Net Metering

Net-metering is the process of measuring the difference between the electricity supplied by Carroll Electric and the electricity generated by a net-metering facility that is fed back to the Cooperative over an applicable billing period.

A net metering facility is a system installed for the production of electrical energy that:

• 1. Uses solar, wind, hydroelectric, geothermal, or biomass resources to generate electricity, including, but not limited to, fuel cells and microturbines that generate electricity if the fuel source is entirely derived from renewable resources;
• 2. Is located in Carroll Electric's service area;
• 3. Can operate in parallel with the Cooperative's existing electric plant facilities; and
• 4. Is intended primarily to offset part or all of the net-metering customer requirements for electricity.

Yes, there are size limitations for net-metering facilities. Net-metering is intended to primarily offset part or all of a customer's requirements for electricity.

Residential Customers

For residential customers, a net-metering facility cannot have a generating capacity that exceeds:

• Twenty-five kilowatts (25kW) or
• one hundred percent (100%) of the net-metering customer's highest monthly usage in the previous twelve (12) months.

Non-residential Customers

Unless otherwise approved by the Public Service Commission, a net-metering facility for non-residential customers cannot exceed one thousand kilowatts (1,000 kW).

Once a net-metering facility is properly installed, a completed net metering agreement is submitted to Carroll Electric. If the net-metering facility effectively passes a Carroll Electric safety inspection, the Cooperative will then install a meter that can measure both the quantity and direction the electricity is flowing at that location.

The electricity the net-metering facility produces (in kilowatt-hours) is first used by your home or business. When your net-metering facility is producing more electricity than you are using at the time, the excess electricity is recorded by the meter as it flows back onto the Cooperative's electric grid.

• If you send fewer kilowatt-hours to the electric grid than Carroll Electric delivers to you in a billing period, the kilowatt-hours charge will be based on the difference between the kilowatt-hours used and the kilowatt-hours sent back to the electric grid.
• If you send more kilowatt-hours to the electric grid than you use in a given period, the kilowatt-hours charge will be zero ($0) for that billing period. However, service availability charges and other applicable fixed charges will still be applied to your electric bill.

The kilowatt-hours generated in excess of the kilowatt-hours used in a billing period are accumulated and credited to the account associated with the meter physically attached to your net-metering facility. These accumulated kilowatt-hours can also offset usage on future billing periods and/or multiple account locations that are under common ownership with the generation meter.

Please see the question “Can my net-metering facility offset electricity usage at my other Carroll Electric accounts?” for additional information on this subject.

To see Carroll Electric's net-metering interconnection process, click here.

To view Carroll Electric's net-metering tariff, click here.

The vast majority of net-metering facilities installed in Carroll Electric's service area are roof-top solar facilities. With that in mind, we have created a brief, yet informative document that may offer help in the decision-making process.

To access Carroll Electric's net-metering member disclosure, click here.

Maybe. The answer to his question is determined by several factors, and there is no clear-cut answer that accommodates every potential net-metering facility.

Current net-metering rules state, “If the electric utility's existing facilities are not adequate to interconnect with the net-metering facility, the net-metering customer shall pay the cost of additional or reconfigured facilities prior to the installation or reconfiguration of the facilities."

Carroll Electric will assess all potential net-metering facilities on a case-by-case basis in order to determine if the Cooperative's facilities must be modified to accommodate the proposed installation.

Yes. Some solar advertisements falsely claim that you can “eliminate” your electric bill if you install solar or some other renewable energy source.

While you can possibly reduce your overall electric bill with net-metering, there are some charges on your bill which simply cannot be avoided. One such charge is the service availability charge. Service availability charges were designed to recover a portion of the fixed costs the Cooperative incurs to provide electric service to its members. These costs occur regardless of how much electricity is supplied each month by the Cooperative.

It depends. The amount of electricity solar systems generate is dependent on several different factors. These factors include the characteristics of the solar system (power ratings, inverter ratings, capacity factors, degradation), the design and installation of the solar system (tilt, orientation, location), and environmental factors. It is important to evaluate all these factors in order to establish realistic expectations for your solar system.

PVWatts is a free online resource that can be used to review your solar system's expected production schedule.

PVWatts is an interactive web application developed by the National Renewable Energy Laboratory (NREL) that allows homeowners, businesses, installers, and manufacturers to easily develop estimates of potential photovoltaic (PV) installations at specific locations.

Power Ratings

Power ratings represent a solar panel's expected power production under optimal sunlight and temperature conditions. The power rating for solar panels tends to be stated in Direct Current (DC).

Inverter Ratings

With a solar power system, an inverter is responsible for converting a DC electrical current into an Alternating Current (AC) electrical current, the type of electrical current that normal home appliances use. The inverter's DC to AC ratio is an important parameter when designing a solar project.

Capacity Factors

Capacity factor is the ratio of actual electrical output to the total possible electrical output of a generation source. This ratio is usually expressed as a percentage. For example, if a 5 kilowatts DC solar system produced 7,500 kilowatt hours AC in year one, the capacity factor for the solar system would be 17% or 7,500 kWh ÷ (5 kW * 365 * 24). Capacity factors for solar installations vary and can range from 10% to 25%.

Degradation

Solar panels produce less electricity as they age. This process is called degradation. Manufacturer's typically guarantee 90% of the solar panels' production for the first ten (10) years. After ten years, that percentage drops to 80% for the remaining useful life of the solar panels.

Tilt

The tilt of your solar panels can have a major impact on the overall output of your system. Ideally, you would want to adjust the tilt of your panels throughout the year because the sun is higher in the summer and lower in the winter. However, systems that track the sun are more expensive and require more maintenance because they have moving parts. Every fixed tilt system, such as roof-top solar installations, has an optimal angle that will make the most out of each season, and, while a few degrees may not make a drastic difference in a single year the difference over the lifetime of the system could be much more substantial.

Orientation

Solar panels will generate the most energy if you optimize the orientation of your panels. In the United States, you will achieve optimal annual energy output, if your solar panels are facing due south.

Location

The location of solar panels can have a major impact on production. In both Arkansas and Missouri, the average peak sun hours are four (4) hours per day. Peak sun hours refer to how much sun exposure is useable for efficient energy production in an area and actually differ from hours of daylight exposure. Although your solar panels may get an average of 7 hours of daylight per day, the average peak sun hours are less.

Another item to consider that relates to the location of solar installations is shading. Solar panels are composed of individual solar cells, and if those cells are covered by shade, then they will not generate at full capacity. If a portion of your solar panels are shaded, the other panels will still operate, but it will decrease the amount of electricity that the system produces overall.

Environmental Factors

Solar panels work by absorbing the light from the sun - not the heat from the sun - and turning it into usable electricity. If the outside temperatures are too hot, it can actually hinder the performance of the solar cells and reduce the output of a photovoltaic (PV) solar panel system. In fact, the output of a solar panel is inversely proportional to the temperature of the panel. In other words, as temperature increases, panel performance generally decreases. The Temperature Coefficient of Power quantifies this relationship between heat and power output. It's expressed as a % Power / °C. The smaller the temperature coefficient of power, the better the panel will perform at higher temperatures. If you happen to live somewhere hot, a low-temperature coefficient will be important in maximizing your system's efficiency.

When we think about things that block the sun, we often think of trees and cloud cover but, on a smaller scale, you also have to worry about the dirt and debris that accumulates on solar panels and all other surfaces over time. This is referred to as soiling. If left unattended, standing dirt and debris can also limit a solar panel's production.

For Carroll Electric's graphic on how to read your net-metering electric bill click here.

Yes, but there are conditions. The current net-metering rules allow for meter aggregation if:

• The meters are under common ownership;
• The meters are located in Carroll Electric's service area;
• The customer must give at least 30 days' notice to Carroll Electric to complete the request;
• If more than one additional meter is identified, the customer must designate the rank order (no more than once every year) for the meters to which net excess generation is to be applied;
• Net excess generation shall first be credited to the net-metering customer's generation meter;
• Any remaining net excess generation shall be credited to one or more of the customer's additional meters in the rank order provided by the customer.

A generation meter can offset usage for multiple additional or aggregate meters. However, a generation meter cannot offset usage from another generation meter. In other words, an additional meter's usage cannot be offset by multiple generation meters.

Definitions

An additional meter (or aggregate meter) is a meter associated with the net-metering customer's account that may receive credit from net excess generation from a generation meter. An additional meter can be in a different class of service than the generation meter.

Net excess generation refers to the amount of electricity as measured in kilowatt hours that a net-metering customer has fed back to the electric utility that exceeds the amount of electricity as measured in kilowatt hours used by that customer during the applicable period.

A generation meter refers to a net-metering customer's meter to which the net-metering facility is physically attached.

Throughout the day, your home or business is actually using the electricity generated by your net-metering facility.

The Reverse Production (in kilowatt-hours) detailed on your electric bill is the amount of electricity your net-metering facility sent back to the electric grid. This is not the same as the total amount of electricity generated by your net-metering facility.

Reverse production occurs when your net-metering facility is producing more electricity than your home or business requires.

All things being equal, the reverse production kilowatt-hours listed on your electric bill should be less than the total kilowatt-hours your net-metering facility generates for the applicable billing period.