Your Questions About Solar Energy And Solar Panels, Answered
8 - Minute Read
Sep 15, 2022
Are you considering adding solar power to your home? If so, you likely already know that solar power is more than a passing fad – it helps you do your part to combat greenhouse gas emissions and reduces your individual dependence on fossil fuels. In addition, it saves you money. (What could be more of a win-win?)
In this piece, we help answer general questions about solar energy, such as "How do solar panels work?" and "How does solar panel installation work?" We'll also walk through how to pay for and maintain solar panels and address many other frequently asked questions.
What's The Forecast?
Solar Panel General Questions
Are you already mentally putting solar panels on your roof, wondering how they'll look and how they'll work? Even if you are, you still might have some questions about how a solar panel works and other general questions, so let's dive into them.
How Do Solar Panels Work?
Most solar panels work by collecting solar energy from the sun, usually with a flat-plate collector on the roof of a building. Panels usually look like large sheets of black metal covered by glass. Solar panels are made up of photovoltaic cells (which are usually silicon), and these cells linked together make up a solar panel.
Photons, or particles of light, reach the solar cells and interact with the silicon. This interaction releases electrons which in turn generate direct current electricity. This process is called the photovoltaic effect.
When the sun shines on a solar panel, the photovoltaic cells absorb energy from the sun. Electrical charges then move in response to an internal electrical field in the cell, causing electricity to flow – the cell turns the light energy into electricity.
Do Solar Panels Work When It's Not Sunny?
While weather can impact solar energy production, photovoltaic panels can generate power with either direct or indirect sunlight – even when clouds partially block the light. However, solar panels are most effective in direct sunlight. Solar panels may generate 10% – 25% of their normal power output on a cloudy day.
How Do I Know If My Home Is A Good Fit For Solar Panels?
Here are some key criteria took look for when considering solar panels for your home:
- Average sunlight and weather in your area
- Average sunlight your roof gets: Ideally, your home will get will get full sun between the hours of 9 a.m. and 3 p.m. throughout the year. You can learn about the availability of peak sunlight in your area by checking the National Renewable Energy Laboratory (NREL) map. The more peak sunlight that shines on your home, the more solar energy it can generate.
- Roof material and condition: Solar panels are a long-term investment. If your roof is near the end of its life, consider replacing it before installing a solar system.
Even if you believe that your home is a good candidate for solar panels, an installer should come to your house to do a feasibility study of your property to determine how suitable it is for solar. If roof panels are not a viable option, an installer may suggest ground panels or recommend that you not get solar panels.
How Much Will Solar Panels Save Me On My Utility Bill?
The amount of savings you can experience depends on a number of factors, including where you live and the average cost of your electricity bill. A study conducted by the NC Clean Energy Technology Center at North Carolina State University researched the 50 largest U.S. cities and ranked them by best solar investment. During the first year after system installation, according to the research, individuals who invest in a 5kW solar PV system save an average of $44 – $187 per month.
You'll also save money over time. Use a solar panel calculator to estimate your solar potential and savings over time based on your address, electricity bill and roof type.
Can I Store Solar Power?
Yes, you can store solar power. Solar energy can be stored in a few different ways:
- Battery storage: Electrochemical batteries, commonly lithium-ion batteries, can store excess solar energy until its needed.
- Thermal energy storage:Thermal energy storage uses insulated storage tanks to boil water for energy generation.
- Mechanical storage:Mechanical energy storage converts surplus electrical power into mechanical power which is converted back into electricity for later use through pumped storage, compressed air storage or flywheel storage.
How Long Do Solar Panels Last?
Unfortunately, solar panels don't last a lifetime, but they might survive for the amount of time you live in your home. For example, if you plan to live in your home for 30 years, you might get the maximum use out of your solar panels.
National Renewable Energy Laboratory (NREL) data shows that solar panels degrade at a rate of 0.5% per year. After 20 years, a solar panel could produce about 90% of what it could when it was new. Solar panel manufacturers typically offer warranties of about 25 years or more; panels can last for 30 years.
Get An Estimate
Solar System Installation
How does someone install solar panels? We'll answer some specific questions about how that process works.
How Many Solar Panels Do I Need?
The number of solar panels you need depends on a few factors, including your annual electricity usage (the number of kilowatt hours you use in a year), the solar panel wattage you’re considering, and production ratios which refers to the estimated energy output of a system over time.
You can use a mathematical formula to estimate the number of panels you’ll need:
Number of Panels = System Size / Production Ratio / Panel Wattage
Most solar panels range between 250 – 400 watts of power. In most cases, a home needs 20 – 25 solar panels to cover all electricity usage, but it does depend on geographic location, panel efficiency, panel rated power and your family's energy consumption habits.
How Much Do Solar Panels Cost To Install?
The average cost to install solar panels is about $12,000 after federal tax incentives. You can install a smaller system for around $5,000, while higher range models can cost $40,000 or more.
Can I Install Solar Panels Myself?
Yes, you can install solar panels by yourself. However, there are some disadvantages to going it alone. You’ll need to obtain certain permits to start the installation and for electrical work. Even with the proper permits, you may not want to mess with high-voltage wiring. And keep in mind, buying a home solar kit may cost less but you don't get the same quality equipment that solar installers can offer.
Another important consideration: Equipment manufacturers will only honor their warranties if a qualified installer installs the equipment. Many installers also offer warranties on their own work, so the DIY route may not be worth it.
How Do I Find A Reputable Solar Installer?
Every state requires licensed, qualified installers to install solar panels. The North American Board of Certified Energy Practitioners (NABCEP), a renewable energy certification organization, maintains two directories to help you find qualified, accredited and certified installers: The NABCEP Company Accreditation Directory and the Certified Locator Directory.
The installer should also help you file specific permits and applications needed – you cannot connect to the grid without a certified electrician's confirmation.
What Is An Inverter And When Is It Necessary To Have One?
An inverter in a solar energy system converts the solar-generated direct current (DC) electricity, to alternating current (AC) electricity – this is what the electrical grid uses. ,/p>
In other words, most homes use AC energy, not DC energy, so you can't immediately use the current your solar panels use on their own. That’s where inverters come in.
There are three different types of solar inverters you can choose:
- String inverter: This type of inverter involves a string of panels wired together and connected to a single inverter, where the electricity is converted from DC to AC. These are also known as central inverters.
- Power optimizer plus inverter: Power optimizers are located next to or integrated with solar panels. They harness DC electricity from each panel and feed it to a string inverter. =
- Microinverter: A small inverter installed at the site of each individual solar panel that converts DC to AC in each panel.
How Are Solar Panels Installed?
A solar panel installer will make sure your shingles or tiles are adequately attached and prepare the electrical wiring to connect to your panel. They will install racks to support your panels, and once attached, the panels will nestle into the racking. Finally, the installer will connect the inverter and panels to the electrical grid. The entire process – installation, permitting, inspection and going live – can take between 2 and 6 months.
Paying For And Maintaining Solar Panels
Once they're up and running, what happens next? How do you pay for and maintain the solar panels? In this section, we'll discuss the different incentives available for residential solar systems. We'll also include information about any ongoing maintenance that’s needed, net metering and whether solar panels can increase the value of your home.
What Government Incentives Are Available To Reduce The Cost Of Solar Panels?
If eligible, you can claim a Residential Clean Energy Credit on the cost of completed installation on solar panels. The federal government provides a 30% tax credit for systems installed through 2032, 26% for systems installed in 2033 and 22% for systems installed in 2034.
You can also get state tax credits for installing solar, and the Tax Cuts and Jobs Act of 2017 placed a $10,000 limit on state and local tax deduction.
For more information, talk with your tax accountant about other deductions you could receive.
What Kind Of Maintenance Do Solar Panels Require?
Solar panels require little to no maintenance but may require cleaning every so often. Sticks, leaves, dirt and debris can collect on the panels and block light from getting to the panels. It's a good idea to check on your panels after storms, to make sure they are completely free of all debris.
What Is Net Metering?
Kind of like doing extra credit in school, net metering gives you a reward for going the extra mile. Put simply, net metering refers to a utility billing process that credits residential and business customers for the electricity they add to the grid. The billing apparatus allows you to “sell” your unused solar energy to your utility company.
Will Adding Solar Panels Increase The Value Of My Home?
According to Energy.gov, purchasing a solar energy system will likely increase your home’s value. In fact, even among certain market factors, a study showed that solar can increase the value of a home by about $15,000 on average.
What Warranties Exist For Solar Systems?
Solar panels have two primary types of warranties, a performance warranty and a product warranty:
- Performance warranty: Most manufacturers have a performance warranty that guarantees the performance of a panel will stay above a specified degradation rate for 25 to 30 years. This means that your system should produce a certain amount of energy during a specific timeframe. The provider will reimburse you to meet the production rate if your system does not perform the way it should.
- Product warranties: Product warranties help protect you from defects that show up on the product before or during the manufacturing process. The manufacturer may choose to repair or replace the product at their discretion.
Can You Fix A Cracked Solar Panel?
Things happen (baseballs, tree limbs, etc.) and you may wonder if a solar panel that cracks will still work. If a cell is minimally damaged, it should produce voltage. However, constant exposure will continue to erode the cells after they've been damaged. It’s unlikely that a damaged panel can be repaired, so it’s recommended to keep trees trimmed back and prevent damage risk as much as possible. Consult your solar panel installer or panel manufacturer if damage occurs to figure out your best next steps.