SOLAR FAQs

SOLAR FAQs

Discover comprehensive answers to all your questions about solar energy, its benefits, installation process, and how it can transform your energy consumption.

Frequently Asked Questions

1. What is a Solar PV System and how does it work?

PV, short for Photovoltaic, derives its name from the process of converting light (‘photo’) directly into electricity (‘voltaic’). Simply put, a Solar PV system is a power station that generates electricity from sunlight.

The main components of a Solar PV system are:

  • Solar Panels or Modules:

    Solar panels consist of a group of small cells made from semiconductor material. When the sun’s light falls on the modules, it excites the electrons, thereby creating direct current (DC).

  • Solar Inverter:

    The DC electricity goes into an inverter that converts it into alternating current (AC). We use AC for running our household or office or factory equipment.

  • Storage Battery (optional):

    The best use of solar energy is to consume it while it is being generated. If the requirement is to store this power and consume it in the non-sunny hours, then solar energy can be stored in batteries for later consumption.

2. Does a Solar PV system produce same energy output throughout the day?
Since Solar PV works on the basis of the intensity of sunlight it gets, your solar system typically wakes up at around 6am in the morning and goes to sleep at about 6 or 7pm in the evening. The energy output increases gradually and peaks at around noon and then gradually decreases as the Sun starts setting. But since the solar energy produced integrates either with your existing electrical connection or with your batteries, the running of your electrical equipment is not impacted. Moreover, if your Solar PV system is designed well, all your electrical equipment is totally safe.
3. What factors are important to consider when planning to go solar?

When planning to go solar, it is important to consider:

  • How much of your energy needs can you meet with solar?
  • How much can you save by going solar?
  • Do you have enough shadow-free space (land or roof)?
  • How much do you want to invest in your solar PV system?

Every Solar PV system is customized based on your site conditions. Therefore, you need a fair assessment of your energy requirements, site conditions and the solar energy generation potential at your site which would directly impact your savings.

4. Can solar be my sole energy source?
Technically speaking, yes, if batteries are used. But practically, if grid power is available, then it is recommended to use solar in combination with grid. Solar PV can be integrated with your existing power sources (like grid power, inverter, diesel generator, etc.) in such a manner that the first priority is automatically always given to the solar power to be consumed first. However, if you are using Solar PV for night time usage or in a remote location, it is quite common to have Solar systems which are battery-backed.
5. What is the life and reliability of a Solar PV System?
Solar PV is a highly proven and reliable technology and have been in use since 1950s. A PV system that is designed, installed, and maintained well will operate for 25 years or even more than 25 years. The Inverters, which are an integral part of a Solar PV system, may need a replacement once in the 25 years lifetime of the system. Moreover, since there are no moving parts (unless you are using tracking devices to move modules tilt with the movement of the Sun), there is practically negligible wear and tear.

Frequently Asked Questions

1. What is the CAPEX and OPEX / RESCO/ PPA model of Solar?

The CPEX, OPEX(RESCO) and PPA are two models of buying solar energy. Here are what they mean and how they are different from each other:

  • CAPEX:

    CAPEX stands for Capital Expenditure. If you go solar under the CAPEX model, you are required to pay the total cost of the solar system upfront. This allows you to own the solar system and makes you eligible to avail the accelerated depreciation benefits.

  • OPEX/ RESCO/ PPA:

    OPEX or RESCO stands for Open Expenditure. If you go solar under this model, you essentially choose to not buy the solar system but the solar energy produced by the solar system. The solar system in this mode is installed and owned by the solar installer or a third party and you are required to sign a Power Purchase Agreement(PPA) of purchasing the electricity from the solar system at a specified rate for a certain number of years. These agreements are usually signed for 15~25 years.

2. Which is the best model of buying solar – CAPEX, Deferred Payment Agreement (DPA) or Power Purchase Agreement (PPA)?

From the cost perspective, the CAPEX model of going solar is considered the best model of buying solar followed by DPA and PPA. The reason behind this consideration is that since the cost solar PV system is paid upfront under CAPEX, the cost of solar energy is lower in CAPEX than in DPA and PPA. Under DPA, the cost of the solar system is split into monthly instalments and the entire cost of installation is initially borne by the installer, you are therefore required to pay a minimum interest in your monthly instalments. This increases the overall cost of the solar system. Under PPA, the Solar PV installation cost is borne by the installer and you only pay for the per unit cost of electricity that you consume and therefore the Levelized cost of solar energy is higher in PPA than in CAPEX and DPA.

Also, additional benefits like Accelerated depreciation and relaxation in taxes can only be availed in CAPEX or DPA, because availing these benefits requires ownership of the solar system.

3. What is the Feed-in tariff?

A Feed-in tariff is the rate/cost at which you sell the electricity generated by your solar system to your discom either via net-metering or gross metering. This tariff rate varies from state to state depending upon the solar policy of the state. The tariff also differs across consumer categories. This tariff is often referred to as net feed-in tariff in case of net-metering and gross feed-in tariff in case of gross metering.

4.What is Solar tariff?

Solar tariff is the rate/cost at which you purchase the electricity from the installer/owner of a solar system under a Power Purchase Agreement(PPA). The rate is agreed upon for a certain period of time as per the clause of the agreement. This insulates you from any tariff hike in the near future. However, the solar tariff may be subject to an increase depending on the terms and conditions of the signed agreement.

To get an estimate of the solar tariff that you may be required to pay if you solarize your business under PPA, you can run the MYSUN Solar Calculator. The calculator will show you your estimated solar tariff for a PPA ranging from 10 to 25 years. You will also be able to compare the solar tariff to the levelized cost of solar energy if you went solar under the CAPEX or DPA(Deferred Payment Agreement) model. With the advanced feature of the calculator you will also be able to check an estimate of the total cost of solar energy your business will be paying throughout its solar journey at a given solar tariff.

5. What is Gross-metering?

Gross metering is a mechanism in which the entire energy generated by your solar system is exported to the grid at a certain rate. In this case, the energy generated from your system is not consumed by you in any capacity. Once the energy is generated from your solar system it is transferred to the grid, and the grid further sells the energy to the power consumers at a certain tariff rate.

Gross-metering is often confused to be a synonym of net-metering. However, it is not. In the case of net-metering, the power generated by the solar system is first used for self-consumption and if there is any leftover surplus energy, only then it is transferred to the grid in exchange for compensation. Net-metering requires installing of a bi-directional meter because in net-metering both the import and export of energy is taken into account to calculate the net consumption of electricity. But in the case of gross-metering, a unidirectional meter is installed to track the total export of electricity from the solar system to the grid.

Gross metering makes sense for those property owners who have idle space and don’t need to generate solar power for their own consumption. They can install a solar system to utilise the idle space and export the entire generated energy to the grid in exchange for financial benefit.

6. How does solar power compare with diesel generator (DG) and Home Inverter?

Diesel Generators (DG) are not just a highly expensive means of power generation but are also extremely damaging to the environment. And contrary to popular belief, the cost of energy from home inverters is also very high. The cost of power from a typical DG in a housing society is Rs. 17 – 18/ unit (kWh), while from a typical home inverter it is Rs. 14/ unit (kWh). In comparison, solar is a much cheaper and cleaner source of energy.

7. What are my solar buying and financing options?

There are broadly five solar buying and solar financing options that you can opt for while going solar:

  • There are broadly five solar buying and solar financing options that you can opt for while going solar:

    You purchase the Solar PV system and pay the 100% cost of the solar system upfront. This allows you to get the best deal as you would be saving any additional cost such as interest rates.

  • Buying a Solar System under a Deferred Payment Agreement(DPA):

    You purchase the solar system at a downpayment of 25~30% and defer the remaining capital cost of the system in easy instalments at lucrative interest rates. The benefits of buying solar under DPA is that it makes going solar affordable and flexible. With MYSUN DPA you also get an option to make your own payment plan and keep your monthly instalment less than or equal to your monthly power bills. This will help your solar system pay for itself.

  • Buying a Solar System by opting for a Solar Loan:

    You purchase a Solar system and opt for a solar loan to pay the 100% cost of the solar system to your solar installer. Under this model of buying solar, though you buy the solar system at the CAPEX cost you are required to pay off the loan at an agreed-upon interest rate.

  • Buying only solar power under RESCO/ Power Purchase Agreement(PPA) Model:

    You do not purchase the solar system but only the solar energy produced by the solar system. A solar power developer owns the Solar PV system set up on your rooftop/ land. You only pay for the generated electricity at a pre-agreed tariff. This usually requires a long-term buying commitment and guarantees from your side and entails a lengthy credit appraisal process. This mode of buying solar is usually available to only commercial and industrial power consumers.

  • Equipment leasing:

    An equipment leasing company will lease the Solar PV system to you and will charge you a fixed monthly/ periodic fee. This also requires long term commitments and guarantees from buyers. However, equipment leasing is not widely available as of now. Click here for more information.

8. What is net metering?

Net metering is a billing mechanism which allows you to sell excess (unconsumed) solar power generated by your solar system to the DISCOM. For example, if on a given day you generated 20 units from your solar system and consumed only 18 units, the balance 2 units will be sold to the DSICOM at a set tariff. This ensures that you maximize your savings from solar. Click here for more information.

The mechanism of net-metering can be availed only if your building mains is connected to the grid. Therefore it can only be installed with on-grid and hybrid solar systems. The availability of net-metering varies from state to state and depends on the solar policy of your state. For example, in the state of Rajasthan, the net-metering is only available to power consumers going solar under the residential category. For commercial and industrial consumers of the state the facility is available only above a certain sanctioned load.

9. How much does a Solar PV system cost?

Solar PV system costs vary depending on the size of the system. On an average, an on-grid system of a size up to 10kWp costs Rs. 50-74/Wp, between 10 – 100 kWp costs Rs. 35-50/Wp and above 100KWp costs Rs. 34-36/Wp systems.

For utility-scale solar projects, costs can be even lower than Rs. 30/Wp. However, for off-grid systems with battery backup cost goes up significantly and lies between Rs.100 -125/ Wp.

To Determine the system size and cost most relevant to you, run the MYSUN Solar Calculator now!

10. Do I need to buy Insurance for my Solar PV system?

Solar PV systems are highly reliable if designed well. Moreover, the key components of a Solar PV system are backed by guarantees & warranties . However, since solar is like any other asset that you own, it is generally advisable to buy an insurance cover.

How can I get my PV system Insured?

Most insurance companies nowadays provide policies to insure your Solar PV system. These policies usually insure your solar system from the threats of fire and burglary, machinery breakdown and other natural calamities as per the details of the policy.

Since going solar is a sizable investment, the returns from which you will reap over a period of 25 years, it is therefore important that you don’t just insure your solar system but secure it for better performance. To help our customers with the same, we at MYSUN, offer comprehensive service and maintenance packages to our clients across India. These packages include not just solar system insurance but warranty, breakdown maintenance, preventive maintenance, regular cleaning, system performance monitoring support and etc to our clients. With a minimum amount, our clients are able to keep their solar investment safe for the complete 25 years of their solar journey.

To know more about these packages and to get your solar system insured you can get in touch with our Customer Delight Team at info@itsmysu.com or 1800 3012 0101.

11. Is solar power cheaper than grid power?

Yes, solar power today is cheaper than grid power for a lot of consumer categories across most states. Moreover, solar is a one time investment while grid tariff keeps increasing every year. Therefore, by choosing to go solar today, you are locking in a fixed energy price for the next 25 years.

Illustration for an average residential customer in Delhi:

A 2kW Solar PV system costs around Rs 1.4 lacs and has a life of at least 25 years with low recurring costs. This translates to a per unit levelized cost of Rs7 – 8 /kWh for the next 25 years.

Let’s compare this with the cost of grid power. The discom charges the consumer slab-wise but on an average the consumer pays Rs 7.3/kWh. And this price keeps increasing by about 5% per annum, which means you may be paying Rs 24.7/kWh at the end of 25 years. This translates to a per unit levelized cost of approx. Rs 10 – 11/kWh when compared with the 25 year life of Solar PV system.

How does solar power compare with diesel generator (DG) and Home Inverter?

Diesel Generators (DG) are not just a highly expensive means of power generation but are also extremely damaging to the environment. And contrary to popular belief, the cost of energy from home inverters is also very high. The cost of power from a typical DG in a housing society is Rs. 17 – 18/ unit (kWh), while from a typical home inverter it is Rs. 14/ unit (kWh). In comparison, solar is a much cheaper and cleaner source of energy.

Should I buy solar now or wait?

For most Indian electricity consumers, the answer is Go Solar Now !

Solar PV system is a proven technology which reduces electricity bills and with today’s reduced capital cost of the solar system, the Levelized Cost of Solar electricity is lower than the grid electricity tariff for a lot of consumers.

Moreover, going solar helps you cut down on your electricity expenses from day one. And delaying your decision will lead to a monetary loss because you will be paying what you could have saved.

However, if your cost of grid electricity is very low, it may make sense to wait for some time. Run the MYSUN Solar Calculator to get an unbiased view on if you should go solar now or wait.

12.What is the return on investment (ROI) and payback period of solar PV?

The payback period for your solar PV system stands for the amount of time it takes for your initial investment in the solar system to be recovered from the savings it yields. The Return on Investment (ROI) refers to the effective returns that your investment would generate throughout the life of the solar system. The higher your monthly savings on power bills from solar is, the quicker your initial investment would be repaid and the higher your ROI would be. Typically, commercial & industrial consumers should expect payback in 3 – 5 years and residential consumers should expect payback in 5- 7 years. Once the initial cost of your system is paid back, the energy generated by it for the next 18 – 22 years is almost free of cost.

The point to note when it comes to ROI of your solar investment is that the returns are assured. Unlike other market investments which are subject to risks, investment in solar gives assured returns as solar systems will always generate electricity till the sun is around.

Run the MYSUN Calculator to determine your ROI today.

Frequently Asked Questions

1. How much time does it take to install a solar PV system?

It takes about 2-4 weeks to install a smaller system and about 4-8 weeks for larger systems. However, the actual construction time at the site is much lower since almost half of the time is spent on off-site activities such as design, engineering, procurement, etc. In certain cases, there may be variations to these timelines on account of access to the site, rains, etc.

What should I do to get my site ready for a solar installation?

Not much. You just need to ensure that there is clear access to the site for movement of material and manpower and that your site is clear from any unwanted material. The solar installer may need access to power & water.

Will my power supply be affected during the Solar PV system installation?

No, there will not be any interruption in your power supply.

2. What factors are important to consider during Solar PV system installation?

Good solar installers follow standard procedures and quality standards. So once you’ve chosen the right installer, you don’t have to worry about supervision. However, it may be a good practice to:

  • Ask for layout drawing and bill of material.
  • Ensure that the delivered material is as per the bill of material, is damage free and is kept at a safe place.
  • Ensure that cables and wires are properly tied and clamped.
3.What would be the annual maintenance cost for a solar PV system?

The annual maintenance and recurring costs are almost negligible, since there are no moving parts and the input fuel (sunlight) is free. For optimum performance, the system only requires cleaning of modules and basic preventive and corrective maintenance. However, for off-grid systems where batteries are used, the maintenance costs are higher on account of battery replacement every 3-5 years. To ensure high generation and low maintenance cost, regular monitoring through data loggers is highly recommended. Typically, the maintenance costs for smaller Solar PV systems is about 2% of the initial system cost, and for larger systems is about 1% of the initial cost.

What maintenance does a Solar PV system require?

The two primary aspects of maintaining a solar PV system are to regularly monitor your system’s performance through the data logger and to clean the panels about 6-10 times in a year. Beyond this, it is advisable to have your installer conduct at least two visits in a year just to check the general health of your system.

4. What permits & approvals do I need to install a solar PV system?

No permits would be needed, if you are going to install off grid Solar PV system or grid connected system for captive (self) consumption. For net metering and gross metering system, certain permits and approvals are required. For Net & Gross Metering:

1. Approval from DISCOM for grid connectivity.

2. CEIG(Chief electrical inspector to the government of state) approval for the capacity more than 10 KW(This capacity may vary from state to state).

Will my system installer assist me in getting the permits and approval?

Yes, the system installer will! But it is better to discuss and finalize all of these things with the installer before signing the contract.

5. What steps should I take to buy a Solar PV system?
  • Run the MYSUN Calculator and check your potential savings
  • Register Your Rooftop with MYSUN
  • Get your site visit done and start receiving quotes from pre-qualified installers
  • Compare quotes and select your installer
  • Finalize the terms (pricing, guarantees, etc.) and the order with the selected installer and start your solar journey
How do I evaluate solar quotes?

Different installers may consider different parameters (like system size, equipment makes, energy generation potential, etc.) while quoting for your Solar PV system. This makes the comparison and your decision making difficult. MYSUN enables you to make an apple-to-apple comparison through its easy-to-use tools.

When comparing quotes, some of the critical parameters to consider are price, equipment make & specifications, guarantees & warranties, payment terms, installer credentials, etc.

Frequently Asked Questions

1.Which Solar PV system is suitable for me?

Depending on your energy consumption pattern (consumption during day vs night), power outage pattern, availability of policies like Net Metering and access to grid power (for rural areas), you can choose between an on-grid and an off-grid Solar PV system. On grid systems are the most commonly used systems and are the least expensive and require very little maintenance. Off-grid systems use batteries which cost significantly more and need high maintenance.

What is an on-grid and an off-grid Solar PV system?

On-Grid: An on-grid system is interconnected with your existing electrical system. The solar energy generated is simultaneously consumed, and if the solar panels are not generating sufficient energy to cater to your consumption, the differential is automatically sourced from the grid. It is also possible to connect the system with batteries, home inverters, diesel generators, etc. Off Grid: An off-grid system is an independent, battery-backed Solar PV system which is not connected with grid. During daytime, solar energy generated runs your appliances. Any excess energy is stored in the batteries, which can be utilized at night. Off-grid systems are used for standalone applications like traffic & streetlights, billboards, agricultural pumps, telecom towers, rural applications, etc.

How can I use Solar during a power outage?

On-grid Solar PV systems are designed to run with grid power. Therefore the system will not be able to function if grid power is not available. This is a safety feature to avoid feeding power back into the grid while the line-men are working on the grid. If you want power from solar PV system during grid failure, you can choose an inverter that can use other sources of power like diesel generator or batteries etc.

2. How do I know that my system is working efficiently?

To keep a regular check on your system performance, it is recommended that you install a data logger (data monitoring device) along with your Solar PV system.

This device will allow you to compare the actual with the estimated performance on a daily, monthly and annual basis.

What is a data logger?

This is a device that helps you as well as your installer/ O&M contractor to monitor your Solar PV system’s performance on a real time basis on your mobile phone or laptop. Data logger indicates parameters like generation on a daily, monthly & yearly basis, plant performance ratio, etc. and can send alerts in case of any faults or low generation. The device can also be configured to send you regular performance reports through SMS and email.

What are the typical Solar plant performance metrics?

The generation from your Solar PV system depends on the quality of your system, the solar irradiation and the quality of maintenance. Performance Ratio (PR) is a measure of the quality of your system, whereas, Capacity Utilization Factor (CUF) is the overall metric that takes into account both the quality as well as the solar irradiation. For example, if the quality (and hence the PR) of your system is low, even if the solar irradiation is high, your CUF (generation) will be low, and vice versa. To know how to calculate PR & CUF, click here.

3.What is the unit of electricity?

Electricity is measured in kWh (Kilo Watt Hour). It is the amount of electricity consumed by an appliance in a specified period. For example, 100W bulb * running for 1 hour = 100Wh which is equal to 0.1 kWh (unit). Your electricity bill mentions the kWh (Units) consumed by you in your billing cycle.

What is the difference between kW & kWp in relation to Solar PV systems?

KWp is the nameplate rating of Solar PV modules and kW is the actual power delivered to the load. For instance, a 0.3kWp (300Wp nameplate) module under ideal conditions (25 degrees C and 1000 watts per sq. metre radiation, etc.) will give an output of 0.3kW. However, in real life weather conditions, the output will be lower than the nameplate rating which is denoted in kW.

What is the difference between kW and kVA?

Both are units of power , kW is active power whereas kVA is the apparent power because only a certain portion of the available kVA can be utilized kVA=kW+kVAR. If you take a mug of coffee, you can see its two component coffee+ foam. Here the portion of coffee is active power(kW), foam is reactive power caused by certain electrical equipment, and coffee + foam is apparent power (kVA).

4.What are the key factors that affect solar power generation?

To ensure that the generation from your Solar PV system is maximized, the following should be kept in mind:

  • Location (Solar Irradiation/ weather conditions)
  • Plant layout
  • Shading and roof orientation
  • System design
  • Equipment quality
  • Operations and maintenance
How do plant layout and system design impact the Solar PV system generation?

Every solar installation is site specific. Therefore, the layout and the design of your Solar PV system has to be determined after a thorough engineering analysis. In this exercise, things like the tilt of the solar panels, the gap between different rows of solar panels, any shadowing objects, specification of solar equipment, cable sizing, arrangement of solar panels, etc. go a long way in ensuring that that your system generation is optimized for the next 25 years.

How often should I clean the solar panels?

Solar Panels do not require much cleaning. Generally it is recommended to wash your panels in 30 to 45 days in summer, 45 to 60 days in winter. Cleaning in rainy season is not required as the rain does all the cleaning for you. Cleaning of solar panels is as simple as cleaning your car or house windows. Just ensure that you use clean water.

5. Will my roof be able to bear the weight of a Solar PV system?

A Solar PV system generally weighs 15 to 20 Kg per square meter. This weight can be easily borne by most roofs. Since the life of a Solar PV system is about 25 years or more, do ensure that your roof is in good condition to bear the system’s load over its lifetime.

Will the Solar PV system installation damage my roof/building?

Solar installation methodology is proven and safe. A wide range of installation techniques are available and depending on your roof type a suitable methodology can be adopted.

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