Solar Netmetering System

Net-metering approach to RTPV promotion is ideally suited for India, since it is socially equitable, economically viable, and environmentally sustainable.

Andhra Pradesh State Government announced its policy for encouraging solar power production in the State. A GO MS NO 22 to this effect has been issued dated 25.03.2013. Keeping in view the good potential for harnessing solar power, it was felt that net metering facility be provided to the consumers to generate solar power for self-consumption and feeding excess power into the grid when it is not being consumed by them.

APTRANSCO has already installed 100 KW solar plant at Vidyut Soudha, Hyderabad on a pilot basis and is following the net metering facility.

As per the new policy, net metering facility will be implemented for the consumers who intend to encourage solar green energy and set up solar PV plants at unutilized places on roof-tops, waste lands, buildings of individual households, industries, offices, institutions, residential complexes etc.

Subsidy will be provided by the Government of India through NREDCAP up to 30% of the cost of the panel up to a capacity of 500 KW without battery support.

How to supply Solar Power to Grid

There is no cost involved in the transmission of energy unless the power is transmitted at high tension (HT) levels (11 kV or 33 kV), and special monitoring and metering hardware are deployed at HT levels. In the current scenario, metering arrangements for rooftop grid-interactive power plants are under active consideration by the government.

While no special arrangements are required to inject power into the grid, there is a safety aspect that needs to be factored in while transmitting energy. There is always a risk involved, as when the grid fails the solar power system automatically stops injecting power into the grid. This is called “islanding”, where the inverter isolates itself. This is a standard feature built into solar power inverters, making these safe for residential and commercial applications. A standalone feature in the inverter would enable captive consumption of the solar power generated in the event of any grid outage.

The solar energy can be used for captive consumption or exported to the grid. The electrical energy (DC) or the solar power generated by the solar PV modules during the sunshine hours is stored in the batteries for use, as and when required. The energy stored in the batteries is converted using an inverter. This energy automatically synchronizes with the grid and gets injected into it.

More benefits for commercial units

Rooftop installation makes more sense for commercial establishments as these can utilize the solar power during peak-load daytime periods, thus saving the money required to set up battery banks. Any amount of power not used can be stored in a battery bank for use at night when energy consumption is the least (about 10 per cent compared to the day).

Moreover, for small business establishments or small and medium enterprises (SMEs), a rooftop installation for grid connection is far more profitable than a multi-megawatt plant which requires installation of six to eight transformers. Transformers are at most 98 per cent efficient and therefore while generating solar power, some energy is lost due to the inefficiency of these transformers. So it is profitable to install smaller power plants with 100 per cent of electricity production, which can then be transferred to the local utility.

Future prospects

The Jawaharlal Nehru National Solar Mission of the Indian government is planning to install rooftop photovoltaic systems with the combined capacity of up to 20 gigawatts by 2022.

Augni Solar – Scheme evolved to install Roof Top Net Metering Solar Power Pack

Augni Renewable Energy System (India) Private Limited has evolved a novel scheme to encourage the manufacturing organizations, commercial establishments, etc for installation of Roof Top Net Metering Solar Power Pack:

The salient features of the scheme are as under:

There should be one or more parties for raising funds required for installation of the Roof Top Net Metering Solar Power Pack who at all times called as “Investor”

There should be a party who owns the roof top of manufacturing organizations, commercial establishments, etc. on which the investor is proposed to install the system who at all times called as “Vendor”

The vendor may be a direct consumer of solar generated power or may be a lessor rented the premises (not being a roof top) to any other third party or parties.

The Vendor shall apply to the respective DISCOM for getting approval for installation of Net Metering Solar Power Pack, on his name.

The Vendor shall allow the roof top under an agreement to Investor to enable him to install the Roof Top Net Metering Solar Power Pack system under Built-Operate-Transfer system.

The Investor shall make his own arrangements for installation of the system.

The vendor is responsible to collect the power charges as per the units generated under the roof top solar net metering system and to pass on the same to the investor.

In case the investor has availed any term loan for raising funds for installation of the system, the amounts shall be passed on through an escrow account by the vendor, which may be a stipulation of the financial institution.

The investor shall maintain the system in good condition and the arrangements to that effect shall be made by him.

The investor shall enjoy the proceeds for a period of 15/17 years as per the agreement and subsequently leave the roof top together with the system installed, unconditionally.

The vendor shall be the absolute owner of the system from 15/17 years onwards as per the agreement and can enjoy the proceeds without any terms and conditions.

The vendor is not responsible under any circumstances the amounts if any due to the financial institution with respect to the funds raised by the investor at the time of installation of the plant.

Benefits to the interested parties under the scheme:

To Investor

  • Low Investment in case the investor raises any funds for the project from any of the bank/financial institution.
  • There is no investment on land/rooftop.
  • As an investor of the system he can enjoy the power charges received under net metering system generated from solar power pack installed.
  • He can enjoy the proceeds for a continuous period of 15/17 years as per the agreement entered into between Investor and vendor.
  • He can receive a variable tariff from the vendor under an agreement in case there is any increase in tariff applicable to sector.

To Vendor

  • There is absolutely no investment from his end except a little towards charges payable to DISCOM for obtaining Net Metering facility.
  • A value addition to the building
  • He can insist a rack rent for the premises due to value addition.
  • He can be an absolute owner of the system after certain period under an agreement with investor.
  • He can enjoy higher power tariff spell from 15/17 years as per the agreement entered into between Investor and vendor, until 25 years and also beyond the period, being the owner of the premise.
  • He can enjoy the residual realizations in case the termination of Net Metering facility after 15/17 years as per the agreement entered into between Investor and vendor.

To consumer/lessee

  • He can utilize the solar power during peak-load daytime periods.
  • A value addition to his business, thereby increase in revenue without any additional cost of expenditure on diesel generator and fuel.