Solar energy’s popularity has been growing in the past couple of years. Awareness about its benefit to Mother Earth and one’s electricity bill continues to spread. That is why many are starting to install this clean source of energy in their homes and businesses.
If you are thinking of doing the same thing but find it a bit daunting, and you want to know how it works. Don’t fret. In this post, we’ll discuss how solar panel works, what’s the solar panel voltage, how to measure it, and the factors that affect it.
The Solar Panel: The Most Visible Component
When you think about solar energy, one of the first things that come into mind is either a single rectangular blue with a grid or rows of this rectangular blue on an open field. It is also called a photovoltaic (PV) panel. The standard solar panel voltage is between 12 volt and 24 volts. It is made of solar cells, which both have a negative and positive layer allowing it to create an electric field.
Once the sunlight hits the panels, an electric current is produced. This current is then moved by voltage then goes through the wires and components of the system like Nature’s Home power backup.
The two most common types of panels are monocrystalline and polycrystalline panels. The light blue panels which we’re more familiar with are called polycrystalline panels. The black panels are the monocrystalline ones. In essence, the:
- Monocrystalline solar panels are produced from a single silicon crystal, while
- Polycrystalline solar panels are created out of many silicon crystal fragments that are mixed during the manufacturing stage.
Monocrystalline panels have a higher efficiency but are more expensive because of their complex manufacturing process. And, to reach the same power output as its counterpart, polycrystalline panels needed to be installed more. They are cheaper and less efficient.
You can check out this article What is the Difference Between Polycrystalline and Monocrystalline Solar Panels for more information on the difference between the two kinds of solar panels.
Solar Power Voltage Terms to Familiarize and How it Works
It is important to get the numbers right as you don’t want to overload your inverter or underutilize your home power backup. But to help you understand more about solar power voltage and how it works, here’s a list of terms to familiarize:
- AC Volts - refers to the converted voltage from DC Volts to AC Volts.
Nominal Voltage - is a reference on the voltage class your circuit or system is under such as 300 volts, 120/240 volts, etc. This is different from the operational/operating voltage (i.e. if you have a 240-volt circuit but it is operating at 234 volts).Actual Voltage Measured Under Load - is about the circuit’s actual voltage once an appliance has been connected.
- Voltage Maximum Power (Vmp) - is measured with a multimeter. It refers to the solar panel’s maximum capacity when connected to a load. The actual VMP will differ throughout the day due to shading, temperature and other factors.
- Potential or Open-Circuit Voltage (VOC) - is the circuit’s voltage measurement when not connected to a load.
With this knowledge in mind, let’s take a look at how it works.
- A standard solar panel is made up of 36 crystalline cells. And, those cells are quite powerful:
- A cell’s voltage under load is at 0.46 volts which is about 3 amperes of generated current;
- Each cell inside that panel can generate 1.38 watts, approximately;
- A single cell has about 0.5 to 0.6 of open-circuit voltage;
In short, a solar panel has:
- Peak Open-Circuit Voltage Output: 18-21 volts, and
- Actual Voltage Measured Under Load: 12-14 Volts.
This is just about enough to power a 12-volt battery.
4 Factors that Affect Solar Panel Voltage
The type of panel used for your solar power system plays an important factor in your output voltage requirements. Other external reasons can cause the panel's voltage output to fluctuate. Some of them are the following:
- Panel Orientation
To reach the peak performance and maximum of the solar panels and their output voltage, it is a must to ensure that they are tilted towards the sun. While having them lay flat is okay, being in a tilted position meant more sunlight hits their surface at a perpendicular angle. This allows for a more efficient conversion of solar energy to electricity.
- Shading and Location
It is important to make sure that the panels or any of their parts aren’t shaded. Having an unobstructed view of the sun meant they can soak in all the energy and be efficient in storing them.
Shaded cells aren’t able to generate as much electrical energy as the cells that are fully exposed to sunlight.
That is why it is also good to note if you live in an area that gets to experience more peak sun hours.
For those living in Arizona, a 400-watt panel can produce at least 3 kWh of electricity since it has 7.5 hours of peak sun hours. Meanwhile, if you’re living in New Jersey, the same 400-watt panel can only produce 1.6 kWh of electricity because it only has 4 hours of peak sun time.
Like any appliance or gadget, a solar panel’s performance is also affected by the temperature. The voltage output decreases as the panel’s temperature increases. This is because the electrons within the solar cells move slowly the higher the temperature is. Thus, resulting in a reduced amount of generated electrical energy.
- Panel’s Age and Maintenance
Cleaning the panels regularly is necessary to make sure that they receive the right amount of sunlight. Remove any debris and dust that accumulated on top of the panels to avoid a drop in the production of electricity.
Like any gadget you own, wear and tear also affect the solar panel output voltage a.k.a. the panel’s efficiency.
Typically, solar panels degrade at about 0.5% per year. So, if you have had the panels for 25 years, their efficiency is down to 85%, which is still enough to lower your utility bills.
To achieve this slow degradation rate, it should be a must to regularly check on the status and quality of each part of the panel and its system. After all, as cliché, as it may seem, prevention is better than cure. Or in this case, way better than wasting your savings.
To put it all together…
One of the first things that come to mind when thinking about solar energy is rows of solar panels on the open field or the roof. After all, they are the most visible component of this renewable energy system.
Determining the solar panel output voltage and how much solar input it needs are required when building the perfect home battery backup for your home or business. But there are factors to consider that may affect the efficiency of the output voltage, such as temperature, location, shading, panel orientation, and age and maintenance.
Regardless of how tedious the research work can be, the long-term use of solar energy is worth every time and money spent because of its benefits to one’s savings and nature.
* We want to give credit where credit is due. Professional writer, Cris Ilao, contributed research and content to this blog titled: Solar Panel Voltage Thank you, Cris, for your contributions!