Eleven-year-old Itzcuauhtli Roske-Martinez is proving to the world that sometimes the most powerful thing you can say is absolutely nothing.
Today marks Day 22 of the indigenous eco-rapper's silent strike demanding science-based climate action. His T-shirt explains, “I am taking a vow of silence until world leaders take action on climate change." After classmates suggested that one sixth grader in Colorado couldn't influence leaders, Itzcuauhtli added, “When I say world leaders, I'm talking about us."
Accusing “so-called 'leaders'" of failing, Itzcuauhtli (pronounced “eat-squat-lee") asks why his generation should “go to school and learn all this stuff if there is not going to be a world worth living in? Maybe it's up to youth. Maybe each one of us has to be a world leader."
Judging by the hundreds of thousands of hits his site is getting, kids worldwide agree. Several classmates even tried to join his campaign, only to be forbidden by parents certain it wouldn't change anything.
“He was so disappointed," his mother, Tamara Roske, said. “He cried silent tears. It was heartbreaking." Itzcuauhtli, who will begin homeschooling after Thanksgiving, is bolstered by “overwhelming" international support, especially since actor and father-of-three Mark Ruffalo called the boy's campaign “brave and thoughtful."
Itzcuauhtli's greatest champion, however, is 14-year-old brother Xiuhtezcatl, director of Earth Guardians and a co-plaintiff in a youth climate lawsuit, the Supreme Court will consider Dec. 5. The brothers, raised in the Earth-honoring ceremonies of their father's Aztec culture, perform a passionate eco-rap and count Trevor Hall, Robert F. Kennedy Jr. and Michael Franti among their fans. They rocked Brazil's 2012 climate summit and, more recently, were part of the 400,000-strong at the People's Climate March in New York City.
After the march, though, Itzcuauhtli despaired when people insisted it was too late to avoid an apocalyptic future. On the white board he now communicates with, he writes, “I felt desperate. I had to do something drastic to change the outcome of our future. I decided I wasn't going to speak again until there was concrete action on climate change."
He looks hopefully toward the 2015 Paris UN conference, where leaders could agree on meaningful—and binding—recovery plans.
When asked why last week's historic U.S.-China climate deal didn't prompt him to resume the boisterous jokes his family misses, Itzcuauhtli responds, “It's not strong enough. [Former director of NASA's Goddard Institute] James Hansen says we have to cap carbon in the next year. If we wait another 15 years, which is when China said they would cap carbon, it's going to be too late.
Itzcuauhtli will resume speaking when he sees "we're moving together in the right direction." That means applying a planetary “prescription" written by 18 top climate experts, who outlined a recovery plan based on science, not politics—the same remedy demanded in his brother Xiuhtezcatl's lawsuits against state and federal governments. To achieve the six percent global carbon cuts necessary for a livable planet, Itzcuauhtli invites children and adults to “join me in this vow until world leaders:
- Agree on and implement a Global Climate Recovery Plan to get us back to a safe zone of 350 ppm
- Massively reforest the planet to help absorb our excess carbon
- Support renewable energy solutions to replace the dirty fossil fuel industry"
Roske wonders when she'll hear her “little comedian" talk again. “Next month's climate gathering in Peru on Dec. 10 would be first day he'd break his silence. As a mom, I prefer he start talking before that." But, she acknowledges, she may have to wait more than a year. “That 2015 Paris climate summit will determine these guys' future on some level."
Itzcuauhtli vows to continue as long as he must, despite calling his strike “the hardest thing I have ever done." While he still laughs and finds ways to communicate with peers, he expresses special gratitude for friends old and new who support him or, better yet, join his campaign to “amplify the voices of children everywhere."
“One person alone can start the revolution. It takes all of us to be the revolution."
Visit ClimateSilenceNow to join Itzcuauhtli's silence “even for an hour!"
Mary DeMocker writes about climates of all sorts and is cofounder of 350 Eugene. Visit her website for more of her work.
Making the switch to solar energy can help you lower or even eliminate your monthly electric bills while reducing your carbon footprint. However, before installing a clean energy system in your home, you must first answer an important question: "How many solar panels do I need?"
To accurately calculate the ideal number of solar panels for your home, you'll need a professional assessment. However, you can estimate the size and cost of the system based on your electricity bills, energy needs and available roof space. This article will tell you how.
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Factors That Influence How Many Solar Panels You Need
To determine how many solar panels are needed to power a house, several factors must be considered. For example, if there are two identical homes powered by solar energy in California and New York, with exactly the same energy usage, the California home will need fewer solar panels because the state gets more sunshine.
The following are some of the most important factors to consider when figuring out many solar panels you need:
Size of Your Home and Available Roof Space
Larger homes tend to consume more electricity, and they generally need more solar panels. However, they also have the extra roof space necessary for larger solar panel installations. There may be exceptions to this rule — for example, a 2,000-square-foot home with new Energy Star appliances may consume less power than a 1,200-square-foot home with older, less-efficient devices.
When it comes to installation, solar panels can be placed on many types of surfaces. However, your roof conditions may limit the number of solar panels your home can handle.
For example, if you have a chimney, rooftop air conditioning unit or skylight, you'll have to place panels around these fixtures. Similarly, roof areas that are covered by shadows are not suitable for panels. Also, most top solar companies will not work on asbestos roofs due to the potential health risks for installers.
Amount of Direct Sunlight in Your Area
Where there is more sunlight available, there is more energy that can be converted into electricity. The yearly output of each solar panel is higher in states like Arizona or New Mexico, which get a larger amount of sunlight than less sunny regions like New England.
The World Bank has created solar radiation maps for over 200 countries and regions, including the U.S. The map below can give you an idea of the sunshine available in your location. Keep in mind that homes in sunnier regions will generally need fewer solar panels.
© 2020 The World Bank, Source: Global Solar Atlas 2.0, Solar resource data: Solargis.
Number of Residents and Amount of Energy You Use
Households with more members normally use a higher amount of electricity, and this also means they need more solar panels to increase energy production.
Electricity usage is a very important factor, as it determines how much power must be generated by your solar panel system. If your home uses 12,000 kilowatt-hours (kWh) per year and you want to go 100% solar, your system must be capable of generating that amount of power.
Type of Solar Panel and Efficiency Rating
High-efficiency panels can deliver more watts per square foot, which means you need to purchase fewer of them to reach your electricity generation target. There are three main types of solar panels: monocrystalline, polycrystalline and thin-film. In general, monocrystalline panels are the most efficient solar panels, followed closely by polycrystalline panels. Thin-film panels are the least efficient.
How to Estimate the Number of Solar Panels You Need
So, based on these factors, how many solar panels power a home? To roughly determine how many solar panels you need without a professional assessment, you'll need to figure out two basic things: how much energy you use and how much energy your panels will produce.
According to the latest data from the U.S. Energy Information Administration (EIA), the average American home uses 10,649 kWh of energy per year. However, this varies depending on the state. For example:
- Louisiana homes have the highest average consumption, at 14,787 kWh per year.
- Hawaii homes have the lowest average consumption, at 6,298 kWh per year.
To more closely estimate how much energy you use annually, add up the kWh reported on your last 12 power bills. These numbers will fluctuate based on factors like the size of your home, the number of residents, your electricity consumption habits and the energy efficiency rating of your home devices.
Solar Panel Specific Yield
After you determine how many kWh of electricity your home uses annually, you'll want to figure out how many kWh are produced by each of your solar panels during a year. This will depend on the specific type of solar panel, roof conditions and local peak sunlight hours.
In the solar power industry, a common metric used to estimate system capacity is "specific yield" or "specific production." This can be defined as the annual kWh of energy produced for each kilowatt of solar capacity installed. Specific yield has much to do with the amount of sunlight available in your location.
You can get a better idea of the specific yield that can be achieved in your location by checking reliable sources like the World Bank solar maps or the solar radiation database from the National Renewable Energy Laboratory.
To estimate how many kW are needed to run a house, you can divide your annual kWh consumption by the specific yield per kilowatt of solar capacity. For example, if your home needs 15,000 kWh of energy per year, and solar panels have a specific yield of 1,500 kW/kW in your location, you will need a system size of around 10 kilowatts.
Paradise Energy Solutions has also come up with a general formula to roughly ballpark the solar panel system size you need. You can simply divide your annual kWh by 1,200 and you will get the kilowatts of solar capacity needed. So, if the energy consumption reported on your last 12 power bills adds up to 24,000 kWh, you'll need a 20 kW system (24,000 / 1,200 = 20).
So, How Many Solar Panels Do I Need?
Once you know the system size you need, you can check your panel wattage to figure how many panels to purchase for your solar array. Multiply your system size by 1,000 to obtain watts, then divide this by the individual wattage of each solar panel.
Most of the best solar panels on the market have an output of around 330W to 360W each. The output of less efficient panels can be as low as 250W.
So, if you need a 10-kW solar installation and you're buying solar panels that have an output of 340W, you'll need 30 panels. Your formula will look like this: 10,000W / 340W = 29.4 panels.
If you use lower-efficiency 250-watt solar panels, you'll need 40 of them (10,000W / 250W = 40) panels.
Keep in mind that, although the cost of solar panels is lower if you choose a lower-efficiency model over a pricier high-efficiency one, the total amount you pay for your solar energy system may come out to be the same or higher because you'll have to buy more panels.
How Much Roof Space Do You Need for a Home Solar System?
After you estimate how many solar panels power a house, the next step is calculating the roof area needed for their installation. The exact dimensions may change slightly depending on the manufacturer, but a typical solar panel for residential use measures 65 inches by 39 inches, or 17.6 square feet. You will need 528 square feet of roof space to install 30 panels, and 704 square feet to install 40.
In addition to having the required space for solar panels, you'll also need a roof structure that supports their weight. A home solar panel weighs around 20 kilograms (44 pounds), which means that 30 of them will add around 600 kilograms (1,323 pounds) to your roof.
You will notice that some solar panels are described as residential, while others are described as commercial. Residential panels have 60 individual solar cells, while commercial panels have 72 cells, but both types will work in any building. Here are a few key differences:
- Commercial solar panels produce around 20% more energy, thanks to their extra cells.
- Commercial panels are also more expensive, as well as 20% larger and heavier.
- Residential 60-cell solar panels are easier to handle in home installations, which saves on labor, and their smaller size helps when roof dimensions are limited.
Some of the latest solar panel designs have half-cells with a higher efficiency, which means they have 120 cells instead of 60 (or 144 instead of 72). However, this doesn't change the dimensions of the panels.
Conclusion: Are Solar Panels Worth it for Your Home?
Solar panels produce no carbon emissions while operating. However, the EIA estimates fossil fuels still produce around 60% of the electricity delivered by U.S. power grids.
Although the initial investment in solar panels is steep, renewable energy systems make sense financially for many homeowners. According to the Department of Energy, they have a typical payback period of about 10 years, while their rated service life is up to 30 years. After recovering your initial investment, you will have a source of clean and free electricity for about two decades.
Plus, even if you have a large home or find you need more solar panels than you initially thought you would, keep in mind that there are both federal and local tax credits, rebates and other incentives to help you save on your solar power system.
To get a free, no-obligation quote and see how much a solar panel system would cost for your home, fill out the 30-second form below.