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Solar FAQs

Renewable Energy

Renewable energy is electrical, mechanical or thermal energy produced from a method that uses one or more of the following fuel sources: solar technologies, wind energy, geothermal technologies, wave or tidal action, hydro-power facilities and biomass.

Yes, as long as the interconnection follows procedures established to protect our customers and Mississippi Power employees. If your renewable generation is connected to your electrical wiring system, it is connected to the Mississippi Power electric grid.

There may be specific city, county, state or federal requirements for renewable generation particularly if you are considering applying for incentives or rebates. There may also be building and electrical code requirements and property association rules. Additionally, Mississippi Power has specific requirements for interconnection to our electric grid.

Yes. Working with the Mississippi Gulf Coast Community Foundation, Mississippi Power is contributing up to $3 million annually for a total of up to $15 million by 2029 to support both renewable energy and energy efficiency programs. The Foundation will strive to use 50 percent of the funds for the installation of solar or wind energy systems for nonprofit (501(c)3) or educational institutions. If you are a leader with such an organization and want more information about how you can participate in the program, contact the Gulf Coast Community Foundation at 228-897-4841.

Net Metering and Interconnecting to the Grid

Net metering is the process by which individual electric utility customers who generate electricity from renewable energy, such as solar panels, can sell their excess power back to their local utilities. The customers are compensated at a rate established by the Mississippi Public Service Commission for the electricity they produce and place on the electric grid.

No. When you install a renewable energy system at your home or business, the system will offset, or replace, at least some portion of the electricity you would have otherwise used from the electric grid. Net metering refers only to the process of exporting to the grid excess electricity from your system.

This is a function of both energy supply needed for the home or business at any given point in time as well as factors that cause changes in how much sunshine the panels receive, such as on a cloudy day and at night. When the PV system produces more power than is needed for the residence or business, the system will seamlessly export that excess power to the utility grid. This may happen many times a day, an hour, or even within a minute or second, depending on conditions.

For Mississippi Power customers, the rate paid for electricity placed on the grid by a net metered customer is 2.5 cents/kWh above the company's avoided-cost rate. For residential net metered customers that qualify as low-income customers, an additional 2 cents/kWh will be added to the avoided-cost value in addition to the 2.5 cents/kWh. These rates are established by Mississippi Public Service Commission rules.

Avoided-cost is the cost a utility would have incurred had it supplied the power from its generation resources. Mississippi Power's avoided-cost currently ranges from 2.29 to 3.62 cents/kWh, depending on the time of day and season of the year. This rate is from the company's most recent federal Public Utilities Regulatory Policies Act (PURPA) analysis of avoided costs and is also filed with the Mississippi Public Service Commission.

Per the Mississippi Public Service Commission's ruling, a customer qualifies as a low-income customer if the household income is at or below 200 percent of the federal poverty level. The low-income benefit adder will remain in place for a period of 15 years from the date the customer begins taking net metering service. The low-income benefit adder will only be available to the first 1,000 qualifying low-income customers. Any Mississippi Power customer may determine if they are eligible for the low-income rate for net metering by calling the toll-free number 1-855-847-0555 to speak with a representative from Catholic Charities. The customer will be directed to a representative, general information will be taken and customers will be provided a list of documents required for an appointment.

The Mississippi Public Service Commission established a limit of net metered generation capacity, measured in kilowatts, on the Mississippi Power grid at 3 percent of the company's total retail peak at the time of the company's total system peak. This value is recalculated on an annual basis. However, there is no limit on the amount of energy, measured in kilowatt-hours, that may be produced by net-metered customers.

Mississippi Power's step-by-step process for interconnecting to the company's electric grid and being able to net meter a renewable energy system can be found here.

No. Backup generators are not typically designed to be operated in parallel with Mississippi Power's electric grid. Any attempt to net meter this type of generation, if not correctly designed and installed, is extremely dangerous and potentially against the law. In addition, you should make sure your qualified solar installer or other renewable energy system installer is aware of any standby generator you have so that appropriate allowances can be made in the design of the renewable energy system.

Solar Energy

Solar energy has drawn a lot of interest as a way for residential and business electricity customers to generate a portion of the energy they use. The systems are typically mounted to the customer's roof, thereby not taking up yard or other space around homes and buildings.

Solar panels absorb energy from the sun by way of a semiconductor (typically silicon) and generate a direct current (DC) electrical source. An inverter is used to convert the source to an alternating current (AC) electrical source like that typically used in homes and businesses. Learn more about how solar works here.

Some of the key ways solar PV technologies differ is by temperature coefficient and efficiency. The temperature coefficient represents the relative change in power output with respect to the ambient temperature. Solar panel efficiency is related to the quality of the panels and solar cell technology (monocrystalline, polycrystalline, thin film). Panel efficiency commonly ranges from 12 percent to 21 percent with respect to the cell technology.

Probably, as long as the location selected is clear of obstructions that will block sunlight and there is sufficient south-facing or west-facing roof or land areas. Some shading may be unavoidable, but you want the system to have direct sunlight most of the time. Your qualified solar installer should be able to measure or calculate the degree of shading that would affect the system's operation. If the system is roof-mounted, factors such as the age, type and condition of your roof are important to consider.

It is highly recommended you use a qualified solar installer for PV installations. Compliance with local building and electrical codes may be required.

Mississippi Power recommends using a qualified solar installer certified by the North American Board of Certified Energy Practitioners. Mississippi Power recommends that you obtain multiple proposals prior to committing to a project.

Learn more about NABCEP and find certified professionals in your area here.

Price is only one factor to consider when selecting a qualified solar installer. Here are some other things to consider:

Is the company certified?
Is the company experienced?
Will the company provide a copy of its current business license?
Does the company have any judgments or liens?
Will the company provide references?
Does the company have a record with the Better Business Bureau?
How many systems has the company installed in the last year?
How long will the installation process take?
How long will the company monitor the installations after they are completed?
What is the warranty period? What does it cover?
What repair services are offered? What are the rates?
What type of operation or maintenance training is available?
Is the installer able to measure or calculate the impact of any shading of the PV system?
Does the installer guarantee energy production or energy cost savings?
Does the installer offer financing? What is the interest rate? What are the total financing charges?
Will the installer provide any assistance or support in filing for any available tax credits?
Is the installer familiar with your specific utility rates and policies?
What is the estimated simple payback, in years, of the proposed solar system?
What assumptions does the installer make about future utility rates in their analysis?
Are any maintenance or repair costs included in the proposal?

Battery storage is required for PV systems to provide power at night. However, this method requires additional maintenance and can be costly. Most customers remain connected to the grid for access to continuous, reliable electricity at all times.

Yes, clouds can disperse or block sunlight. This in turn will restrict the amount of sunlight absorbed by the solar panels and can reduce the energy output by as much as 90 percent or more.

Yes. Efficiencies differ based on panel material and quality. Typical efficiencies range from 12 percent to 21 percent.

The output of a panel is a function of the panel efficiency but typical output values range anywhere from 125 watts to more than 300 watts.

A typical PV system that is economically feasible will not have the capability of providing enough power to supply an entire home or business without support from the utility grid. Many electrical appliances, particularly air conditioners, require large electrical currents to start and run. This becomes more feasible if batteries are included in the PV design, but this may cause the system to no longer be affordable or economical.

In order to become a net metering interconnect customer in Mississippi, the size of a residential PV system must be 20 kW or less. For a commercial or industrial PV system, the system must be 2 MW or less.

PV system size is directly related to how much generation you need and the available area you have. By observing your monthly and annual usage, you can calculate your ideal PV system size. This is a topic you should discuss with a qualified solar installer.

Residential panels can vary in dimension but are typically around 5½ feet x 3 feet.

A typical residential system is approximately 4kW, which is a common size for a residential application. A good area estimate is about 70 square feet per kW using a 250-watt panel.

A 4-kW system (1 kW = 1,000 watts) might be composed of 16 250-watt panels. This could be arranged using two rows of eight panels with a width of approximately 24 feet and a height of approximately 11 feet.

Currently, the initial installation cost of a small roof-mounted solar PV system typically averages between $3-$4 per watt. Therefore, a 4,000-watt system may cost around $12,000 to $16,000. Variables specific to the installation site, available incentives and tax credits can change the price significantly.

Most solar panels are under warranty to produce 80 percent efficiency for 20-25 years, though some panels have been known to perform in excess of 40 years. Other components of the solar energy system have other lifespans. For example, micro inverters typically carry a manufacturer's warranty of 25 years, while string inverters typically carry a 5-year to 10-year warranty.

Yes, minimal maintenance is required. Panels should be cleaned of debris and anything else that can block the sun to ensure maximum output. Some components may need regular inspection by a professional. It should be noted that most small PV systems are located on roofs. Special care should be taken if working on the roof and while using ladders. Be aware of any electrical lines that may be in the area.

There are many variables that are involved in establishing the efficiency of a PV system. These variables include but are not limited to: amount of available sunlight (irradiance), ambient temperature, clouds, wind speed, optics (glass clarity), contamination (debris) on panel, electrical losses, and of course the quality of the system itself.

This is a question for your insurance company. It is strongly advised you consult with your insurance provider prior to installing a PV system.

Islanding, also known as feed back, is a term used to describe a situation when electricity from your utility has been lost but the solar PV system continues to export power to the grid, causing a dangerous condition for utility employees and others. Inverters must adhere to the UL1741 standard which prevents this situation.

This standard requires inverters to be designed in such a way that they shut down after sensing that the utility power supply has been lost. This is a safety design that prevents the hazardous condition of islanding. The PV system must wait five minutes before reconnecting to the grid after utility power supply is restored.

An uncapped 30 percent federal income tax credit is available for solar equipment purchased and installed by Dec. 31, 2019. If purchased and installed during 2020, the credit is reduced to 26 percent and further reduced to 22 percent if purchased and installed in 2021. There is no credit for systems purchased and installed after 2021. Please consult your tax advisor to determine how this federal incentive may apply to your particular circumstances.

Find information about tax incentives at the Database of State Incentives for Renewable Energy.

Mississippi Power does not currently offer a community solar program but could offer one in the future.