Before you zero in on an inverter you must evaluate your requirement of power backup. Is it only for running appliances like a fan, domestic lighting when normal electricity supply fails? If that is the case, the honest answer is that any “normal” inverter will do.
By normal inverter what is generally meant (though it may not be written on the label, or explained by the vendor) is a square wave inverter. This kind of inverter converts the stored DC power in the batteries into an AC current with the wave form as illustrated below. On the other hand, though more expensive, sine-wave inverters produce an output that is a smoother wave form as shown.
With this broad understanding you can appreciate the reasons for not investing in a normal inverter
- The first is to do with efficiency of conversion of DC power into AC output. High quality sine wave inverters are rated at 90-95% efficiency. Lower quality modified sine wave inverters are less efficient at 75-85%, while square wave ones are even less efficient. Lower the efficiency, more the losses in conversion, which will reflect in your electricity bill.
- The second reason is to do with the shape of the output wave. A sine wave resembles the grid power (the power supply when the mains have not failed) so it is suitable for all appliances, unlike the square wave output of a “normal” inverter.
- An upgraded square-wave type—a modified sine wave inverter— actually has a waveform more like a square wave, but with an extra step or so. Motors, such as refrigerator motor, pumps, fans etc. will use more power from the inverter due to lower efficiency. Most motors will use about 20% more power. And again, this will lead to higher cost.
- This brings us to the evaluation of needs. In other words, you might want to run your computer when the power fails. There might be your smartphone plugged into the charger too. More importantly, your needs could cover a commercial establishment with expensive devices running on motors.
- If you avoid a normal inverter, you don’t need to purchase a separate UPS for your desktop computer as sine wave inverters take care of your PC like a dream. Some branded stabilizers and compact computer UPS won’t accept the wave form of square wave inverters. In such cases, the TV stabilizers or computer UPS need to be bypassed or removed to continue using the TV or computers with a square wave inverter. You don’t need to face such a problem with pure sine wave inverters, as they operate seamlessly with any type of stabilizer and compact computer UPS.
- Another important factor involves the wave form and inductive loads i.e. an appliance where an electrical coil is involved, which will include anything with a motor. Any waveform that is not a true sine wave (a square, or modified square wave) will be less efficient when powering inductive loads – the appliance may use 20% more power than it would if using a pure sine wave. Together with reducing efficiency, this extra power usage may damage, or shorten the life of the appliance due to overheating. So, you can operate your mixer or grinder safely with sine wave inverters (850 VA inverters and above) but not that safely with a square -wave one.
- The market has a variation of the “normal” square-wave inverter—this is the modified sine wave inverter. It is somewhat cheaper than the pure sine wave. Sine wave inverters give extended power backup compared to modified sine wave of square wave inverters. It saves on your current bill. So, don’t go just by the price of the inverter. Choose a reputed brand.
- For higher efficiency and reliability go for the latest advanced technology. Digital Signal Processor (DSP) based Genus high capacity inverters offer exceptional performance and efficiency at every level of operation. The DSP ensures that your appliance gets the frequency and power output appropriate for it, throughout the power outage.
- Go for the flexibility of solar as well as generator-compatible inverter solutions. Genus inverters and UPS can be connected with power sourced from the electricity grid, from solar PV panels, or fuel-based generators. This is particularly important for today’s evolving energy scenario.
- Especially important for critical commercial applications like elevators, the inverter should recharge quickly after a power outage. Owing to the turbo charging option, Genus inverters and UPS can recharge very fast and are always ready to supply sufficient power reliably, even during long and frequent power cuts.
- Whatever be your application, compared to a normal inverter, pure sine-wave reduces audible and electrical noise in fans, fluorescent lights, audio amplifiers, TV, fax, and answering machines. It prevents crashes in computers, weird print-outs and glitches in computer monitors. Imagine the impairment to performance, as well as customer dissatisfaction from the noisy, distorted running of sensitive appliances, which you could experience with a wrong choice.
- The final and most significant reason for not choosing a normal inverter is the total cost of ownership concept. This calls for calculating your savings in monthly electricity bills and adding the saving (over the medium to long term) in the replacement cost of expensive equipment. By now, you must have understood the reasons why a pure sine-wave inverter protects equipment, thereby extending its life.
So, do keep the above points in mind while investing in an inverter for the long-run.