Solar energy is one of our most in-demand and fastest-growing renewable energy technologies. It could play a major role in our transition away from fossil fuels because it has low levels of carbon dioxide (CO₂) emissions and minimal environmental impact. So, we had to ask: how effective and efficient is solar energy?

Solar energy effectively converts sunlight into energy while improving air quality and promoting energy security; however, it can also be intermittent. Solar energy is efficient because it generates few waste products, promotes energy decentralization, and has a high energy conversion rate. 

Keep reading to find out how effective and efficient solar energy is, what its pros and cons are, how safe or dangerous it is, and how it can mitigate climate change.

The Big Picture of the Effectiveness and Efficiency of Solar Energy

Solar energy is the conversion of solar radiation into electrical energy either through the use of photovoltaic (PV) panels or solar radiation-concentrating mirrors. The energy produced is then used to generate electricity or can be stored in batteries or thermal storage for use at a later time. 

“Solar Energy: energy that uses the power of the sun to produce electricity”

Cambridge Dictionary

Harnessing the power of the sun falls into two main categories:

1. Photovoltaic (PV) solar cells: photovoltaic cells in solar panels absorb energy from sunlight, creating an electrical charge. This charge moves in response to an internal electric field in the cell, causing electricity to flow. 

2. Concentrating solar thermal plants (CSP): mirrors reflect and concentrate sunlight onto receivers that collect and convert solar energy into heat. This is utilized in very large power plants.

Both systems take the energy from the sun and convert it to electricity, just by slightly different mechanisms. PV solar is the main mechanism used today to harness solar energy.

Solar energy began to establish itself as a part of the mainstream electricity industry in 2010, with increases in investments and the establishment of large solar production facilities. Today, solar energy is our third-largest renewable electricity technology behind hydropower and wind energy.

Here’s How Effective and Efficient Solar Energy Are

In terms of effectiveness, solar panels and concentrating mirrors are effective ways to convert sunlight into electricity. In addition, solar energy has a low carbon footprint, protects air quality, and promotes energy security and independence.

In terms of efficiency, solar panels are efficient at converting sunlight into electricity. In addition, solar energy is a renewable and sustainable energy source, increases the efficiency of the power grid, and generates few waste products.

How Effective Is Solar Energy

Effectiveness involves completing a task with a desired outcome, typically a successful one. 

“Effective: producing the result that is wanted or intended; producing a successful result”

Oxford Dictionary

In terms of effectiveness, solar panels are effective at converting sunlight into electricity. In addition, solar energy has a low carbon footprint, protects air quality, and promotes energy security and independence.

Solar Energy Is An Effective Way To Convert Sunlight Into Electricity

Enough sunlight strikes the surface of the earth in an hour and a half to account for the world’s energy consumption in a year. Solar panels and concentrating mirrors are effective ways to harness this vast amount of energy and turn it into solar energy, as evident by the increase in installed capacity and electricity generation in recent years. 

Starting in 2010, there was a push to increase solar energy capacity worldwide. Global installed solar capacity increased from 96 GW in 2012 to 1,180 GW in 2022. 

Solar energy is currently the third-largest renewable electricity technology behind hydropower and wind energy. PV solar accounted for roughly 4.5% of total global electricity generation in 2022. 

In 2022, electricity generation from solar energy increased by 270 TWh (26%) to reach 1,300 TWh. This was the largest generation increase for all renewable energy technologies, surpassing wind energy for the first time in history. 

PV solar installed capacity is to exceed natural gas by 2026 and coal by 2027, becoming the largest in the world.

Solar Energy Has a Low Carbon Footprint

Solar energy has the fifth-lowest carbon footprint out of all energy types.

The carbon footprint is one of the ways we measure the effects of human-induced global climate change. It primarily focuses on the greenhouse gas (GHG) emissions associated with consumption and includes other emissions such as methane (CH₄), nitrous oxide, and chlorofluorocarbons (CFCs).

“Carbon footprint: the amount of greenhouse gasses and specifically carbon dioxide emitted by something (such as a person’s activities or a product’s manufacture and transport) during a given period”

Merriam Webster

On a life-cycle basis, concentrating solar energy emits 38, PV roof solar energy emits 41, and PV utility solar energy emits 48 grams of CO₂ equivalent per kWh of electricity produced. 

Have a look at the illustration below to see the average life-cycle CO₂ equivalent emissions of different energy sources and how they compare to solar energy.

Overall, solar energy has the fifth-lowest carbon footprint out of all energy types, making it one of our cleanest energy sources. 

Solar Energy Protects Air Quality

Solar energy produces a fraction of the pollution and toxic chemicals that fossil fuels produce, helping to protect air quality.

Air pollution can cause numerous health problems including asthma, breathing difficulties, brain damage, heart problems, and cancer. Fossil fuel (coal and natural gas) combustion emits coal ash residue, toxic heavy metals, CO₂, carbon monoxide (CO), sulfur dioxide (SO₂), and nitrogen oxides into the atmosphere, impairing public health.

Rather than combusting toxic materials like coal does, solar power plants harness the energy of the sun to generate electricity. PV panels and concentrating mirrors produce minimal greenhouse gasses and emit no sulfur dioxide or nitrogen oxides, thereby helping to protect air quality.

Solar Energy Promotes Energy Independence and Energy Security

Solar energy can help us transition away from fossil fuels and towards an energy-independent future.

Being able to produce your own electricity without the aid of foreign countries is an important step in becoming more self-sufficient. For example, in the US, Former President George W. Bush signed the Energy Independence and Security Act of 2007 to reduce U.S. dependence on oil, expand the production of renewable energy, and confront global climate change. 

Although solar energy alone cannot shoulder the burden of the world’s electricity needs, it can shoulder some. Solar energy is currently the third-largest renewable electricity technology behind hydropower and wind energy. PV solar accounted for roughly 4.5% of total global electricity generation in 2022, demonstrating the largest generation growth and surpassing wind energy for the first time in history. 

Solar Energy Is An Intermittent Energy Source

Solar energy production is heavily influenced by location, time of year, and weather patterns, making it unpredictable at times. 

Two of the main drawbacks associated with renewable energy are intermittency and lower levels of energy output, with solar energy being no exception.

The amount and availability of sunlight varies by location, time of day and year, and weather. The amount of solar radiation a surface receives in a designated amount of time – called insolation – is influenced by latitude, climate, and weather patterns. The unpredictable nature of solar means we cannot rely on it fully to produce all of our energy. 

One way to combat intermittency is to store solar energy in batteries and draw from them in times when solar panels cannot produce energy, like at night. 

Solar Energy Has High Upfront Costs and Can Be Expensive to Maintain

Solar energy has a high upfront cost associated with solar panel installation.

The cost of installing a residential solar system varies by location and system, but installation can cost thousands of dollars upfront. For example, the Solar Energy Industries Association estimates it costs roughly $25,000 to install an average-sized residential solar system in the US, before taking into account any tax incentives. 

Solar batteries are another possible expense. Given that solar energy is intermittent, one way to ensure constant access to solar is to store unused solar energy in batteries for use in times where solar panels cannot capture sunlight, such as at night. However, solar batteries can cost between $12,000 and $20,000 to install, depending on the type and size.

In addition to high upfront costs, solar energy can be expensive to maintain.

Solar panels themselves have an average life expectancy of 25-30 years. This can be extended for many decades with proper maintenance because the panels do not have moving parts and are typically only damaged by poor installation or inclement weather events. 

Routine solar panel maintenance can cost between $140-$180 per service, or $280-$720 annually, depending on the type of solar panels. Solar panel cleaning can cost $25 per panel, or $425-$525 for an average solar system with 17-21 panels. 

In addition to regular maintenance, solar energy can come with hidden expenses such as optional solar system monitoring, roof and solar panel repairs, and tree trimming. Repairing solar panels can cost $300-$1300 on average, with external damage on the lower end and internal damage on the higher end of the price range.

How Efficient Is Solar Energy

Efficiency involves performing a task while using the least amount of resources and producing the least amount of waste possible.

“Efficient: working in a way that does not waste a resource (= something valuable such as fuel, water, or money)”

Cambridge Dictionary

In terms of efficiency, solar panels are efficient at converting sunlight into electricity. In addition, solar energy is a renewable and sustainable energy source, increases the efficiency of the power grid, and generates few waste products.

Solar Energy Panels Efficiently Convert Sunlight Into Energy 

Solar energy boasts a high-efficiency rate per solar panel and is an efficient use of farmland.

Efficiency involves performing a task while using the least amount of resources and producing the least amount of waste possible.

“Efficient: working in a way that does not waste a resource (= something valuable such as fuel, water, or money)”

Cambridge Dictionary

Solar energy efficiency has drastically improved since the creation of the first PV solar cells in 1883 by American inventor Charles Fritts. His solar cells had an efficiency, also called an energy conversion rate, of 1-2%, meaning they converted only 1-2% of the total sunlight captured into usable energy. 

Today’s PV solar cells have an average commercial energy conversion rate of 15-20% and an experimental conversion rate of more than 30%. High-efficiency panels can reach as much as 23%.

In order to increase the efficiency of solar energy we would have to increase the energy conversion rate. Experts have calculated the ceiling of solar cell efficiency, known as the Shockley-Queisser limit, as somewhere between 29% and 33%. So we are already approaching the limits of what is theoretically possible.

In addition, solar energy can require large amounts of land to establish solar farms, but it is an efficient use of that land, specifically farmland. One acre of solar panels can produce roughly 40 times more energy than one acre of corn devoted to ethanol production. 

Solar Energy Is a Renewable and Sustainable Energy Source

Solar energy is a renewable and sustainable resource that can reduce emissions for generations to come.

Renewable energy sources are resources that naturally replace themselves over time. 

“Renewable Energy: energy that is produced using the sun, wind, etc., or from crops, rather than using fuels such as oil or coal | types of energy that can be replaced naturally such as energy produced from wind or water”

Cambridge Dictionary

Solar energy is classified as a renewable energy source because the sun generates energy at a rate faster than we can consume it. We can also continue to harness the sun’s energy almost indefinitely, or until the sun goes supernova (which won’t be for another 5 billion years).

Solar energy is also classified as a sustainable energy source. Sustainable energy sources meet the needs of our current generation without compromising the ability of future generations to meet their own needs.

“Sustainable: The ability to be maintained at a certain rate or level | Avoidance of the depletion of natural resources in order to maintain an ecological balance”

Oxford Dictionary

Solar energy emits minimal greenhouse gas emissions (GHGs) and does not negatively affect the environment, provided that proper siting and disposal methods are followed. This means future generations can continue to harness solar energy for many years.

Solar Energy Increases The Efficiency Of The Power Grid

Solar energy promotes the decentralization of our energy supply which increases power grid efficiency by reducing peak time usage and decreasing the likelihood of power outages. 

The traditional grid works something like this:

1. Power plants generate electricity
2. Transformers step up voltage for transmission
3. Transmission lines transport electricity over long distances
4. Neighborhood transformer steps down voltage
5. Transformers on poles step down electricity before it enters homes

Our traditional grid worked fine in the past when energy demand was much lower, but globally our electricity usage is steadily increasing, and renewable energy makes up an increasingly bigger share of our total energy consumption. 

Renewable energy, including solar energy, draws energy from various geographic locations, so the grid can distribute power from multiple plants. Although the addition of large amounts of renewable energy to the grid at one time may seem like it would have a destabilizing effect, renewable energy actually becomes more predictable as it is added to the grid. This is thanks to the law of large numbers. 

“Law of large numbers: as the number of identically distributed, randomly generated variables increases, their sample mean (average) approaches their theoretical mean.”

Britannica

In terms of renewable energy, the output of every solar panel that is connected to the power grid Is less volatile and more stable than the output of one individual generator. This decentralization in turn reduces peak time usage and decreases the likelihood of power outages. It also increases the efficiency of power production and power distribution.

In short, solar energy can be sourced from various geographical locations which helps increase the efficiency of the global power grid.

Solar Energy Generates Few Waste Products

Solar energy generates few waste products upon operation, and solar panels can be recycled.

In terms of emissions, solar energy produces few waste products, generating between 38 and 48 grams of CO₂ equivalent per kWh of electricity produced and zero sulfur dioxide or nitrogen oxide emissions. 

Solar panels themselves can be classified as hazardous waste depending on the type of metals present in the semiconductor and solder. For example, lead, arsenic, and cadmium are considered to be detrimental to human health and the environment, at high levels, and are therefore classified as hazardous. If solar panels containing toxic metals are dumped into landfills, the metals may leach out into the environment. 

Recycling end-of-life solar panels can help ensure any toxic chemicals do not leach out into the environment. Many of the components of solar panels can be recycled, including glass, aluminum, copper wire, and the plastic junction box. Specialty metals and silicon cells can also be separated and purified via chemical and electrical techniques.

The solar panel recycling industry is still in its infancy and continues to evolve. Just in 2018, Europe’s first solar panel recycling plant opened in southern France. Previously, solar panels were recycled in traditional recycling facilities where the glass and aluminum were separated and the rest burned in cement ovens. 

The International Renewable Energy Agency estimates that by 2030, the value of the recoverable raw materials from solar panels at the end of their lifespan will reach $450 million, which would be enough to produce approximately 60 million new solar panels. This highlights the importance of recycling solar panels.

How Can Solar Energy Help Mitigate Climate Change

Climate change is a severe, long-term consequence of fossil fuel combustion. If left untreated, atmospheric CO₂ can remain there for tens of thousands of years and exacerbate the negative effects of climate change. Solar energy emits less CO₂ upon operation than fossil fuels and can therefore reduce our total emissions. 

How is Climate Change Defined

Climate change is arguably the most severe, long-term global impact of CO₂. Every year, we emit approximately 37 billion tons of CO₂. The carbon found in fossil fuels reacts with oxygen in the air to produce CO₂. 

“Climate change: changes in the earth’s weather, including changes in temperature, wind patterns, and rainfall, especially the increase in the temperature of the earth’s atmosphere that is caused by the increase of particular gasses, especially carbon dioxide.”

Oxford Dictionary

When carbon enters the atmosphere, it absorbs sunlight and solar radiation, trapping the heat and acting as an insulator for the planet.

Since the Industrial Revolution, Earth’s temperature has risen a little more than 1 degree Celsius (°C), or 2 degrees Fahrenheit (°F). Between 1880-1980 the global temperature rose by 0.07°C every 10 years. This rate has more than doubled since 1981, with a current global annual temperature rise of 0.18°C, or 0.32°F, for every 10 years. 

How Does Solar Energy Specifically Help Mitigate Climate Change

The global average concentration of CO₂ in the atmosphere today registers at over 400 parts per million, the highest ever recorded. Solar energy can help lower this concentration because it can replace some of the burning of fossil fuels (e.g., coal, oil, natural gas) with a cleaner form of renewable energy.

Solar emits roughly 0.05%-0.08% of the amount of CO₂ (grams of CO₂ equivalent per kWh) as fossil fuels. Solar also has a life-cycle global warming emission between 0.08 and 0.2 pounds of CO₂ equivalent per kilowatt-hour (kWh), whilst coal power plants have an estimated emission between 1.4-3.6 pounds of CO₂ equivalent per kWh. 

Increasing solar energy usage can reduce CO₂ emissions, and the more we reduce CO₂ emissions, the more we combat the negative effects associated with climate change including temperature rise, sea-level rise, ice melting, and ocean acidification. When these rates are slowed, the earth’s biodiversity does not have to struggle to adapt to temperature and pH changes. People will not be displaced due to the flooding of coastal areas. And icebergs will continue to provide climate regulation. 

What Are the 6 Pros and 4 Cons of Solar Energy

Solar energy is a renewable and sustainable energy source, has a low carbon footprint, protects air quality, is efficient, generates few waste products, has low maintenance costs, and promotes energy independence and security.

However, solar energy is also an intermittent energy source, faces high upfront and maintenance costs, and has specific land requirements.

These Are the 6 Pros of Solar Energy

Solar energy has various pros that make it effective at reducing carbon emissions.

These Are the 4 Cons of Solar Energy

Understanding the drawbacks of solar energy is important in order to effectively mitigate climate change. 

How Safe or Dangerous Is Solar Energy

Overall, solar energy is not considered to be dangerous. Holistically and throughout its life cycle, solar is safe and beneficial for human and animal health, the environment, and the energy grid. It is also significantly safer than fossil fuels and other types of renewable energy.

Here’s How Safe Solar Energy Is

Overall, solar energy is a safe form of energy regarding human and animal health, the environment, the energy grid, and throughout all stages of its life cycle.

Here’s How Dangerous Solar Energy Is

Overall, solar energy is considered minimally dangerous in terms of human and animal health, the environment, the energy grid, and through all stages of its life cycle. 

Final Thoughts

Solar energy is effective because it has a low carbon footprint, protects air quality, and promotes energy security and independence. It has grown to make up almost 5% of our total global electricity generation, making it an effective renewable energy technology.

Solar energy is efficient because it is a renewable and sustainable energy source that increases the efficiency of our power grid and generates very few waste products. Over the years, technological advancements have increased the conversion rate of solar panels, meaning they can more efficiently convert sunlight into energy.

Beginning to reverse the climate crisis means we have to cut CO₂ emissions now, and solar energy can help us do that. It has the fifth-lowest carbon footprint out of all energy types and emits a fraction of the CO₂ and air toxics that fossil fuels emit. Although its unpredictable nature means we cannot rely on it solely for energy generation, incorporating more of it into our power grid has many environmental benefits.

Stay impactful,

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