As you learn about solar energy, you will hear electrical terms like volts, watts, and amps being used to describe solar power equipment, energy production and consumption, and battery storage. Having a strong working knowledge of what those technical vocabulary words really mean can be helpful to understand how solar works. It’s important to know how solar power can supply your home with all of the electricity that you need to run your daily life.
You aren’t the only person who finds electricity terms like volts, watts, and amps confusing. You may have even given up trying to understand them, but we can give you hope. In this article, we will simplify these words so that you can know what they stand for and gain a deeper appreciation for the science of solar technology.
Electricity Is Like Water
Let’s begin this discussion with an analogy, showing how electricity is like water. It’s a way to better understand what solar electricity is, how it works, and the terms you’re trying to understand.
Imagine water flowing through a hose as you take care of your backyard. When the water pressure is high, water exits the hose with more force. With low pressure, water leaves the hose with less force.
In our analogy, the water represents the electricity, the hose represents the wires that transmit the electricity, the diameter of the hose is the electric current, and the water pressure is the power of the flow. As you stand in your backyard, you keep the hose free of blockages and twists so the water flows freely. You can also change the power of that flow by adding pressure with your finger over the end, which adjusts the current.
These concepts translate to common electricity terms we want to help you understand:
Now we can talk about these words with greater clarity.
What is a Volt?
Voltage is the pressure with which electricity flows from a source to power a device. More specifically, it’s the variation in electric charge between two points, or the electric potential of sending one watt of power through one amp of current.
Any variation in that pressure affects voltage, which can result in either poor or peak performance. You just have to make sure you don’t exceed the voltage limit for a device or outlet.
Looking back to our water analogy, volts can be thought of as water pressure.
Volt is the International System of Units (SI) term used to measure voltage. The word volt is used in honor of Alessandro Volta, the Italian physicist who invented the electric battery. Since volt is symbolized by the letter “V”, 4V indicates a pressure of 4 volts or voltage units.
Since the voltage output of electrical outlets can differ, authorities standardize them to ensure they are safe for use. In the US, residential outlets are standardized at 120V.
Additionally, the higher the voltage, the stronger the current a gadget can release. That’s why industrial electric appliances have a higher voltage than household appliances - they have to do more, so they need more voltage.
Several factors affect the voltage of your solar panels, including:
As a form of renewable energy, solar energy uses the sun as its source of power. If your panels are wired in series (one panel is wired to another, which is wired to another, and so on, before being wired to the solar inverter) and some are shaded, the solar power system will not work efficiently because poor power generation on just one panel can impact the entire array. Solar installers avoid this by not wiring the panes in series, or by positioning panels where they all receive full sunlight without any shade.
Solar power is generated when rays of sunshine knock electrons off thin layers of silicon, and those negatively charged electrons seek out positively charged protons. When temperatures are low, the electrons are less excited and calmer. In this situation, you can channel them through your transmission lines in larger quantities, meaning you can generate more solar power.
However, when temperatures rise, the electrons get excited. They can hardly rest, making it more difficult to channel them through transmission lines. Therefore, you generate less solar energy during hot days since electrons are most active. This means you experience lower voltage on hot sunny days and higher voltage on cold sunny days.
What is an Amp?
Amperage measures the flow of constant electrical current moving from one point to the other. When one volt acts through a one-ohm resistance, it produces one amp.
Looking back to our water analogy, amps can be thought of as the volume of water flowing past a specific point at a single moment.
Amp is the short form of ampere, and it derives its name from the 19th century French physicist, André-Marie Ampère, often referred to as the father of electromagnetism. According to SI, amps are abbreviated with the letter “A” with 3A indicating three amps.
What is a Watt?
Watts are units of measure for power. When one amp of current flows with a pressure of one volt, it creates one watt of power. Thus, watts are the result of multiplying volts and amps:
Volts x Amps = Watts
We use watts to refer to the amount of power an appliance needs to function. It is equivalent to the electricity flowing at the rate of one unit per second.
Looking back to our water analogy, if the hose was being used to spin a waterwheel, watts would represent the energy created to power that waterwheel.
Now that we have a basic understanding of those three electricity terms, let’s talk about the relationship between power and energy.
What Is The Difference Between Energy And Power?
Power measures capacity, while energy measures delivery. In other words, energy is the total amount of work done, while power is how fast you can do that work.
Looking back at our water analogy, if you imagine filling a bucket with the hose, power, measured in watts, is the flow rate of the water, and energy, measured in watt-hours, is the amount of water that ends up in the bucket.
In terms of your solar panels, “power” represents how electricity flows, while “energy” represents the amount of electricity that is flowing.
Power is measured in kilowatts. If an appliance consumes 1,000 watts of energy when operating, it is said to have a 1-kilowatt (kW) capacity. Energy is measured in kilowatt-hours, the unit of measurement that equals the energy used to keep a 1,000-watt appliance operating for 1 hour. In other words, it would take 10 hours for a 100-watt lightbulb to use 1 kWh of energy.
The more powerful an object is, the more power it uses and the more energy that flows through it.
What Is The Difference Between Kilowatts And Kilowatt-Hours?
1,000 watts is equal to one kilowatt. This means a gadget with a one-kilowatt capacity will consume energy equal to 1,000 watts.
For example, you may have 60-watt items throughout your home. That means each item has the potential to consume 60 watts or 0.06 kilowatts if you operate it continuously for one hour.
Thus, the difference between the two measures is one of capacity and potential, of power and energy. Kilowatts measure how much power can be used, while kilowatt-hours measure the energy involved in using that power over a period of time.
Get Solar Power For Your Home
Now that you have a better understanding of electricity terms like volts, amps, and watts, you might be interested to know how many watts are needed to power your home. With Palmetto’s Free Solar Estimate, we’ll show you how many kilowatts of solar we recommend to offset your energy needs, how much you can save with that solar power system, and your personal impact on the environment to help stop climate change.