Renewable energy is a cornerstone of sustainable building design, serving to reduce dependency on fossil fuels and minimize carbon footprints. Green building certifications such as GRIHA, IGBC, LEED, and others emphasize the integration of renewable energy systems to enhance energy efficiency, promote environmental sustainability, and support net-zero energy goals. This article explores the renewable energy requirements in green building certifications, focusing on their criteria, compliance measures, and comparative analysis.
GRIHA (Green Rating for Integrated Habitat Assessment)
Criterion 18: Renewable Energy Utilization
- Mandatory Clause: The rated capacity of proposed renewable energy systems must equal or exceed 1% of internal lighting and space conditioning loads.
- Optional Clauses: Additional points are awarded for systems meeting higher percentages of annual energy requirements for internal lighting consumption:
- 5% (1 point)
- 10% (2 points)
- 20% (3 points)
- 30% (4 points)
- Criterion 19: Renewable-Energy-Based Hot Water Systems:
- Systems must meet 20% or more of the annual energy required for water heating (3 points).
- Incremental points are available for saving 20-50%, 50-70%, and more than 70% of energy requirements.
- Responsibility: Electrical, Energy, and Plumbing consultants oversee compliance.
Criterion 8: Renewable Energy Utilization (2019 Update)
- Alternate 1: On-site or combined on-site and off-site renewable energy systems must offset internal artificial lighting, HVAC, and domestic hot water energy consumption:
- 1% (Mandatory)
- 10% (1 point)
- 15% (2 points)
- 20% (3 points)
- 25% (5 points)
- Alternate 2: Off-site systems must offset 100% of these energy needs (Mandatory + 5 points).
IGBC (Indian Green Building Council)
Energy Performance
- Focuses on incorporating renewable energy to achieve energy efficiency and reduce greenhouse gas emissions.
- Points are awarded based on the percentage of energy offset through renewable energy systems:
- 5% of connected loads (1 point)
- 10% (2 points)
- 20% (3 points)
- 30% (4 points)
Solar Hot Water
- Encourages solar water heating systems, particularly for residential, hospitality, and institutional buildings.
- Points are provided for meeting 25%, 50%, and 75% of hot water demand through renewable sources.
LEED (Leadership in Energy and Environmental Design)
Energy and Atmosphere (EA)
- LEED emphasizes renewable energy through two key credits:
- Renewable Energy Production: Awarded for on-site renewable energy systems offsetting a percentage of total building energy cost:
- 1% (1 point)
- 5% (2 points)
- 10% (3 points)
- Green Power and Carbon Offsets: Recognizes projects that procure renewable energy credits (RECs) or carbon offsets for 50%-100% of building energy consumption for a minimum of five years.
- Renewable Energy Production: Awarded for on-site renewable energy systems offsetting a percentage of total building energy cost:
- Systems such as solar PV, wind, biomass, and geothermal are recognized.
Hot Water Systems
- LEED encourages renewable energy use for domestic hot water needs but integrates this requirement into overall energy strategies rather than as a standalone criterion.
Comparative Analysis
| Aspect | GRIHA | IGBC | LEED |
|---|---|---|---|
| Focus Areas | On-site and off-site renewable energy for lighting, HVAC, and hot water systems. | Energy offset through solar PV, wind, and hot water systems. | Renewable energy credits, carbon offsets, and on-site production. |
| Mandatory Requirements | 1% of internal lighting and space conditioning connected loads. | 5% of connected loads for on-site systems. | Procure RECs for 50%-100% energy consumption. |
| Optional Points | Incremental points for meeting 5%-30% of lighting energy needs. | Points for 10%-30% of energy needs through renewable sources. | Points for 1%-10% of total energy cost offset through renewables. |
| Hot Water Systems | 20%-70% of hot water energy from renewables. | 25%-75% of hot water demand from solar systems. | Integrated into overall energy performance. |
| Off-Site Systems | Recognized with mandatory compliance and additional points. | Limited focus; primarily on-site systems. | RECs and carbon offsets are central. |
| Applicability | Residential and non-residential projects. | Wider applicability with specific emphasis on solar systems. | Global applicability with flexibility in renewable energy sourcing. |
Conclusion
Renewable energy integration is a critical component of green building certifications, with varying emphases on on-site systems, energy offsets, and hot water systems. GRIHA provides a comprehensive approach with specific criteria for lighting, HVAC, and hot water systems. IGBC prioritizes solar-based systems and emphasizes on-site solutions, while LEED offers flexibility through RECs and carbon offsets, catering to diverse project needs.
Each certification system provides a pathway to reduce dependency on conventional energy, promote sustainability, and achieve energy efficiency goals, allowing stakeholders to choose the framework best suited to their project’s needs.