What is a Solar Inverter?
Solar inverters are a vital piece of equipment that ensures your clean energy system can be used at home. They transform the direct current electricity from solar panels into alternating current electricity, which is what you and your appliances use at home.
Solar inverters can come in either a string or central type. Both serve the same function but have different advantages and disadvantages.
DC to AC Conversion
When sunlight hits solar panels they generate a current of electricity called direct current, or DC power. Solar batteries use DC power as well, but household appliances and lighting systems operate with alternating current, or AC power.
The inverter takes the energy that arrives at it in a DC format and turns it into an AC current your home can use. It does this by running the energy through transistors that switch on and off extremely quickly to feed two varying sides of a transformer.
This process requires some power to be lost, but it’s a very important step in the Solar lnverter solar energy process. Without this conversion, the DC power would simply be sent back to the battery and charged and discharged again. This cycle would shorten the battery’s life significantly.
The inverter’s size is important because it determines the amount of AC power it can output during a day. To maximize your system’s performance, it is important that the inverter be sized to exceed the maximum power output of your solar panel array. However, if the inverter is over-sized it can experience excessive clipping losses, which can decrease its efficiency and power generation over time.
Maximum Power Point Tracking (MPPT)
Maximum Power Point Tracking, more commonly referred to as MPPT, is a feature that is built into all grid tied solar inverters. In short, it ensures that your solar panels always work at their peak efficiency. It does this by converting high DC power into low DC power, optimizing it for efficient usage. The resulting power is then converted into AC electricity, the kind of energy that we use in our homes.
It does this by checking the voltage and current variation of your solar panels and comparing it to your battery’s voltage. It then adjusts the voltage to match, ensuring that you get maximum AMPS into your batteries (remember that it is AMPS into your batteries that counts).
MPPT works all the time – even when the sun isn’t shining. This is because the shape of the MPP voltage-current curve is constantly moving. MPPT essentially tries to find the “best” MPP every second, which isn’t an easy task.
Most modern digital MPPT controllers use microprocessors to do this work – so they shut down for a few milliseconds once or twice a minute, take a look at the panel and battery and then decide how to best optimize. Depending on your system design, you may have one or two MPPT channels. Having separate channels provides monitoring information at the channel level for a more granular and detailed understanding of your energy production.
Reactive Power
The electrical energy that moves through a circuit is created when the voltage and current switch back and forth. This energy is real power that can be used by appliances and the grid to perform work. However, the alternating patterns of voltage and current can cause them to get out of sync with each other. This causes a delay between the two and reduces the amount of actual electricity that can be absorbed by the system. To counteract this, utilities supply reactive power to help bring the voltage and current in sync. Reactive power is hard to transport over long distances, so distributed energy resources like solar provide an important source of it. Modern inverters can both provide and absorb reactive power to help balance this critical resource.
To do this, the inverter calculates its active power by comparing the measured DC voltage of the capacitor (V’dc) to the voltage of the electric grid (Vgrid). It then uses the error between these two values to control its output active current.
Inverters can also provide other grid services, such as responding to deviations in the voltage or frequency of the grid. Smart inverters can ride through small disruptions, but if they are too large or last for a prolonged period of time, they will disconnect from the grid and shut down. By providing reactive power, they can support the voltage of the grid and reduce losses in transformers and cables.
Grid-Tied
A grid-tied solar inverter (sometimes called an on-grid solar inverter) connects directly to the utility power grid. It converts direct current from your solar panels into alternating current that your household appliances can use. outdoor battery power supply It then synchronizes its AC output with the voltage and frequency of the grid, allowing homeowners to send excess electricity back into the utility power grid (if permitted).
With this technology, a homeowner can reduce their electric bills by producing their own clean energy and selling any surplus back to their local electrical company. Grid-tied systems are often more cost-effective than off-grid or hybrid systems that require battery storage.
This system can also be more efficient than a home solar power system with batteries because it does not waste energy by running appliances when the sun is not shining. Additionally, the inverter can be designed to automatically shut down if there is a power outage on the utility grid – a safety feature that protects the line workers who are trying to restore power.
Many grid-tied solar inverters now come with battery backup, allowing them to continue providing a steady flow of electricity even if the grid goes down. This is especially important if you live in an area with frequent power outages, or if you plan to operate your solar panels during peak usage times when the grid may not be available.
