mono-crystalline modules could not have more market share due to challenge in crystal growth by C-Z technology compared to casting technology for conventional poly. Mono modules are earlier costing 10% more than poly. However, high efficiency mono-crystalline modules with PERC technology will capture 35-40% market share by end of 2018. Also to be noted that thin film technology modules are good with Cadmium telluride (CdTe) & Copper indium gallium selenide (CIGS) and may see a greater demand from the industry going forward.
How Should Developers Select Their Module Partners?
Developers or EPC players normally do the due-diligence in the market & shortlist few module suppliers. Thereafter, tie up with module manufacturers during pre-bidding stage. Usually, a MOU is signed between a developer & module manufacturer with expected module price at least three months earlier of COD. Developers select the module type either thin film or c-si based modules based on the corresponding factors: model No (Poly/Mono, 60/72 cells, 1000/1500 VDC etc) & also the location. The engineering team analyses the generation data based on PVSYST results.
Solar technology is evolving with time.Is there anything that you are looking forward to happen in the next few years? How do you think the Industry would shape up in near future?
- Presently, Solar PV industry is dominated by single glass, EVA encapsulated & back-polymer based module technology using ALBSF screen printed poly solar cell
- Mono PERC cell is taking a good lead in near future. The present p type Mono cell efficiency is more than 20.5% compared to 18.5% poly cell. Lot of Tier1 modules players are working with n-type mono cells efficiencies more than 21.5%.
- Present 1000 VDC modules will be upgraded to 1500 VDC shortly with suitable inverters to reduce the DC cost
- Glass-Glass modules will be a good choice beyond 2018 with 30 years warranty which ensures very low degradation
- Glass-Glass bi-facial modules with tracking system will make a huge impact on LCOE beyond 2020
- Few higher efficiencies evolving technologies for c-si cell/module: such as Inter Digitated Back Contact, Metal Wrap Through (MWT), Smart Wire, Hetero
-junction Technology (HJT) & HJT Bi-Facial Smart Wire Technology.
Anything else you would like to add for our readers.
3rd Inspection & testing: It is very important for developers & EPC players to check quality of the module to meet the challenging prices in India, should not affect adversely on module quality.
Therefore, the following three tests or inspections are essential at the manufacturers facility as per mutually agreed Quality Control Plan (refer to Module Procurement Agreement):
1. In-Line Factory Inspection: 3rd Party inspectors usually inspect in module manufacturing shop floor (24 X 7) for
- BOM verification- Process & Quality testing as per control plan
- Test & Measuring Equipment calibration & Gold/Secondary reference criteria
- Flash test & EL inspection of randomly selected modules as per agreed protocol
2. Pre-Shipment or Pre-dispatch Inspection for 5 or 10 MW lot size. Sample modules quantity (no of modules) to be picked up from the warehouse or shop floor storage area for verification of the following tests as per agreed AQL standard
- Visual Inspection
- Flash Testing
- EL Inspection
- Dimension checking etc.
3. 3rd Party laboratory testing for 5 or 10 MW lot size. Sample modules quantity (no of modules) to be selected & arranged to dispatch 3rd Party laboratory for further verification of the following tests as per agreed AQL standard
- Flash Testing
- EL Inspection
- Few more tests as per IEC 61215 standard as per module purchase agreement