Because the installation of a solar panel system is expensive, and has such long-lasting implications (most panels last 25-30 years), it is very important to thoroughly and carefully consider the many aspects of installing a solar panel system before purchasing one. Because “green” energy is such a hot topic in today’s global environment, more homeowners than ever are considering installing solar panels on their home’s roof. Because of this increased demand, the number of companies selling and installing solar panels systems has increased in recent years. But not all of these companies have the best interest of their customers in mind. HES/energynet has learned that some solar salepersons are providing less than truthful information to prospective purchasers. As a public power utility, HES/energynet exists to serve the best interests of our customers. For this reason, we’ve put together the following information to assist our customers in the consideration of installing solar panels on their home.
If you would like to personally discuss any aspect of installing solar panels on your roof, contact HES at 887-0767.
Click on each line to view the answer.
General Solar Array Information
Technically, yes. However, for solar panels to operate at peak efficiency, they need to face due South at a tilt of approximately 32 degrees (an 8/12 pitch roof). As your roof direction and pitch vary from these “ideals”, the efficiency of the solar panels will decrease.
Possibly. A few things work against installing solar panels on homes in Kentucky. Mostly overcast winter months greatly diminish yearly electricity production from solar panels. And according to the U.S. Energy Information Administration, Kentucky is typically in the top 25% of all states for having the lowest electric rates in the U.S. Additionally, HES/energynet electric rates are typically some of the lowest in western Kentucky. So with less than ideal yearly sunshine, and lower than average electric rates, the benefit of solar panels is much less than in states with a higher percentage of sunny days and much higher electric rates.
Solar Panel Information
No. At this time, there are 4 main types of solar panels on the market. Each type varies in composition, efficiency, and cost. A quality installer can explain the differences and recommend the best type for you home.
Most solar panels have an estimated lifespan of 20-30 years. However, their ability to convert sunshine into electricity diminishes each year. Most solar inverters, the component that converts the DC power from the solar panels to AC power that can be used in your home, last approximately 10 years and will require replacing at some point.
Yes, but depending on the cloud density, the electricity produced can be greatly diminished.
Solar panels will create electricity even if dirty. However, for maximum efficiency, it is recommended to periodically wash them to remove the film of dust that tends to accumulate on the panels.
Solar panels typically have two warranties, a product warranty and a performance warranty. Warranty periods can vary from 10-25 years, so it pays to ask how long the warranty is for the panels recommended for your solar array. The inverters and batteries typically have warranties of approximately 10 years.
Purchasing a Solar Panel System
Only a quality solar installation company can provide an accurate quote to install solar panels on your home. They should ask many questions, as many factors influence the final cost. It is very important to ask for detailed information regarding the total cost of the system and the estimated financial benefits the system should provide. HES/energynet has created this webpage explaining how to perform a basic cost analysis for a solar panel system.
A qualified solar installation company can help you determine how many solar panels you need. Many factors, such as your goals for installing solar, your home’s electricity usage, whether you install a battery, your roof’s size, pitch and direction, and other factors all have to be considered.
Absolutely not! Some unscrupulous companies greatly exaggerate the benefits of solar and typically provide no calculations to prove their claims. They also tend to put pressure on customers to decide quickly. Solar installers in TVA’s Green Connect Program have been vetted by TVA to provide accurate information and high quality installation of residential solar panel systems. It also pays to obtain multiple quotes to compare system prices, component warranties, etc.
Because the TVA Dispersed Power Program only pays their “avoided cost”, or the cost to produce the electricity themselves, HES recommends that home owners install a battery system so that they can store and use most, if not all, of the electricity produced by their solar array.
At this time, there is a federal tax credit of 26% (thru 12/31/22) of the total cost of installing a residential solar array. This credit will decrease to 22% in 2023.
Solar panels typically have a warranty period of 20-30 years. Removing the panels and associated racking to install a new roof can significantly increase the cost of putting a new roof on the house. It is wise to consider the age of the existing roof before installing solar panels.
If you can’t pay cash for a solar panel system, a lease may be an attractive alternative. A third party installs and owns the panels and you make a monthly payment for the energy generated by the solar panels. However, you are not entitled to any tax benefits from the installation, and selling the house may be tricky because most leases are long-term. It pays to read the fine print to know and understand the pros and cons of a lease agreement.
Solar Generated Electricity
If you have a battery installed with your solar panel system, then yes. But the “run time” on your battery will depend on the size of the battery and the state of charge when the sun goes down and your panels quit producing electricity.
If you do not have a battery installed with your solar panel system, then the excess electricity flows back onto the grid to be used by other consumers. You may receive compensation for this electricity by signing up for the TVA Dispersed Power Program.
If you have a battery installed with your solar panel system, then yes. But your “run time” on your battery will depend on the size of the battery, the state of charge when the outage occurs, and the electrical load from you house. If you do not have a battery, then during a power outage, your solar inverter will shut down and not allow electricity to flow through to your house. Inverters are designed this way to protect utility workers from electricity from solar panels back feeding onto the grid during a power outage.
HES/energynet and Solar Panels
No. TVA is the purchaser of residential solar power in the TVA service area and currently pays their “avoided cost”, or the cost to produce the electricity themselves. That cost is typically 2-4 cents per kilowatt hour.
Any electricity generated by your solar panels and used by your home will reduce the amount of electricity you purchase from HES/energynet, lowering your monthly electric bill. However, most homeowners who install solar panels obtain a loan and make monthly payments. So even though your electric bill may be lower, you’ll also have a monthly loan payment. It is very likely that your electric bill and solar loan payment combined will be higher than your normal electric bill without solar panels being installed. It is very important to do a cost analysis comparing your total monthly energy-related expenses with and without solar before installing a solar array on your roof.
It is possible, but very unlikely. If you choose not to install a battery to store your excess electricity, you can sign up for TVA’s Dispersed Power Program (DPP). This program pays you at TVA’s “avoided cost” (approximately 2-4 cents per kilowatt hour), or the cost to produce the electricity themselves, for any excess electricity you put onto the grid. Since the typical HES residential rate is 8-9 cents per kilowatt hour, HES recommends that homeowners install batteries so they can store and use their solar generated electricity to get the most value out of their solar panels system.
During an outage, when the sun is shining, HES needs to insure that the electric lines are “dead” before allowing lineman to perform any repairs. When HES commissions a new solar panel installation, we test to make certain the inverter shuts down and does not feed power back onto the power lines during an outage. In addition, HES places special caution signs on poles near houses with solar panels to alert linemen to check lines for backfeeding when conducting repairs during an outage.
The commissioning of a new solar array involves two important steps. First, HES inspects the new electrical connections. Second, HES performs a test to make certain, that during a power outage, the solar array shuts down and does not back feed electricity out onto the power lines, which could endanger HES lineman performing repairs. In addition, HES places special caution signs on poles near houses with solar panels to alert linemen to check lines for backfeeding when conducting repairs during an outage.
