Measuring the Efficiency of Solar Panels
Solar energy systems have the added benefits of very high efficiency, durability, and service life – they’re engineered for sustainability. This means fewer replacements and repairs, saving even more energy and precious resources.
A solar panel’s efficiency is measured by the percentage of power the panel converts absorbed sunlight to electricity. Because panels vary in size, the power produced is measured against the size of the panel. For this reason, it’s better to have a smaller panel that produces more energy. It is better to have a 2.5’ x 5’ panel that produces 4.5 kilowatt hours (kW) than a 3’ x 6’ panel that produces the same amount.
Sadly, not all solar panels are created equal. The highest quality panel operates at 42% efficiency. There are panels that produce energy at far lower efficiency rates—most of which are purchased through retail. This is why we don’t recommend building your own system.
Generally speaking, the more you invest up front on a solar panel system, the greater your return will be year after year. Overtime, the higher efficiency panels perform better, giving you a better bang for your buck.
Five Myths of Solar Power
With so much information available to consumers, it’s no wonder that some people have many misconceptions about the benefits of solar power. We’re here to bust those myths! Here are five common misconceptions about solar power:
MYTH #1: Solar devices require more energy to manufacture than they produce in their lifetime.
FACT:
In a study by the National Renewable Energy Laboratory (NREL) conclusively demonstrates that energy payback for photovoltaic (PV) power is, in the worst case, less than 4 years. Given that PV module lifetimes are generally in excess of 30 years, a PV system will produce far more energy than it consumes over its lifetime.
Energy output and input ratios for concentrating solar power (CSP) and solar thermal devices are even more favorable, given their simple manufacture. This myth has its origins in the early history of PV power, when devices were essentially custom-fabricated for military, space and research markets.
MYTH #2: Solar won’t work where I live.
FACT:
Solar thermal is dependent on heat and PV Solar devices are dependent on light – and this light does not need to be direct.
More important than place-to-place variations in solar intensity is the price of daytime electricity where you live and the existence of state incentives for clean energy.
MYTH #3: Photovoltaics cannot significantly offset environmental emissions.
FACT:
PV systems produce no atmospheric emissions or greenhouse gases. Compared to fossil-generated electricity, each kilowatt of PV electricity annually offsets up to:
- 16 kilograms of nitrogen oxides
- 9 kilograms of sulfur oxides
- 2,300 kilograms of carbon dioxide (CO2)
If the industry grows by the 25% per year as predicted PV in the United States will offset 10 million metric tons of CO2 per year by 2027 — equivalent to the annual increase emitted by U.S. fossil fuel electricity generation. This means that the emission rate will become negative thereafter as the PV contribution grows!
MYTH #4: Photovoltaic systems are too expensive and will never compete with “the big boys” of power generation. Besides, you can never get the energy out that it takes to produce the system.
FACT:
The energy payback period is dropping rapidly. For example, it takes today’s typical crystalline silicon module about 4 years to generate more energy than went into making the module in the first place. The next generation of silicon modules, which will employ a different grade of silicon and use thinner layers of semiconductor material, will have an energy payback of about 2 years. This means that these modules will produce “free” and clean energy for the remaining 28 years of their expected life.
MYTH #5: Solar power systems are too expensive for widespread usage.
FACT:
Solar PV technologies have declined in price every year since they were introduced onto the market, driven by improved research and development, and most of all by steady increases in sales volume. (In 1954, approximately one watt of PV generating devices was manufactured. In 2004, approximately one billion watts will be manufactured worldwide.)
Every solar panel purchased makes the next one cheaper, in stark contrast to nonrenewable sources, which become scarcer and more expensive with every ton that is burned.
PV has recently exploded into a number of industrial markets, where it is quite simply the lowest -cost source of power available. These include highway warning signs, rural irrigation applications and remote electrical and communications devices. Similarly, for any application more than about half a mile away from the electrical grid, a solar system will likely prove less expensive than will power line construction.
The most rapidly-growing segment of the solar industry is for “grid connected” systems – rooftop solar panels on homes or businesses that remain connected to the conventional electrical grid. In some cases, as where electricity is more expensive during the middle of the day, or when solar is used to support power-critical applications (e.g. banking, microchip manufacturing), the economics are very compelling without further incentives. In other places, comparatively modest state or federal incentives can make solar a great investment for home or business owners that better with every year.
Four Reasons Why Building Your Own Solar Panels Is a BAD Idea
If you Google solar panels, most of the top results are for websites selling DIY solar panel kits. The same search on YouTube is filled with videos on making your own solar panels.
While building and installing your own solar panels might seem like a good way to save some money, there are several reasons why doing it yourself is a bad—sometimes even dangerous—idea. Here are five reasons why you should work with a professional solar panel installer:
1) You will pay more for materials.
Professional solar panel installers are able to obtain a higher quality product at a lower price. The panels you get at Home Depot or other online retailers are, to say the least, a much lower quality. They are less efficient and will generate less electricity, meaning that you will have to install more panels to generate the same amount of energy, which will ultimately cost you more than a high-quality solar panel you get from a professional company.
2) Doing your own electrical can be dangerous.
This might seem obvious to some, but you’d be surprised how many people think that can do their own electrical work without having any formal training. Unless you are an electrician, installing your own electrical devices, much less a set of solar panels, can be incredibly dangerous. A professional installer will have both roofing and electrical experience, and will know how to safely install your solar panels.
3) Protecting your purchase through the warranty
Companies can be picky about their warranty. If you install your own solar panels, even the smallest mistake can void your warranty. Then you’re stuck with a system that might not be working right, has no warranty protection, and still cost you some money to install while not generating any income.
4) Paperwork, Paperwork, Paperwork
It’s great to use green solar technology and do your part to improve the environment and reduce our dependence on oil. But there’s also a financial benefit, with federal, state and local solar tax credits and grants, not to mention getting Solar Renewable Energy Credits (SRECs).
Obtaining those tax credits, grants and SRECs can be a bureaucratic nightmare. There are numerous forms to fill out, certifications to be obtained, and other hurdles that the homeowner might have to jump through. And if you make a mistake on any of your forms, you have to start all over from the beginning. Doing all this yourself can add months—sometimes years—to the time it takes for you to see a financial benefit of your solar panel system.
A professional solar installer can help you get every single cent you deserve from your solar panels, while installing a higher quality product safely.
We don’t like to brag too much (after all, this blog is about more than our company), but here at Solar Energy World, we take pride in helping our customers through every step of the solar installation process. From the first free solar analysis, through the installation and inspection, to the processing of paperwork, we provide customers with a seamless experience that makes switching to solar easier.
Far easier than doing it yourself.
Prince Georges County Homeowner Reduces Carbon Footprint and Saves Cash
One of the systems we’re particularly proud of is a unique ground install in Bowie, MD. The Blackwells, the family who hired Solar Energy World, were facing a rather steep $7,550 annual electricity bill.
The Blackwell’s are the owners of a large single-family home built in 2006 in Bowie, Maryland. The two-story home sits upon an approximate 40,000 square foot lot. So, with available space, the Blackwell’s explored the use of ground mounted solar panels to reduce their energy costs.
Our solar analysis showed that the Blackwells that it pays to go solar. The family opted for a 10.32kW solar electric system that includes 48 – 215 watt ground mounted panels. After the federal tax credit, state grant and local property tax credits, the Blackwell’s expect their solar panel system to cost nearly 50% off of the total installation cost.
In addition to the government incentives, the Blackwell’s will be saving $2,471 per year on their electricity bills and earning $4,435 per year by selling their Solar Renewable Energy Credits; making their ground mounted solar electric system pay back in less than 6 years.
We also installed an Enphase monitoring system along with the solar panels. The monitoring system showed that in just the first 10-days of operation, the system produced 505 kilowatt hours; which could power 1,529 light bulbs, 505 computers and 15 homes for one day.
Powering up the Blackwell’s solar panel system also reduced their carbon footprint, with a carbon offset of 865lbs. Within the same 10-day period the offset equivalent of planting 10 trees, not consuming 45 gallons of gas, and not driving 26 cars for a day.
Not only that, but they look amazing. Check out these other pictures of the solar system or read the solar case study.
40 Environmental Facts
In celebration of Earth Day’s 40th anniversary, we’ve list 40 interesting and alarming environmental facts. We’ve posted these facts every day for the past 40 days – thanks for listening and sharing with others!
- Approximately 20 million people across the United States celebrated the first Earth Day, on April 22, 1970. Today, more than 1 billion people around the world take part in the event.
- In 1995 over 200 of the world landfills were full.
- Each person throws away approximately 4 pounds of garbage per day.
- Approximately 5 million tons of oil produced in the world each year ends up in the ocean.
- The energy we save when we recycle one glass bottle is enough to light a traditional light bulb for four hours
- In, 1931, Albert Einstein, collected a Nobel Prize for is work in solar and photovoltaic experimentation.
- Every ton of paper that is recycled saves 17 trees, 2 barrels of oil, 4,100 kilowatts of energy, 3.2 cubic yards of landfill space and 60 pounds of air pollution.
- 14 billion pounds of trash is dumped into the ocean every year
- 84% of all household waste can be recycled
- More than 1/3 of all energy is used by people at home
- Most families throw away about 88 pounds of plastic every year
- Everyday in the United States, we produce enough trash to equal the weight of the Empire State Building
- The Great Pacific Garbage Patch is a swirling vortex of waste and debris in the Pacific Ocean. This area is twice the size of the continental US and is believed to hold almost 100 million tons of garbage.
- The human population has grown more in the last 50 years than it did in the previous 4 million years
- John Herschel, a British astronomer, converted solar power by using a solar collector box to cook food while on an African expedition, in 1830.
- In some elementary schools, after Halloween and Christmas, Earth Day is the third largest celebrated holiday
- One in four mammals is at risk of extinction – 78% of marine mammals are threatened by accidental deaths such as getting caught in fishing nets intended for other species.
- At least 50 million acres of rainforest are lost every year, totaling an area the size of England, Wales and Scotland combined.
- Average temperatures will increase by as much as 12 degrees Fahrenheit by the end of the 21st century if greenhouse gas emissions continue to rise at the current pace.
- If the entire world lived like the average American, we’d need 5 planets to provide enough resources.
- A world record was set in 1990 when a solar powered aircraft flew 4060km across the USA, using no fuel.
- In one hour more sunlight falls on the earth than what is used by the entire population in one year.
- April 22 is the first official day of Spring in the Northern hemisphere and of Fall in the Southern hemisphere and was chosen to be Earth Day for this reason
- More than 20,000,000 Hershey’s Kisses are wrapped each day, using 133 square miles of tinfoil. All that foil is recyclable, but not many people realize it.
- Only 11% of the earth’s surface is used to grow food.
- If every newspaper was recycled, we could save about 250,000,000 trees each year. Unfortunately only 27% of all American newspapers are recycled.
- A highlight of the annual Earth Day ceremony at the United Nations is the ringing of the Peace Bell that was given to the UN by Japan. It is made from coins given by school children to further peace on our planet.
- By using renewable energy sources to provide your daily energy needs we can decease CO2 emissions with 20,000 pounds less of carbon dioxide each year, including 50 pounds of nitrogen oxide less, and 70 pounds of less sulfur dioxide omitted into our atmosphere.
- Americans throw away enough aluminum to rebuild our entire commercial fleet of airplanes every 3 months.
- The U.S. is 5% of the world’s population but uses 25% of its natural resources. We use one million gallons of oil every two minutes.
- More than 100 million Americans live in urban areas where the air is officially classified by the EPA as unsafe to breathe.
- The US has less than 4% of its forests left.
- 40% of our waterways are undrinkable.
- 200,000 people a day are moving to cities from environments that no longer support them.
- According to the National Academy of Sciences, on average there are 27 oil spills every day somewhere in the waters of the worlds
- Residential lawns and gardens are doused with 80 million pounds of chemical pesticides and 70 million tons of fertilizers annually.
- It would cost about $13 billion annually to satisfy the world’s basic sanitation and food requirements. That’s roughly equivalent to what Americans and Europeans spend on perfume and cologne every year.
- Each year Americans alone throw away 18 billion disposable diapers. In perspective, this is enough to extend from the earth to the moon and back 7 times.
- Ford Motor Company indicates that 75% of every vehicle is recyclable.
- In 1 year, the earth will travel 1.6 million miles in its annual journey around the Sun, the 4.6-billionth such round-trip. It will rotate about its axis exactly once.
Sources: WebEcoist, PlanetPals, History.com, Yumsugar.com, Stumblerz.com, Daily Green, Gree.Autoblog.com