In an hour and a half, the amount of sunshine that touches the earth’s surface is enough to power the entire world’s energy usage for a year. Photovoltaic (PV) panels or mirrors that concentrate solar radiation are used in solar technologies to convert sunlight into electrical energy. This energy can be converted into electricity or stored in batteries or thermal storage.
Solar radiation basics, photovoltaic and concentrating solar-thermal power technologies, electrical grid system integration, and non-hardware factors (soft costs) of solar energy are all covered in the resources and information listed below. You can also read more about the solar energy sector and how to go solar. You can also learn more about solar energy and how the US Department of Energy’s Solar Energy Technologies Office is driving creative research and development in these fields.
Solar Energy 101
Solar radiation is light emitted by the sun, also known as electromagnetic radiation. While every area on Earth receives some sunlight over the course of a year, the amount of solar energy reaching any given spot on the planet’s surface fluctuates. Solar technologies absorb this radiation and convert it to energy that may be used.
STEP 1:Sunlight activates the panels.
A layer of silicon cells, a metal frame, a glass casing wrapped by a specific coating, and wiring make up each individual panel. The panels are joined together in “arrays” (an ordered series) and placed on rooftops or in big outdoor settings for maximum effect. During daylight hours, the solar cells, also known as photovoltaic cells, absorb sunlight.
STEP 2:The cells produce electrical current.
A thin semiconductor wafer comprised of two layers of silicon is contained within each solar cell. An electric field is formed when one layer is positively charged and the other is negatively charged. When sunlight contacts a photovoltaic solar cell, it energizes it, causing electrons to ‘break loose’ from atoms within the semiconductor wafer. The electric field surrounding the wafer causes those unbound electrons to move, resulting in an electrical current.
STEP 3: The electrical energy is converted.
You now have solar panels that are efficiently converting sunlight into electricity, but the electricity created is known as direct current (or DC) electricity, which is different from the alternating current (or AC) electricity that powers most homes. Fortunately, a device known as an inverter can quickly convert DC current to AC electricity. These inverters can be arranged as a single inverter for the entire system or as separate microinverters installed behind the panels in newer solar systems.
STEP 4:The converted electricity powers your home.
When solar energy is converted from DC to AC, it passes via your electrical panel and is dispersed throughout your home to power your appliances. Nothing in your home needs to alter because it operates just like the electrical electricity generated by your electric utility provider through the grid. You can automatically pull additional electricity from the grid to compensate any solar shortages because you’re still linked to your standard power company.
STEP 5:A net meter measures usage.
Your solar shingles or panels may not be able to capture enough sunlight to utilize for electricity on cloudy days or overnight; conversely, when no one is home during the day, they may collect surplus energymore than you need to power your home. That’s why a meter is used to track the amount of power coming into and out of your home. Any surplus power you send back to the grid will usually earn you credits from your utility company. This is referred to as net metering.
Now that you understand the fundamentals of solar energy, you may marvel at how modern photovoltaic technology can harness the sun’s tremendous power to power a home. It isn’t rocket science, but it is certainly human inventiveness at its finest.
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Step-by-step, how does solar energy generate electricity?
The equipment your utility provider uses to measure your electricity consumption is your electric meter (sometimes known as a “utility meter”). It’s how they figure out how much to charge you each month. The energy company has someone check your meter in person once a month since older electric meters have analog dials that spin as current flows through them. Even yet, that meter reading is merely a summary of your monthly electricity usage.
When you go solar, you use power generated by your solar panels rather than electricity from the grid, which reduces the amount of electricity you use from the grid. As a result, your electric meter records significantly less consumption, and you save money by not paying the utility provider for that electricity.
Most solar-powered homes have a smart meter installed, which tracks your home’s exact electricity consumption. Your local utility provider receives real-time usage data from smart meters for invoicing, customer service, and research purposes. By detecting exactly how much electricity is used, a smart meter eliminates the need for anticipated bills.
Smart Meters and Net Metering
If your home is equipped with a smart meter, you can use net metering if it is accessible in your area. Net metering allows you to receive credits from your local utility company for any excess electricity generated if your solar panel system is connected to the electricity grid (which most are).
Your smart electric meter will track both production and consumption, and if you generate more energy than you need for your home, you may export it to the grid and earn credits that can help you save money on your electric bills in the future.
What exactly is solar electricity and how does it function?
Solar power works by transforming the sun’s energy into electricity. For our purposes, the sun generates two types of energy: electricity and heat. Both are produced using solar panels, which range in size from residential rooftops to large-scale’solar farms’ covering hundreds of acres of rural land.
China 205 GW
According to the IEA’s Renewables 2020 report, China has by far the world’s largest installed solar energy fleet, with 205 GW in 2019.
In the same year, solar energy generated 223.8 terawatt hours (TWh) of electricity in the country.
Despite being the world’s highest emitter, China’s huge energy needs can handle both the world’s largest coal and renewable fleets due to the sheer size of its economy.
During the late 2010s, government subsidies boosted activity in the industry, while commercial project subsidies have since been taken out in favor of a competitive auction approach.
The Huanghe Hydropower Hainan Solar Park (2.2 GW) in Qinghai province is China’s largest single solar project.
United States 76 GW
In 2019, the United States has the world’s second-largest installed solar capacity, with 76 GW providing 93.1 TWh of power.
As the US intensifies its renewable energy initiatives and aims to entirely decarbonize its electricity system by 2035, solar installations are expected to reach over 419 GW over the next decade.
The solar sector in the United States is dominated by utility-scale projects, with California, Texas, Florida, and Virginia among the most active states.
The renewable portfolio standards (RPS) law, which requires energy retailers to produce a percentage of electricity derived from renewable sources, is a primary driver of growth in the United States. In recent years, expansion has been aided by lower implementation costs and applicable tax credits.
Japan 63.2 GW
According to the IEA’s data, Japan ranks third among countries with the biggest solar power capacity, with a fleet totaling 63.2 GW in 2019, generating 74.1 TWh of electricity.
Alternative energy sources such as solar and other renewables have grown in popularity after the Fukushima nuclear disaster in 2011, which caused Japan to drastically reduce its nuclear energy activities.
Feed-in-tariff (FiT) systems have been successful in Japan in incentivizing the deployment of solar technology, although the solar PV market is anticipated to decrease slightly in the following years.
According to the IEA, PV additions in Japan will begin to decline in 2022, owing to the phaseout of the generous FiT plan for large-scale projects and undersubscribed capacity in earlier auctions.
Nonetheless, depending on government policy and cost reductions, installed solar capacity in Japan could reach 100 GW by 2025.
Germany 49.2 GW
With a national fleet of roughly 49.2 GW in 2019, Germany is the leading country in Europe for solar deployments, providing 47.5 TWh of electricity.
Competitive auctions have helped the industry in recent years, and the German government recently suggested raising its 2030 solar installation target to 100 GW, as part of a goal to achieve a 65 percent renewable energy mix by the end of the decade.
In Germany, small-scale, private installations are prevalent, with government support mechanisms such as reimbursement for surplus generation incentivizing them, while utility-scale projects are likely to rise in the coming years.
The 187-megawatt (MW) Weesow-Willmersdorf facility north of Berlin, created by German utility EnBW, is the country’s largest solar project to date.
India 38 GW
India has the world’s fifth-largest installed solar capacity, with 38 GW built in 2019 and 54 TWh produced.
India’s energy demand is predicted to expand faster than any other region in the coming decades, and as the world’s third-largest carbon emitter, policies are being devised to transition the country away from coal and toward renewables.
Solar is expected to play a key role in the government’s goal of 450 GW of renewable energy generation by 2030.
Under current policy aspirations, solar is expected to account for around 31% of India’s energy mix by 2040, compared to less than 4% today, according to the IEA.
The agency attributes this shift to India’s “exceptional cost-competitiveness of solar,” which “out-competes existing coal-fired electricity by 2030 even when supplemented with battery storage.”
To expedite the development of India’s solar power market in the future years, transmission-grid constraints and land-acquisition problems will need to be overcome.
Renewable Energy Source
Among the many advantages of solar panels, the most crucial is that solar energy is a fully renewable source of energy. It can be used in any part of the world, and it is available 24 hours a day. Solar energy, unlike certain other forms of energy, cannot be depleted.
Solar energy will be available as long as the sun exists, therefore we will have access to it for at least 5 billion years after the sun dies, according to scientists.
Reduces Electricity Bills
Your energy expenses will decrease since you will be able to fulfill some of your energy needs with the electricity generated by your solar system. The amount you save on your bill is determined by the size of your solar system and the amount of power or heat you use.
If you run a business and utilize commercial solar panels, for example, this transition can save you a lot of money because the large system size can cover a lot of your energy expenses.
Furthermore, not only will you save money on your electricity bill, but you may also be eligible for Smart Export Guarantee reimbursements for extra energy you export back to the grid (SEG). If you generate more electricity than you consume, you have a surplus (considering that your solar panel system is connected to the grid).
Solar energy can be put to a variety of uses. You can use photovoltaics to generate power or heat (solar thermal). Solar energy can be used to generate electricity in areas where there is no connection to the grid, to distill water in areas where pure water is scarce, and to power space spacecraft.
Solar energy can also be incorporated into the building components. Sharp just released transparent solar energy windows.
Low Maintenance Costs
Solar energy systems, in general, do not necessitate a lot of upkeep. You only need to keep them clean on a regular basis, so cleaning them a couple of times a year will suffice. If in doubt, you can always rely on specialized cleaning agencies, which charge between 25 and 35 for this service.
There is also no wear and tear because there are no moving parts. Because it is always working to convert solar energy into electricity and heat, the inverter is usually the sole part that needs to be replaced after 5-10 years (solar PV vs. solar thermal). Apart from the inverter, your solar power system’s wires must be maintained to ensure maximum efficiency.
So, once you’ve paid for the solar system, you should anticipate to spend very little on maintenance and repairs.
The solar power industry’s technology is always improving, and this trend will continue in the future. Quantum physics and nanotechnology advancements have the potential to improve the efficiency of solar panels and double, if not triple, the electrical input of solar power systems.
What are the benefits of solar energy?
The sun produces more than enough energy to meet the entire world’s energy needs, yet unlike fossil fuels, it will never run out. Solar power’s main constraint as a renewable energy source is our capacity to convert sunlight into electricity in an efficient and cost-effective manner.
Solar energy – a clean source
When solar panels are used to generate power, no greenhouse gas emissions are emitted into the atmosphere. Solar power is an important energy source in the transition to clean energy production because the sun delivers more energy than we’ll ever need.
No fuel to burn
Solar panels offer minimal operating costs compared to other kinds of energy generation once they are installed. Because no fuel is required, solar power may generate vast volumes of electricity without the risk or price of ensuring a fuel supply.
In a home, how does solar energy work?
Solar panels are actually rather easy! Solar panels basically record the sun’s energy and then work to turn that energy into electricity for your home. When sunlight strikes solar panels, it is absorbed by photovoltaic cells and delivered to an inverter, where it is converted from DC to AC electricity. The electricity is then ready for you and your home to consume, or it can be routed to the grid to be used by your neighbors. In some circumstances, such as with the Tesla Powerwall, the energy is stored in battery banks.
Whether or not you use a battery bank is entirely up to you, and is frequently influenced by your budget. Every customer who installs solar panels should also consider building a solar battery bank, according to Sun Badger. While the battery bank won’t allow you to totally disconnect from the grid, it will help you reduce your reliance on it.
In basic terms, what is solar energy?
Why is it that the day is brighter and warmer than the night? The answer is straightforward: solar power. Solar energy is nothing more than the sun’s light and heat.
- Solar thermal technology uses the sun’s heat to generate hot water or steam.
- Passive solar heating is as simple as allowing the sun to shine through windows to warm a building’s interior.
Where does solar energy come from?
Photons that reach your solar cells and form an electric current originate in the sun. The continual nuclear fusion processes that occur deep within the sun produce solar energy. When protons (which are essentially the same as hydrogen atoms) collide and fuse under severe temperature and pressure to form helium, this is known as nuclear fusion. This process releases a tremendous amount of energy (plus more protons), and it occurs continuously in the sun’s core, producing roughly 500 million tons of hydrogen atoms every second.
What’s the end result? Our sun is constantly generating tremendous amounts of energy in the form of electromagnetic radiation at a temperature of roughly seven million degrees Fahrenheit (EMR). EMR comes in a variety of forms, and the sun generates all of them, which are then transmitted to Earth in the form of photons.