How To Choose The Right Solar Inverter In India?

What is a solar inverter and how does it work?

The solar inverters are the most important components of a solar power system for a house. It makes an effort to switch from direct to alternating current. It also switches over the energy generated by the solar panels. If you don’t do this, your solar power system won’t be able to light your whole house and power the majority of your equipment.

What are the different types of solar inverters?

Different types of inverters are available on the market:

Inverter with Sine Wave:

This kind of inverter produces the sine wave that an appliance is intended to produce. The majority of appliances can operate safely on this kind of power.

Square Wave Inverter:

This kind of inverter is often referred to as a digital inverter. It produces square wave AC output, which is insufficient to power all types of household appliances since the equipment is designed to operate solely on a sine wave AC pattern. Some of the gadgets will also be emitting a buzzing sound. Although the gadgets may withstand this, it is not advised that you use this square wave to power your household appliances.

Stepped Sine Wave Inverter:

This inverter is a hybrid of the two kinds mentioned above. The Quasi Sine Wave pattern is likewise hard to come by on the market. This kind of inverter seems to be a low-cost power option for computers and other electrical devices

There are many kinds of solar inverters on the market, so getting the correct one is a lot of work. Aggressive marketing may be deceptive. So, before purchasing one, you must first decide what needs you have. Read on to learn more about buying guides below.

Determine your electricity needs.

Before purchasing an inverter, you should establish an approximate estimate of your power needs. Keep in mind that an inverter is not a generator. Each solar inverter has its own set of restrictions. A regular inverter cannot power and operate your whole house. If your energy need exceeds 4000 VA, an inverter alone will not be able to meet your needs effectively. Most certainly, a powerful inverter can power your refrigerator and air conditioner, but to what extent? Your battery won’t last more than a couple of hours here. Going forward, it is best to go for high-capacity solar panels.

Typical household appliance wattage ratings

Power for Appliances

50-75 watt ceiling fan

Table fan (25-50 watts)

18 Watts CFL 18 Watts

Computer power ranges from 80 to 150 watts.

Laptop power ranges from 20 to 75 watts.

150 Watts LCD TV (32″)

160 – 250 watts Refrigerator

40 Watt Tube Light

Starting and operating power

Each electric equipment has its own set of starting and operating power requirements. A 18 Watt CFL consumes about 25 Watts of energy to begin, and after a few minutes, it balances out to 18 Watts. Some equipment, such as refrigerators and washing machines, need twice the power to start as compared to normal operating power. As a result, before selecting an inverter, you should determine the beginning power.

What are the VA and Watts of a solar inverter?

The difference between Watts and VA ratings of inverters and other household appliances is often misunderstood. Power used by equipment (such as bulbs, refrigerators, washing machines, air conditioners, stabilisers, and so on.) and generated by equipment (such as solar panels, generators, inverters, and UPS) may be conveyed in Watts or VA (Volt Ampere).

This is when the difference comes into play. The real power taken or supplied by a gear is measured in Watts. The seeming power (more imaginary) obtained by replicating the Voltage and Current drawn/provided by a hardware is referred to as VA. We may contrast the VA and Watts evaluations as follows:

Power in Watts = VA Power – Losses

OR

Power in Watts = Power in VA x Equipment Efficiency (Power Factor)

Solar inverter or solar UPS?

If you compare a solar inverter to a solar UPS, they both perform much the same function of converting direct current to alternating current, which is then used as a backup control generating device if there is a problem with the mains control. As the name implies, a solar UPS provides Uninterrupted Power Supply to devices.

The gadgets will not notice the switch from mains to solar UPS power. A typical UPS has a switching time of 3 to 5 milliseconds. A typical inverter takes approximately 500 milliseconds, which is insufficient for hardware devices such as PCs, modems, routers, printers, and so on. So, before buying a solar inverter or solar UPS, you should first examine your existing equipment to see whether you can handle the incursion on control supply.

The Solar Battery

The basic component of a solar inverter is the solar battery. The execution and longevity of a Solar inverter are dependent on the Solar battery. There are a few groups of Solar inverter batteries visible. Solar inverters are often powered by high-capacity lead-acid batteries. Lead corrosive batteries are classified into different kinds based on their use, design, innovation, and so on.

Battery Capacity

A battery’s capacity is measured in Ampere Hours (Ah). It represents the amount of current that a battery can provide in a particular amount of time. If a battery has a capacity of 100 Ah, it can provide 100 amps of current for one hour, or one amp of current for one hundred hours, or two amps of current for fifty hours. Inverter batteries typically have capacities of 100 Ah, 150 Ah, or 180 Ah.

A solar inverter’s power consumption

A solar inverter in India converts solar energy into electrical energy for charging the battery. Solar inverters may be inefficient when it comes to charging and can still waste power even when the battery is full.  To prevent it at home, you can see how it works. Discard the whole set-up except for the mains power supply to the inverter, unplug the batteries, and find out how much power is being used during a specific period.

Battery backup duration

To determine the battery life under load, we have an equation.

The time it takes for a battery to charge is equal to the voltage of the battery multiplied by the battery capacity divided by the efficiency of the inverter.

For example,

12 V means the battery voltage

The capacity of the battery is 150 Ah.

The load of two fluorescent lights (40 Watts each) and one ceiling fan (75 Watts) together produce a total of 155 Watts.

The inverter efficiency is equal to 80 percent.

Backup time is equal to 12 * 150*0.8/155, which is 9.29 hours (Approx)

Additional features

As opposed to outdated inverters, which used conventional indications like lights and numerical displays, newer inverters have LCD status indicators to show the different conditions including battery charge level, load, input/output voltages, and battery life.

An Earth Leakage Protection unit prevents electric shock and appliance damage in the event of earth leakage. More modern solar inverters have circuit protection for earth leakage that constantly monitors the problem and cuts off the power to protect the users.

Comparing various solar inverters’ energy efficiency

An inverter’s efficiency is defined as the ratio of output power to input power when specific operating conditions are in place. While choosing a solar inverter, it is essential to take into consideration the efficiency of the solar inverter. Additionally, not all inverters are suitable for domestic usage. Thus, buyers must study inverters in-depth before making a decision.

Checking the Inverters for Durability

Those that make a long-term investment in a solar inverter may see returns on their investment in the future. Therefore, to guarantee their strength and performance in adverse weather circumstances, you should examine and compare them. Additionally, inverters may have performance problems while operating at high temperatures. Thus, it is always good to know and have an understanding of the requirements, and then choose the one that is highly resistant to adverse weather conditions.

Restrictions on funds

There are wide variations in the cost of inverters based on their design. Affordable purchasers may want to consider a grid-connected inverter. Net metering customers may cut their utility costs by going with this alternative. A viable alternative for individuals who want to keep their utility grid use minimal is to use off-grid inverters.

Selection of Brands

To find out as much as possible about the brand you are interested in, it is crucial to do research. You can learn a lot by asking other people what they think about a product, and looking at reviews and blogs. You should consider buying a product with competitive pricing combined with a warranty.

How to determine the right size of the inverter?

Big and small solar inverters in India may be found in a variety of sizes. The size of an inverter is usually specified in watts (W). Installers will consider three main variables when it comes to solar inverter sizing: the size of your solar array, your location, and various site circumstances.

Your solar array’s surface area

It is critical to ensure that the size of your solar array corresponds to the size of your solar inverter. To ensure your solar inverter can handle all the power your array generates, your system must include a DC-to-AC inverter.

An assumption should be made in this situation: If you are putting in a 6 kW system, the inverter you are looking at should be around 6 kW plus or minus a little percentage.

The specification sheets of inverter manufacturers usually provide recommendations for the array capacity their inverters may be partnered with. Manufacturers may invalidate their guarantee if the size of the solar array and its inverter exceeds the specified limitations.

Geography

Not only does geography influence the size of your solar inverter, but it also affects the amount of energy your solar panel system produces. For two separate systems to generate a fixed quantity of DC power, the inverters must be able to manage the electrical demand regardless of which system is used. In locations with a sufficient amount of sunlight and temperatures that do not exceed 82°F, inverters will most likely be designed to provide an approximate maximum power output that matches the wattage of the solar array. A less probable scenario is that under low radiation or high-temperature circumstances, your solar array will not be able to generate the maximum power output specified by the DC rating (STC). A smaller, undersized inverter may do the job in these situations.

Site-specific factors

While designing your solar array, the particular design and specifications of your site will affect the size of your solar inverter. Because the tilt and azimuth your solar array is set up on are similar to geographic coordinates, how much energy your system will generate depends on them. The array will also be affected by variables like shade, dust, and so on, which have an impact on the amount of sunlight that reaches the array.

Equipment efficiencies, variables like sun insolation, and other factors will all go into the total output estimate for your solar panel system. As your system derates, everyone’s contribution increases to decide what it will generate in a real-life situation (as opposed to the STC specs determined in a lab.) Systems with greater shadow tilts or that face east rather than straight south have larger derating factors.

Solar panel systems with greater derating factors will have a lower maximum energy output and therefore smaller inverter capacity than the size of the array, meaning less is needed to produce the same amount of electricity.

Solar inverter size calculations

In the end, the size of your solar inverter in India is determined by the maximum DC rating of your solar array. The array-to-inverter ratio measures the DC rating of your solar array divided by the maximum AC output of your inverter. Let’s use an example: Suppose your array has a 6 kW power source with a 6000 W inverter. That would result in an array-to-inverter ratio of 1. Installing a 5000-inverter array on the same sized array gives a ratio of 1.2. While inverter manufacturers and solar system designers usually suggest inverter-to-solar panel connections have a ratio no greater than 1.55, it is believed that most installations will have a ratio between 1.15 and 1.25.

The most important takeaways terms for buying Solar inverter in India

  • Certificate for Safety: It is verified for safety by any independent testing facility.
  • Watts: This is the amount of power consumed by a gadget when it is turned on. The Watt is defined as the number of joules consumed each day. If a gadget draws 20 amps for 12 hours, that is 120 watts. It’s the sum of volts and amps.
  • Watt-hours:- It is the product of the number of watts and the number of hours the gadget was utilised. When a 100-watt bulb is operated for 8 hours, it consumes 900 watt-hours.
  • Amps: This is a unit of measurement for electrical current at a certain time. It is measured in coulombs per second.
  • Amp-hours: It’s the sum of amps and times. It is the primary metric for determining battery capacity. The majority of inverters are powered by a battery. The amp-hour capacity of the battery defines its capacity and provides an indication of how long it will operate.
  • THD (Total Harmonic Distortion) of less than 6% is adequate for residential use. The RMS voltage regulation must be less than or equal to +/- 5. Peak voltage regulation must be less than or equal to 10% of the total voltage.
  • Efficiency The ratio of output power to input power is referred to as efficiency. It is difficult to attain total efficiency. Because part of the electricity is wasted as heat. The efficiency of a solar inverter is affected by the load. An efficiency graph is included in the inverter specs. It’s the efficiency versus load graph.
  • Internal protection: – The components of the solar inverter must be protected against overload, lightning surges, and so on. It must have sensing circuitry to detect issues and shut off automatically. If the supply voltage is too low, it must be turned off. Otherwise, the battery may overcharge and could be destroyed.

Consider the following points while selecting an inverter:

  • A sine wave inverter is preferable since it lowers heating and increases inverter lifespan. A buzzing sound is produced by the square wave inverter. A sine wave inverter may be used to decrease the buzzing sound. The sine wave inverter supply is superior to the grid supply.
  • Choose an inverter with the appropriate capability for the load.
  • The inverter’s idle power consumption must be minimal.

It must use a little amount of energy from the grid.

  • The inverter battery must be branded.

Conclusion:

Before purchasing a solar inverter, the buyer must evaluate his energy needs. It is critical for an inverter sizing plan, therefore this is mandatory. Another way to put it is: For instance, a user who is interested in a 5kW system for solar panels will have to go with an inverter that generates as much electricity. Buying an inverter with a capacity that is a little over your anticipated needs is also a good idea since there are some energy losses in the system.

Ensuring that you don’t overlook any of the factors to be examined before buying a solar inverter in India is made simple with this list. Looking up product information or doing some research on the item you want to purchase may help you avoid poor bargains.

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