Wind vs. Solar

November 25, 2016

Wind vs. Solar

Why Solar is a Better Investment Than Wind 

Our heads up battle!

Ah, the question I get asked all the time: “Tyler, why are you recommending solar panels when everyone is putting up wind turbines?” There are a lot of misconceptions about wind and solar so I thought I would address some of those in this article.

First, this post is specifically designed to address systems located in Southern Iowa and much of the surrounding area. In areas with higher wind speeds and/or higher solar irradiance, the economics I am about to outline will be quite different. Also, this article will not address utility scale wind turbines (2.5 MW+). This is specifically a comparison of solar panels to small scale wind turbines for small businesses, homes, farms, etc.

MAINTENANCE

Solar: For standard arrays with a grid-tie inverter or micro inverters (i.e. those without battery backup), there is very little maintenance. On an annual basis, you should check connections, tighten bolts, clean the panels, etc. But honestly, if you are lazy with your maintenance, you probably aren’t going to have many problems. The advantage to solar is the fact that there are no moving parts. The sun shines on the solar cells and it produces an electrical current; it’s as simple as that.

Wind: Maintenance on a wind turbine varies greatly from manufacturer to manufacturer. For example, direct drive turbines requires very little maintenance because there are only a few moving parts. On the other hand, some turbines have a gearbox which requires annual maintenance. In either case, the manufacturer includes an annual maintenance schedule in their owners manual.

Winner: Solar

INTEGRATION OPTIONS

Solar: Solar panels can more or less be mounted anywhere and they will produce power; as long as they are facing the sun. You can mount them on the roof of a building, on the ground, on the side of a building, on the side of a pole, wherever; there are infinite mounting options for solar panels.

Wind: Wind turbines, at a minimum, need to be mounted 30 feet above anything within 500 feet. This presents a problem when you live in an urban environment or near trees. There are typically ordinances in place for maximum structure heights. But mainly, they just don’t work in town because there are too many objects that block the wind. Yes, I know, it seems windy in town, but it doesn’t even come close to the amount of wind outside of town when you look at annual averages.

Winner: Solar

MORE PREDICTABLE ENERGY OUTPUT

Solar: When I am calculating the estimated energy production of a solar array, I can safely use the same daily average for almost the entire state of Iowa. There is a slight difference when you get into the northern part of the state but the average is still relatively close. Since solar irradiance is so predictable, the inherent risk of the system is significantly lower than that of a wind turbine due to the fact that there are fewer variables.

Wind: Average wind speeds at a location are much more complex as there are many variables. You have to take into account all of your surrounds (trees, buildings, terrain, etc) and make an educated guess as to what the average will be. For example, you may have a 12 mph average wind speed in one location and then only average 8 mph half a mile down the road. If the wind turbine is not sited properly, you may not realize the return on investment that you expected.

Winner: Solar

WARRANTIES AND DESIGN LIFE

Solar: Most of the manufacturers with good quality equipment warranty their solar modules for 25 years. The warranty on inverters varies greatly but typically they range from 10 – 25 years. Most of the inverters we sell come with 25 year warranties. The design life of a solar array is 30 – 40 years (even considering minimal maintenance). Be careful though, you should take the company’s history into account when looking at warranties. If the company has a long history in the solar industry, chances are they are high on the bankability index. Bankability is essentially a measurement of the likelihood that the manufacturer will be around in 25 years to honor their warranty.

Wind: Most wind turbine manufacturer’s warranty their turbines and inverters for 5 – 10 years. However, you can typically purchase an extended warranty. The design life of a wind turbine varies between manufacturers but typically they estimate 20 – 25 years (some claim up to 40 years). Annual maintenance will be required to maximize the life expectancy of the turbine.

Winner: Solar

NOISE

Solar: Solar panels are silent during operation.

Wind: At higher wind speeds, its not uncommon for small wind turbines to operate in the 90 – 100 dB range. As a reference, a lawn mower operates around 100 dB.

Winner: Solar

LOWER COST PER KWH PRODUCED

Below, I will compare the net system cost of a solar array and a wind turbine, both with an annual energy output of 16,500 kWh.

Solar: 44 solar panels will produce 16,500 kWh annually. The gross system cost is approximately $39,000. After tax credits and depreciation (commercial systems only), the net system cost is $8,700.

Wind: A 10 kW wind turbine in an area with decent wind exposure (12 mph) will produce 16,500 kWh. The gross installed cost of the system is around $55,000. After tax credits and depreciation (commercial systems only), the net system cost is $22,137

Solar has a $16,000 lower upfront cost (29% reduction) and a 61% reduction overall.

Winner: Solar

As you can see, solar is the obvious choice on a small scale. It only starts to make economic sense when you look at it from a utility scale. From maintenance and noise to warranties and economics, solar wins in every category.

Tyler Anderson

by Tyler Anderson

  1. John

    Thanks for the detailed explanation. Very helpful.

  2. WowKhan

    As biased as it could be!
    What if you want electricity at night????

    • Depending on your utility provider, they may allow you to net meter. The utility would then act as a battery back-up so you can produce more energy than you need midday and then use those credits at night.

      Alternatively, we could install a battery bank to shift the solar production to different times of day. Battery technology has come a long way in the past few years and is now to the point of being economical. Even with this additional expense, the solar array would be more economical than a wind turbine.

  3. bob

    what would happen if it is a cloudy day

  4. bob

    what does the fox say?

    • Dingering

      Ring-ding-ding-ding-dingeringeding!
      Gering-ding-ding-ding-dingeringeding!
      Gering-ding-ding-ding-dingeringeding!

  5. Jamie

    Depending on where you live can affect the cost, for example Minnesota past a new lawallowing coop to evenly charge customers for energy regardless of solar or wind, because some were producing more to profit and the coop found this to be unfair.

  6. Blaine

    What happens if you want a solar powered house, would you like need to install lights and install extra to power lights or will the solar power the lights?

  7. secret

    this really helped out

  8. Khan

    I have read so many articles in recent days about Wind Vs Solar and every author has championed solar for some odd reasons or for their negligence of facts. The writer forget to mention that wind can in theory flow for 24 Hr and Sun is hardly out for few hours. To get better and more output from Wind you need to get wind turbine with higher blade span ( higher the blade span, lesser the wind speed is required to obtain the desired output). I guess most bloggers are not engineers they are just sales and marketing people who don’t have a clue how both technology works. If you require more guidance which system can work better for you, feel free to contact or study some research articles, refer to IEEE material which would provide you far more accurate information and data.

  9. Chris

    I have been off the grid for 10 years now and have only used solar panels. They are fantastic as long as the sun is out. But ever so often the sun could be in the clouds for 3 or more days. The first day is ok, but the second day, I have reduce power for the night. And if there is no sun for 5 days, I have to force myself to use a generator.

    So… Now I am looking at Wind power to supplement the time when the sun is not out. This will reduce the use of a generator, which is not even practical in my situation.

    Unfortunately, as I read about Wind power, there is a lot you need to know before you implement it. We all know about repairs, because you mentioned that. But you need a Charge Controller.

    The Charge Controller was easy as the solar panels uses this as well. But you need a DIVERT LOAD
    3 PHASE BRAKE SWITCH, RECTIFIER.

    Divert Load: You need somewhere to dump that extra current when your turbine is spinning more than your batteries could absorb. If you don’t have this WARNING.. your batteries will EXPLODE. No Charge Controller will prevent this as would your solar panels.

    View: What I understand about this, is the solar panel gradually generates power. But the turbine generator various from mild to extreme.

    3 PHASE BRAKE SWITCH, RECTIFIER: This device controls the rotations and functions of your turbine. If your turbine spins too fast, it will burn itself out.

    All of this will run you about $300.00 excluding the Turbine, which you can get a 400 watts at $200. This does not include the mast, cables and other accessories you would need to install your system.

    Is this bad? If you don’t have the resources. However, look at it this way. There really no guaranteed that it is going to be sunny everyday. Although the batteries offer a cushion, it is not the total solution.

    One thing I know about batteries, they are expensive. And Solar Panels require space to install.

    One thing about solar panels and batteries, you can have too much of one thing and not enough of another.

    What am I saying? For instance, I find my solar panels charging too much for the battery bank that I have. And other days, I had too many batteries for what the panels were putting out.

    I think the turbine would provide a balance. Because for the days I don’t have sun, I have wind. I won’t have to fill more needed space for more solar panels that become useless for times of good sun.

    Look at it this way, my power requirements are a lot higher in the Summer than in the winter. But the Sun plays less of a role in the Colder months.

    This is where a turbine would be good and that is why I’m looking into it.

    Sorry for such a long comment, but I think people need something more to go on, before they make their decision.

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