| Net energy metering or NEM is a way to encourage the use of eligible renewable energy electricity generators by residential and commercial customers. Hawaii Electric Light Company (HELCO) supports net energy metering as mandated by Hawaii state law. Here is information that we hope will be helpful. 1. What is net energy metering?
If you own or lease an eligible renewable energy generator, you may enter into an agreement with HELCO to connect your generator to the utility grid to export surplus electricity to the grid. Net energy metering means that any kilowatt-hours your renewable energy generator feeds to the grid will be subtracted from kilowatt-hours of electricity you obtain from HELCO to determine the net amount of kilowatt-hours you receive from the utility. You will be billed only for those kilowatt-hours. Here is the formula: Kilowatt-hours from utility
- Kilowatt-hours self-generated and fed to the grid
= Net kilowatt-hours 2. What is the value of net energy metering?
Net energy metering allows you to get more value from the electricity you generate with your renewable system. It allows you to offset the purchase of electricity from your utility against excess electricity produced by your renewable system at the retail rate. Net metering gives value to the excess electricity you produce from your renewable system. As an example, if you have a renewable system, you would first use electricity generated by your own system to supply your needs and purchase additional power you need at the regular retail rate. When your system generates excess power that is exported to the grid, you receive credit at the retail rate. Without a net energy metering agreement, you cannot receive that credit. Or, if you have a power-purchase agreement with HELCO, you are compensated only at the lower wholesale rate. 3. What types of generators are eligible?
Hawaii law specifies that net energy metering applies to solar, wind, biomass or hydroelectric generating facilities, or a hybrid system of two or more of these technologies, with a capacity up to 100 kilowatts. (For more information about these technologies, visit the website of the State of Hawaii, Department of Business, Economic Development and Tourism, Strategic Industries Division, Energy Branch). The Public Utilities Commission (PUC), by rule or order, can increase the maximum allowable capacity. 4. I am installing a solar water heating system. Does that qualify for net energy metering?
No. Net energy metering applies only to systems that generate electricity. Solar electric systems, known as photovoltaics, use solar cells to convert the sun’s light into electricity. By contrast, solar water heating systems use heat from the sun directly to heat water for your use. Since solar water heating systems do not produce electricity, they cannot feed into the grid and do not qualify for net energy metering. 5. How many customers can sign up?
Under the law, the cap on the total power producing capacity of generators signed up to take advantage of net energy metering is set at three percent of HELCO’s system peak demand. The PUC, by rule or order, can increase this percentage. The actual number of customers who can sign up before this cap is reached depends on the combined size of the individual renewable energy systems. Forty percent of the cap is reserved for systems of 10 kW or smaller. 6. Why is the number of customers who may sign up limited?
The cap is provided in the law for system engineering and cost reasons. It is necessary due to the system-wide impact that as-available distributed generation systems have on the costs and reliability of the electric grid. Most net energy metering systems only produce power as-available from the sun or the wind. This power generation fluctuates, sometimes very rapidly, which results in variations in how much electricity the customer takes from or sends to the grid. These changes can impact the reliability and quality of power delivered to all customers. HELCO must balance the power generation fluctuations from as-available sources, with the power needed by all customers by having stand-by dispatchable firm power ready at all times. As net metering increases, it becomes more challenging and costly to maintain stable power on the entire grid for all customers. Net energy metering customers get credit at the retail rate for self-produced electricity. The retail electric rate that HELCO charges includes not only the cost of producing electricity, but also the cost for facilities (e.g., lines, substations, etc.) to deliver power to customers, and for maintaining and operating these facilities, plus other costs such as billing. In essence, the customer who net meters is receiving a subsidy from all other customers. The cap enables HELCO to cost-effectively deliver reliable power to all customers, while adding renewable energy sources to the grid. Setting aside a percentage of the cap for smaller systems assures that a few larger systems will not deprive smaller generators of the benefits of NEM. 7. Do I need a new meter and, if so, do I need to pay for it?
New and existing net metering systems will require new meters able to track the amounts of electricity exported to the grid, in effect a meter that turns both ways. HELCO will provide the meter at no cost to you. You may be required to provide space for an additional metering socket if an added meter is required. Do not activate your NEM system before the meter has been replaced, because your bill will not be accurate. It is important to follow the NEM application requirements so that you will receive the appropriate energy credits for your system. 8. What happens to my electric bill if I generate more electricity than I use from HELCO?
Billing is on a monthly basis and you are responsible for a minimum charge even if you export more electricity than you use from HELCO. The minimum charge covers some of the fixed costs of maintaining your electric account, including reading your meter and billing. Unused credit (excess net generation expressed as a monetary value) is carried over monthly for 12 months. Unused credit left at the end of each 12-month reconciliation period may not be carried over to the next 12-month period. With net energy metering, you can only receive credit. Under the law, to receive actual payment for electricity exported to the grid (at wholesale rates) you must have a different kind of agreement, called a power-purchase agreement. 9. What do I have to do to sign up?
Call or e-mail HELCO early in your planning process to inform us of your intent to install a new NEM system, or expand the size of a current system. This initial contact can be made by you or your system installer. We will advise you of any special circumstances for your connection, such as whether or not an interconnect requirement study will be needed for your location and system size, and whether or not the system cap will allow for more systems on the HELCO grid. For official system approval for NEM – and before you install your system – you will need to submit specific documentation as required for your system. You can download the forms you need. Forms are also available from HELCO. You must obtain any building permits needed in Hawaii County. You must also have an inspection by a licensed electrical contractor to certify that your renewable system meets the necessary standards to ensure that it can safely be connected to the utility grid. In general, systems up to 10 kilowatts require a simple customer agreement with HELCO. Systems over 10 kilowatts and up to 100 kilowatts require a more detailed customer agreement, and also proof of an appropriate general liability insurance policy, for commercial or residential systems. The customer agreement will require you and the licensed electrical contractor who installs your system to certify that your renewable energy system meets the necessary safety standards and that an electrical permit was issued. For all systems, HELCO will perform an interconnection review. Unless a more detailed study is needed, this review will be at no charge. Additional costs for an interconnect requirement study, as well as any facilities needed to complete the interconnection, are the responsibility of the customer. Download the forms you need. Forms are also available from HELCO. For photovoltaic systems up to 100 kilowatts, the interconnection process is more streamlined if your system has an approved DC-AC inverter. Here is a list of approved inverters. On the HELCO grid, the inverter trip frequency must be set to 57Hz with a 300 second clearing time, and installers have been notified of this requirement. 10. Why are these requirements necessary?
These requirements are needed for safety, to ensure power reliability to all customers, and for accurate billing to NEM customers. Safety is a concern, because if your generator mistakenly back-feeds power into an electric line that the utility thinks is de-energized, our repair and maintenance crews can be seriously injured or even killed. Power reliability is a big concern on our island electrical grid. Renewable sources of energy such as solar and wind fluctuate with the availability and intensity of sunlight and wind. Large amounts of such distributed generation on the island grid can contribute to degrading power reliability and increasing costs for all. The variable output of these generating systems must be balanced with the load on the distribution circuit, and with the system generation capacity. These requirements help to assure that all customers continue to receive reliable service and good power quality, avoiding potentially disruptive power outages and swings in voltage levels that could damage both the customers' and utility's equipment. The NEM application also ensures that you will be billed accurately and provided the credit from your renewable energy system. Whether you are installing a new renewable energy generator or considering net energy metering for an existing generator, compliance with all safety and other codes is required. 11. How are requirements established for net energy metering?
The 2005 Legislature, by Act 104, gave the Public Utilities Commission authority – by order, tariff, or rule – to set requirements, limits, as well as safety, performance, and reliability standards for Net Energy Metering. 12. How can I get more information about renewable energy systems that might qualify for net energy metering on Hawaii Island?
Please call for more information:
E-mail: lvm@helcohi.com
General questions: 327-0519, 969-0343, or 969-0358
Billing questions: Hilo 969-6999, Kona 329-3584, Waimea 885-4605
For information on how to obtain a county building permit (if needed), call:
961-8331 (Hilo)
327-3520 (Kona) # # # | 
