Andhra Pradesh Grid Interconnection
APSPDCL Net-Metering & Solar Interconnection Guide
Technical feasibility norms, voltage thresholds, bi-directional metering specifications, and utility liaison for rooftop solar under Southern Power Distribution Company of Andhra Pradesh Limited.
Distribution Utility Profile
APSPDCL
Southern Power Distribution Company of Andhra Pradesh Limited
Operational Jurisdiction
10 Districts CoveredGrid-connected solar net-metering applications and MRT meter testing for all administrative revenue circles in these districts are processed through APSPDCL divisions:
Key Urban Centers
Tirupati, Nellore, Kurnool, Kadapa, Anantapur, Chittoor, Ongole, Hindupur
Technical Feasibility & Specs
Interconnection norms & thresholds
Statutory supply voltages, transformer capacity ceiling, and bi-directional meter specifications applicable for solar rooftop connections under APSPDCL.
Supply Voltage Thresholds
Permissible interconnection supply levels based on total solar inverter AC output capacity:
- LT Single-Phase
- Up to 3 kW (single-phase 230V, extendable to 5 kW based on service line)
- LT Three-Phase
- Above 5 kW up to 56 kW (415V three-phase LT supply)
- HT 11 kV Supply
- Above 56 kW up to 1,000 kW (11 kV HT supply)
- HT 33 kV Supply
- Above 1,000 kW up to 5,000 kW (33 kV HT supply)
Supply conversion application can be bundled with solar feasibility filing.
Transformer & Load Caps
Statutory limits enforced by regulatory orders during technical scrutiny:
- DTR Capacity Ceiling: 100%
- Cumulative solar capacity on distribution transformers is permitted up to 100% of rated capacity under APERC Solar Rooftop Regulations.
- Contracted Load Limit: Up to 100%
- Consumers across residential, commercial, and agricultural/institutional categories can install up to 100% of contracted load, subject to a 500 kWp net-metering ceiling.
- Settlement Cycle
- Monthly energy netting with credit carry forward across billing cycles
- Banking Carry-Forward
- Annual settlement period with surplus unutilized credits adjusted as per APERC tariff orders
Feasibility approval is valid for project execution and agreement signing.
Bi-Directional Net-Meter
Utility hardware specifications and calibration protocols:
- Bi-Directional Net Meter
- DLMS-compliant bidirectional four-quadrant static meter (Class 1.0 for LT, Class 0.5s for HT) complying with IS 13779 / IS 14697 and APERC technical regulations
- Solar Generation Meter
- Unidirectional solar generation check meter installed on inverter AC output
- Protocol Compliance
- DLMS / COSEM protocol compliant with optical communication port
- Testing Laboratory
- APSPDCL Meter Relay Testing (MRT) Laboratory
Leo Solar handles procurement, lab testing delivery, and installation liaison.
Step-by-Step Workflow
4-Step Interconnection Timeline
From initial feasibility registration on the portal to grid synchronization and commissioning certificate release with APSPDCL.
Feasibility Application via Online Portal
Submission of online application on the APSPDCL Solar Portal or PM Surya Ghar National Portal using Service Connection Number (SCNO). ADE (Operation) conducts field feasibility study on transformer loading within 15 working days.
Technical Feasibility Clearance and Agreement Execution
Receipt of feasibility sanction letter followed by execution of the APERC standard Net Metering Interconnection Agreement with the APSPDCL Divisional Engineer.
Plant Erection and MRT Laboratory Testing
Turnkey installation of solar array, inverter, earthing pits, and surge protection. Delivery of meters to APSPDCL MRT testing laboratory for calibration, accuracy check, and official sealing.
Site Inspection, Net Meter Synchronization, and Commissioning
Physical inspection by APSPDCL ADE (Operation), execution of anti-islanding functional test, installation of sealed bi-directional meter and generation check meter, and release of formal Commissioning Certificate.
Regulatory & Technical Guidance
Frequently asked questions for APSPDCL
Clear answers to common questions regarding distribution transformer headroom, billing adjustment, meter testing, and safety norms.
Why do districts like Ananthapuramu and Kurnool under APSPDCL experience higher solar yields?
The Rayalaseema region features some of the highest solar irradiance levels in southern India, typically exceeding 5.5 kWh per square meter per day, leading to strong seasonal generation performance.
What is the transformer capacity limit under APSPDCL?
Under APERC guidelines, cumulative solar capacity is allowed up to 100% of the transformer rated capacity. APSPDCL provides online tracking of available transformer capacity.
What are the high-tension (HT) net-metering requirements in APSPDCL?
HT installations (above 56 kW) connect at 11 kV or 33 kV, require Class 0.5s CT/PT metering, CEIG (Chief Electrical Inspector to Government) safety clearance, and vacuum circuit breaker (VCB) protection.
How does energy banking operate under APSPDCL net-metering?
Net export credits are banked in energy units (kWh) and adjusted against future consumption within the settlement year, helping seasonal agricultural and commercial establishments balance variations.
Can housing societies and gated communities in Tirupati or Nellore apply for group net-metering?
Yes. Housing societies can install rooftop solar on common roofs connected to their common-services meter (lifts, water pumps, lighting) under APERC net-metering guidelines.
Full Liaison Included
Ready to connect solar to APSPDCL?
Leo Solar handles your roof survey, structural design, online portal registration, MRT laboratory testing, and physical bi-directional meter synchronization with Southern Power Distribution Company of Andhra Pradesh Limited.
Direct consultation with our Telangana & Andhra Pradesh utility engineering team.