7 Things to ensure before buying a solar inverter

So you have already decided to opt for the clean solar power system at your home or office. But before implementing the solar installation make sure that that you are going for the right solar inverter which is considered to be the heart of your solar power system. It is said so because a solar panel can convert the direct current into alternating current only with the help of an inverter. Not only this but a solar inverter reduces the user’s overall electricity consumption and the money spent on paying the monthly utility bill. So keeping up in mind its immense importance, we have aligned some important aspects to look for in a solar inverter.

 

1) Calculate your power requirements

Before buying a solar inverter you should know what are your power requirements. When there is a power cut determine what are the equipments that are necessary for you at such time. Then look for the power ratings of these equipments. For eg: you would want to use three ceiling fans(90W each), three tubelights(30W each), one CFL(15W), one laptop(70W) and one desktop(120W). Then your power requirement will be the sum of the watts of all the equipments i.e 565 W.

 

2) Determine VA rating of the inverter

Often VA rating and Watt rating are confused to be the same but they are actually not. Watt is the power drawn or supplied by an equipment. VA is the apparent power which is obtained by multiplying the Voltage and Current supplied by an equipment. The relation between VA and Watt is as follows –  Power rating of the inverter (VA) = Total power requirement (Watt)/Power Factor (PF) of the inverter.

Check the PF of the inverter, generally, it lies between 0.6 to 0.8.

So applying the above, you would need an inverter whose VA rating lies between 706 VA to 940 VA (Approx).

If the amount of VA rating is less than your power requirement then your inverter will get tripped because of overload and nobody wants that to happen at their hour of need.

 

3) Check the certifications of the inverter

Certifications ensure that your solar inverter is not only safe but also at par with the standards set by the leading solar power generating organizations. There are some standards that are mandatory to have in the solar inverter while other standards are used to verify the various power ratings as promised by the manufacturer. All in all make sure your inverter is certified for the respective standards. Typically Solar Inverters should comply to several of the IEC standards and a few required certifications are stated here.

  • IEC 62116- Anti-islanding
  • IEC 62109- Safety
  • IEC 61683- Efficiency
  • IEC 60068- Environmental
  • EN 61000- EMC
  • IEC 60529- Ingress Protection

 

4) Servicing and maintenance 

Generally, the lifespan of a good solar inverter is in many years, even when it is subjected to very harsh conditions. But to make sure that the inverter is working with its full efficiency, yearly servicing is required. This includes qualified technicians to check the proper connections between the cables and the removal of the worn out parts of the inverter.

Make sure that the company is always available for you when the time comes and always show support.

 

5) Support during Voltage variation  

There are times when there are sudden variations in voltage such as low grid voltage. So at those times, it is important for the inverter to maintain giving continuous power supply to the household/workplace. For a good solar inverter, the voltage variation support should range from 120V to 280V.

 

6) Load Surge Capacity

Most equipments like AC, washing machine and pumps need inrush currents that can range from 3 to 10 times their steady-state currents. For eg – A 1KVA inverter with 3x surge rating can smoothly handle an AC or a washing machine than a 2KVA inverter with 1x surge rating. So it is very important for the solar inverter to have the surge capacity to handle such kind of sudden loads that is necessary for starting above stated electrical equipments.

 

7) Protections

Apart from all the above features that a solar inverter must have, you should always go for the one that has protections like – short circuit protection, battery protection, IP protection(for eg- If you are placing your inverter outside, please make sure you have at least IP 54 rating,though IP65 is the best option) and earth leakage protection. With these savior features put all your worries to rest and enjoy the clean solar power energy at your home.

 

Solar Inverters

As we all know solar energy is one of the key answers to our energy problems. But technology to harness this energy is fragmented, with no single solution to address all the issues. Existing Solar Inverter technologies force the user to make a choice of whether to invest in an off grid or on grid solution.

On Grid solutions are impractical where power outages & fluctuations are more, like in remote villages and many tier 2 cities. Power outages & fluctuations during the day time cause wasting solar energy, which can be neither used locally nor fed back to the grid. Besides the wastage, grid feed solutions cannot provide 24 hour power backup and users will have to invest in additional backup infrastructure. An Off grid solution involves heavy investment in batteries and maintenance of the same.

Here we are analyzing these inverters below

Off Grid Systems

                                                                             Courtesy: Whole sale Solar

Off grid connected solar is a solar electricity system with battery backup. During the day, the batteries get charged as well supplies to the load. During the absence of sun ie evening or rainy days, can utilize the stored power in the battery. As it is off the utility grid its called Off grid system. It is also known as standalone systems.

Now days off grid systems are connected to grid to ensure there is no black out. In the absence of solar & battery backup, it makes sure that the loads are working either in bypass mode or battery which is being charged from the grid.

While designing the system, have to make sure the connected load should be equivalent to the capacity of the inverter and have enough surge handling capability if there is an inductive load.

Merits:

  • Standalone independent system (Can be used for remote places, forest & hill areas where utility grid reach is not possible)
  • Back up

Demerits:

  • Recurring cost of batteries (based on the life of batteries it may vary. Improper charging of batteries may cause recurring cost even worse. Lithium Ion batteries are with longer life, but the cost is too high as they are in the initial stages)
  • More losses
  • High System Cost

Grid Tied Solar System

                                                                          Courtesy: Whole sale Solar

 Grid tied or grid connected solar is a solar electricity system without batteries. During the day time, the generated power will be feed to the utility grid, if the grid is available. These inverters take grid voltage as reference voltage and fed to the grid.

 In the absence of grid, it will not feed to the grid, even though solar is available

Merits:

  • No recurring cost
  • Fastest ROI
  • Highly efficient

Demerits:

  • No back up
  • It will not generate power, if there is a high fluctuations in the grid
  • It will not generate power, if the grid is not available

Why Hybrid system?

As we seen above, there are merits and demerits in both the systems. If we have a system with the merits of both systems would be the answer for hybrid system. Hybrid system is nothing but grid tied system with battery bank.

During the day time it will charge the battery as well as supply to the load. If there is excess energy is generating, will feed back to the grid.

                                                                          Courtesy: Whole sale Solar

 Why ThingsCloud?

 We are building the next generation of clean, connected, controllable inverter that can work round the clock, irrespective of the state of local grid. Also it can learn our usage patterns and store only as much we required to serve the load, the balance will be sold back to the grid. And what we need is actual 24 hour access to energy. We believe, it can actually make a difference and accelerate adoption of solar solutions among the masses.

Our patented technology gives users the freedom from having to choose between an on grid or off grid solution. With our grid interactive solution, users can generate, consume, store or sell the solar energy. In addition, our machine learning algorithms, coupled with mobile app which can control, monitor, and improve your power consumption, generation and storage patterns. Learning of energy requirement patterns can improve the life of battery by controlling the charge-discharge cycles.

The “Things HiFi” inverter from Things Cloud does all of this and more. “Things HiFi” sends all energy generation and consumption parameters to the cloud, where algorithms are run to ensure every system runs at peak efficiency. Our mobile app keeps the user up to date and gives him regular tips on how he can improve energy efficiency. We can push improved control system algorithms to the inverter from the cloud. It is an always on, always learning solution.