When you look at the statistics, solar power seems to be at a disadvantage compared to wind energy. In 2017, 21% of the renewable energy produced in the US came from wind and only 7% came from solar power. Don’t let this fool you, however, because while wind energy is best suited for large-scale and utility applications, solar power remains the best solution for most households.
In short, it’s difficult to argue that one of these two forms of renewable energy is better than the other in all case scenarios. Which is better depends largely on where you live and just how much electricity you need, on average. Here’s why.
Solar vs. Wind: How Do They Work?
Whether to save money, be more energy independent, or just rid the environment of more polluting sources of power, an increasing number of home- and business owners are installing solar panels and wind turbines for their energy needs.
These technologies are rather new in terms of widespread, domestic use, which has led to a healthy a solar vs. wind debate surrounding benefits, drawbacks, costs, and effectiveness. But before we jump into pros and cons, how do these different forms of renewable energy work?
The basics of solar energy
The average solar installation for a home will include several photovoltaic (PV) solar panels installed either on the rooftop or somewhere near the house. The panels themselves contain a special kind of semiconductors that are made of silicone, a material which reacts to the energy of light by creating an electric current.
As light starts to hit the panel, an electric charge builds through the conductors. The charge is directed by an electric field to flow in one direction, thereby yielding direct electrical current (DC). DC power is then passed through an inverter, which transforms it into an alternating current (AC) that may be used by any home appliance.
Because of ever-growing prices of electricity, and scarcity of fossil fuels, various governments and state authorities now offer tax rebates for homeowners who are willing to install a solar system. As we will see, low maintenance costs also makes solar a winner in the solar vs. wind cost per watt category.
The basics of wind energy
Unlike solar cells, we’ve been harnessing the power of the wind since the invention of the first sailboats in the 1st millennium B.C. However, the first windmill designed with the purpose of generating electric power was built in Scotland, in the late 1880s. Throughout the 20th century, wind energy was mainly used to power buildings that were too far away from electric grids. The typical windmill looks just like a propeller mounted on top of a tower at a height that can vary from 50 ft. (15 m) to 120 ft. (36 m).
The way in which wind power works is quite intuitive. When the wind blows, the propeller blades start moving. These are linked to a shaft that is directly connected to a generator. The latter harnesses the energy input from the rotation and turns it into electricity, first DC and then AC by means of an inverter. In many instances, large enough systems that combine both wind and solar installations have allowed homeowners to go off the grid entirely.
As such, although the debate is often framed in terms of solar vs. wind energy, the two are commonly used together, since the absence of sunlight is usually correlated with increased low-surface winds and vice-versa.
Solar vs. Wind: Cost and Maintenance
Despite the fact that wind power is the cheapest and most environmentally friendly way we have to create electricity at present, two of the major points of dispute in the problem of choosing between wind versus solar energy are the costs and maintenance associated with either of them. Below, there is a list of known and likely expenses associated with each.
The cost of a solar power system
Judging the debate by the solar vs. wind cost factor, solar power systems are clear winners. To set-up, a PV installation capable of generating 5kW will require anything between $25,000 and $35,000. The costs vary widely depending on your location, availability of panels, and the number of companies competing on the same market. The federal tax rebate, or the ITC, will take 30% off any solar system you decide to purchase, while state subsidies can help you save even more. You can get the final net cost down to as much as $10,000 or under by using both local and federal credits.
From the solar vs. wind cost per watt perspective, namely how much energy a solar array is capable of generating, every square foot can generate 15W under direct sunlight. For a system that has 30 solar panels, each with a surface of 17.6 square feet, the solar system can output 11,000kWh every year. The U.S. national average cost for the installation of a solar watt is $3.1 before tax credit. Moreover, the maintenance of solar panels is quite carefree.
The installation features no moving parts, which makes it more durable, while yearly maintenance focuses on the inverter and any dirt accumulated on the panels.
The cost of wind energy
The typical cost of a wind turbine capable of generating 10kWh is anywhere between $40,000 and $50,000. These expenses can vary according to the same variables as with solar power installations, but the turbine might require more height (which further increases the costs) in order to be effective. The solar vs. wind cost per kWh is slightly tilted in favor of propellers, which manage a better $2.0 national average per kWh produced.
The trouble is that, unlike solar energy, wind power does not come with such generous subsidies. The best you can hope is to get the cost down to around $20,000 for an installation of 10 kWh capacity.
Furthermore, the most significant argument in the wind versus solar cost debate lies in the maintenance cost of each. Regardless of the turbine you purchase, there will be moving parts, which means there will be plenty of noise, a gearbox, and parts that will start to fall apart after a couple of years.
Wind Turbine vs. Solar Panel: Efficiency and Reliability
Now that we’ve looked at how these two systems work and what kind of financial investment each of them requires, it’s time to take the comparison down to what matters most: the effectiveness of wind versus solar. How good is a wind turbine compared to a solar panel and which of the two is more reliable long-term?
How effective is a solar panel?
The efficiency of a solar panel is given by how much of the sunlight it receives can be converted to electricity. Of the total number of photons that hit the earth in a particular spot, a solar panel will be able to convert about 15% to 20% into power that can be used in your home or business.
Panels manufactured by notorious brands such as Panasonic or Sunpower can reach efficiency ratings of up to 21%. Recently developed concentrating PV cells can increase these numbers to over 40%, but they are currently available only for utility purposes and not for conventional home use.
Generally speaking, the most cost effective panels available for home use will function at a conversion rate of approximately 17% to 18%.
How effective is a wind turbine?
In the case of wind turbines, efficiency is given by the amount of kinetic energy (resulting from the movement of the blades under the influence of the wind) that is converted into electricity. The average wind turbine will usually function at a 50% (up to 60%) conversion rate.
However, not all of this energy can be processed at a time. Due to the way electrical generators are currently manufactured, only about 45% (up to 50%) of the kinetic energy can be used at peak functionality.
Solar vs. Wind: Which Is More Efficient?
Of course, when you look at wind versus solar in terms of efficiency, you have to consider that the numbers represent different types of conversion rates and cannot be simply compared for clear results. In fact, the two forms of renewable energy can each be more effective in given situations.
For instance, for utility applications where massive wind turbines can be employed at just the right locations, wind energy is by far more efficient. Wind energy systems use less energy to function, are more environmentally-friendly, can produce electricity all day long, and have a greater overall power output. In fact, one massive wind turbine can produce as much electricity as several thousand solar panels.
However, wind turbines are actually impractical for most households. They require perfect (and high) positioning in order to function effectively and cannot be used in densely populated areas. They are furthermore quite noisy, as well as a terrible obstacle for birds. For these reasons, home- and small business owners often prefer to install solar power systems rather than wind turbines.
Solar vs. Wind Pros and Cons: A Summary
So when you put it all together, what conclusions can you draw in terms of wind versus solar? What are the pros and cons of each of these forms of renewable energy? And which should you invest in for your home or business?
The pros and cons of solar power
If you choose to go solar, these are some of the benefits you can expect:
- Solar panels can be mounted virtually anywhere or placed on the ground. Certainly, they will produce less energy if they are exposed to less sunlight during the day, but they will work nevertheless. In addition, solar panels can blend seamlessly into the design of your home, especially if you opt for solar shingles.
- Solar panels require far less maintenance than wind turbines. Basically, once the solar array is mounted and connected, very little maintenance is required on a yearly basis. This is mainly because solar power systems feature no moving parts and are therefore more durable.
- Solar panels are more predictable. Yes, they only work during the day, but once you’ve calculated the average output, you can rely on the fact that your solar power system will provide this amount of electricity on a daily basis.
- Solar panels are silent.
- Solar panels have higher lifespans and longer warranties.
One the other hand, some of the cons of solar power include:
- Solar energy is intermittent. Electricity is only produced during the day, while the panels are exposed to sunlight. To power your household during the night or power outages, you need to equip your system with one or several batteries.
- Solar energy is not cost-effective in certain regions. If you get very little daylight where you live, current solar panel technologies might not be enough to satisfy the electricity needs for your household.
- Not all roofs are suitable for solar panels. The size, angle, and orientation of your roof are all important factors that can decide whether or not it’s worth going solar.
The pros and cons of wind power
If a wind power is the renewable energy of your choice, then these are some of the benefits you can expect:
- The kinetic energy of the wind can be harnessed both during the day and during the night. This means that, so long as the wind travels at an adequate speed, your turbine can produce electricity on demand. Batteries are therefore optional rather than necessary.
- Wind power is cleaner. Especially because wind turbines do not require batteries to run, it is widely considered that wind power is more environmentally-friendly than solar.
- Wind farms are the ideal solution for utility or large-scale applications. This is mainly because a properly-positioned wind farm can generate electricity on a massive scale. The output of such an installation far outcomes the possible output of a solar power system using the same amount of space.
- Wind turbines are also a great solution for homes built by the coast or surrounded by fields. A farm in an area that gets sufficient wind, for instance, is perfectly positioned to benefit from a wind turbine.
- Wind turbines can be built offshore. For utility applications, wind turbines placed off the coast of a region can power thousands of homes and benefit from virtually constant wind.
There are, of course, some disadvantages to consider with wind power, particularly for small homes in crowded areas:
- Wind turbines must be perfectly positioned in order to be effective. At times, this means additional expenses to position the turbine high enough in the air. In densely populated areas, wind turbines are completely impracticable.
- Wind turbines require much more maintenance. They are constructed primarily with moving parts and are therefore more likely to become worn out. They are also more exposed to lighting and wind damage.
- Wind can be an unpredictable energy source. If your home is not located off the coast or in an area that gets constant wind, then there is no way to predict whether or not the turbine will function at maximum capacity from one day to the next.
- Wind turbines are noisy and hazardous for birds.
- Wind turbines are more expensive to install and to maintain, while subsidies for them are not as generous.
Overall, a wind versus solar comparison is highly susceptible to changes depending on the applications you have in mind and the region where you live. Even in terms of solar vs. wind cost per watt, both forms of renewable energy can be preferable – wind, for utility use, and solar, for households and small businesses.