How to Choose the Right Solar Power Generator

The following are some tips which might help our customers in choosing the right solar power generator Or Solar Power Plants for their residential and commercial needs.

In an era of increased environmental consciousness, rising costs and volatility of conventional electricity sources, the sun is shining brightly on Kerala with more and more residences opting to go for solar energy in one form or the other.

Be it a simple solar water heater or a solar power plant to partially or fully reduce dependency on conventional power, there is a high degree of awareness among homeowners on the plethora of solar energy options available in the market.

Whilst ANERT is spearheading the growth of solar energy adoption in the state, it also helps to know the options at hand, especially with the mountain of information available today in various publications online/visual and so on.

The fundamental question that arises in the mind of a homeowner is,

1, How to arrive at the right solar energy generation system and

2, How to derive maximum value from that investment.

To address these concerns, the easiest is to address the 3 W’s, namely the why, the What and The How.

1, The Why

WHY – should be the objective of deciding to go for a solar energy system in one way or another – is it to have uninterrupted power throughout for a resident in a town/village with frequent power interruptions, or is it to reduce the power bills by a certain percentage – say 40 % or 60 % or even 100 %, or is it for the owner of an upcoming house to make it environment friendly and sustainable? Obviously, the questions lead to two key parameters namely convenience and budget.

2, The What

Once the consumer has arrived at the Why, it’s easier to evaluate the What, namely the types of solutions available in the market. Solar power solutions in general can be categorized into three


Off-grid plants are the most conventional of all options, loads are connected to a solar inverter and are supported by batteries. During day hours, Solar energy powers the load and charges the batteries, after sunset batteries power the loads till sunrise and the cycle continues.

In case energy used in a night is beyond the design load and the batteries reach their Depth of discharge, loads are bypassed to KSEB, with some inverter also charging these batteries which might negate the benefits gained.

It’s ideal in these systems to design the batteries to have a depth of discharge cut off of 50 % so as to obtain a life of at least 2000 cycles which is roughly 5 years.


Grid-tied plants are the most economical and sought-after solar power solutions these days. The loads are never connected directly to the solar inverter. The output from the grid tie inverter is synchronized directly with the incomer KSEB line. Energy generated thus is first used for loads and any excess is exported back to the KSEB grid under their current net metering program. 

A bidirectional inverter records both export and import, the net of which will be the billed units at the end of the month. The only downside is that grid tie systems need to shut down during power cuts for anti-islanding protection by law, or simply put to prevent any export back to the line on which a technician is working that could cause electrocution.


The third and the best of both worlds solution is a HYBRID plant which works exactly like a grid-tie plant, but during power, cuts will disconnect the line from the mains KSEB grid, However, with the support of a nominal battery backup, continues to provide back up to the loads connected thereby ensuring maximum use of energy generated.

Although hybrid plants are widely used in most states in India, its not yet adopted by KSEB. Hybrid systems are a highly potential configuration to mitigate frequent power outages and make use of most energy generated.

3, The How

The last part is the how, the starting point for any consumer is to arrive at the size of the system required. Although specialists will engage in custom design as a rule of thumb, the 1-kilowatt peak of the solar power plant will provide a usable AC output of roughly 3 units a day. So setting out a load profile would help arrive at these parameters.

Writing down or tabulating loads, wattages, usage hours etc. – to illustrate a table could look like 20 w LED, 10 nos 6 hours a day, 55 w fan, 5 no’s, 8 hours a day and so on with the multiple of these providing the consumer with the total units required a day in watt-hours.

So roughly someone who needs 9000 watt hrs a day would need a 3 kW solar power plant and so on. It’s very important to arrive at a balance between price and quality, with plants available in a wide range, the key driver for decisions should be life-cycle cost rather than upfront cost as if a plant fails at say year 2 or year 6 it’s a major loss to the customer who expects a life of 25 years with minimal parts replacements.

A low-priced plant may be attractive and comfortable at purchase but may give a lot of recurring replacement costs and diminishing outputs over the years.

European technology, in general, gives the highest efficiency and durability ensuring the consumer gets to use maximum energy generated.

With a lot of professional players available in the market today, the consumer should always seek a detailed techno-commercial proposal that outlines the technology used, warranties, data sheets, standards, previous references and so on and ideally takes the advice of an expert to evaluate these and arrive at the best option.

As yet another year dawns in, so does a sunny year for Kerala, with solar energy slowly taking centre stage as an affordable, dependable and sustainable technology to reduce power bills, provide uninterrupted power and of course a cleaner Kerala.

Leave a comment