Solar Panel Efficiency vs. Photosynthesis

Are plants more efficient at converting sunlight to energy than solar panels? It is an interesting question. It is also a little of comparing apples to oranges.

Still, in terms of straight efficiency, plants are far less efficient at converting sunlight via photosynthesis than solar panels. 

In this blog, we discuss: 

  • Energy production goals vs. energy production efficiency
  • Why plants need less sunlight to make energy
  • Which is better, solar energy or plant energy from photosynthesis
  • The similarities and differences of plants and solar panels
  • The efficiency of solar panels vs. photosynthesis
Close up of a leaf Photosynthesis

Solar panel efficiency vs. photosynthesis

There is no doubt that solar panels are more efficient at collecting sunlight than plants through photosynthesis.

The key, though, is to understand that both are highly successful in each goal. 

Plants have an added job of creating energy that supports their lives, and their jobs at achieving a healthy life do not stop when the sunsets. 

Solar panels shut off without sunlight, but plants continue to use the energy they bring in to support all of their systems. 

They are akin to a solar array with a battery backup, and they store enough energy to support their ongoing needs. 

The efficiency of photosynthesis is less than two percent. It can be as low as .01 percent, whereas solar panels, at least a high-efficiency solar panel, can have an efficiency rating of 17-23 percent.

What does that mean? Efficiency is the percentage of sunlight that the panel or plant takes in, compared to the total amount of sunlight that falls on a leaf or a solar panel. 

Why the big difference in efficiency ratings? 

Without getting overly science-like, plants have a lot more challenges to deal with than a solar panel does. Their solar receptors (leaves and stems) are not stationary.

They are not flat, and they are not always positioned in the best location to receive the best sunlight. 

Also, plants do not need to take in 400 watts of energy because their needs are straightforward. 

They produce energy not specifically from sunlight but through a chemical breakdown of bonds that hold molecules together.

Thus, their energy needs are also limited. That is the apples to oranges view. If given a situation where the needs of plants changed and more energy was a requirement, plants would likely evolve to become massive producers of energy. 

See also: Alternatives To Solar Panels For The Home (Great Options)

Are plants or solar panels more efficient?

How you answer this question depends on the goals you have for energy creation and usage. In terms of pure energy collection – solar panels are far more efficient at collecting the sunlight that strikes their surface.

At best, plants take in about two percent of the sunlight that they receive. Solar panels take in 17-23 percent of the sunlight that strikes their panels. 

The difference in efficiency for solar panels is due to factors such as:

  • The brand of the solar panel
  • The number of solar cells in the panel
  • Its position and facing direction 
  • The location of the building on which it is mounted – farther north vs. equatorial. 

Plants also have challenges collecting sunlight which include:

  • Differences between plant species – some are more adept at capturing sunlight than are others
  • Energy needs, plants do not need as much energy as a house would. 
  • Position of leaves
  • Leaf structure – leaves are rarely flat 

Plants also are not 100 percent reliant on sunshine for energy production. They can use soil nutrients in conjunction with sunlight and water to make energy.

That means they do not need as much sunlight since their recipe for energy is broader than that of a solar panel.

A solar panel must have sunlight because that is the primary source that generates the actions that create energy. 

How does solar energy compare to photosynthesis?

The goals of both are very different. Solar energy production has goals that focus on energy levels to power objects that may not be life-sustaining, only convenient.

On the other hand, a plant must support its life force using photosynthesis, and that process includes more than just sunshine. 

Another big difference is that plants are a complete energy production life form. 

They continue to use the energy they collect during the day to power food and energy production at night. Solar systems shut down at night. 

Which is better at capturing the energy from sunlight leaves or photovoltaic cells?

In terms of pure efficiency, solar panels are much better at capturing sunlight than are plant leaves. However, it is essential to understand that energy goals are different between plants and solar panels.

Because plants do not rely 100 percent on sunshine to make energy, they do not need as much sunlight—their evolution changes based on plant species, as does the amount of sunlight needed. 

Plants use sunlight, water, and soil nutrients to create energy. 

Then, they use the stored energy in chemical bonds to power their life systems. For example, a solar panel uses sunlight, which interacts with the solar enzymes to create energy.

Plus, solar panels need to produce more energy because the demand for energy in a house is much greater than the demand for sunlight by plants. 

one-way leaves are different from solar panels. 

The structure of a leaf and the size of its solar cells make them very different from solar panels. The flat surface of solar panels must be repositioned to collect as much solar energy as possible.

Because most leaves cannot follow the sun, they adapt a physical structure that is textured, bumpy, or with tiny fissures that cause specific cells to point in different directions. 

So, whereas the solar panel repositions itself to follow the sun, the leaves on a plant use the tilt of position from its physical structure to collect as much sun as possible. 

Percentage of sunlight used for photosynthesis 

Each plant species is different, but in general, only about three percent of sunlight is used during the photosynthesis process.

So, for example, even a low efficient solar panel would use around 14-24 percent of the sunlight that strikes its surface. 

How are plant cells and solar cells similar 

Plant leaves and solar panels are similar in that they both use the photons from sunlight to produce a form of energy.

However, they do not produce the same type of energy. 

How are solar panels and photosynthesis similar? 

Both have designs that capture sunlight and turn them into energy. There is a dye-Sensitized type of solar panel that comes close to mimicking photosynthesis.

The process works by capturing excited electrons and then funneling them into a cell similar to a chloroplast. A chloroplast is a specialized cell in plant leaves that captures sunlight and converts it into a chemical form of sugar.

In the dye-sensitized solar panel, the excited electron is shuttled down a circuit where its energy becomes electricity. 

What energy does a solar panel use? 

Solar panels use energy from the sun—specifically, photons to produce electrical energy. The process is purely electrical, whereas a plant uses sunlight to produce a chemical form of energy. 

Are solar panels based on plants? 

The idea of solar energy comes from plants, and one type of solar panel uses a dye-sensitized cell that mimics photosynthesis, but there is a big difference. Solar panels produce electrical energy. Plants produce chemical energy.

Can plants be used as solar panels? 

Technology is on the brink of using plant waste to produce electrical current. The process works by extracting the photosynthesis cells and chloroplasts applied to a solar panel.

The panel then uses sunlight captured by the chloroplasts to produce an electrical current. However, the technology is very new, and not much information is available on the statistical results. 

How are plants and solar panels different? 

The big difference is that plants produce chemical energy, whereas solar panels produce electrical energy.

This is because the process of using chemical energy requires that chemical bonds be broken, and the energy from that explosion becomes the usable energy for plants. 

How is solar energy essential to plants?

Solar energy in plants is the primary method by which plants produce food. Without solar energy, plants die. 

Plant Photosythesis vs. Solar

So, which is better, plant photosynthesis or energy produced by a solar panel? 

They are both successful, and solar continues to improve as technology within the solar energy industry improves.

Plants have had millions or billions of years to perfect their solar capabilities, and they have done just that. 

While plants have a lower efficiency rating of collecting incoming solar radiation, they meet their energy requirements.

Thus, differences in plant health have less to do with how efficiently plant leaves take in solar radiation and more to do with issues like shading. 

Solar panels are by far more efficient than plants at taking in solar radiation. Solar panel solar efficiency ranges from around 17-23 percent – sometimes less and sometimes more.

Plant leaves have an efficiency that ranges from .01-2 percent, and for most plants, that is just about right. 

Which is better? That answer comes down to energy needs, and plants have worked out a system that requires less solar energy because their energy production is not limited to just sunshine.

Their energy cycle is also 24-hours, where a solar panel can only produce energy while the sun is shining. 

In terms of efficiency, plants are much more efficient at energy production because their system allows for energy production to continue without sunlight. 


Photo of author
Elliot has 20+ years of experience in renewable technology, from conservation to efficient living. His passion is to help others achieve independent off-grid living.

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