Introduction to PISSA Technical Series

This document forms part of the PISSA Technical Series developed for members of the PAN INDIA SOLAR SECTOR ASSOCIATION (PISSA). The objective of this series is to provide structured, experience-based guidance that reflects real-world execution challenges faced by EPCs, developers, and stakeholders across the renewable energy sector.

Topic 1: Solar Rooftop & Ground-Mounted Productivity Enhancements

This topic focuses on improving productivity and execution efficiency in both rooftop and ground-mounted solar PV projects. While industry best practices exist, actual project execution is frequently challenged by tight timelines, coordination complexity, regulatory dependencies, and fluctuating component costs.

The implementation roadmap outlined here spans from early project assessment through commissioning and operations.

Discussion Framework & Core Focus Areas

To make this technical chapter more practical and experience-driven, PISSA proposes using the implementation roadmap as a discussion framework. Members are invited to share insights based on their on-ground execution experience.

Focus 1: Reducing Implementation Time While Maintaining Quality

• Identification of stages that consume maximum time in practice
• Opportunities for parallel execution instead of sequential tasks
• Role of early-stage planning and standardization
• Practices that shorten timelines without compromising safety or performance

Focus 2: Cost Optimization Without Compromising Quality

• Stages offering maximum cost-optimization potential
• Design, logistics, and execution-driven cost efficiencies
• Distinguishing safe cost controls from false economies
• Maintaining quality control under budget pressure

Phase 1: Assessment & Feasibility

Common for Rooftop & Ground-Mounted Systems:

• Energy yield assessment using site-specific solar data
• Preliminary system sizing and DC/AC ratio selection
• High-level financial feasibility and LCOE estimation

Additional for Ground-Mounted Systems:

• Land acquisition or lease assessment
• Zoning, permitting, and statutory clearances
• Grid proximity and evacuation feasibility studies

Deliverable: Go / No-Go feasibility report

Phase 2: Site Investigation & Detailed Studies

Rooftop Systems:

• Structural load assessment
• Roof waterproofing evaluation
• Detailed 3D shading analysis

Ground-Mounted Systems:

• Geotechnical investigations and soil analysis
• Topographic and boundary surveys
• Environmental and social impact assessments
• Hydrology and drainage studies

Deliverable: Bankable site investigation package

Phase 3–5: Engineering, Procurement & Construction

Engineering & Permitting:

• Electrical, mechanical, and civil system design
• Foundation and tracker system engineering
• Drainage, road, fencing, and security design

Procurement & Logistics:

• Vendor qualification and compliance checks
• Factory acceptance testing (FAT)
• Bulk logistics and spares strategy

Construction:

• Mounting and module installation
• Civil works and tracker alignment
• QA/QC inspections throughout execution

Phase 6 & 7: Commissioning, Operations & Continuous Improvement

• Electrical testing and inverter commissioning
• Tracker calibration and backtracking optimization
• Performance monitoring and PR assessment
• Preventive maintenance and vegetation control
• Data-driven O&M optimization

Financial Impact – Return on Investment (ROI)

Rooftop systems generally have higher cost per watt but faster permitting and strong tariff hedging benefits. Ground-mounted systems benefit from scale efficiencies, lower $/W, and higher absolute energy generation.

Indicative IRRs range from 10–16% for rooftop projects and 12–20% for utility-scale ground-mounted plants.

Lifetime Value Optimization

• Importance of O&M quality
• Tracker availability and uptime
• Cleaning automation and soiling control
• Structural durability and spare strategy

A 1–2% improvement in annual performance ratio typically delivers higher lifetime value than equivalent CAPEX reduction.

Environmental Benefits & Sustainability

• Rooftop systems maximize land efficiency
• Ground-mounted systems deliver higher absolute carbon offsets
• Responsible land-use and biodiversity planning
• Drainage and soil protection measures