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SOLAR PROJECTS

Solar PV ProjectAll components of a photovoltaic system other the photovoltaic panels

• Inverters• Mounting & Racking Systems• Electrical Equipment and Installation

• Cabling-AC & DC• Transformers & Breakers• Combiner Boxes• Earthing• Transmission Line, etc

• Civil Work & Development• Inverter Rooms, CMCS• Roads, Boundary, Drainage,

Cleaning Systems, etc• Land• Miscellaneous

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SOLAR PROJECTSSolar Project Cost Breakup

Source: Fraunhofer ISE, 2016

• Efficiency of average commercial wafer based silicon module has grown from 10% to 17% in last 10 years• Best efficiency multi-crystalline module:

19.2%

For every 5W increasein module wattage• project costsdecrease by 0.27%• BOS costs reduceby 0.8%

For every 10% increase inoverloading• project costs decrease by 1.25%• BOS costs reduce by 3.5%

Smart DC Block Sizing

• Big Plant sizes allow DC block sizing optimization

• Leap Frogging saves 25% cable cost in the case of tracker.

• String Monitoring removed, relying on inverter zone monitoring.

Cost Benefit Analysis• Till Generation gain surpasses increase in cost

DC side cabling costs have decreased by about 40% due to efficient design in the last few years

String Fusing by Y-connectors-> Solar Cable & SCB Cost reduction by around 30%

With effective design optimization on the DC side, a reduction of 1.1% and 3.6% on project cost and BOS can be achieved.

Inverters• Inverter costs have reduced by more than 70% from 2010-11•Driven by•Scale of Production (Inverter learning rates vary from 18-20%)1

• Technological advancements:ü Material (SiC, GaN)ü Block SizeüVoltage Increase (1500V)• Localization• Inverters are predicted to see price reductions of 8-9% per annum upto 20202

Tranformers• Have shown reduction in costs in recent years due to:• Higher transformer capacities due to bigger block size• Metal Prices• Multi- winding transformer (5-winding, 7 winding) resulting in BOS optimization

Source: 1. Fraunhofer ISE, 20152 Greentech Media, 2015.

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Case Study: Impact of Block Size on BOS

SOLAR PROJECTS

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Case: 65MW Plant with 5 nos. Of 10MW and 1 no. of 15MW Block Feeder

Comparison of 1500V v/s 1000V

Saving of INR 0.45/W due to Block Size Increase and use of 5-winding Transformer.

• Higher DC and AC voltage i.e. lesser current and lesser cabling

• Lesser current allows the increase in inverter block power, lesser BOS

• 50% longer strings, implying lesser strings, and 33% lesser junction boxes

• Lesser monitoring, and economical installation

• IEC certifications are in place

• Higher yield

Advantages

Disadvantages• Component availability limited at

present, thus driving BOS costs higher

• Higher inverter costs due to 1500V components

• For same DC ohmic losses, a 7.5MW block can be formed in 1500V when compared to 5MW block.

• Bigger block size would mean optimization can be carried on AC side.

• The cost of land for solar projects has risen about 6-10 times as compared to 2010-11

• Not only expensive, but difficulties in acquisition.• As the cost of PV modules decrease, land use

optimization by decreasing the tilt, and increasing the power density (kW/sqm)

Comparison of 1500V v/s 1000V (Alternate Optimization)

LAND COSTING

1500V

7.5MW1000V

5MW

SOLAR PROJECTS

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• 20 X 315Wp modules in series = 6.3kWp = 1 Table

• 1MWp = 160 Tables (approx.)• A team of 3 persons will take 15

minutes to change tilt of 1 table (on an average), hence, 32 tables per day.

• Five such teams i.e 15 persons per day shall be able to change tilt of 1MWp installation.

• At a labour rate of Rs. 350/- per day, it takes less than Rs. 6000 to change tilt of 1MWp installation.

• Assuming an increment of 3T / MWp between fixed and seasonal tilt, additional capex comes out to be Rs. 2.4Lacs approx.

• Pre fab rooms offer significant time advantages in execution timelines hence bring generation gains and more efficient supplies

• Instances where Pre fab buildings are not considered, decking sheets with concrete layer on top can offer same benefits. It provides both required strength, insulation and quicker installation benefits

• Recent designs leverage on the density of array yard and consider lower values of k2 factor in design calculations of structures.

• Outer rows are designed with higher sections as they have more impact of wind speeds, however inner rows are designed 10-15% lighter to leverage the shielding that outer structure provides One name that has echoed in procurement teams lately. It’s a fine play and tight walk on the line between Optimization and Under design Galvalume suits fixed tilt structures and can be very good for optimization

• Use of galvalume in seasonal tilt structures has seen many failures recently and resulted in loss of PV modules & of course generation

• Extra caution to be exercised while tilting galvalume based structures and must be done only using proper jacks. Manual tilting is a strict no, if not particularly addressed during Engineering.

East-West Mounting

Shift from Fixed to Seasonal- How numbers work

Structure Trend - Seasonal Tilt - Y 2014 – 60T

Pre Fab rooms and Decking Sheets

Wind Shielding of Outer most structures

• For places closer to equator, i.e. latitude <10°, solar modules can be mounted in east west fashion at low tilt angles (around 3°)

• High land utilization, with GCR>80% can be achieved

• Wider peak

• Lesser structure and foundation cost

• Lesser BOS cost

• Marginal drop in generation

Structure Trend - Seasonal Tilt - Y 2015 – 40T

SOLAR PROJECTS

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• Cheaper compared to HT cable (30-40% lesser at full load evacuation)

• Maintenance friendly, and lesser probability of fault

• Higher current carrying capacity. New age AAAC panther conductors can carry

• 25MW on single circuit, whereas typical 33kV cables will take around15MW

• Best practices assimilation across the industry• Module efficiency• Technological developments• Incremental design improvements, such as higher overloading,

mounting structure, block size, etc• Localization including streamlined logistics• Increase in market volume• Automation in production, development and installation• Based on the above factors and historical trends, we foresee a BOS

cost reduction of 30%-35% by 2020

Cost Saving by Internal Transmission Line

Pros:

Main Drives of BOS Cost Reduction in future

Site specific: If land is not highly constrained, and HT cables are running along northern boundary

• Land wastage around poles due to shadow

• Land wastage can be minimized by planning TL along boundary, and suitably oriented to north direction

Cons:

SOLAR PROJECTS