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Customers in Hawaii offered net metering


Hawaii was the 34th state in the US to enact net metering regulations. Metering International asked Hawaiian Electric Company Inc. (HECO) about its net metering programme for residential and small commercial customers. HECO and its subsidiaries MECO (Maui Electric Company, Ltd.) and HELCO (Hawaii Electric Light Company, Inc.) have supplied power to 93% of Hawaii’s
1.2 million residents.

MI: Why did HECO decide to introduce net metering?

HECO: We supported State of Hawaii legislation in 2001 to allow net energy metering because we felt it was a way to support the installation of more renewable energy systems by residential and small commercial customers. These are the groups that would have a harder time affording the installation of a renewable system. We worked very hard after the passage of the law to make it as simple and streamlined as possible for these customers to sign up. We quickly created a customer net metering packet (also available on our web site www.heco.com) with a brochure, a one page utility agreement and references to information about various renewable resources.

Figure 2

MI: How does your system work?

HECO: Small (under 10 kW) privately-owned renewable energy systems can be connected to a home or business without having to install an additional electricity meter. During the month, the meter will run forwards when the building is using energy, and backwards when the renewable energy system is producing more electricity than is being used.

So, instead of charging for or paying for electricity on a moment-by-moment basis, the total – positive or negative – at the end of the month is all that counts in determining the net metered customer’s electricity bill. If the net amount of energy used during the month is positive, the customer pays for that net amount.

But if the net amount is negative (in other words, the customer produced more energy than he used) the excess power is ‘granted’ to the utility. The customer will still pay a minimum charge to cover administrative expenses such as meter reading and billing.

Net metering, and the simplified interconnection agreement with the utility, make it easier and more cost effective for Hawaii residents and business owners to install small, on-site renewable energy systems.

Figure 3

MI: How many customers are on your net metering programme?

HECO: At 31 December 2003, HECO had 10 NEM customers, HELCO had 11, and MECO had 12, for a three-company total of 33 customers.

MI: What kind of technology are they using to generate power?

HECO: All systems through 2003 use photovoltaic technology.

MI: What tariffs are involved? In particular, are there different tariffs for net electricity consumers and net electricity producers?

HECO: No special tariffs are involved. Customers remain on the same tariff they were assigned prior to installing NEM systems. However, for tracing and reporting purposes the suffix ‘NM’ is added to the rate schedule designator. For example, a residential customer is on an ‘R’ schedule, while a residential NEM customer is on an ‘RNM’ schedule. The rate remains the same for both.

Figure 4

MI: What percentage per month of your customers are net electricity consumers, and how many are net electricity producers?

HECO: The Net Energy Metering statute was enacted in 2001, so it is relatively new. Consequently, at this early stage the percentage of net energy metered customers is statistically negligible. To illustrate HECO has about 275,500 customers, HELCO has about 62,500, and MECO has about 56,500.

MI: What impact has the additional data requirements as a result of introducing net metering had on your IT systems?

HECO: At this time none, because the bills are being processed manually.

MI: Which meters are you using for net metering?

HECO: We are using standard bi-directional meters for NEM systems. These meters can run forward to register the amount of electricity delivered to the customer and backward to ‘credit’ the customer for electricity exported to the utility from the customer’s NEM system.

MI: In what circumstances does HECO introduce an additional meter or meters?

HECO: Special electronic meters are installed on an as-needed basis at no cost to the customer. These meters are able to record electricity imported and exported by the NEM customer. They are temporary meters and are used when technical concerns are raised, either by utility personnel or by the customer.

MI: How do you enforce safety and performance standards?

HECO: The state NEM statute requires that all systems comply with the National Electrical Code, the Institute of Electrical and Electronics Engineers, and accredited testing laboratories such as Underwriters Laboratories, and the Hawaii Public Utilities Commission rules. These requirements have been adopted by our local County building departments. We accept NEM agreements only after the systems have passed County building department inspections. If we encounter safety or performance problems after we have accepted a system, we have the right to lock out the system until the problem is corrected.

MI: Thank you for your input.