There is growing interest among Clay Electric members in cutting their electric bills by using electricity generated by the power of the sun. So far, the co-op has 810 residential customers who have installed photovoltaic (PV) systems.
Increased interest in PV systems is reflected in a higher number of calls Energy Services Supervisor Glenn Stanley is receiving from members. The following article addresses some of these questions being posed by members, such as “how long will it take to recover the cost of a PV system?” and “what size PV system do I need for my home?,” and a very important question, “how much will a PV system cost me?”
How long will it take to recover the cost of a PV system?
Basically, photovoltaic systems are designed to offset all or a portion of the electrical requirements in the home.
Before deciding to spend thousands of dollars on a PV system, Stanley says it’s wise to evaluate how energy-efficient your home is, and how much your family’s lifestyle affects your energy usage. Without knowing this information, you really can’t determine the size of the PV system that’s right for your home.
Determining your home’s efficiency and energy consumption can be complicated, but Clay Electric can help. The co-op has three trained energy analysts who can perform an analysis of your home and ask questions which help determine the amount of energy a family might use each month.
“Sometimes it’s best to have a person trained in this process make these evaluations,” Stanley said. “After an analysis is performed, we can make recommendations as to where the member can best invest his or her dollars to make the home more energy-efficient. We can also point out areas that contribute to higher electrical bills.”
For some members, less expensive energy efficiency improvements around the home may be the most cost-effective way to reduce monthly electric bills. It’s best to investigate the energy efficiency improvements that provide the most bang for the buck before deciding to commit substantial funds to a PV system.
What size PV system do I need for my home?
If you’re still committed to going solar as a way to cut your power bills, you’ll need to determine the size of the PV system to meet your electricity needs.
“This is important, because the less electricity you use on a daily basis, the smaller your PV system will need to be,” Stanley said.
To determine your monthly electricity usage, review several electric bills. Each bill statement provides the kilowatt hour (kWh) usage for the month, plus an average daily usage figure.
“The daily average usage is the key number,” Stanley said. “For example, 1,500 kWh per month with a 30-day billing cycle represents 50 kWh per day.”
For members to realize a “net zero” electric bill (the PV system would produce enough electricity to offset the electricity used from Clay Electric), a PV system that generates 50 kWh per day would be needed.
“If your daily power usage is currently 50 kWh per day, and you have a PV system that provides 25 kWh, the PV system would reduce your electrical usage by half,” Stanley explained. “But if you wanted to cover your daily usage completely with sun-generated power, you’d need to install a PV system twice as big to realize a net zero bill.”
To further explain, PV systems are rated in watts. A 5,000-watt (5 kW) PV system can provide 5 kilowatts of electricity per hour under optimum conditions. According to Stanley, the Florida Solar Energy Center has determined there are 1,489 optimum solar generating hours per year, accompanied with hours of less than optimum generation. This means a 5kW system generates 25 kWh (5 kW x 5 hours per day) of electricity daily under optimum generation conditions.
How much will a PV system cost me?
According to Stanley, a general rule of thumb for calculating the cost of a PV system is $3.50 per installed watt. A 5,000 watt (5 kW) PV system costs approximately $17,500 initially. Currently, the federal government offers a 30 percent tax credit (you have to file income tax to qualify), lowering your out-of-pocket expenses to $12,250.
What about the cost effectiveness of a PV system?
Stanley figures it takes in the neighborhood of 10-14 years to recover the cost through lowered energy usage, using Clay Electric’s current electrical residential rate. While there are many reasons why a member might decide to purchase a PV system, he or she is the only one who can answer the question, “Is it cost-effective?”
What happens if there is an interruption in Clay Electric’s power?
“Unless you’ve invested in a battery storage-type PV system, you will not have the availability of electricity if Clay Electric experiences a power outage,” Stanley said. “The inverter portion of your PV system, which converts direct current generated by the solar panels to alternating current for use in your home, is designed to de-energize whenever power interruptions occur, and it remains off until utility power has been restored.”
There will also be times when your electrical requirements may exceed what your PV system can produce at any given moment during the day. That can occur, for example, when an air conditioning unit starts, which requires available electrical power of 20,000-plus watts.
“A member could be totally dependent on utility power during non-solar generating hours unless they have battery storage capabilities,” Stanley said. “Since utility power can’t be increased and decreased instantaneously, our power provider - Seminole Electric - has to generate at a generous capacity so electricity is available whenever it’s needed. Installing PV systems can reduce kilowatt hour requirements during the day, but during the evening hours and during times of instantaneous requirements, PV systems aren’t able to offset that demand.”
With the emphasis on folks “going green,” there’s growing interest in photovoltaic systems. The first step in going green is to start with your home’s energy efficiency, followed by your lifestyle. After these areas are addressed, then evaluate installing a PV system.
What about commercial members?
In addition to the federal tax credits, commercial members may be able to fully depreciate the system over a 5-year period.
What does Clay Electric require from me?
Clay Electric will install a net meter. The member/contractor will need to supply:
- an Interconnection Agreement
- a copy of Personal Liability Insurance
- ≤ 10kW requires $100,000
- ≥ 10kW requires $1,000,000
- PV Panel information
- Inverter information
- a line diagram of electrical connections
- a county permit
- a manual disconnect between the inverter and the home’s electrical panel