How much power does a solar panel produce? Would it surprise you to know that solar panels can produce enough energy to keep a solar airplane flying continuously?
You’re unlikely to be making a manned or unmanned solar airplane in your backyard any day soon. But, you can certainly benefit from solar power today. Can it really power your home and all your expanding energy needs? How does solar power work anyway?
The answer to the first question is yes, and we’ll find out why using the answer to the second question. Are you ready to go through this quick 101 course on solar power?
Time to take notes, so keep reading—you’re about to be illuminated.
How Does Solar Energy Work?
The National Oceanic and Atmospheric Administration, NOAA, estimates that the amount of solar energy hitting the earth every minute has the potential to cover the world’s yearly power usage over 10,000 times! How much energy is that? More than 173,000 terawatts.
It’s very abstract, looking at it like that, so let’s break down what that means a bit.
A watt is a unit in the International System of Units or SI. It’s the unit of power equal to one joule per second in a circuit where the current is one ampere (amp), and the potential difference is one volt. In basic terms, the rate of transfer of energy from one form to another.
Let’s say it takes 2 W to power a typical phone display. That means if you have a 12-volt battery with 5000mAh (ampere-hours), you have 60Wh or watt-hours. We could power that phone display for about 30 hours.
It’s great to understand something on these small scales because utility services usually charge by the kWh or kilowatt-hour. That’s 1,000 watts, with the average U.S. home spending 10.6MWh, or megawatt-hours (10.6 million watts). So you don’t have to sweat your phone’s power usage too much.
Your phone power consumption equals about 24 cents worth in a whole year on a daily charge.
Where Does Electricity Come From?
Now that you understand how to measure solar energy, we can talk about how solar power works.
A traditional solar panel is made up of many photovoltaic cells linked together. The basic concept of a photovoltaic cell is a sandwich of laminated materials based on silicon.
These materials create a negative charge on one side and a positive charge on the other. A photon comes along and knocks an electron free and the electric field created by the negative and positive charge sends it to a metal conductive plate.
This plate collects the electrons and transfer them to wires, and into your home, battery, or off to the electrical grid.
What Can We Do With It?
In the past decade, photovoltaic cells are seeing a massive increase in research and development. This is powering a new wave of high-tech photovoltaic cell innovation, from solar roads, solar paint, and (soon) solar wearables.
Some engineering problems for solar roads include making a product that is durable but allows enough electron excitation to produce usable energy. For wearables and other applications, it isn’t a matter of extreme durability but how to get a lot of power out of a small package.
Another issue is storage. Since the sun moves through the sky during the day and during the night there’s no sunlight at all, there are several engineering and storage problems to overcome. The engineering problems have to do with angles of direct sunlight that aren’t optimal.
There’s some work underway with mechanical and material solutions to solve that problem, so light can be focused or captured at all times of the day.
As far as storage, battery technology is increasing daily. Our phone batteries often store less than 3000mAh of energy at 3.5-4.5V, or 12Wh. A battery for storing solar power for residential use can often hold 4kWh or more.
The problem is they are incredibly expensive, and because it isn’t a solid-state battery technology just yet, there is a risk of fire or leakage. These deep cycle battery systems are also used heavily in the marine and EV industries, so the technology and experience for electrical storage on this level are very well documented.
How Much Power Does a Solar Panel Produce?
The question is hard to answer because there are different kinds and styles of solar panels, but since you know how energy is measured and how it works we can find the power potential of any panel.
If you’re feeling a little stuck, that’s what professionals like Blue Raven Solar can help you with.
Part of the equation has to do with the efficiency rating of a cell. This particular panel has a reading of 17.4%, which is a lot lower than 22% which is capable at the higher end of ratings now. The record for efficiency in a solar cell was developed in Golden, Colorado at the National Renewable Energy Laboratory at 47.1%!
That is the portion of energy received by the solar cell turning into usable electricity. Part of the problem is that you cannot have one-for-one transference of energy from one form to another. When we turn on a lightbulb we make light, but also heat and sound.
In the case of a solar cell, we’re doing the opposite, but we lose part of the energy to heat and other forms of energy.
For the sake of argument, if we have a solar panel that claims 20% efficiency, for every square meter you’ll get 200kWh per year, theoretically. To reach the average yearly household electrical usage of over 10.6MWh, you’ll need a little more than 53 square meters.
To have a little extra, just in case of not reaching those theoretical production rates, let’s say you get 55 square meters. That’s 592 square feet of solar panels.
Although, a lot of this is based on the theory of where you’re living and the intensity of sunlight there. To get a more accurate view, check out some resources, like energy.gov’s solar energy potential map.
Solar Power 101: Class Dismissed
Can you answer: How much power does a solar panel produce? We think by now you should have a firm grasp on photovoltaic basics and even explain it to others. So what will you do with your newfound solar knowledge?
At Rocky Mountain Savings, we’re all about helping you save money on good deals. Since the price of solar power is always dropping compared to fossil fuels, it’s a great way to save money and maybe even make a little back. Don’t you think?
If you enjoyed this solar energy article, make sure to check out our other energy-saving ideas!