Solar Vs. Wind: Which Green Energy Source Is Best For Homes?

Many homeowners are looking for ways to reduce their utility bills and dependence on fossil fuels, and installing a home renewable energy system is an excellent way. Electric power production accounts for 25% of U.S. greenhouse gas emissions and produces a lot of air pollution; switching to renewable energy sources is better for the environment. Although both wind energy and solar power are options, solar is more suitable for most residential applications.

While wind turbines are more efficient at converting energy into electricity and are easier to recycle, solar panels may be a better fit for homeowners who want to produce clean energy. A solar system requires less space, is usually cheaper, and seldom needs maintenance.

Why Homeowners Install Solar Panels

The cost of installing solar panels has fallen by more than 60 percent over the last decade. Now, purchasing a solar energy system is affordable to many homeowners, partially due to tax credits and other incentives.

Solar panel efficiency has also increased significantly in the last couple of decades. Today’s solar panels are commonly between 15% and 23% efficient at converting sunlight into electricity.

This means that more home roofs have sufficient space to generate all the electricity the property needs. The average U.S. household consumes 10,632 kilowatt-hours (kWh) of electricity annually or 886 kWh monthly, but this amount varies widely. In addition, as efficiency increases, labor, shipping, racking and wiring costs also decrease because fewer panels are needed to produce the same amount of solar power.

The amount of solar panels a home needs to produce all its own power varies depending on location. If you live in California, Nevada, Utah, New Mexico, Arizona, Colorado, Texas or Florida, you live in one of the states with the most solar irradiance, or the highest power density of solar radiation.

Renewable energy systems are one of the few home improvements that pay for themselves over time. The solar panel payback period is between about 6 and 10 years in most areas, but it depends on the installation cost, available sunlight, the cost of electricity in your area and available solar incentives.

The cost of a solar system can even vary based on the property itself. For example, if your home roof is shaded and you must install the photovoltaic panels using a ground mount or on a detached garage, this usually increases the cost. Sometimes, if the roof is too shaded, homeowners may decide to join a community solar farm to purchase clean energy, but this isn’t an option in every state.

What Homeowners Should Know About Wind Turbines

Although wind energy has grown in popularity, most wind turbines are utility-scale and located at large wind farms that produce power for hundreds or thousands of households. Although residential wind energy is also an option, it is only viable for a small percentage of homes.

Wind turbines usually require at least one acre of land, so they aren’t conducive for most urban or even suburban properties. It’s best to leave enough space to raise and lower the tower as needed, plus room potentially for guy wires to support the tower. The output of a home wind turbine varies widely by location, and windy areas are obviously the most cost-effective. Therefore, proper placement is critical to maximizing wind energy output.

Remember that the wind resource on your property can vary depending on the exact location. Obstructions such as buildings and trees can slow down the wind, so it is best to place the turbine upwind from them.

Also, it is best to have the turbine 30 feet taller than any obstructions within 300 feet. Siting can be especially difficult in urban areas because there can be many obstructions. Likewise, zoning laws may limit where you are allowed to put a wind turbine. A qualified wind energy contractor can help you determine the best location.

Unlike solar panels, wind turbines require regular maintenance and can be unsafe without them. The U.S. Department of Energy recommends:

• Inspecting and tightening bolts and electrical connections as needed
• Checking the turbine for corrosion and the guy wires for adequate tension
• Looking for and replacing any worn leading-edge tape on the turbine blades, if appropriate
• Replacing turbine components such as blades or bearings as needed

A 1.5-kW wind turbine will generate about 300 kWh per month if located in an area with 14 MPH average annual wind speeds, which is about a third of the power that an average home consumes. Therefore, if you have a windy site for a wind turbine and your home consumes a moderate amount of energy, you will need between a 5 and 15 kW wind turbine to generate most or all of your electricity.

The payback period of your wind turbine will vary depending on the site's wind resource, how you finance the turbine, the cost of the equipment and installation and your electricity rate. The average payback is around 15 years, but this can be greater if the area is less windy or repairs are needed. The Office of Energy Efficiency and Renewable Energy has a Wind Energy Payback Period Workbook that helps calculate this.

Environmental Impact Of Wind Turbines And Solar Panels

Even though solar panels and wind turbines create green energy, the manufacturing, transportation and maintenance of renewable energy systems does impact the planet.

• The energy payback time (EPBT) is the required period a renewable energy system needs to be in operation before it has generated as much energy as it consumed throughout its lifecycle. This should include the energy used to mine, transport, refine, manufacture, decommission and eventually recycle components at the end of its life.
• The EPBT for onshore utility-scale wind turbines is usually between 5 and 8 months, but the EPBT of solar panels is longer, at 1 to 5 years, depending on the technology. Thin-film solar usually has a shorter EPBT than other solar PV technologies. Therefore, wind turbines have a smaller carbon footprint than solar panels.
• Many components on a wind turbine are readily recyclable, but the blades are an exception. Although most of the materials in solar panels are readily recyclable (glass, aluminum and silicon), they contain toxic metals like lead and cadmium, which are difficult to recycle.
• Wind turbines and solar panels are both proven ways for homeowners to reduce their carbon footprint, especially if they keep the system in operation for many years.
• Renewable energy systems have a smaller environmental impact when land doesn’t need to be cleared or severely altered for the project. Therefore, rooftop solar systems make efficient use of space, especially if no trees need to be removed. Likewise, wind turbines installed on farmland are an excellent option because few if any trees need to be removed.

Wind Energy Pros And Cons

Wind energy is praised for increasing energy security, reducing greenhouse gas emissions, creating green jobs and decreasing home energy bills, but it also has some drawbacks.

• Wind turbines are about 50% efficient at converting kinetic energy into electricity.
• The average cost of a 5 to 15 kW residential wind turbine varies widely between about $15,000 and $75,000 including the installation. However, federal tax credits and other wind energy incentives can significantly reduce this cost.
• A well-maintained wind turbine can last about 20 years. Inspection and oil maintenance should be performed twice a year on home wind turbines because unlike a solar system, they have moving parts. It is important to consider maintenance costs when considering the total cost of owning a wind turbine.
• Most wind turbines require at least an acre of land, which is ideally free from trees and other obstructions.
• Unfortunately, wind turbines are known to kill bats and birds, especially when they are located in bird migration corridors.
• Wind turbines need a strong wind resource to produce ample amounts of wind energy. Therefore, they shouldn’t be located on sites with insufficient wind or downwind from obstructions. The ideal sites for wind power production have average annual wind speeds of 10 mph or greater to have sufficient wind energy production.
• Wind turbines can produce wind power 24/7 and not just during the day.

Solar Energy Pros And Cons

When comparing solar and wind power, there are both advantages and disadvantages for each technology.

• Solar panels are about 15% to 23% efficient at converting sunlight into solar electricity.
• The cost of a 6 kW solar system is about $16,000 or $17,000 installed minus the value of incentives, such as the solar tax credit. This can vary widely depending on the area and type of panels installed.
• Solar panel maintenance is minimal, especially if you don’t need to clean them. If you need to clean your panel varies depending on if debris, bird droppings and dust accumulates on them.
• Most properties have sufficient space on the roof for solar panels unless it is heavily shaded or has a lot of obstructions, like skylights, dormers and chimneys.
• Rooftop solar systems do not have a major impact on wildlife. However, clearing land for utility-scale solar farms impacts wildlife habitat.
• A solar system can last between 25 and 30 years, but the inverter might need to be replaced.
• Most solar systems produce more electricity in the summer and less in the winter.
• Solar systems in sunnier climates will produce more electricity than in cloudy areas. For example, a solar system in San Diego or Phoenix will produce more solar power than an identical system in Seattle or Anchorage.

The Bottom Line: In Most Cases, Solar Beats Wind For Homes

Residential wind turbines can be difficult to site on many properties, especially if they are in urban or suburban locations. Although wind turbines have a smaller carbon footprint than solar panels and are easier to recycle, they require consistent maintenance and their energy output can be unpredictable.

Solar system prices have plummeted in recent years, so this technology has grown in popularity. Solar panel systems do not require regular maintenance and can produce clean power for 25 to 30 years. In addition, rooftop solar systems typically do not impact wildlife habitat unless trees need to be cleared, so they have a relatively small environmental impact.

Want to learn more about a solar energy system for your home? Contact a Rocket Solar Advisor today!