Think of the inverter as a translator and AC and DC as two different languages. Every electrical wire in your home “speaks” or carries AC, as do your common appliances. However, your solar panel “speaks” DC.
Thus, there is a communication barrier. Your solar system can’t transmit power to your home without some help, and an inverter provides that help. But are there any exceptions to this rule?
Can a solar panel work without an inverter? Solar panels require an inverter because their Direct Current (DC) output must be converted into Alternating Current (AC). AC comes into our homes and powers our appliances because it is more efficient and safer than DC.
The inverter accomplishes the conversion job by getting DC electrical energy from the solar cells. The inverter then uses various electronic components to help the DC input oscillate. The output is an electrical current called AC, which our home appliances can use to function correctly. In other words, a solar panel, to a large extent, cannot work without an inverter.
This article explores why solar cells require an inverter and why we use AC instead of DC in our appliances.
A polycrystalline or monocrystalline solar cell is a gadget in solar panels that transforms light energy into electrical energy. Converting light energy into electrical energy is called the Photovoltaic (PV) effect.
In other words, solar cells are PV cells that generate electric power when exposed to sunshine. A solar module is formed when these cells come together.
A PV cell consists of semiconductor material (e.g., silicon). When photons (particles of solar energy) strike a PV cell, they might pass through the cell, reflect off the cell, or be absorbed by the semiconductor material.
The absorbed photons are the only ones that provide energy to produce electricity. Once the semiconductor material absorbs enough solar energy, electrons are freed from the material’s atoms.
Solar panels provide direct currents in the same way as ordinary batteries do. Usually, DC is more consistent than AC, and PV cells generate it without any additional electronics to manage the electricity.
When sunlight strikes a solar cell’s surface, it allows the electrons to flow, and eventually, a current is generated. These electrons are known to flow in one direction.
An unrestricted single-direction flow causes the generation of a direct current. Solar cells generate only a DC form of electric energy, which justifies using an inverter that converts the DC form to AC.
The DC form of energy may still be necessary on certain occasions. Your smartphone would be an ideal example of this. It comes with a USB cable that plugs into the phone’s port and a little adaptor that fits into a conventional wall socket. And because a smartphone charger only needs 5V, this converter transforms AC to a lower voltage that is more appropriate.
There are two main reasons we use Alternating Current in our homes instead of Direct Current. They include:
- Most of our household appliances and outlets use the AC. They can’t be powered directly by DC electricity.
- The electricity from the power grid is also in AC form.
Unless you are going completely off-grid, you’ll need to source power from the utility power grid to power your home appliance.
Electricity generation companies transmit power from their plants via distribution lines. Usually, these lines utilize low current and high voltage AC power to cut on electrical losses. Therefore, your solar panel system must adjust to your home’s power needs in AC format.
An inverter is among the most critical components in a solar energy system. An inverter works by taking in DC from your solar panels and running it via a transformer to convert it into the typical household AC (alternating 120/240V current). From there, the current goes through the fuse box to your appliances.
DC is the form of electricity that most home appliances such as refrigerators, TVs, and music systems need to function correctly.
In other words, the inverter system acts as a middleman. Without it, the power harnessed by the solar panels would be worthless.
There are different types of solar inverters in the market today. They include:
- String inverter
- Central inverter
- Hybrid inverter
String inverters are an inverter that can power many solar cells at once. The maximum number of solar panels that can be connected to a string inverter is determined by the inverter’s input voltage rating.
On the other hand, a central inverter (a grid-tie inverter) can power a group of solar cells simultaneously. They are ground or floor-mounted, contrary to string inverters, usually installed on walls or other vertical structures.
Microinverters, as their name suggests, are super small and the ratio of the microinverter to the solar panel is usually 1:1. The advantage of a microinverter over other types of inverters is that they optimize each solar panel individually, resulting in more energy (particularly in shady conditions).
Finally, a hybrid inverter is worth considering when setting up a new solar system with storage.
Why is this?
Solar batteries usually store electricity in DC form. Thus, a hybrid inverter can convert the incoming DC to AC while also passing on any excess surplus power to the battery for storage. When the stored energy is needed, it is inverted to AC and used to power your household appliances.
Some household gadgets such as mobile phones or laptops are powered by DC electricity. You may skip the inverter element of your solar system if you use solar energy for home appliances that need DC power.
However, if you want to power an AC device, such as a refrigerator or pool pump, you will need to utilize an inverter because those devices require AC, and solar panels only produce DC.
DC to AC conversion is crucial for solar systems and buildings with energy storage banks. Owning a suitable inverter will allow you to successfully power your home appliances, which usually require 120V amplitude.
When purchasing a solar inverter, you should weigh the specifications, features, and nominal capacity against your home’s power needs and budget.