Introduction
Since fossil fuels won’t last forever, solar power generation seems to be leading the way in clean and renewable energy generation. Almost every home now relies on batteries for power backup.
Solar power plants have been built in China, once thought to be the world’s largest polluter. India further aims to generate 100,000 MW of electricity solely from solar power plants by the year 2023.
Tesla has taken the decision to build a solar power plant that will be the only source of energy for the Hawaiian island of Kauai. For the purpose of storing solar energy for use at night, Tesla is offering its commercial battery packs. They are ensuring they can power the entire island without sunlight for up to three days. Amazingly, it can be recharged after only seven hours of sunlight.
Around the world, the most popular area of research is efficient solar energy production. Let’s see what it takes to turn sunlight into electricity. Before that let’s understand some essential points regarding the solar power plant.
Solar Power Plant
Among the various non-conventional sources of energy, solar energy seems to hold out the greatest promise for mankind, as it is freely available, inexhaustible, and non-polluting. Solar power is a form of energy harnessed from the power and heat of the Sun rays. It is renewable and therefore it is a “Green” source of energy.
“A solar power plant is based on converting sunlight into electricity, either directly using photovoltaic or indirectly using concentrated solar power. Concentrated solar power systems use lenses and tracking systems to FOCUS a broad area of sunlight in a small beam”.
Solar power is the cleanest, most reliable form of renewable energy available and it can be used in several forms to help in power supply for residential premises and businesses.
Solar-powered photovoltaic panels convert sun rays into electricity by exciting electrons in silicon cells using photons by the light from the sun.
How does a Solar Panel turn Sunlight into Electricity?
Silicon is a well-known semiconductor with metal and nonmetal properties. To make a solar panel, this silicon is doped with a pentavalent impurity, which converts it to positive-type silicon, also known as p-type silicon. Similarly, the other component is converted to negative or n-type silicon.
As the name implies, the p-type has an excess of holes (positive charge) and the n-type has an excess of electrons. Then these two are combined one on top of the other until they reach the atomic level. Due to their opposite charges and contact, electrons flow from n-type to p-type and holes from p-type to n-type interfere with each other.
The current produced by this charge movement is known as diffusion current. Another important aspect of this potential barrier is that it leads to electric fields that flow from n-type contacts to p-type contacts (the area of potential generation).
Due to this electric field, holes from n-type begin to flow toward p-type, and electrons from p-type begin to flow toward n-type, resulting in a current known as drift current. At first, the diffusion current is greater than the drift current, but as the potential difference grows due to diffusion, the drift current also grows. When diffusion current equals drift current, the current stops flowing.
Conversion of Sunlight
Sunlight arrives on Earth as small energy particles known as photons. When this photon hits the p-type region, it energizes the electron and it flees from the hole. The electric field created by the potential difference at the p-n junction causes electrons to travel to the n-type region, causing current to flow.
But there is something else to know in order for this electric field to be strong enough to travel to the n-type region and not recombine with the hole from which it has been separated.
The n-type and p-type regions are connected to the positive and negative battery terminals, respectively, to strengthen the electric field; this is referred to as the “reverse bias condition.” This increases the likelihood of an electron traveling all the way to the n-type region after being separated from a hole. As a result, the efficiency of a solar panel increases.
Let’s discuss the important components of solar power plants.
Different Types of Solar Energy
Solar energy is changing the way in which we look at how we source the energy we need. Given how fast technology has marched on in line with our search for cleaner energy, let’s take a look at the different types of solar energy available.
Traditionally, our electricity comes via the grid, whereby we generate it by burning coal or natural gas. Despite this, our reliance on electricity generated from fossil fuels cannot continue. Thankfully, our quest to go green is helping us in our journey to find less polluting alternatives 1.
Solar energy is a type of renewable energy that is better for the environment, so what is there to not love about it? Of course, like any technology, solar comes with its own pros and cons. Whether it is commercial systems or residential systems 2. the various types of solar demonstrate the range of benefits we can expect from renewable energy.
What are the Different Types of Solar Energy?
Photovoltaic Solar Energy
The history of solar photovoltaics dates back to around the 1830s when the photovoltaic effect was discovered. Later, in 1954, Bell Laboratories in the US built the first solar PV panel.
To gain an understanding of this type of solar energy, it helps to think of the solar panel on a calculator. Solar panels work by turning direct sunlight into electricity.
Photovoltaic solar systems are one of the most popular types of solar power systems available. Typically a number of solar cells make up a photovoltaic panel, producing a direct current that converters turn into alternating current. A group of solar PV panels connected with the required kit to turn sunlight into electrical energy is known as a solar cell system.
Today we can see some of the largest countries in the world, including China, the United States, and the European Union rolling out large-scale solar farms to increase solar capacity. As of 2018, these countries had a total solar capacity of 175,018MW, 62,200MW, and 115,234MW respectively. Meanwhile, developing countries are moving to seek freely available energy harvested from solar radiation as populations expand.
In 2018, Asia was striding ahead in terms of solar panel installations 4. The region made up 75% of global solar power installations, proving that PV panels generating power from sunlight look to be one of the most popular forms of solar energy.
Domestically, the price of installing photovoltaic solar power cells has dropped dramatically as a result of government incentives and rebates. As a result, busting the expense myth, more and more homes now benefit from clean usable energy derived from the sun.
As far as efficiency goes, a photovoltaic solar panel system will produce around 200kWh under normal test conditions. This is based on a solar panel that has an efficiency of 20% and an area of 1m2.
As the technology has advanced, thin film solar cells have become more versatile, and thinner. As a result, we can now see solar energy technology used for roof tiles and in other more innovative applications such as building exteriors.
Concentrated Solar Energy
Today, concentrated solar power, or CSP, is normally found in large-scale installations that provide electricity to the grid.
Concentrated solar has an interesting history that many believe dates back to Archimedes and his burning glass. This form of energy uses mirrors and lenses to concentrate a large area of sunlight onto a receiver.
It was in 1866 that a parabolic trough was used to produce steam making it possible to power the first solar steam engine. However, Alessandro Battaglia obtained the first patent in 1886, and in 1929, Dr. R.H. Goddard created a solar power system using a mirror dish 6.
As it currently stands, there are four types of concentrated solar technologies that exist. These are the parabolic trough, dish, concentrating linear Fresnel reflector, and solar power tower.
The first system was deployed in 1984 and by the end of that year, the number of systems had reached 14. By 2019, installations globally had reached a total of 6,451. Modern installations use thousands of mirrors, concentrating the sun’s energy into a small area that gets very hot. The heat then drives a steam turbine to generate electricity.
This form of solar energy best suits those countries that see extremely high levels of sunshine. Therefore, it is no surprise that Spain has the largest capacity of 2,300MW while the US and South Africa follow close behind with 1,738MW and 400MW.
Concentrated solar power is not quite as popular for large-scale applications as using photovoltaic or PV panels, however, they do have a conversion efficiency of as much as 25% to 35%.
Water Heating Solar Energy
Water heating solar energy began with black paint painted onto tanks and used to heat water. As the black paint absorbed the heat from the sun, it would heat up the water inside it. As primitive as this may seem, it shows that we understood the power of solar from early on.
The very first thermal solar power plant was located in Maadi, Egypt. However, it wasn’t until the 1920s that flat plate collectors were used for solar water heating in Florida and Southern California 5.
We commonly see this form of solar energy in domestic, commercial, and industrial situations. Using the technology that we have available, a working fluid is heated up using a sun-facing collector. This will then pass into a storage system where we can heat water surrounding pipes containing the working fluid.
Towards A Cleaner Energy Future
Types of solar energy take many different forms and that is a real positive in an adaptability sense. Because there are several types of systems that can be deployed to suit certain circumstances. Ranging from PV panels and curved mirrors to generate electricity to systems that are ideal for heating hot water and pools. The variety of solar systems and technology including solar cells, passive solar, and solar panels could help us to take a step away from our reliance on traditional methods.
In most cases, solar has a significant history that might surprise many. Today, solar is now evolving faster and becoming more mainstream as environmental concerns and efficiencies increase and costs come down. Especially given many of the technologies are over 100 years old.
In the future, we’re likely to see more and more solar panels on roofs and solar power plants dotted across our landscapes. There’s little doubt as we pursue cleaner energy sources that the different types of solar energy we know about today, and perhaps some yet to be invented, will be at the forefront of the clean green solar energy revolution we’re seeking.
Three new types of solar power plants emerge in 2019
2019 was a year of change for the solar and energy storage industry, as we shifted from deploying pure wattage to making projects a lot smarter with oversized DC-AC ratios, up to 60% capacity factors, and solar plants that shine only at night.
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For a long while, the job of solar power was to deliver daytime electricity – starting to pump the juice in earnest around 10 a.m. and finishing at 2 p.m. — with every single drip of electricity used to get investors into the project. This is no longer the reality.
For instance, Minnesota is now overbuilding solar power and dumping “extra” electricity.
In July of this year, a project in Connecticut was completed with a DC to AC ratio (the ratio of total solar panel wattage to solar inverter capacity) of 1.8:1. A value greater than the average 1.3:1 shows that large developers are deploying a strategy that takes full advantage of cheap solar panels to gain greater benefit.
While a normal solar power plant might start clipping—i.e., dumping electricity produced by the solar panels that the inverter isn’t able to export—as the day approaches noon, a plant with a high DC to AC ratio will begin clipping much sooner. Generally, this wasted electricity is lost revenue and designers abhor it. However, a plant like this will also offer a more consistent amount of electricity delivered to the power grid—starting much earlier and ending much later.
It will also offer a greater amount of electricity during the low sun wintertime periods. An analysis by Fluence suggested that these extra solar panels, beyond the 1.3:1 ratio, cost approximately 60¢/Wdc to install—far cheaper than standard system pricing.
What might be the most significant solar project of the year was developed by 8minute Solar Energy—the Eland Solar Power Plant totaling 400MWac/600?MWdc plus 300MW/1,200MWh of energy storage. The facility will sell its electricity to two separate California buyers at just under 4¢/kWh.
But the real kicker of this facility, and the reason there is a “?” after the 600 MWdc above, is the capacity factor that approaches 60% per CEO Tom Buttgenbach. This value is far above the peaks of AC capacity factors found in the 35% range per recent research. There are a few reasons this plant can offer a value like this:
- The plant is located in the Mojave Desert with some of the world’s best sunlight
- Single axis trackers “widen the shoulders” and up production overall by 15-30%
- DC coupled energy storage captures and later delivers the clipped electricity
- It is probable that bifacial solar modules and/or an oversize DC to AC ratio are pumping out extra electricity for those batteries to grab.
We can assume that an advanced group like 8Minute Solar Energy has done the math on all of these potential output-increasing techniques, because this is the same group that has oversized DC to AC ratios of 3-4-5 to 1 and energy storage with 15 hours of capacity that will deliver electricity 24 hours a day on its drawing blocks.
The third facility is one that delivers its solar electricity only at night. Engie was awarded a project in Guam that couples 50MWdc of solar power with 50MW/300MWh of energy storage. The facility will deliver its electricity for up to seven hours into the evening, suggesting an inverter sizing of approximately 42MWac, and a relatively normal DC to AC ratio of 1.16:1. The facility will deliver 85GWh of electricity per year, approximately 5% of the island’s annual 1,600GWh needs.
These three projects—and others—herald the next stage of solar power. A stage in which solar power plants will be designed as the grid needs, to meet the requirements of society, versus society learning to absorb what the sun has to offer. And these plants are why solar power, along with energy storage and wind generation, will come to dominate our future clean energy power grids.
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Commercial Solar Guy is a commercial utility solar developer, general contractor for commercial and residential solar, as well a consultant. We construct projects in MA, RI, NY, and soon PA.
What Is the World’s Largest Solar Power Plant?
The largest solar power plant in the world is the Bhadla Solar Park, which was completed in 2020. This solar thermal power plant is located in Bhadla in the Jodhpur district of Rajasthan, India. The Bhadla Solar Park is a 2.25GW solar photovoltaic power plant and the largest solar farm in the world, encompassing nearly 14,000 acres of land. The construction of Bhadla Solar Park cost an estimated 450.4 billion (98.5 billion Indian rupees). What are some Bhadla Solar Park benefits? Solar infrastructure projects such as the Bhadla Solar Park help reduce India’s dependence on imported fossil fuels. In rural areas, solar power provides a much more healthy, safe source of indoor lighting than kerosene. Additionally, solar power plants like the Bhadla Solar Park drive economic growth and job creation in surrounding areas. The renewable energy jobs sector is rapidly developing around the world; in 2020, the growth rate of the world’s renewable energy capacity jumped 45%. Solar power installations increased 23%.
The region where the Badla Solar Park was constructed is known for its solar-friendly high temperatures and sunny days; in fact, much of India enjoys around 300 sunny days per year, making it an ideal place for solar power plants. Solar power in India is rapidly developing, with many solar photovoltaic power plants being built across the country. As of March 2021, the installed capacity of solar power plants in India was 40 GW, but the National Institute of Solar Energy has assessed that the country’s solar potential is about 748 gigawatts! The National Solar Mission (a major initiative launched by the government of India with active participation from the U.S.) has set a goal of reaching 100 GW of installed solar thermal power plant capacity by 2022.
What Are the Largest Solar Farms in the World?
The top twenty biggest solar plants in the world are as follows, ranked by solar energy capacity:
- Bhadla Solar Park (Rajasthan, India) — 2,245 MW
- Huanghe Hydropower Golmud Solar Park (Golmud, Qinghai, China) — 2,200 MW
- Pavagada Solar Park (Karnataka, India) — 2,050 MW
- Benban Solar Park (Benban, Egypt) — 1,650 MW
- Tengger Desert Solar Park (Zhongwei, Ningxia, China) — 1,547 MW
- Noor Abu Dhabi (Sweihan, United Arab Emirates) — 1,177 MW
- Mohammed bin Rashid Al Maktoum Solar Park (Saih Al-Dahal, United Arab Emirates) — 1,013 MW
- Kurnool Ultra Mega Solar Park (Andhra Pradesh, India) — 1,000 MW
- Datong Solar Power Top Runner Base (Datong City, China) — 1,000 MW
- NP Kunta (Andhra Pradesh, India) — 978 MW
- Longyangxia Dam Solar Park (Gonghe County, Qinghai, China) — 850 MW
- Villanueva Solar Park (Viesca, Coahuila, Mexico) — 828 MW
- Copper Mountain Solar Facility (Boulder City, Nevada, United States) — 802 MW
- Mount Signal Solar Farm (Calexico, California, United States) — 794 MW
- Charanka Solar Park (Patan, Gujarat, India) — 790 MW
- Rewa Ultra Mega Solar (Rewa, Madhya Pradesh, India) — 750 MW
- Solar Star (I and II) (Rosamond, California, United States) — 747 MW
- Kamuthi Solar Power Project (Kamuthi, Tamil Nadu, India) — 648 MW
- Dau Tieng Solar Power Project (Tay Ninh Province, Vietnam) — 600 MW
- Desert Sunlight Solar Farm (Desert Center, California, United States) — 550 MW
Of course, size isn’t everything. The best solar power plant in the world is one that provides electricity to those in need while preserving the planet and reducing a country’s reliance on fossil fuels. With solar power initiatives gaining momentum worldwide, it is clear as day that solar power is the future. If you are interested in joining the solar power movement, check out the rebates and incentives available in the United States.
What Country Has the Most Solar Power?
Here are the top five countries that had the most solar power capacity as of 2019:
Of course, these numbers are influenced by the size and population of each country. To provide a more accurate perspective of countries that use the most solar energy, here are the top five countries with the most solar power capacity per capita:
- Australia — 637 W per capita
- Germany — 593 W per capita
- Japan — 498 W per capita
- Netherlands — 396 W per capita
- Belgium — 394 W per capita
What Are the Countries With the Most Solar Potential?
One of the best ways to advocate for solar energy is to compare the most water-stressed countries with their solar potential, since power generation from solar photovoltaic power plants requires minimal water use. Here are the top five water-stressed countries that could harness the most solar energy based on solar irradiance (watts per square meter):
Here is a timeline of the biggest solar power plants since 1982, by solar energy capacity in megawatts:
- 1982: Lugo (United States) — 1 MW
- 1985: Carrisa Plain (United States) — 5.6 MW
- 2005: Bavaria Solarpark (Mühlhausen) (Germany) — 6.3 MW
- 2006: Erlasee Solar Park (Germany) — 11.4 MW
- 2008: Olmedilla Photovoltaic Park (Spain) — 60 MW
- 2010: Sarnia Photovoltaic Power Plant (Canada) — 97 MW
- 2011: Huanghe Hydropower Golmud Solar Park (China) — 200 MW
- 2012: Agua Caliente Solar Project (United States) — 290 MW
- 2014: Topaz Solar Farm (United States) — 550 MW
- 2015: Longyangxia Dam Solar Park (China) — 850 MW
- 2016: Tengger Desert Solar Park (China) — 1,547 MW
- 2019: Pavagada Solar Park (India) — 2,050 MW
- 2020: Bhadla Solar Park (India) — 2,245 MW