Wind Turbines vs. Solar Panels for Home — Which Is Better?

In the U.S., electricity generation accounts for 25% of national greenhouse gas emissions, slightly less than the top-emitting sector, transportation (accounting for 29%). About 60% of that electricity comes from fossil fuels—including natural gas, coal, and petroleum—even though this kind of energy is indisputably the most polluting. Increased concern for the climate crisis has propelled many to install wind turbines or solar panels at home. 

There are pros and cons to both. Wind turbines require more space (and, of course, an abundance of wind) but far surpass the efficiency of most solar panels. Solar panels are cheaper and more reliable but more difficult to recycle. Which is the better renewable energy source for you depends on many factors, from geographical location to budget.

Home Solar Panels

Solar panels can be installed on a roof or ground mount to convert sunlight into electrical energy for the home. The panels themselves are made up of photovoltaic cells that contain two layers of a semi-conductive material like silicon.

A home solar panel can produce between 150 and 370 watts of solar power, depending on its size and efficiency. According to the solar power company SunPower, the typical residential panel is 65 by 39 inches (about 17.5 square feet) and is 15% to 20% efficient. A 290-watt solar panel that gets five hours of direct sun per day will produce 1,450 watts—about 1.5 kilowatt hours—per day. Considering the average house in the U.S. uses about 29 kWh per day, 20 residential solar panels would be needed to completely offset an electricity bill.

Most at-home solar systems are connected to the grid—i.e., "grid-tied"—via a regular utility meter, unless they contain their own solar battery bank in which to store energy. Having a solar battery bank allows homeowners to tap into their own energy reserves when the sun isn't shining or when the grid goes down. However, solar battery banks can cost between $5,000 and more than $10,000. 

Cost of a Home Solar System

According to the nonprofit Center for Sustainable Energy, a home solar system costs $3 to $5 per watt. With 5 kilowatts being the average residential system, the upfront cost is between $15,000 and $25,000—not including the optional addition of a solar battery bank. There are, however, federal investment tax credits and state and local incentives available to offset the cost. 

The good news is that residential solar systems are virtually free to maintain. They require almost no maintenance save the occasional light clean and often come with 20- or 25-year warranties. Well-cared-for panels can last 20 to 30 years.

Environmental Impact

Although solar energy is 100% renewable, it isn't quite carbon neutral. The generation of solar energy alone produces no greenhouse gas emissions; but the manufacturing and recycling of the panels do. Fabricating photovoltaic panels requires the use of toxic chemicals—among them sodium hydroxide and hydrofluoric acid—plus an abundance of water and electricity. The mixture of materials—silicon, glass, plastic, and aluminum—also makes these panels difficult to recycle. Today, manufacturers and states are beginning to offer photovoltaic module takeback programs.

All things considered, generating enough solar energy to power your entire home can reduce your household carbon footprint (from electricity alone) by a reported 80%.

Home Wind Turbines

Wind turbines are another way to produce clean energy at home. They're composed of propellerlike blades connected to a rotor, perched on a tower ideally taller than surrounding trees and buildings. The turning of the blades causes the rotor to spin and send kinetic energy to a generator, which turns it into usable electrical energy (AC).

As with residential solar systems, home wind turbines can be grid-tied—the energy is sent to the grid via a special inverter—or off-grid, which requires a deep-cycle battery bank. You can also have a system that's both on- and off-grid, which would require both the special inverter and battery bank. This is an attractive option because it ensures you won't lose electricity during long spells of no wind or when the grid goes down.

The rotor diameter of residential wind turbines can range between 3 feet and 23 feet, and stand at least 60 feet to 100 feet tall. The general rule is to set the turbine 30 feet above any obstacle within a 300-foot radius of the tower. This deters urban green-energy seekers because most zoning ordinances restrict the height of structures to as low as 35 or as high as 100 feet.

Wind turbines can extract about 50% of the energy that passes through them, compared with the 15% to 20% efficiency of home solar panels. The U.S. Department of Energy says the typical residential wind turbine can produce 400 watts to 20 kilowatts of energy. A single 4.5-kilowatt turbine will produce 900 kWh per month (about the national average) in a location where the average wind speed is 14 mph.

Of course, whether wind is an efficient source of energy depends largely on the location. Wind turbines work best in flat, remote areas with few obstacles. The U.S. Department of Energy recommends wind power for people who live in an area with an average annual wind speed of at least 10 mph.

Cost

Although the cost of a home wind system varies by location, the average price in 2019 was $8,300 per kilowatt (so, about $41,500 for a system that would fully offset the average electric bill). That's about double the cost of a residential solar system, and turbines tend to cost more in maintenance than solar panels because they're prone to wind damage and lightning strikes, and they can typically only be repaired by specialized technicians. Again, tax credits and incentives are available.

Environmental Impact

Wind power is one of the cleanest energy sources available, producing an emissions footprint of just four grams of carbon dioxide equivalent per kWh produced compared to six grams for solar, 78 grams for gas, and 109 grams for coal. This includes the manufacturing, transporting, running, and disposal of wind turbines, which are designed to last about 20 years. Perhaps a more worrisome environmental pitfall, however, is that wind turbines can reduce and degrade natural habitats, and their constantly spinning blades sometimes collide with bats and birds.

Is Solar or Wind Power Better?

There are great benefits to both solar and wind power, both being considerably greener than traditional fossil fuel power, albeit significantly more expensive. Which is best for you depends largely on your space and budget. Solar panels are generally cheaper, more compact, and more widely tolerated in urban and suburban environments. They're also known to be a more reliable source of energy because they can absorb light on cloudy days whereas turbines only spin when it's windy.

Overall, though, wind power is the more efficient and environmentally friendly option. Turbines can harness 50% of kinetic energy from wind whereas today's photovoltaic panels harness only 15% to 20% of solar energy from the sun. Wind power currently has a lower carbon footprint than solar power, and a single home would need only one five-kilowatt turbine to fully power it, as opposed to 20 solar panels. 

Even though solar panels produce more predictable energy outputs than wind turbines, the latter continues harnessing energy through the night whereas the former only works during the day. As a bonus, it's potentially easier to find wind turbines made in the U.S.—therefore eliminating the carbon footprint of international shipping—than it is to find domestically sourced solar panels. Most solar panel equipment is imported from Asia (specifically, Malaysia, China, South Korea, and Vietnam), whereas wind turbine components are between 40% and 90% domestically sourced.

To live entirely off the grid without having to worry about intermittent blackout periods, the best (and most expensive) option is perhaps to install both a solar and wind power system. That way, you're almost guaranteed to have power throughout long, winter nights and periods of low wind.