What Are The 2 Main Disadvantages Of Solar Energy? Solar Panels Cons

Solar energy may be a great step in the right direction, but it does come with several disadvantages. The first main drawback is that solar energy is reliant on the weather. The second is that solar panels can’t store electricity. 

What Are The 2 Main Disadvantages Of Solar Energy Solar Panels Cons

These are the main two disadvantages of solar energy, but there are some more drawbacks to cover, including their efficiency, cost, and potential toxicity.

We’ll cover more about the disadvantages of solar energy in this article, including how cloud cover affects solar panels, and whether solar panels contain toxic chemicals or not. 

The Main Disadvantages Of Solar Energy

Before we get into the article, here are the main drawbacks of solar energy for you to consider before reading the rest of this page. 

  • Reliant on the weather – clouds affect energy output
  • Solar panels need light, so they don’t work in the night
  • Can be toxic and over time, bad for the environment.
  • Costs a lot to install, especially if they require batteries
  • Not that efficient 
  • Solar output in watts relies on the sun’s energy, or irradiance, in a specific area.
  • Large area required for a big system
  • Full sun heats solar panels too much, lowering their output
  • DC Solar photovoltaic electricity output needs inverters to turn it into AC 

Pros And Cons Of Solar Energy

When solar energy was relatively new, one of its drawbacks was cost. Solar panels still cost a lot of money to install, but the price has fallen by a lot over the years. Many homeowners have considered solar panels to save them money on electricity overall.

Despite this, solar panels do have important advantages and disadvantages which need to be considered. 

Advantages Of Solar Energy

  • Doesn’t produce pollution after installation
  • Doesn’t need any moving components
  • Substitute for fossil fuels, lowering emissions
  • Creates more jobs
  • Renewable energy source, sun permitting 
  • Lowers overloaded power grids

Disadvantages Of Solar Energy

  • Production releases pollution
  • Made with toxic chemicals
  • Hard to and costs a lot to recycle
  • Energy output relies on the weather
  • Costs a lot for the average consumer to install
  • Cannot store electricity

We’ll explore some of the main disadvantages of solar energy in more detail below.

Main Disadvantage #1: Weather Reliant

Solar energy is a wonderful invention. It’s clean, doesn’t involve any moving components, and it can be used to save our planet.

Despite this, solar panels have a glaring drawback – that they don’t work unless the sun is shining. If there isn’t enough sunlight, the panels won’t generate any electricity. This is one of the main drawbacks of solar power. 

What Are The 2 Main Disadvantages Of Solar Energy Solar Panels Cons (1)

It may be a sunny day, but if shady clouds start passing by, a solar panel will stop producing enough power. This isn’t the case with geothermal power, another type of renewable energy source.

Geothermal energy is always available, but solar panels still have a few advantages over non-renewable energy sources. 

Are Solar Panels Efficient? 

The majority of commercial solar panels have between 18% and 20% efficiency. A few brands, like Dokio, can have around 25% efficiency, but this is still a low value.

To put this into perspective, every 1000 watts of the sun’s energy that touches the solar panel’s surface turns into 200 watts of electricity. The conversion efficiency rate isn’t that high. 

On the other hand, solar water heating, which uses the sun’s energy to warm water, has a 75% efficiency. What’s different here is that this process uses heat transfer, it doesn’t convert one type of energy into another. 

How Location And Irradiance Affect Solar Energy Output

Irradiance refers to how much of the sun’s energy shines onto solar panels. This changes with each location. 

For instance, the irradiance in London, UK, is 2.374. The figure changes for San Francisco, CA, with a value of 5.699. 

You can measure irradiance in kilowatt-hour per square meter each day, a measurement also known as peak-sun-hours. Solar installers need the irradiance value to work out how much energy a solar panel will create. 

The USA’s average irradiance is 4 peak sun hours. To work out how much energy a 100-watt panel will produce, you multiply 100 watts by 4 peak sun hours. This works out to 400-watt hours.  

Some locations with high irradiance may do well with solar panels, but others, like Alaska, may not find solar panels that beneficial.

Cloudy weather and low irradiance have the same effect, as they both prevent the sun’s energy from falling onto solar panels. 

How Cloud Cover Affects Solar Panels

Every solar power system will experience a few losses which affect how much power a solar panel produces. 

We can deal with some of these issues, like cleaning the solar panels regularly. However, some of these, like cloudy weather and gray skies, are harder to deal with.  

Bad weather can be responsible for shading losses, as much as 7%. If a general solar system of 6kW was affected, this is a loss of 420 watts, which is nearly half of a kilowatt.

If solar panels aren’t protected well, 60-cell solar panels can waste as much as 75% of power, even if just a single cell is affected. 

In reality, all the cells on a solar panel will be affected by lower irradiance, as cloud cover varies in different locations. As solar panels aren’t very efficient, all of these extra losses can add up over time. 

Shading Protection For Solar Panels

When home solar power systems had just started becoming popular, individual inverters were required to transform DC from the panels into AC needed by household appliances.

This method worked well as long as all of the panels were in contact with full sunlight. Despite this, if just a single solar panel became covered, the system’s output would reduce by a lot. 

Now, a popular solution is to install smaller groups of panels, or build micro-inverters around them. This reduced the amount of power that is lost to smaller components of the solar energy system. 

Types Of Shading Protection

Here is a list of inverters and power optimizers from least to most expensive. 

Central Inverter

  • Transforms DC to AC in a single area
  • Doesn’t monitor local panels
  • Entire system output affected by shading

String Inverter

  • Transforms DC to AC for multiple panels
  • Can monitor string
  • Just the string’s output can be lowered by shading


  • Transforms DC to AC on the panel’s plane
  • Monitors and optimizes the panel level
  • Shading can only affect a single panel’s output

String Inverter and Power Optimizer

  • Transforms DC to AC for multiple panels
  • Adds panel level MPP function – optimizes DC at panel’s plane
  • Shading can only affect a single panel’s output

Main Disadvantage Of Solar Energy #2 – Won’t Work At Night

Solar panels will not work when night falls. Research is looking into creating solar panels which operate at night, but as of yet, they don’t exist. 

Solar panels operate best in full sunlight, within 4-5 hours around midday. Their power output reduces drastically early in the morning and later in the evening. 

If power is needed at night when using an off-grid solar power arrangement, batteries will be needed. It can cost a lot to add batteries to a solar system, as much as 30% of the initial price.

This is another drawback of solar power.

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This is still undesirable for grid-tie systems, as power is removed from the grid when night falls. Just a couple of cloudy days can minimize the amount of savings connected to solar systems on the grid. 

One way of solving this problem is by installing home energy storage batteries. These can even be linked to the grid.

The batteries will always be recharged with electricity and ready to act as a power supply at night, or during electricity shortages. 

Disadvantage Of Solar Energy #3 – Bad For The Environment

Another important disadvantage of solar power is that while they are clean in action, solar panels are possible pollutants.

Solar panel brands provide warranties ranging from 25-30 years, which promise an output of 85% afterward. Solar panels can keep producing power for up to 50 years. 

Homeowners may choose to replace their solar panels once the guarantee period finishes. Replacing is better than living with lower output levels, especially if prices keep decreasing.

Thousands of solar panels are being installed at this minute, but if these will be thrown away in 25 years, where will they go?

Solar Panels And Toxic Chemicals

One of the main parts of solar cells is silicon. This active part is a level semiconductor. Most of the materials used to make solar panels are toxic heavy metals.

Other dangerous materials include sulfuric acid, nitric acid, gallium arsenide, and hydrogen fluoride. 

So if solar panels contain toxic materials, the question is, how can we dispose of them after their lifespan has ended? 

Many studies are looking into how to recycle solar panels back into usable ones. This isn’t possible at the moment, so the only way of disposing of them is by throwing them in landfills.

This isn’t ideal for the long term, as heavy metals, like lead and cadmium, will seep into the environment. Fully recycling solar panels can be done, but it costs a lot of money to do so.

You’d need to pay 3 times more to recycle solar panels instead of burying them in a landfill. 

Are Solar Panels On My Roof A Good Idea?

Solar panels do have their disadvantages, but they are still a good idea for producing electricity from renewable energy sources. However, installing solar panels on your roof comes with a few drawbacks. 

Here are some things to consider when thinking about installing solar panels on your roof. 

  • Your roof might not face the sun’s direction enough to produce enough output
  • The roof might be too small to install enough solar panels on it
  • Other structures or trees might shade the roof, preventing the panels from producing electricity

Installing solar panels can lead to other issues occurring too. For instance, if solar panels are installed incorrectly, they can leave holes in your roof.

These holes can allow water to pass through, which can cause a lot of damage to the outside and inside of your home. 

If you do want to install solar panels, thoroughly research different installation facilities and make sure your choice has several good reviews. 

Solar panels also need extra support to stay secure, as the panels do weigh a lot. If your roof isn’t strong or has any weaker areas, the heavy panels can flatten your roof as time goes on.

If this isn’t fixed, your roof may crack or even collapse under the weight of the panels. 

Before you install your solar panels, pay for an assessment of your roof’s integrity. This will ensure that your roof will be able to bear the weight of the solar panels. 

Lastly, if your solar panels are built-in at a steep angle, the panels may move over time, damaging the roof in the process. Panels that are installed too low or high can block gutters and lead to issues in your attic. 

These problems might affect any roof warranty that you currently have. Always check with your roof’s installation facility before installing solar panels to make sure that they won’t affect your coverage. 

Important Solar Energy Facts

Solar energy’s main drawbacks include how their potential toxicity affects the environment, the inefficiency of solar panels, and how they are so reliant on the weather and sunlight. 

Here are a few facts you should know about solar energy.

  • Solar panels have around 18% efficiency, which is very low.
  • Solar system output reaches 75% because of system losses
  • Monocrystalline panels cost more than polycrystalline, but they are more efficient
  • Solar photovoltaic systems require an inverter to change DC into AC
  • Solar panels have a lifespan ranging from 25-30 years. 


Most people believe that solar power is a great renewable energy source, but in reality, harnessing solar energy comes with many drawbacks. 

The main two disadvantages are that obtaining solar energy requires sunny weather, which isn’t always possible. The next is that solar panels cannot store electricity for later.

You’ll need to install batteries on them to use electricity at night, or during cloudy days. 

Another huge disadvantage is that producing solar panels involves toxic chemicals. As it’s currently too expensive to fully recycle solar panels, they are likely to be thrown into landfills at the end of their lifespan.

The toxic substances inside these panels will then leak into the environment, which defeats the purpose of using solar panels to save the planet. 

Solar energy is a fantastic idea, but much more research and development are needed before it becomes reasonably priced, environmentally friendly, and efficient.

Joe Danner