Solar Panels Are A Joke
Solar panels have been in development for over 150 years. The basic technology behind solar panels was first discovered in 1839 by French scientist Edmond Becquerel. He discovered the photovoltaic effect, or the creation of a voltage when sunlight hits certain materials like selenium or silver chloride. Over the next several decades, various inventors experimented with solar energy devices, including a selenium solar cell that could convert sunlight into electricity which was created by Charles Fritts in 1883 A Brief History of Solar Panels. However, the low efficiency of early solar cells prevented widespread use.
It wasn’t until 1954 that Bell Laboratories developed the first practical photovoltaic cell made of silicon Solar panel. This ushered in the beginning of the modern solar panel industry. In the 1960s, solar panels were used to provide power aboard space satellites. But it still took decades before solar power became economically viable for widespread terrestrial use. Continued improvements in solar cell efficiency along with mass production have now made solar panels a competitive renewable energy source.
How Solar Panels Work
Solar panels generate electricity through the photovoltaic effect. When sunlight hits the semiconductor material in solar cells, the photons from the sunlight knock loose electrons from the atoms in the semiconductor material. This creates an electric current that can be captured and used as electricity. The photovoltaic effect was first observed by French physicist Edmond Becquerel in 1839 when he noticed that certain materials would produce small amounts of electric current when exposed to light. Today’s solar panels use advanced semiconducting materials like silicon to optimize the photovoltaic effect for generating electricity from sunlight.
The photovoltaic effect allows solar panels to directly convert sunlight into usable electricity without any moving parts or environmental emissions. Solar panel systems can be installed on homes, buildings, and even integrated into devices to provide renewable electricity from the sun.
Types of Solar Panels
There are three major types of solar panels: monocrystalline, polycrystalline, and thin-film. The key differences are:
- Monocrystalline solar panels are made from silicon formed into high-purity crystals. They have a uniform black appearance and are the most efficient, but also the most expensive. Monocrystalline panels typically have efficiency ratings of 15-22% (Source).
- Polycrystalline solar panels are made from fragments of silicon crystals melted together. They have a speckled blue color and lower efficiency ratings of 13-16%. However, polycrystalline panels are cheaper to produce than monocrystalline (Source).
- Thin-film solar panels are made by depositing silicon layers on glass or stainless steel. They have the lowest efficiency rating of 7-13%, but can be easier to install and integrate into buildings because of their flexibility (Source).
Understanding the trade-offs between efficiency, costs and installation requirements can help homeowners choose the best solar panel type for their needs and budget.
Efficiency and Output
The efficiency of a solar panel indicates how much of the sun’s energy striking the panel is converted into usable electricity. It is measured as a percentage, with higher percentages translating to greater efficiency and power output. Most residential solar panels on the market today have average efficiencies ranging from 15% to 22%.
There are a few key factors that affect a solar panel’s efficiency and power output:
Maximum power rating – This specifies the peak wattage a panel can produce under optimal conditions. Panels with higher power ratings will produce more electricity.[1]
Cell technology – Panels made with newer monocrystalline and PERC cells tend to rate higher in efficiency compared to older polycrystalline cells.[2]
Temperature – Solar cells become less efficient as they heat up. Cooler operating temperatures lead to higher efficiency and energy production.[3]
Orientation and tilt – Optimal orientation towards the sun’s path maximizes irradiance and increases output. The angle of tilt also affects production.[2]
Shading – Even minor shading from trees, poles or buildings can greatly diminish output. Maximizing unobstructed sunlight is key.[1]
Overall, higher efficiency solar panels will deliver more power under real-world conditions. However, efficiency is just one metric to consider along with factors like cost, warranties, and manufacturer reputation when selecting panels.
[1] https://solartechnologies.com/understanding-solar-panel-performance-metrics/
[2] https://eepower.com/technical-articles/how-is-solar-panel-efficiency-measured/
[3] https://www.ourworldenergy.com/solar-panel-metrics-what-you-need-to-know/
Costs
The upfront costs of installing solar panels can seem daunting. However, there are incentives available to help offset the initial investment. The average cost to install solar panels ranges from $2.50-$3.50 per watt, with the total system cost for a 2,000 square foot home coming in around $15,000-$21,000 before incentives (source 1).
However, tax credits and other incentives like Solar Renewable Energy Certificates (SRECs) can reduce the net cost by 26-50%. The federal solar tax credit allows you to deduct 26% of the total system cost from your federal taxes (source 2). SRECs provide additional incentives by creating tradeable credits for solar production that you can sell (source 1).
Even with incentives, solar panels still require an upfront investment that is recouped over time. But the long-term savings can be substantial. Once installed, sunlight is free. So after covering your initial costs, you can generate free electricity for decades with minimal maintenance expenses. This provides protection against rising energy rates. Over 20 years, solar systems can yield $15,000-$30,000 in energy savings, making them a smart financial decision (source 2).
While solar panel costs have dropped significantly, upfront price remains a barrier. But incentives paired with long-term savings make them a sound investment for many homeowners. Careful analysis of costs and offsets can determine if solar panels make financial sense for your specific situation.
Installation
Proper installation of solar panels is crucial to maximize efficiency and output. Solar panels can be installed on rooftops or ground mounted. Rooftop systems are most common for residential installations, while ground mounts allow the panels to be tilted for optimal sun exposure.
For rooftop systems, the solar panels can be mounted flush with the roof or titled using racking. Tilted systems usually generate more power, as the angle can be adjusted for the site’s latitude and conditions. However, they require additional mounting and hardware. Tracking systems, which follow the sun’s movement throughout the day, can further increase output but have higher costs.
Solar panel installation can be completed as a DIY project for the mechanically inclined. However, professional installation is recommended for most homeowners. Qualified solar installers have the skills, experience, and equipment to properly mount, wire, and connect the solar array for safety, durability, and performance. They also handle permitting and inspections. DIY installs often run into issues that increase costs over hiring a professional initially (source).
The average cost of solar installation ranges from $2 to $4 per watt depending on system size, electric rates, incentives, and site conditions. Installation represents about 15-25% of the total solar system cost (source). Factors like roof type, tilt, and accessibility can impact labor time and difficulty, driving cost. Permitting fees and structural upgrades may also add expenses.
Maintenance
Proper maintenance is crucial to maximize solar panel efficiency and lifespan. Solar panels should be inspected and cleaned around 2-4 times per year, depending on environmental factors like pollen, dirt, and snow (Source). Cleaning should be done with water and a soft brush or sponge to remove debris without damaging the panels.
It’s important to take care not to scratch the glass surfaces during cleaning. Any cracks or damage to panels should be repaired promptly to prevent efficiency losses. Check that mounting equipment is still secure, and adjust the angle as needed to optimize sun exposure throughout the year (Source).
Most solar panel manufacturers provide a 20-25 year performance warranty, so following the recommended maintenance steps will ensure the system remains in good working order. Annual system inspections by a professional are also advised to spot any potential problems.
Environmental Impact
Solar panels have far fewer emissions and waste compared to fossil fuels. According to the Union of Concerned Scientists, solar panels generate electricity without air pollution, greenhouse gas emissions, or water use. In comparison, fossil fuels like coal, oil and natural gas produce significant emissions of carbon dioxide, nitrogen oxides, sulfur dioxide, particulate matter and other pollutants that contribute to acid rain, smog and health issues.
The manufacturing of solar panels does involve some hazardous materials like sulfuric acid and phosphine gas. However, the environmental impact is much lower compared to the emissions from burning fossil fuels for energy. According to the U.S. Energy Information Administration, the use of solar energy can reduce the use of fossil fuels and lower the overall environmental impact when it replaces or reduces the need for nonrenewable energy sources.
Challenges and Limitations
While solar energy has many benefits, it also comes with some challenges and limitations that need to be addressed. Three major issues with solar power are intermittency, storage, and regulations.
Intermittency refers to the fact that solar energy relies on sunlight, which varies depending on location, weather, and time of day. Solar panels do not produce energy at night, and their output can be reduced on cloudy days or periods of heavy rain (1). This inconsistency can make it difficult to integrate solar power fully into the existing electric grid without storage capabilities or backup power.
Storing solar energy is possible using batteries, but battery technology has not advanced enough to store solar power cost-effectively on a large scale. Until more affordable and scalable storage is available, intermittency remains a barrier to widespread solar adoption (2).
Finally, regulations related to connecting solar energy to the electric grid can also impede growth. Policies regarding net metering, interconnection, permitting, and electricity rates for residential solar customers are still developing. Unfavorable regulations by utilities or local governments could discourage consumers from adopting solar panels (3).
While solar power brings clean energy, addressing intermittency, storage, and regulations remains pivotal to unlocking its full potential.
(1) https://www.constellation.com/energy-101/energy-innovation/solar-energy-pros-and-cons.html
(2) https://hbr.org/2021/06/the-dark-side-of-solar-power
(3) https://www.greenmatch.co.uk/blog/2014/08/5-advantages-and-5-disadvantages-of-solar-energy
Future Outlook
The future of solar energy looks very promising, with projections for continued growth and improvements in efficiency and affordability.[1] Research shows that solar panels and systems will likely become even more efficient at converting sunlight into usable energy. [2] Advances in photovoltaic technologies and materials science are expected to drive increases in the efficiency of commercial solar panels up to 30-35% by 2024 and beyond, up from 20-22% today.[3]
Solar energy capacity is projected to continue growing globally as costs fall and solar becomes even more cost competitive with fossil fuels. The International Energy Agency predicts solar PV capacity could grow from around 600 gigawatts today to over 2500 gigawatts by 2030.[4] With such tremendous growth, solar is positioned to become one of the main sources of electricity generation around the world within the next decade.
