Photovoltaic Systems (Solar)
The following information is provided to assist you in this decision making process and help you to get the most out of any solar purchase, should you elect to make one.
Parts of a PV system and installation.
There is more to a PV system than just the solar panels. A typical PV system not only consists of solar cells linked together to form solar panels, but also an inverter to convert the electricity from direct current ( DC) into alternating current (AC), the mounting system hardware, and the wiring needed to connect the PV system to the home or business’ electrical system. The PV panels can be mounted on a roof, or on a stand-alone mounting system, which is typically a pole or a system of racks.
For greatest efficiency, the panels need to face southward and be in direct sun throughout the day. The inverter(s) should be certified by Underwriters Laboratory (UL) 1741. This UL certification insures that, in the event of a power outage, the PV system will shut down and will not back feed electricity on to the electric distribution system which could potentially create an unsafe condition for line workers or other customers.
How much electricity will it produce?
The output of a PV system depends on a number of factors include the direction it faces, the shading, the tilt, the efficiency of the panels, and several other parameters. It is recommended to thoroughly review the type, size and make of the various components of any system you are considering installing.
Keep in mind that your peak output will be based on the output of the inverter, not necessarily the size of your panels. Therefore, if you install a 300 Watt DC panel, but your inverter is only 250 Watts DC, then you will not be producing to the maximum capability of your panels. Also, there is typically some energy loss between the panel and the point where it enters your home’s electrical distribution panel.
The following calculator can provide you with an estimate of what you might expect to produce, from an energy prospective, in our geographic area: PV Watts (National Renewable Energy Laboratory).
Sawnee EMC Monthly Billing with a PV system Installed
Sawnee EMC offers a Net Energy Metering Rider (“NEM”), which complements any standard rate, for accounts with PV systems that meet certain program requirements and limitations. By qualifying to receive service under the NEM Rider, a SEMC member will be able to directly benefit from the electricity their PV system produces.
A NEM Rider account, which has produced more energy than the account used at the end of the billing period (“net negative” usage), will receive a credit based on the amount of excess energy they have produced, multiplied by the rate specified in the NEM rider, as well as any other applicable charges. Qualifying NEM rider participants, when they do not “net negative” for the month, will continue to be billed for energy purchases at their applicable SEMC rate schedule; the NEM Rider only enters the equation when excess energy is produced in a given billing period.
Choosing the size of a PV system
The size of a PV system should depend on a number of factors including economics and the amount of available space for the PV system including the panels. Questions such as “do you intend to fully offset your electric bill”, or “do you simply want to offset a portion of your usage?” need to be answered to properly size the PV system.
With this in mind, you should first decide how much available space you have and where the panels might be installed. Then review your kilowatt-hour (kWh) consumption over the past 24 months and make your determination as to which system you feel might benefit you.
Also, if you want our staff’s assistance, you can contact Sawnee EMC’s Marketing Department at 770-887-2363 ext. 7133 to discuss your current usage and options with a Marketing Representative.
Getting a Proposal
We would suggest that you carefully study any proposal that you receive for the installation of a PV system. Proposals should include items such as: site surveys which include roofing evaluation if installing on a roof, an electrical assessment, and any shading impacts in the proposed installation area. The proposal should also include performance estimates (both monthly and annual energy production). Your site survey may include a value assessment or pay-back calculation. We would suggest that you compare your “existing” SEMC electric energy bills, without the effects of a PV system installed, to these proposed performance calculations to determine how much money you may be estimated to be saving each month.
Make sure any value assessment or payback calculations adequately projects the future energy costs of electricity when using Sawnee EMC’s future rates as a comparison. Although we can’t fully predict energy costs in the future, Sawnee EMC’s past history has proven we have kept electricity costs at a very consistent rate. Finally, be sure to use the PV Watts calculator to see if the performance calculations on your proposal makes sense.
I want to install a PV system, what do I need to do?
If you have decided that a PV system is right for you, then be sure to review the Sawnee EMC interconnection requirement documents needed in the hyperlinks on the right side of this page to:
- Make sure you have completed and signed your Sawnee EMC membership application,
- Submit an interconnection notification prior to installation,
- Be sure your system meets National Electric Code (NEC) guidelines, the inverters are Underwriters Laboratory (UL) 1741, and it meets all other applicable requirements found in the SEMC application, and
- After Sawnee EMC receives the required interconnection documents, your PV system will be reviewed.
Upon approval for interconnection, and that you are approved to participate in our net metering program, your meter will be reprogrammed to reflect NET metering
What does Sawnee do with my PV information?
Sawnee EMC uses the information relating to your PV system to conduct an engineering assessment of the site, and our distribution facilities in the area to ensure we can maintain reliable service in your location and those around you.