The sun is the most important source of heat and light in the universe. During primitive times, the sun was solely used for its heat and light for all day to day activities, when there was no electricity. With increased usage of fossil fuel and thermal electricity, there is now a risk of global warming. It is being feared that if Earth progresses at the rate at which it is currently moving on, there will not be much of resources left for our future generations. All this has led the world incline towards alternative sources of power. While wind and hydro energy are also making progress, it is solar energy that has become the favoured one amongst masses, mainly due to its increased affordability.

Also Read about Solar Cookers

What is a Solar Dryer

A solar dryer is another application of solar energy, used immensely in the food and agriculture industry. Though sun is still used as the direct source for drying food items and clothes in certain parts of the world. An indirect source of solar power can also be used for the same purpose in the form of a solar dryer. The main disadvantage of drying directly under the sun is contamination – dirt, animals, insects etc. Also there is a fear of sudden change in weather conditions like wind or rain.

When using a solar dryer, you do not have to worry about all this!

solar-dryerA Solar Dryer for drying cocoa seeds

Types of Solar Dryer

A solar dryer can most conveniently be classified as direct or indirect.

Direct Solar Dryer – The item to be dried is exposed directly to solar radiation through a transparent material that covers the structure. The heat generated from the solar energy is used to dry the crops or food items and also heats up the surroundings. The main disadvantage of using the direct mode is that the heat that will be absorbed by the item cannot be controlled. Available in many sizes, ranging from kilograms to metric tons, the simplicity of the product and its affordability are its USP.

Read about Solar products in India

Indirect Solar Dryer – As the name suggests, this method does not expose the crop directly to the sunlight. The solar radiation is absorbed and converted into heat by another surface (like a black top) usually called the collector. Air that will be used for drying is passed over this surface and gets heated, which is then used to dry the food item inside the dryer. The main advantage of indirect mode of drying is that the temperatures can be controlled. The sizes can vary from kilograms to metric tons, but it is expensive and more complex to construct when compared to direct solar dryers.

solar-dryer-diyImage source

These are also commonly referred to as food, cloth or crop dryer, based on the items used for drying using the Solar Dryer. Many people can assemble/ construct a solar dryer with the help of DIY instructions available on the internet. The image shown above is self explanatory. Solar Dryer will find increased applications in the food, agriculture and plantation industries where food and crop items need to be dried before using. It helps in maintaining the quality of these items without contamination fears. In economies, where people hardly have power for their daily life, these devices will help a great deal in reducing the load on the main grid, and electricity from the grid can be used for other purposes.

State of Indian Solar Manufacturing

The Indian solar manufacturing industry is a heavily fragmented and uncompetitive one. Its costs and price are typically 15-20% more than the imported Chinese solar panels. The only reason why producers are afloat is because of the DCR (domestic content requirement) in some of the government tenders. While the cell capacity also exists, there are onlye 2-3 producers of those and they also run due to the government’s protectionist policies. The Indian government and industry has failed to create a vibrant industry, despite strong dometic demand and a long history of solar manufacturing in the country (Webel, Tata BP Solar etc.).

rajasthan solar

While MNRE shows that the current capacity of solar panels is 5000 MW and a leader of an industry group claims that it will increase to 10000 MW, what will be the use of these panels. A recent report shows that India imported 75% of solar panels last year from China alone. Another 10-15% would be imported from countries such as Malaysia, Taiwan, USA which would mean that Indian players would be making around 500 MW of solar panels, which implies a factory utilization for the overall sector at just around 10%.

Also read Is India’s Solar Industry moving to a Fixed Tariff model from Reverse Auction tenders?

Increasing the capacity to 10000 MW would not make sense, given that most of the capacity is lying unutilized. I would suspect that a large portion of the current 5000 MW capacity is junk and obsolete. Creating more capacity does not make sense unless the Indian players can be cost and technologically competitive. While the new plant made by Adani of around 1.2 GW makes sense from the scale perspective, most of the other Indian solar power plants are just 50-100 MW in size which makes them completely useless in being sustainable over the long term.

Mr. Saluja from SEEMAT has boldly said that capacity would double. Yes it could but what is the value addition to the Indian economy or the players themselves. Yes the demand in the Indian market is there, but can the Indian players even hope to be compettivie to serve the Indian demand. The Chinese companies are already selling solar panels at 40 cents/watt and might go lower, if the overcapacity persists.The  Indian companies do not have a snowball’s chance in hell of selling these panels at those prices. Even Mr Saluja’s company makes a pathetic 100 MW of solar panels and 50 MW of cells. This makes no sense from a scale perspective. Large Chinese companies have a capacity of around 4000-5000 MW and are still fighting to make decent margins.

The government is also sitting on its ass not announcing its “integrated solar manufacturing policy” which has been in the works for a long time. Time is of essence, if India needs to become a manufacturing power and dilly dallying on a crucial industry does not inspire confidence

India is also likely to double its module and cells manufacturing capacity to 10,000 MW and 2,000 MW in the next couple of years. However, “lack of easy and cheap funding, expectations of a high GST rate and increasing cheap imports from China and Taiwan is hurting the domestic industry,” said Singh.


100 MW Solar Power Plant by TATA

A 100 MW solar plant have been commissioned by Tata Power Solar in Anantapur, Andhra Pradesh. It is India’s largest solar plant commissioned till date, using solar cells and modules manufactured in India itself. This plant is expected to offset 110,000 tons of Co2 in the first year itself and will produce 160 million units of energy annually thereafter.

Read more about Solar Power plants in India.

Not only has this plant built a record of being the largest plant in India so far and using domestically manufactured components, but also being completed 3 months ahead of its stipulated timeline.

TPS AP project

Tata Power Solar has over 25 years of experience in manufacturing and EPC services and have built over 250 MW of utility scale projects across 13 states in India. This plant was built for NTPC and also provided employment opportunities for more than 50 local people in that area. NTPC has a target of adding about 1,000 MW through renewable resources by 2017. Anantapur is the largest district of AP getting the lowest rainfalls in India. The company has already done more than 90 solar installations (including solar water pumps) in this district, generating more than 800 kWh of energy per day.

Also read about the largest solar farms across the globe here.

Some of NTPC’s solar projects already commissioned in India:

Dadri Solar PV Uttar Pradesh
Port blair Solar PV Andaman & Nicobar Island
Ramagundam Solar PV (Phase -I) Telangana
Talcher Kaniha Solar PV Odisha
Faridabad Solar PV Haryana
Unchahar Solar PV Uttar Pradesh
Rajgarh Solar PV Madhya Pradesh
Singrauli Solar PV Uttar Pradesh
Ananthapuram Solar PV Andhra Pradesh

A.K. Jha, director technical, NTPC said, “Given our ambitious target for green power, we were aware that our requirement of rigorous timelines and cost-efficiency was a challenging one.”

Source: Economic Times

Tata Solar Power projects in India

Other popular Tata Solar projects in India are:

  • 50 MW solar power project for NTPC in Rajgarh, Madhya Pradesh
  • 17 MW solar plant in Mithapur, Gujarat
  • 10 MW plant in Chitradurga, Karnataka
  • 5.75 MW plant in Naini, Uttar Pradesh
  • 3 MW plant while maintaining the aesthetics of Mulshi, Maharashtra
  • 2 MW solar plant in Saraikela, Jharkhand

The 50 MW NTPC, Rajgarh plant, has shown a performance ratio of 86% in the one year of operation more than 10% higher than the 74% generation target. All of Tata Power Solar’s solar plants maintain an uptime of 99.6% minimum. Given the company’s experience in this field, it has a lot of government and corporate clients. Tata Power Solar has already built more than 250 MW of projects for these clients, with more than 500 MW under construction.

Fixed Tariff model for India’s Solar industry

Indian solar sector has seen a huge amount of success using the reverse auction tender method, which has led to massive competition amongst solar developers and discovery of declining prices for solar power. Unlike other countries, India has not been burdened with high subsidies that need to be paid for green power. However, this method has been criticized by solar developers for having shortcomings.

Some of these are that non-serious bidders have entered the space and bid irrationally low. This might lead to problems later on if these projects are not built, or some of these developers using low quality components might fail going forward. As the sector has matured and prices have become sufficiently low, the government is examining a new method to grow the solar power capacity in the country in a stable and a predictable manner, which will allow the private sector to earn reasonable returns and also let the government meet its ambitious target of putting up 100 GW of solar capacity by 2022.

NTPC which has been used by the government as one of the main procurers of solar power has been mulling a new model to buy solar power for its next phase of 5 GW of solar energy procurement. Earlier NTPC had been buying solar power through reverse auctions and selling it to discoms by bundling non-committed cheap thermal power from the central pool. However, solar power has not become cheap enough for it to sell, without bundling with thermal power. NTPC might now use a new method where it will set a reference price of 7 cents/kWh for buying solar power. Bidders may bid for a discount or a premium and win the tender for selling to NTPC. This is similar to the SECI method which has a VGF instead of a tariff.

This INR 4.5/kWh will set a reference price for the country and many state governments may follow a similar method of procuring solar power going forward. Given a more stable and consistent regulatory regime will allow most solar power developers to bid in a planned manner. This will ensure a greater success rate of tenders.

Currently India has bid out 20 GW of solar tenders, out of which more than 8GW of capacity has signed PPAs in place. This rapid rate of tendering is expected to continue in the future, given the government’s strong focus on increasing the solar capacity. However, as the industry matures alternative models should be examined for selection of solar developers.

Will Solar suffer with India turning power surplus

We have flagged the risk from the increasing power oversupply in some states, to solar power in the last few months. Indian states which have historically being facing huge power deficit have suddenly turned into power surplus states. With huge expansion plans of power capacity this situation could become more acute, if industrial growth fails to take off; leading to increased supply of power which does not have a home.

The problem has become so bad that India’s ministry for renewable energy has written to the Central electricity regulator to ask power utilities not to curtail the procurement of solar power. Power procurement is sometimes cut off by utilities, when there is a situation of oversupply which could lead to grid instability risks. However, the distribution utilities are using this law to cut off solar power for up to 2 hours at a time. This does not make sense, as solar power is still a fraction of the overall power capacity in the country at around 8 GW out of 270 GW.


Also read Wind producers face large losses due to curtailment by Utilities with India turning Power Surplus.

Curtailing Solar Power is not a good move

Distribution utilities by law should curtail thermal, gas and nuclear power before cutting off solar power, as solar energy in India has a “must run” status. The reason for solar power’s high priority status is that solar power does not require fuel like other energy sources using fossil fuels. This implies that solar power will keep generating power, even if the distribution utility does not buy power from the solar panel farms. It is a case similar for wind power farms which do not require any fuels.

Most of the large solar farms have been built in the country at very low margins, due to the intense competition seen in reverse auctions conducted by the state and central governments. This means that any actualization of a small risk could lead to huge losses for the investors and lenders of the solar project. Most of the solar developers would not have factored in grid curtailment by utilities for up to 2 hours a day in their models. This problem is being seen in Rajasthan and Tamil Nadu which have the most heavily indebted utilities making huge losses.

The other problem faced by solar developers is that they get zero compensation for being forcefully cut off from selling power to the grid. Thermal plant owners generally get compensated for the fixed costs, but in case of solar power there is no compensation at all. Given that 95% of the solar power is fixed costs, this is a problem for the solar developers.

The India government is planning to install 10 GW of solar power this year and with the existing 8 GW capacity already facing problems, it will be a difficult problem to incentivize developers to build out this capacity. If this risk persists, then solar developers will build in these risks into their models, leading to higher costs for consumers. The states which are curtailing solar power may find that there are no bidders for auctions, which sell power to the utilities in these states. They have to be careful as solar power will become the most important power source in India going forward.

Though Kapoor’s letter does not name any discoms, industry sources said those in Rajasthan and Tamil Nadu were the main culprits. Sunil Bansal, General Secretary, Rajasthan Solar Association (RSA), said the problem had been plaguing the state for some time. “In fact, it has been increasing. On average, there are back downs of one hour a day during peak hours,” he said. “That amounts to 1200 MW of capacity remaining unused.”


India Solar Energy Zones

The Indian government has been coming up with a number of policies and initiatives to boost the solar energy capacity in the country. While some have succeeded (reverse auction tenders for grid utility projects) some have failed such as the promotion of rooftop solar through subsidies. The super large solar power plant of 4000-5000 MW capacity known as solar UMPPs have also proven to be a non-starter. The government now has come up with a new plan to substantially accelerate the adoption of solar power in India. This will be done through “Solar Zones,” which will be super large areas of 25,000 acres in size each. The states will have to earmark such area out of wasteland or fallow land lying unused.

Key highlights of Solar Zones:

1) Transmission lines to be built at multiple points in these zones to connect the main transmission network of the country. Note the lack of transmission is the biggest hurdle facing large solar power plants and solar parks in remote areas from getting operationalized. Once a transmission connectivity is there, then it will be easy for developer to build solar projects. Developers will not have to build a transmission line of more than 25 kms

2) 25% of the area will be earmarked for the manufacturing of solar products such as ingots, wafers, cells and panels

3) Another 25% will be reserved for SMEs and youth

4) 50% of the area will be allowed for large grid scale utility projects from large project developers and investors. This implies an area of around 12500 acres, which will be enough to develop around 2.5 GW of solar capacity

California-Solar-Energy-Solar-ZoneCalifornia Solar Energy Zone

Also read about Solar Zones in USA.
5) 10 solar zones will be developed in total

6) The solar zone much have contiguous land (or near to it) and should have a radiation of at least 4 kWh/sq. metre ( 1460 kWh/year)

7) The government has provided an assistance of INR 44 crores for feasibility studies

8) Biggest difference between solar park and solar zone is that the Indian government will only facilitate the acquisition of land, but will not acquire it

9) The solar zones will be built such that they have good road connectivity and easy water and transmission resources nearby
10)  SECI will be the overall agency in charge of these solar zones and will coordinate with other central and state level agencies such as the SNA, PGCIL, NTPC etc.
More details can be read here.