Existing Net Metering system

the customer generates electricity using solar panels fixed on their houses/premises and connected to the grid through net metering system. The consumer has to pay only for the net amount of electricity that he consumed. In this system, if that particular customer’s production exceeds his consumption, he can bring forward the balance and consume it in the months forthcoming. No fee will be paid for the excess electricity produced. The customer will be given the choice of using the balance electricity within 10 year period. (Net Metering)

Net-metering is a policy that allows an electricity customer to use renewable energy sources within his premises to generate electricity and utilise it within his premises, and to export it to the national grid if excess power is being generated, to be recovered when needed. Therefore, the grid acts like an energy bank for the customer. This policy originated in the USA, but has now spread to many countries. Both electricity distributors, that is, the Ceylon Electricity Board (CEB) and the Lanka Electricity Company Pvt. Ltd. (LECO), offer net-metering to their customers.

Both regulations are nearly the same, with the only difference in fees for net-metering. Net-metering involves a ten year contract, a generation facility with a limit of 10 MW or the contract demand of the premises and any renewable resource for power generation. The surplus will be credited to the customer but no payment will be made for the surplus nor can the customer sell it to another customer.

Technically, any renewable resource like hydro, wind, solar and biomass can be net-metered. But at household level, solar PV systems are the preferred option, owing to resource availability, smaller space requirements and ease of operation and maintenance. Solar PV systems are available in the market in wide variety, quality and of course, prices. The most advanced solar technologies require no special expertise to be installed. The basic requirements are a solar PV panel, a micro grid-tied inverter and careful integration of the system together. The inverter output requires to be connected to the household supply, accompanied with necessary protection and isolating equipment, while a smart (two way) meter is installed in the house by the electricity service provider. The net-metering scheme is effectuated upon signing an agreement.

Tips on installing a net-metered system

1It’s appropriate to study the past electricity bills, of about three years, to ascertain variations in the power consumption pattern. The average electricity bill should be considered for the selection of an appropriate system.
2Scan the the surrounding environment of the house and select an exposed, sunny South sloping roof area to locate the panel and inverter.
3 In Colombo, solar panels need to be orientated at an angle of 7 degrees to the horizontal in the southern direction.
4The solar panels should be purchased accompanied with a suitable inverter and other appropriate items, known in the PV industry as Balance of System (BoS), and installed conforming to wiring regulations governing such installations.
5Solar tracking systems are capable of tracking the motion of the sun throughout the day to get maximum power generated from the solar panels. Such tracking systems can be installed for better results, but are significantly expensive.
6The customer is required to enter into an Agreement, with the utility (CEB or LECO), namely, the Agreement and Grid Interconnection Standards for Net-metering of an On-grid Renewable Energy based Generating Facility.
7The electricity distributor would take necessary steps to install the net-metering setup, after which the facility could start generating. The surplus could be banked to the grid legally as per the contract.

Configurators

The SEA developed user-friendly configurators (tools) to help users identify the right size for a solar net-metering solution which would enable making the best choice for a net-metered solar system based on the level of investment.
The tariff effective since September 16, 2014 is applicable for these configurators.

This configurator helps you make choices based on;

(1) your level of investment.
(2) need of replacing or adding electrical equipment

You can make choices based on the two options given above. The configurator will select a suitable system for you, assuming the following.

  • 17% plant factor
  • Utility cost of LKR 65,000
  • System cost of LKR 350,000 per kW
  • Your energy bill will be reduced to the lowest possible value (close to zero). The tool has been optimised, therefore it is practically impossible to get zero units, but the tool would give you the best deal between the highest saving and the lowest investment.

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This configurator is based on data of list prices of panels and inverters provided by solar companies. You can make choices based on;

(1) Prices of systems.
(2) Payback periods

You can make choices based on the two options given above. The configurator will select a suitable system for you, assuming the following.

Results would be displayed at your convenience. For example, if you wish to seek a system that fits your budget, you could select systems sorted according to their prices or simple payback periods. Alternatively, if you wish to seek reputed brands, you could select companies sorted in the alphabetical order. We also give contact details of companies, so that you could get more information about the products from them.

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This configurator is built for micro inverters. Micro inverters are compact units that convert direct current (DC) to alternating current (AC) immediately at the solar module. As compared to solar PV installations that use string or central inverters, micro inverters deliver 5% to 10% greater energy harvest over the system lifetime by applying Maximum Power Point Tracking (MPPT) to each solar module to optimise energy harvest. Micro inverter technology delivers more kilowatt-hours daily, monthly and yearly, even though the partial shade of clouds, trees, or structural obstructions are present. As a result, there is no dramatic reduction in system output when a solar module, or part of a module, has its output reduced by shading or build-up of surface debris. Micro inverters are designed for high reliability operations and they generally have a longer lifespan than that of string or central inverters.

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This configurator is based on data of list prices of panels and micro inverters provided by solar companies. You can make choices based on;

(1) Prices of systems.
(2) Payback periods

Results would be displayed at your convenience, and are listed according to their payback periods.

Sometimes, you may need to replace a few household items, for example, an old refrigerator, incandescent lamps, or even you might need to purchase new items, such as an air conditioner, a double door refrigerator etc. You will lower your electricity bill when you remove items in use, and you would increase your bill when you add new items. This configurator will calculate your new electricity bill, based on the items you choose to add or remove.

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This tool uses the average wattages of common household electrical equipment. The tool will help you make choices based on;

(1) items you wish to replace, add or remove
(2) the tentative duration which these equipment will be operated