Over 250 properties supply GPL with excess power from solar generation

Currently, 290 properties with solar generation systems are supplying the Guyana Power and Light Inc (GPL) with excess power, under a Grid-tied and Net-Billing Programme. The initiative is spearheaded by the GPL and implemented nationwide in collaboration with the Guyana Energy Agency (GEA). Head of the GEA Dr Mahendar Sharma told this publication that 160 are Government buildings, 36 industrial and 94 commercial and residential. Grid-tied systems integrate a building’s solar PV system directly into GPL’s network. These systems operate by capturing solar energy through photovoltaic (PV) arrays, which are then converted by an inverter to power the building’s electrical load. Any excess energy is sent to the utility grid. The Net-Billing Programme allows customers with grid-tied solar PV systems to earn credits for any excess electricity that is fed from their PV system back into the utility grid. It provides an additional financial incentive for renewable energy adoption, while helping consumers manage electricity costs and contribute to living sustainably. A customer with a grid-tied installation is referred to as a ‘Prosumer’. The grid-tied and net-billing arrangement is formalised between GPL and the Prosumer through the signing of a Standard Offer Contract (SOC), which outlines the relevant terms and conditions. Under this arrangement, GPL will compensate the Prosumer for any excess energy exported to the utility grid.
During the commissioning of the US$8 million solar farm at Prospect in Region Five over the weekend, Dr Sharma encouraged more persons to get on board.
“You can use this money you gonna get…when electricity prices come down by 50 per cent…and invest it in energy efficient appliances and inverter refrigerator…and put some solar on your rooftop because that is going to further reduce your energy bill…and then when you don’t use the energy and you sell it to GPL, you’ll get 90 per cent of what you buy it at,” he explained. During the electricity billing period, if the value of the excess energy sent to GPL by the Prosumer exceeds the value of the electricity used by the Prosumer (delivered energy charge), then the difference is credited to the Prosumer’s Energy Credits Bank and can be applied to offset future electricity bills.

Energy credits bank
On the other hand, if the value of the electricity used by the Prosumer exceeds the value of the excess energy sent to GPL’s grid by the Prosumer, then the credits can be withdrawn from the Energy Credits Bank to reduce or settle net energy charge.
At the end of each 12-month period, any unused credit remaining in the Energy Credits Bank will be paid to the Prosumer at 90 per cent of the current tariff rate, after deducting any outstanding amounts owed to GPL. GPL has outlined several requirements in its Interim Technical Guidelines for solar PV grid-tied installations and customers seeking to establish an interconnection agreement. These guidelines cover compliance standards, system sizing and assessment protocols for larger systems. There are compliance standards where all solar PV installations must comply with the National Electrical Code 2014, particularly (but not limited to) Articles 690 and 705. Additionally, all interconnection equipment, including inverters, charge controllers and related components, must comply with Institute of Electrical and Electronics Engineers (IEEE) Standard 1547 and be certified under Underwriters Laboratories (UL) Standard 1741.
Additionally, customers may install systems rated under 100k-kilowatts alternating current (KWac) (inverter rating) regardless of their consumption, provided they meet GPL’s interconnection requirements. Systems 100-kWac and above are subject to approval based on the customer’s maximum demand. To further assist customers, GPL also provides a calculator to determine the size of the system allowed for installation. It is also outlined that installations rated 100-kWac and above will require an interconnection assessment. This assessment, conducted in accordance with GPL’s Grid Code and Interim Interconnection Requirements, must be completed before approval is granted. This process ensures that larger interconnections do not have negative impacts on the local distribution networks.
Moreover, GPL will conduct interconnection inspections to ensure that the proposed grid-tied installation can be safely integrated into the distribution networks. These inspections help to minimise technical and safety risks and mitigate security issues that result from non-compliant connections to the distribution network. It is illegal and unsafe to establish unauthorised interconnections with a GPL distribution network. Customers interested in interconnecting solar PV installations to GPL’s network must submit a formal request for Interconnection of Electricity from Solar Installations with GPL’s Network to the Divisional Director – Customer Services at GPL’s Main Street Office, Georgetown. The request must: identify the account where the grid-tied system will be installed; include the electrical one-line diagram and inverter specifications and be submitted solely by an account holder or an authorised person.