DEPARTMENT OF POWER

Government of Arunachal Pradesh

Frequently Asked Questions

A Grid Interactive Rooftop PV system comprises of electrical and electronic equipment such as solar modules, inverters, cables, switch gears, etc. When these components are connected and placed on the roof of buildings exposed to sunlight, the system starts generating electricity. A GRPV system generates electricity that can either be injected directly into the distribution grid or used for captive consumption at installation premises.

Grid Interactive Rooftop Photovoltaic systems are of two types:

  • Systems without battery storage.
  • Systems with battery storage.
  • Cheaper and environment friendly electricity.
  • Excess energy can be fed into the grid with tariff as determined by the State Electricity Regulatory Commissions.
  • Electricity generation occurs at consumption center thus, saving transmission and distribution losses.
  • Lower payback period.
  • Requires minimal maintenance.
  • 25 years guaranteed lifespan of the solar photovoltaic panels.
  • Subsidy is available from MNRE.
  • Highly modular.
  • Quick installation.

No, Grid Interactive Rooftop Photovoltaic systems cannot generate electricity at night. In case of absence of generation by the system, power supply can be availed from the electric grid. Battery can be used to store energy for later use, i.e., night or monsoon.

Under net metering, electricity generated by the Grid Interactive Rooftop Photovoltaic system is first utilized by the consumer to meet their internal/captive requirements and excess electricity, if any, is exported to the grid. Subsequently, when the consumer imports power from the grid, the exports are adjusted against the imports, lowering electricity bill.

Net meter (bi-directional meter) usually records the energy imported from the grid to meet the load and surplus energy exported to the grid after consumption. Both energy import and export are recorded in the net meter. The difference between import and export readings is the actual energy consumed/delivered.

For each kWp, the Grid Interactive Rooftop Photovoltaic system installed on a south-facing roof will generate four to six units of electricity per day. However, depending upon the weather conditions, the energy generation reduces by around 20 percent for east or west facing roof.

A Grid Interactive Rooftop Photovoltaic system is made up of different components. These include PV modules (groups of PV cells), grid tied inverters, circuit breakers, relays, energy meters (net/gross), module mounting structures (MMS), cables, etc.

The Eligible Consumer may install the Solar Project under the ‘Arunachal Pradesh State Electricity Regulatory Commission (Rooftop Solar Grid Interactive Systems based on Net Metering) Regulations, 2016

  • All eligible consumers of electricity in the area of supply of the distribution licensee can participate in the solar rooftop net metering arrangement (reference to sub clause 2.1(i) of this Regulation).
  • The inter-connecting voltage level of the Grid Interactive System for various capacity ranges shall be as per relevant provision of the Arunachal Pradesh State Electricity Regulatory Commission’s Electricity Supply Code Regulations – 2013.
  • The maximum rooftop solar system capacity to be installed at any eligible consumer premises shall be governed by the eligibility of interconnection with the grid for that eligible consumer.
    • Provided that the installed capacity shall be between 1KWp to 1000 KWp (1MWp).
    • Provided further that the installed capacity is aligned with the provisions of Arunachal Pradesh Electricity Supply Code – 2013 for permitting consumer connections
  • Provided that a variation in the rated capacity of the system within a range of five percent shall be allowed

Most roofs are strong enough for solar installation without any reinforcement. However, in case of larger systems, it is suggested to consult a qualified Structural Engineer.

Currently, the following business models are in vogue namely, self-owned (capital expenditure [Capex] model), Renewable Energy Service Company (RESCO) model and third-party owned model. “RESCO” means an energy service company which provides renewable energy to the consumers in the form of electricity.

Capex Model: Consumers develop solar rooftop plant within their premises to own, operate and generate electricity for self-consumption and sell excess electricity to the utility (under net metering) or sell entire electricity to the utility (under gross metering). Generally, self-owned business model is preferred for its simplicity. However, this model also has disadvantages such as high capital cost for the consumer and high technology and performance risk.

RESCO Model: A RESCO builds, owns and operates GRPV plant in the premises of a consumer to generate and sell electricity to the consumer. Consumer may further engage in net metering or gross metering arrangement with DISCOM.

In RESCO, consumer does not invest in the GRPV power plant; instead, a RESCO developer invests and sets up the system. RESCOs are specialized solar developers; they can handle technology and operation risks in a better way. However, RESCO model faces several challenges such as power off-take risks, contractual risks, etc.

Third Party Model: A Rooftop or Land Owner may lease out / rent the Rooftop Space/ Land to a Solar Project Developer on a mutual commercial arrangement. Under this arrangement, the owner of the roof / land engages a turnkey installer to design and install the project. The Commercial arrangement between the project developer and the Roof / Landowner will be submitted to the Buyer of the Solar Power / Distribution Licensee for the records.

Suitability of these models depend on one’s ability to meet the costs.

Yes. All applications related to Grid Interactive Rooftop Photovoltaic shall be processed through Unified Solar Rooftop Portal – Arunachal Pradesh. Upon submission of Application for Interconnection, DoP, Arunachal Pradesh, will check the technical feasibility and provide a response through the Unified Solar Rooftop Portal – Arunachal Pradesh. Applicants can register themselves through Unified Solar Rooftop Portal – Arunachal Pradesh and apply online directly using relevant forms and formats to the approving authority.

Eligible Consumers are consumer of electricity in the area of supply of the Distribution Licensee, who uses a rooftop solar power system on consumer premises, to offset part or all of the consumer's own electricity requirements given that such systems can be self-owned or third party owned.

The maximum rooftop solar system capacity to be installed at any eligible consumer premises shall be governed by the eligibility of interconnection with the grid for that eligible consumer.

  • Provided that the installed capacity shall be between 1KWp to 1000 KWp (1MWp).
  • Provided further that the installed capacity is aligned with the provisions of Arunachal Pradesh Electricity Supply Code – 2013 for permitting consumer connections

No. Bi-directional and Solar Energy meters (unidirectional meter) shall be required by consumers to avail net metering facility. Check meters are required for installed GRPV capacity of more than 20 kW. Check Meters shall be mandatory for Solar Project having capacity more than 20 kW. For installations having capacity less than or equal to 20 kW, the Check Meters would be optional: Provided that the cost of Check Meter shall be borne by the Consumer, and such meter shall be tested and installed by the Distribution Licensee.

Please refer the Arunachal Pradesh State Electricity Regulatory Commission’s (Rooftop Solar Grid Interactive Systems based on Net Metering) Regulations 2016.

The Project Developers shall adhere to the National & International Standards specified by MNRE & CEA’s Technical Standards for Connectivity of Distributed Generation Resources - Regulation 2013.

Yes, some banks provide loans especially for solar rooftop systems. This information is available on the Unified Solar Rooftop Portal – Arunachal Pradesh.