How does PV Solar work?

A suitably doped P-N junction semiconductor will generate electricity when light falls on it. This is called the ‘Photovoltaic Effect’. This electricity is in the form of a DC current which may be used as it is by a DC device or may be converted by an Inverter to AC current and then used by an AC device.

Will I be able to use solar power during a power outage?

A stand-alone solar PV system which has no connection with the discom (electricity distribution company, e.g., MSEDC) grid will generate electricity as long as the sun is shining and will power DC appliances or, through an inverter, AC appliances.
During the night, the system will not generate electricity, but the solar power generated during the daytime, and stored in batteries, can be used.
Such stand-alone systems are called off-line or off-grid systems.
A lot of solar electricity is generated by on-grid systems which do not have batteries. In such a system, the solar electricity generated is first used by the connected appliances and excess electricity is fed to the discom grid through a net meter. This excess electricity is available free of charge when not sufficient power is being generated by the solar system, for example, at night. An on-grid solar system will not work during power outages.
Hybrid systems are available which work like a combination of an off-grid and an on-grid system. Such a system requires batteries.

Why are you not proposing a stand-alone or hybrid system?

A stand-alone system or hybrid is much more costly compared to an on-grid system which makes it economically unviable in an urban setting where there are few power outages. There is also a major recurring cost of changing batteries every two or three years. Stand-alone and hybrid systems make economical sense only where there are very frequent grid power outages

How does net-metering work?

The net meter records the amount of power consumed from the grid and the power supplied by the solar system to the grid. The discom bills the customer on the net power consumed i.e., the power consumed from the grid less the power supplied to the grid.

What are fixed charges?

When you get an electric connection from a discom, there is a certain minimum amount you have to pay whether you consume any electricity or not. This is called a fixed charge.

What are variable charges? How are they calculated?

Variable charges are those which are levied over and above the fixed charges. These include electricity consumption charges, transmission charges, various surcharges and taxes. For our purpose it is sufficient to know the bill amount and to subtract the fixed charges from that amount.

How have you calculated the variable rate per electrical unit?

Divide the variable charge amount by the electrical units consumed to obtain the variable rate per electrical unit.

How have you calculated the annual consumption?

Annual consumption is the total of the number of electrical units consumed over the last twelve months.

What is the basis for the proposed %age solar power?

The proposal offered by Koku Solar is for an on-grid system. The solar power percentage proposed is a calculated compromise between maximizing solar power production so as to save on electricity charges and avoiding over-generation which will be a loss for our customer. In an on-grid system, excess power generated by the customer’s solar system is supplied to the grid and this excess power is available to the customer for use during the time when solar power is not being generated, say, at night. If this excess power supplied to the grid is not fully consumed by the customer, it will be loss to the consumer. Thus any excess power supplied to the grid is a loss. Koku Solar ensures that the customer does not lose any power to the grid by proposing to generate 75 to 85 percent of the customer’s annual power consumption.

Isn’t there a daily and seasonal variation in power generation?

Yes, there is a variation from sunrise to midday to sunset and a seasonal variation. The annual power generation capacity of a PV solar power system is calculated taking into account all these variations.

How have you calculated installed capacity?

In a place like Mumbai, each KW of installed power can provide approximately 1400 electrical units per annum. Koku Solar have proposed annual power generation in terms of electrical units in their offer. This is divided by 1400 to obtain installed KW capacity. In other places, say, Nagpur, the power generated per KW per annum can be more than 1400 electrical units.

How have you calculated total investment?

The cost of installing the offered KWs, commissioning the system and two years maintenance is the total investment. The cost of installing depends on various factors like the exact design of the structure for your terrace, the distance between the solar installation and the room containing the inverter and other electricals, the distance between the inverter room and the meter room, etc. The quality of the components remaining the same, the cost can vary from Rs 60,000 to Rs 90,000 per KW installed. In our initial offer, we give a rough estimate of the cost. This is calculated more exactly after carrying out the site survey. The site survey gives us a more exact idea of the variables mentioned above.

How have you calculated the annual savings?

We have proposed the annual power generation in terms of electrical units. If you had used the discom grid power for this much consumption, you would have paid at the rate charged by the discom, which is likely to be more than Rs 10 per electrical unit. It costs you much less to generate solar power, of the order of Rs 3 to Rs 4 per unit. The difference is the annual saving.

How have you calculated the recovery of investment?

The total investment divided by the annual savings gives the number of years it will take you to recover your investment. If you are able to avail of subsidy or any tax benefits, e.g., accelerated depreciation, the period of recovery is that much shorter.

Why have you not taken subsidy into account?

Some State Governments, like Maharashtra, do not provide subsidy. Even if subsidy is provided, there is no guarantee when it will reach you. The reason is that subsidy is provided first to certain specified consumers such as hospitals, education institutes, government offices, NGOs, etc. The priority for urban residential housing societies is the lowest. Hence, it may take years for you to actually get the subsidy, if you get it at all. In any case, Koku Solar believes in making you an offer where you can recover your investment within 3.5 to 5 years without subsidy.

What tax benefits are available for solar power installation?

Accelerated depreciation and additional depreciation are available against investment in Solar Power Plant. It may take around 3 years to claim almost 100% depreciation. This results in saving of taxes to the consumer.

When will you make the final offer?

The final offer can be made after carrying out the site survey. We charge a nominal Rs 1,000 to Rs 2,000 for the site survey, depending on your location.

Does the power generation decrease with time?

Yes, the power generation decreases with time. The generation may decrease from about 97.5 % in the first year to 80% in the 25th year. In spite of the decrease, your recovery of investment will still be within 3.5 to 5 years. The effect on your savings after the recovery of your investment will be explained to you at the time of making the final offer and during negotiations.

What happens if less power is generated annually than what is stated in your final offer?

If the generation shortfall is due to our faulty design, additional panels will be installed without any additional cost to you. However, it should be understood that there can be many causes other than a design fault for the shortfall. As an example, if, after the installation and commissioning, a high rise comes up next to your terrace which casts a shadow on the solar panels, there will be shortfall in the power generation which will not be due to any design fault.

What guarantees do you provide?

The company ensures the power generation committed in the purchase order.

How does your price compare with others?

At Koku Solar we believe in offering the best to our customers. Thus, all the components used, including the solar panels, inverter, the support structure, other electrical, cables, etc., are the best amongst those available in the market. Some of the components may be imported if Indian ones do not meet our stringent specifications. So, if you compare our offer with others providing the same quality of material and services, and the same guarantees, i.e., if you compare apples to apples, you will find that the Koku Solar offer is most reasonable.