what is solar energy

What is Solar Energy? Origin, Types & Future Of Solar (2024)

Solar energy is a renewable or green power obtained from sunlight radiation. A nonpolluting energy that is quite opposite to coal, natural gas, and petroleum. It is acquired using various technologies, like solar panels or photovoltaic cells which are designed in such a way that it captures sunlight and converts it into electricity. Therefore, this complete set of processes is called the Photovoltaic effect.

To be able to absorb the sunlight you have to use the solar panels and store the absorbed sunlight you require a solar battery. If you are going to use this rightly, then it will satisfy all your future energy needs.

A report of IRENA Global Renewables Outlook 2023 estimates that the solar PV cells (PhotoVoltaic cells) industry can create more than 30 million jobs worldwide by the end of 2030. By 2028, it is predicted that the solar energy generation capacity will surpass more than 377 GW and solar energy will become the most important renewable energy source in the 21st Century.

solar panels in solar farm

Interestingly, a positive impact is created on the environment by introducing many innovative applications of solar energy. But top Solar Companies and the largest producers of solar power worldwide like Tesla Energy, etc have defined the future of concern about the environmental impact of solar energy and found out many possible ways for innovative applications of solar energy.

You will easily understand the concept of Solar Energy when you get a glimpse of a brief history of solar energy from how they went from being introduced to “what is solar energy” to being able to advance with active and passive solar systems along with different types of Photovoltaic systems and Solar Thermal Energy. Also, there are a few pros and cons of solar energy that you will have walked through by the time you complete reading this article.

Understanding Solar Energy

Solar energy can be harnessed for a lifetime by installing solar panels on the rooftop of your residence in various sizes.

The Solar Panels utilize the components that the sun emits in the form of light and heat. Further, it is generated into electrical power. As these panels have semiconductor material, when sunlight strikes it knocks electrons thus creating an electric current. Indeed the electricity generated by this method can be used for homes, and businesses, or even stored for later use.

The solar power generated from the sun’s radiation can be used as heat or electricity, as long as the sun shines.

Solar Panels are typically made by integrating silicon (5%) along with other materials like glass (76%), plastic pol<7mymer ( 8%), Aluminium (5%), copper (1%) and silver ( less than 0.1 %).

An electric charge is produced when electrons are released due to the exposure of these materials of solar panels to the small packets of sun’s energy known as Photons.

As a result, an electric current ( known as the Direct current) is created due to the PV charge, that gets captured by the wirings in the solar panel. Furthermore, the DC electricity is converted into AC with the help of an inverter. The alternating current is used when your appliances are plugged into the standard wall sockets.

Non-renewable energy sources like fossil fuels (coal, oil, nuclear energy, and natural gas) are getting depleted at a rapid pace by consuming more than 80% of global power, the contribution of solar energy to produce electricity globally remains at a lower rate of 3.6%.

Unlike fossil fuels, solar power is developed without emitting any greenhouse gases into the atmosphere thereby generating electricity with the solar panels playing a crucial role. Additionally, the continuous flow of energy is maintained without causing any air pollution.

Notably, the operational and maintenance costs are low compared to other forms of energy. Importantly, your money is saved when planned for a long-term investment with an easy-to-set-up process.

A Brief History of Solar Energy

  • Pre-19th Century: Passive Solar Design was used in ancient civilizations such as magnifying glasses for heating and making fire.
  • 1839: Alexandre-Edmond Becquerel discovered the photovoltaic effect – The key principle in solar energy conversion.
  • 1954: Bell Labs developed the first practical photovoltaic cell using silicon.
  • 1960s -1970s: Solar technology became important for space exploration and to power the satellites.
  • 1980s: The first megawatt-scale photovoltaic power station was installed in the United States.
  • Late 20th Century: Governments introduced policies and incentives – including feed-in tariffs to promote solar adoption.
  • 2010s: Solar achieved grid equality and led to a global installation surge.
  • 2020 – 2024: Solar energy became the mainstream with advanced technological innovations and widespread adoption.
  • Future: It is much anticipated for immense growth along with ongoing advancements in efficiency, storage, and integration into sustainable energy systems.

You can learn a lot more about solar energy by studying the history of solar energy and solar panels in detail and this will include everything in terms of how solar energy evolved over the time.

How is Solar Energy used?

Now that you know what is solar energy, you must know the 2 methods by which you can harness the sun’s energy.

  • Passive Solar Energy uses design elements to capture and distribute solar heat without the help of any mechanical devices.
  • Active Solar Energy uses technology like solar panels, to convert sunlight into usable power.

Although we have a detailed explanation of active and passive solar energy systems but, I have summarized a few of the main pointers below.

Passive Solar System

A Passive Solar System harnesses solar energy using design-based elements without having to rely on mechanical and electrical components. It uses natural processes to absorb, store, and distribute light generated through solar heat.

The way the Passive solar system works is very interesting:

  1. Solar Gain utilizes the orientation of the building, its material, and its design to double the entry of sunlight into the space.
  2. Thermal Mass is a method of absorbing and storing solar heat during the daytime using materials like concrete and brick which naturally have high heat capacity so that it can be released at night.
  3. Natural Ventilation uses air movements for cooling by designing windows strategically.

Therefore, a Passive Solar System requires proper building orientation to increase exposure to sunlight. It needs to have well-insulated windows as well as walls to retain the absorbed heat and there must be good Thermal mass elements within the building structure.

Passive Solar System is used in residential buildings to reduce the reliance on mechanical systems. It is used in commercial buildings for the best energy efficiency.

As a result, there has been a constant rise in the popularity of the Passive Solar System. Especially amongst those who keep up eco-friendly and energy-efficient building practices.

However, its adoption will keep varying depending upon the promotion of sustainable construction practices. Also, it is very important to be a part of an environmentally energy-efficient.

Active Solar System

In Simple words, an Active Solar System uses technology-based mechanical devices to harness solar energy.

Here are the types of Active Solar Systems:

  1. Photovoltaic Systems such as PV Panels convert sunlight into electricity and these systems are widely used to generate power in residential, commercial, and industrial areas.
  2. Solar Water Heating Systems use Solar Collectors to absorb sunlight and transfer the heat into a liquid form (usually water or a heat-transfer fluid). Later, the heated fluid is used for domestic purposes or space heating.
  3. CSP – Concentrated Solar Power systems use mirrors or lenses to produce intense amounts of heat by maximizing & concentrating sunlight on a small area. This heat is further used to generate steam and drive turbines for electricity generation.

Therefore, an Active Solar System requires components like a pump, fan, and controller to absorb, convert, and distribute solar energy for various applications.

Active Solar System is used in Residential and commercial places to generate electricity and to heat water. Industrial applications for process heat. Large-scale solar power plants for grid-connected electricity.

As a result, the increasing popularity of Active solar systems is due to technological advancements blended with environmental concerns. Its acquisition will vary from region to region depending on high usage in the area.

Photovoltaic (PV) Cells

solar photovoltaic panels

Also known as Solar Cells, Photovoltaic (PV) cells are semiconductor devices that will convert the obtained sunlight directly into electricity. It acts as the building blocks of solar panels and it generates electrical power from the sunlight.

The PC Cells use the most common materials made of Crystalline Silicon. It also uses other materials made with thin film technology using amorphous silicon, cadmium telluride, copper indium gallium selenide, and other organic materials.

To simply understand the workings of Photovoltaic cells you need to know that when sunlight strikes the semiconductor material in a PV cell, it excites electrons. Although it creates an electric current. However, there are layers in the cell that consist of differing electrical charges. Hence, this movement of electrons creates a flow of electricity. The individual cells produce electrical energy which is then combined in the solar panels to generate usable voltage.

Here are the different Types of Photovoltaic – PV Cells:

  • Monocrystalline Silicon Cells
  • Polycrystalline Silicon Cells
  • Thin-Film Solar Cells
  • Organic Photovoltaic Cells

PV cells are used in Residential Solar Panels – Mounted on rooftops to generate electricity for homes. It is used in Commercial places such as Large-scale solar farms. Also, it is used in portable devices like solar chargers for small electronic devices.

Other than these applications, the PV Cells are also used in satellites and spacecraft for power generation. Hence, the affordable cost and versatility are leading to its vast adoption in many different sectors for the best renewable energy production.

Types of Photovoltaic Systems

Here is an overview of the 4 different types of Photovoltaic Systems:

  1. Residential Photovoltaic Systems are designed for individual homes and solar panel installation is done on rooftops. It is connected to the local power grid and includes energy storage solutions such as batteries. You will be able to generate your electricity and reduce your utility bills.
  2. Commercial Photovoltaic Systems are focused on businesses and commercial properties as they are larger than residential installations. You can install this on rooftops, in parking lots, or on open land.
  3. Utility-scale photovoltaic Systems are large installations that are designed to generate electricity on a massive scale. They are often ground-mounted. It plays an important role in meeting the renewable energy targets for utilities and governments.
  4. Community Solar in the Residential Section also known as shared solar allows multiple residential customers to benefit from a single solar installation. This is especially beneficial for individuals who may not have suitable rooftops for solar panels.

Therefore, each type of photovoltaic system provides different benefits according to your needs and the scale you are expecting. It helps in contributing to clean and sustainable energy sources.

Solar Thermal Energy

solar thermal energy power plant

The technology of Solar thermal energy harnesses the sun’s heat to produce thermal energy for various real-life applications such as water heating, space heating, or electricity generation.

Solar thermal energy systems work using solar collectors to absorb the sunlight and convert it into heat. Later, the collected heat is transferred to a fluid form (Water, Oil, or any heat-transfer medium). This heated fluid generates steam, produces hot water, or drives a heat engine to generate electricity.

There are different types of solar thermal collectors and each of them is designed for different temperature ranges and applications:


The Low-temperature collectors are developed for applications such as pool heating. They are Flat-plate collectors that have a very simple design and are cost-effective. It is very useful to heat the swimming pools or any other low-temperature applications.

Medium Temperature

It is best to use Medium-temperature collectors for applications that require moderate temperatures like household water heating, solar water heater, etc. These Flat-plate collectors with selective coatings are more efficient and operate at temperatures lower than required for electricity generation.


As the name says, High-temperature collectors are suitable for electricity generation that requires high temperatures. They use CSP – Concentrated Solar Power to focus sunlight onto a small area. For instance, the solar power towers, or dish/engine systems. Also, it can be utilized in large-scale power plants to generate electricity.

Pros and Cons of Solar Energy

Here are the following pros and cons of solar energy that you must be knowing:

Pros of Solar Energy:

  • Renewable Resource
  • Long-Term Sustainable
  • Environmentally Friendly
  • Reduced Electricity Bills
  • Low Operating Costs
  • Energy Independence
  • Job Creation
  • Technological Advancements
  • More Accessible to Solar Energy
  • Grid Support

Cons of Solar Energy:

  • Intermittent Energy Production
  • High Initial Costs
  • Land Use
  • Unappealing Appearance
  • Non-Evolved Recycling Methods
  • Energy Storage Challenges
  • Geographic Limitations
  • Impact on Wildlife Habitat

Considering both the Advantages (Pros) and Disadvantages (Cons), the present scenario regarding the development of solar energy technologies aims to justify many challenges and also enhance it to a successful sustainable energy source. Knowing about the pros and cons of solar energy will ultimately help you decide whether you should set up your own solar panel system or not.

Environmental Impact of Solar Energy

There are 2 sides of the Environmental Impact of Solar Energy – The Positive and Negative Impact and here are those you must know:

Positive Impact:

  • Solar energy has a minimal carbon footprint, reducing greenhouse gas emissions.
  • It requires less water for operation compared to traditional power sources.
  • Solar technologies contribute to a decrease in air and water pollution.
  • By reducing dependence on fossil fuels, solar energy supports environmental sustainability.

Negative Impact:

  • The production and disposal of solar panels have some environmental implications.
  • Large solar installations may impact local ecosystems.
  • Geographic limitations may affect the feasibility of solar energy in some regions.
  • Initial energy and resource requirements for solar panel production are considerations.

Do you know solar energy is one of the best green and clean energy sources, and the environmental impact of solar energy is a lot more on the side of the positive side.

Innovative Applications of Solar Energy

Solar Energy has been rapidly growing and developing day by day and its innovative applications inspire the upcoming generations. Here are a few mindblowing innovative applications of solar energy:

  1. Solar Windows are transparent windows that are well equipped with thin-film solar cells that generate electricity from sunlight and at the same time allow natural light to pass through it. Integrating solar technology into windows enables buildings to generate clean energy without compromising with obstructing views.
  2. Solar Cars are electric vehicles designed with solar panels on their surface allowing them to harness sunlight and generate additional power. These vehicles reduce dependence on grid electricity and increase the range of electric cars by using solar energy for charging.
  3. Solar Paint consists of photovoltaic materials that can be painted as a coating on various surfaces. Surprisingly it works like a charm, by turning that coated area into solar panels. I would say this amazing technology is a must! It allows everyday objects to become energy-generating surfaces by extending the potential for solar energy.
  4. Solar in Space involves absorbing or capturing solar energy in space using satellites that are well-equipped with solar panels. Further, it transmits the generated power to Earth. This level of approach truly justifies the limitations of Earth-based solar power. For instance, the weather and nighttime provide a continuous and more energy source.
  5. Floating Solar Farms are floating platforms with photovoltaic systems installed on top of water bodies in lakes or reservoirs to support the solar panels. It reduces land constraints and reduces water evaporation.
  6. Solar Fabric integrates photovoltaic materials into textiles so that it will allow that particular clothing, tents, or other fabric to generate electricity from sunlight. It enables us to integrate solar power into wearable technology and portable things.

These innovative applications show us the all-new diversified ways in which solar technology is evolving day by day to meet the energy needs in various sectors.

Future of solar energy

The future of solar energy promises us with the constantly increasing demand and surge in the solar industry. More Businesses and Individuals are exploring solar solutions, as the Growth in the Solar Industry is extensively larger with advancing technologies.

Especially, the Decline in Cost with enhanced Efficiency of solar technology is the present as well as future trend. Although, many ongoing researches have contributed to making it affordable with a high energy-conversion rate. It allows Increased Adoption in Developing Countries as it allows communities to access electricity without depending on energy grids. Also, there is economic development and improvement in sustainability and living conditions.

Surprisingly, the growth extended beyond residential use, as the Expansion in the Industrial and Transport Sectors like Solar-powered factories, vehicles, and infrastructure are becoming more dominant. As a result, it contributes to a much cleaner future by reducing carbon footprints and making modern life better for living. There’s lot more to know about the future of solar energy.

What are the Best and the Worst state for Solar Energy?

California is the Best state for Solar energy which is well known for its abundant sunlight and progressive solar energy policies. Also, California leads the United States in solar installations.

North Dakota is the Worst state for Solar Energy which is known for its Harsh winters and low sunlight levels. Therefore, North Dakota is less favorable for solar installations.

Who Are the Largest Producers of Solar Power Worldwide?

China is the largest producer of solar power worldwide with an awesome solar capacity of 430 GW (As of April 2023). To get a better idea you can read where is solar energy used most in the world?

What Are the Top Solar Companies?

Here are the top 5 solar companies as of 2024:

  1. SunPower: Best in Overall
  2. Tesla: Best for its Availability
  3. ADT Solar (Formerly known as Sunpro Solar): Wide Lease Options
  4. Blue Raven Solar: Good Customer Satisfaction
  5. Palmetto Solar: Best Solar Equipment
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Ray is an avid reader and writer with over 25 years of experience serving various domestic and multinational private and public energy companies in the USA.

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