What Is It Called When You Get Power From The Sun?

Solar power, also known as solar energy, refers to technologies and systems that utilize energy from the sun for electricity generation, space heating, water heating, and other applications. The sun produces energy in the form of electromagnetic radiation from nuclear fusion reactions deep in its core. Some of this solar energy reaches the Earth in the form of direct sunlight. With solar power technologies, this radiation can be converted into useful forms of energy.

Humans have utilized solar power passively, mainly for heating, since ancient times. However, the modern solar power industry really began in the 1950s with research into silicon photovoltaic (PV) cells. These PV cells convert sunlight directly into electricity through the photovoltaic effect. Developments in solar cell technology, manufacturing processes, and installation methods have dramatically increased solar PV system efficiency and reduced costs over the past few decades.

Today, solar power is harnessed actively in two primary ways – through solar heating technologies like solar water heaters, concentrated solar power plants, and passive solar building design; and through solar PV systems made up of solar panels and additional system components. Solar PV can be deployed on a small scale for individual buildings as well as on a utility-scale for delivering electricity to the grid.

How Solar Power Works

Solar power systems convert energy from the sun into electricity through the photovoltaic effect or by heating a fluid. The photovoltaic effect occurs when photons from sunlight strike a solar cell made of semiconducting materials, knocking electrons loose and allowing them to flow as electricity. Solar thermal systems, also called concentrating solar power systems, use mirrors or lenses to concentrate sunlight onto a receiver containing a fluid. The concentrated sunlight heats the fluid to very high temperatures, which is then circulated to drive a generator that produces electricity.

There are a few main types of solar power systems that utilize these effects in different ways:

• Photovoltaic (PV) systems use solar panels made up of many solar cells containing photovoltaic materials that convert sunlight directly into electricity through the photovoltaic effect.
• Concentrated solar power (CSP) systems use mirrors or lenses to focus a large area of sunlight onto a small area to produce heat, which is used to drive a heat engine generator.
• Solar thermal systems, also known as solar hot water systems, use sunlight to heat water rather than generate electricity.

Both PV and CSP technologies produce renewable solar power without carbon emissions, helping reduce dependence on fossil fuels. PV systems are modular and can be installed on homes and businesses, while CSP systems are better suited for utility-scale power generation.

Benefits of Solar Power

Solar power offers numerous benefits that make it an attractive energy source for homes, businesses, and utilities. Some of the main benefits of solar power include:

Clean renewable energy – Solar panels produce electricity from sunlight without any fuel combustion or pollution. Solar does not emit greenhouse gases or other pollutants during operation. This makes it a clean, renewable source of energy.

Reduces fossil fuel dependence – Generating electricity from the sun reduces our dependence on finite fossil fuels like coal and natural gas. Widespread adoption of solar power will help create energy independence and security.

Lowers electricity bills – Homes and businesses with rooftop solar panels can reduce their monthly utility bills by using the electricity generated. Solar power can provide a hedge against rising energy costs. Any excess solar electricity can even be sold back to the grid.

Costs of Solar Power

The upfront costs of installing solar panels can seem daunting, but have decreased substantially in recent years. The average cost to install a residential solar system is around $2.50-$4.50 per watt, with the typical home system costing anywhere from $10,000-$30,000 depending on system size, location, and available rebates or tax credits. Larger commercial and utility-scale solar projects cost more on a per watt basis but benefit from greater economies of scale.

Once solar panels are installed, the fuel – sunlight – is free. This gives solar power a significant advantage over fossil fuels whose costs fluctuate regularly. Solar panels also require little maintenance over their 25-40 year lifespan, mainly just keeping panels clean and checking inverter operation. Though solar power requires an initial investment, the lifetime costs and savings from solar energy typically outweigh the upfront costs. Most solar installations will pay for themselves within 5-10 years through electricity bill savings and then provide decades of free power after that.

Compared to conventional energy sources, solar power is becoming increasingly cost-competitive thanks to falling prices. In many parts of the world, solar is now the cheapest form of new electricity generation. As technology continues to improve efficiency and lower solar costs, its affordability compared to fossil fuels will further increase. The modular nature of solar also avoids the huge infrastructure costs associated with centralized fossil fuel power plants. With solar power, customers can start small and scale up over time as needed and as costs drop further.

Solar Power Systems

Solar power systems convert sunlight into electricity through the use of photovoltaic (PV) solar panels. The key components of a solar power system include:

Solar Panels

Solar panels, also known as PV panels, contain solar cells made from silicon that absorb sunlight and convert it into direct current (DC) electricity. Multiple solar panels are wired together to form an array that is mounted on a roof or ground-based structure.

Inverters

Inverters convert the DC electricity from the solar panels into alternating current (AC) electricity that can be used to power homes and businesses or fed back into the utility grid. There are string inverters for small systems and microinverters for individual panels.

Batteries

Batteries store excess solar energy during the daytime and discharge it when needed. They allow solar panel systems to provide power at night and during power outages. Batteries are more common for off-grid systems.

Charge Controllers

Charge controllers regulate the voltage and current coming from the solar panels going to battery banks to prevent overcharging and damage. They prolong battery life.

Racking

Racking provides the mounting structure to securely attach solar panels in the proper orientation to maximize sun exposure. Rooftop systems use vertical rail or integrated racking.

Wiring

Electrical wires connect all of the solar system components together into a working system. Proper wiring size is important for efficiency.

These major components work together to absorb sunlight, convert it to usable electricity, and manage the power output to meet energy needs.

Residential Solar

One of the most common ways homeowners utilize solar power is by installing rooftop solar photovoltaic panels. These panels convert sunlight into electricity that can power your home. Any excess electricity produced can be fed back into the grid through a process called net metering.

With net metering, your home’s electric meter can spin backwards when your solar panels produce more electricity than your home is using. This excess electricity gets exported to the grid, turning your electric meter backwards. You then get credited for those excess kilowatt-hours, reducing your energy bill.

Many homeowners choose to lease their solar panel systems from a solar provider rather than buy them outright. This allows you to go solar for little to no money down. The solar company owns, maintains, and insures the system while you pay a fixed monthly rate for the solar power produced. At the end of the lease, you can extend the term, have the panels removed or choose to buy the system.

Purchasing a solar system through a solar loan is another popular option. You take out a loan from a lender or solar company to cover the system costs and you own the panels. The loan payments are often less than what you’d normally pay your utility provider. Once the loan is paid off, the electricity generated is free.

Utility-Scale Solar

Utility-scale solar power refers to large solar energy facilities that generate electricity to be fed into the grid and distributed to the public. These are typically solar photovoltaic farms made up of thousands or even millions of solar panels spread across large plots of land. The size of utility-scale solar farms can range from 5-10 megawatts up into the gigawatt range, providing enough electricity to power entire cities.

The main advantages of utility-scale solar farms are economies of scale and the ability to provide renewable power at scale to displace fossil fuel electricity generation. By building massive arrays of solar panels in sun-rich locations, solar farms can produce electricity very efficiently at a price competitive with coal and natural gas power plants. The large upfront investment in these facilities is offset by decades of low-cost solar power production.

Some key examples of large-scale solar farms in the U.S. include:

• Topaz Solar Farm – One of the world’s largest at 550 megawatts, located in California.
• Solar Star – The largest solar farm in the U.S. at 579 megawatts, located in California.
• Desert Sunlight Solar Farm – 550 megawatts, located in California.
• Mount Signal Solar – 200 megawatts, located in California.
• Agua Caliente Solar Project – 290 megawatts, located in Arizona.

Utility-scale solar is poised to expand rapidly in the coming decades to help states and countries meet renewable energy goals and reduce greenhouse gas emissions from the power sector. Continuing technological improvements and cost declines for solar power will enable very large-scale carbon-free electricity generation from the sun.

Solar Policy and Incentives

Governments around the world have implemented various policies and incentives to encourage the adoption of solar power. These range from direct subsidies and tax credits to mandates for utilities to generate a percentage of their electricity from renewable sources like solar. Some of the key solar incentives include:

Solar Investment Tax Credit (ITC) – This federal tax credit allows homeowners in the U.S. to deduct 26% of the cost of installing a residential solar system from their federal taxes. Businesses can deduct an even higher percentage. The ITC has been a major driver of solar adoption in the U.S. but it is currently scheduled to phase down in the coming years.

Net Metering – Net metering allows solar panel owners to get credit for excess electricity they export to the grid. This makes it more economical to install rooftop solar. Many U.S. states have net metering requirements, though some are now re-evaluating them.

Renewable Portfolio Standards – An increasing number of states have renewable portfolio standards (RPS) which require utilities to obtain a certain percentage of their electricity from renewable sources. These mandates create guaranteed demand for solar power.

Feed-in Tariffs – With feed-in tariffs, governments set above-market rates that utilities must pay to solar producers for the electricity they feed into the grid. This enables rooftop solar owners to recoup their investment faster. Feed-in tariffs helped drive early solar adoption in Europe, Japan, and other regions.

Incentives like these have proven very effective at stimulating solar power deployment. However, solar is becoming increasingly cost competitive on its own. Some policies are now evolving from direct financial incentives to programs that encourage solar via community solar, solar mandates on new construction, and streamlined solar permitting.

Future of Solar Power

The future looks bright for solar power. As technology improves, solar panels are becoming increasingly more efficient at converting sunlight into electricity. Companies are developing solar panels that can absorb more of the sun’s light spectrum, allowing them to generate more electricity from the same amount of sunlight. Some emerging solar cell technologies like perovskites have the potential to be much more efficient than traditional silicon solar cells.

Energy storage will also play a key role in the growth of solar power. With improved batteries like lithium-ion and flow batteries, solar power can continue providing electricity when the sun isn’t shining. Energy storage allows solar power to be dispatched on demand, overcoming the intermittency issue.

Solar power is projected to see massive growth in the coming decades. The International Energy Agency predicts solar PV capacity could reach over 5,000 gigawatts worldwide by 2030, a 10 fold increase from 2020. As solar costs continue to fall and technology improves, solar will become increasingly cost competitive with fossil fuels.

However, some challenges remain for wide-scale solar adoption. The intermittent nature of solar power makes it difficult to balance on the electric grid without energy storage. More work needs to be done on upgrading grids and energy storage to support high levels of solar power. There are also some financial and policy hurdles in deregulated energy markets that make it difficult for solar to compete. But with supportive policies and rapid technological innovations, solar power is poised to become a major energy source worldwide.

Conclusion

To summarize, solar power, also called photovoltaics or PV, is the conversion of energy from sunlight into electricity. Solar panels made up of photovoltaic cells collect the sun’s energy and convert it into usable electricity. The benefits of solar power include clean, renewable energy production, energy independence and security, cost savings, job growth, and environmental improvements. While costs have come down substantially, the upfront investment for solar systems can still be significant. Government incentives, policies, and advancing technologies continue to make solar more affordable and widespread. With solar playing an increasingly important role in the renewable energy landscape, the future is bright for broader adoption of solar across residential, commercial, utility, and transportation applications. As solar efficiency rises and storage capabilities grow, solar promises to be a critical component of a clean energy economy.