Understanding solar inverters
To properly implement solar PV panels for your home to generate electricity, the current which is DC should first be converted to an AC current. Therefore, all your electrical appliances can receive the correct current to function correctly. By using a solar inverter, this function will be implemented into your solar system.
Here’s how solar inverter works:
Usually, a circuit with on and off switches can regulate the current polarity which allows the current to change back and forth. This is the same as the AC current that Eskom provides to our homes. This equipment is also known as a PCU or power conditioning unit. Therefore, more tasks get done by the PCU apart from converting DC to AC, however, a rectifier is the device that does the DC/AC conversions. An inverter does the opposite. An inverter inverse and does it the other way around. But let’s not get too technical, it is commonly referred to as an inverter.
The solar inverter alongside the solar panels are the main components needed to power solar system installation. When the solar inverter receives the DC current, it converts the DC current into workable AC current which can be used to power all your AC powered loads.
When it comes to choosing an inverter, you need to first determine the wattage which your solar panels are rated for and also the voltages for the solar array setup. Once you have obtained all the correct wattage, voltages and Amps for your complete system, you can start to browse for a good solar inverter.
Solar inverters are critical components of a solar photovoltaic (PV) system. They convert the direct current (DC) electricity generated by solar panels into alternating current (AC) electricity that can be used to power your home or be fed into the electrical grid. Here’s how solar inverters work technically:
DC to AC Conversion: Solar panels generate electricity in the form of direct current (DC). However, most of the appliances and the electrical grid itself use AC. The primary function of a solar inverter is to convert this DC electricity into AC electricity.
Maximum Power Point Tracking (MPPT): Solar inverters often incorporate Maximum Power Point Tracking technology. This technology continuously monitors the voltage and current output of the solar panels and adjusts their operating conditions to maximize the power output. Solar panels have an optimal operating voltage and current at which they produce the most power. MPPT ensures that the solar panels operate as close to this point as possible, even when conditions like shading or changing sunlight intensity affect the system.
Synchronization with Grid: In grid-tied systems, the inverter must synchronize the AC electricity it produces with the grid’s frequency and voltage. This ensures that the solar power can be seamlessly integrated with the grid and used within your home or sent back to the grid.
Safety Features: Solar inverters also include safety features like ground fault protection and anti-islanding. Ground fault protection detects any current leakage to the ground and shuts down the inverter to prevent electrical shocks. Anti-islanding ensures that the inverter shuts down if the grid goes down, preventing the solar system from energizing the grid during a power outage, which could be dangerous for utility workers trying to repair the grid.
Monitoring and Data Collection: Many modern solar inverters are equipped with monitoring and data collection capabilities. They can transmit data about the system’s performance, including power production, to the system owner or installer. This data is valuable for monitoring the system’s health and performance over time.
Efficiency: Solar inverters aim to be highly efficient in the conversion process to minimize energy losses. Higher efficiency means more of the solar energy is converted into usable electricity.
Cooling and Protection: Solar inverters generate some heat during operation. They typically include cooling systems, such as fans or heat sinks, to dissipate this heat and prevent overheating. They are also designed to withstand outdoor environmental conditions and protect against dust, moisture, and other potential hazards.
Battery Integration (if applicable): In some solar PV systems with battery storage, the inverter may also manage the charging and discharging of the batteries. This involves controlling the flow of electricity between the solar panels, batteries, and the electrical loads.
In summary, solar inverters play a crucial role in converting the DC electricity generated by solar panels into AC electricity suitable for use in homes or for feeding back into the grid. They do this while optimizing power production, ensuring safety, and monitoring system performance. The choice of inverter type and features depends on the specific requirements of the solar PV system and the goals of the system owner.
Solar inverter wattage rating
Many people will buy an inverter because it consists of a specific wattage amount. 1Kw, 3Kw, 5Kw, and 10Kw inverters to name a few. Solar inverters can be much larger than those specified here, but for the sake of keeping things simple, we’ll talk about the more common solar inverters. Solar inverters are manufactured to output a certain amount of Watts. For common off-grid systems, the size inverter you choose to install depends on the size of your solar panel wattages. In an off-grid solar setup, the solar off-grid inverter’s size will depend on the maximum AC current and the size of the battery storage.
Solar inverter Input voltage
There is a wide variety of voltages to accommodate the different types and sizes of solar panel arrays. The radiation that solar panels receive from the sun can also vary depending on the day, is it sunny or cloudy or on the season of the year. Your DC input voltage can be 12 Volt, 24 Volt and 48 Volt in most common solar inverters. These are all standard voltages for home or small business solar energy systems.
Solar inverter AC output
The AC output is the maximum power or load, usually around 230VAC (Volt Alternating Current) that can be received by electrical appliances in your home. In off-grid solar systems, a total load inspection should be conducted to determine the load of the appliances required. The AC output voltage is much more important in solar off-grid systems compared to solar grid-tied systems which have the grid to assist in the AC output voltage alongside the solar panels.
Solar inverter surge power
This is an important aspect especially in solar hybrid inverters and also solar off-grid inverters. Many electrical devices need an additional amount of power to start. This can be the case in electrical motors as an example. When the motor is started, it will require more power to start up compared to when it is in an idle state. This voltage spike should only last for a very short amount of time. Therefore, the inverter should be able to accommodate these devices and produce extra power for that duration of time.
Solar inverter efficiency rating
Solar inverters are rated by their efficiency to process energy. Current losses in the energy such as overheating circuits, voltage drops or low voltages, fluctuation of current flows and the solar inverter’s internal energy consumption are taken into consideration for the rating of the efficiency of the solar inverter. For a more detailed description of a solar inverter’s efficiency, you can look for a weighted efficiency specification or a spec sheet containing an efficiency curve diagram.
Type of sine wave solar inverter
A good solar inverter would provide a true pure sine wave. A sine wave is the flow of electricity and how it gets delivered and in what form, to the electrical appliances. Modified sine wave inverters are inexpensive but the modified sine wave can be harmful to your electrical appliances such as computers. Modified sine wave consists of the idea of a pure sine wave but it’s like a mix between a square wave and a pure sine wave. Electrical appliances can be very picky about how their electricity gets delivered. To have an excellent and healthy flow of electricity, always ensure that your solar inverter can produce a pure sine wave AC electrical current to your appliances. Also, in the long term, the amount of expenses due to appliance breakdowns is not worth the saving on a modified sine wave inverter. JC Solar Panels mainly sell pure sine wave solar inverters.
Ambient temperature range
If you stay in an area where the temperatures can fall to extreme colds or extreme heatwaves, the solar inverter may get harmed in the process related to cold weather. Luckily, in South Africa, we have a stable and excellent climate which shouldn’t be of such a big problem in this scenario. Always ensure that the solar inverter has its built-in cooling system such as fans and heatsinks. Also. Install your solar inverter in a cool, dry area, usually in a garage or cool room dedicated to such devices. Always ensure the inverter is never installed in an area where heat can ever be more than 50 degrees Celsius. A room with a constant temperature of 25 degrees will work perfectly.