Complete detail on Solar Energy

In the Indian context Solar Photo Voltaic is a relatively new concept of power generation.  Solar Photo Voltaic has been in use in smaller equipment like Solar Lantern, Solar Street Lights, Solar powered Signaling Systems etc.



For any interested investor or developer it is necessary to know the Basics Facts of Solar Energy before moving to the advanced stage of site selection and / or site feasibility and study and evaluating Project Viability.

At a preliminary level it is also necessary to overcome any misconception about Solar Photo Voltaic. Mainly these include clarifying doubts related to Solar Energy operations, working in rainy / cloudy / foggy conditions, storage / battery related myths etc. Frequently Asked Questions (FAQs) about Solar Energy have been covered in our Post on Solar Energy FAQs.


1. Solar Radiation (Location Feasibility)
Understanding Solar radiation in a particular area is of prime importance and plays a vital role in Project Viability. The same is generally done by observing the Solar radiation map, using complex software, and using pyranometer and various tools to actually measure radiation data. It thus helps in understanding the output that can be expected from the project in terms of kWh generation.

Below is an old Solar radiation map of India., generally a newer and more advanced version of the same is used :-

Solar radiation - 01

Solar radiation - 02

2. Site Feasibility
Site Feasibility mainly consists of evaluating a Site for its feasibility for installation of Solar Panels. This primarily includes shade-free area availability, Roof analysis (for rooftop projects), Terrain, Soil Analysis, Proximity to load / distribution centre, Proximity to Substation (for grid-feed projects) etc.

One definite advantage of Solar PV is that it does not need any water for its operations. So it can even be planned for isolated locations where water might be an issue. Minimal maintenance and remote monitoring also ensure that manpower onsite is kept to bare minimum.

3. Technology Feasibility
In Solar Photo Voltaic there are various technologies and are mainly categorized into Crystalline and Thin-Film technology. Within each category there are different types. Each technology has its pros and cons and based on the characteristics of a particular site the technology is selected.


The technology feasibility is important as it generally decides the fate of the project in terms of kWh output and also in terms of reliable and stable operations for years to come. More about Technology aspects of Solar Photo Voltaic, Fundamentals of operation, basic manufacturing etc.is given in our Post on Solar Photo Voltaic.

For a trouble-free performance and optimized output of a Solar Photo Voltaic Power Project the initial due diligence is of prime importance. It is especially useful for a long-term reliability and stable performance. With improving affordability of Solar Photo Voltaic it is no surprise that India shall continue to witness an upsurge in the number of Solar Photo Voltaic Power Projects in the times to come.


Is Solar Energy (PV) really affordable?

The most frequented question we come across is whether Solar Energy is affordable. Affordability comes into picture with 2 aspects - Need and Alternative. The need aspect is about the need for stable electrical power. While the alternative aspect is the grid power - in case there is a grid or alternatively DG Sets.

Looking at the Need aspect first- electrical power is a basic requirement for anyone and everyone. Especially for a growing Country like India more power would be needed with increased affordability. Nearly 40% of the household are without power today and the peak deficit is in the range of 12-15%. Let alone power availability many of the rural areas are not even electrified. So then if all the areas are electrified the peak deficit could be a much higher number. So the need for electrical power is certainly there - in semi urban areas which suffer from blackouts / brownouts and rural areas where there is no electrification at all. In fact even some of the Tier-1 cities (except Mumbai) suffer power problems especially during Summers. There is certainly a growing need for power and stable one at that.

Subsidy by Govt. in Solar Power Plant

There is a huge subsidy in chhattisgarh on solar power equipments / systems. Central Govt. is providing the subsidy of Rs. 81.00 per watt to the beneficiaries of solar power plants. Also the govt. of Chhattisgarh State is also providing a handsome subsidy of Rs. per watt to the solar power plant beneficiaries. for the financial year 2012-13. After these subsidies  the beneficiaries of solar power plants will have to bear the balance amount of Rs. 40000.00 per kw. as a beneficiary share.



With regards to Alternative - what exactly is alternative to Solar PV? Wind? Biomass? Hydro? All of them have some or the other issues and that is precisely the reason Solar PV scores above all of the renewable technologies. If one is resistant to changing over from grid power to Solar PV then we suggest that Solar PV is not a replacement for grid but complementing the grid power. With soaring Diesel prices + pollution + maintenance + operational costs people have now realized that DG sets are not a good power option. In fact cost of power generation from Solar PV is much lower than that from DG set.

Antagonist of Solar PV also suggest that Solar Energy cannot work without subsidies or Government incentives. Nothing else can be farther from truth.  Solar PV can easily survive without subsidies or incentives. How?


Consider the following :
Solar PV is one-time investment and the prices have come down significantly.
There are nearly zero or no-maintenance cost associated with Solar PV.
Solar PV critical components have a life of 20-30 years.
Grid power prices are on the rise with another recently announced another rise of 33%.
With increased awareness about benefits of Solar PV the demand for PV is expected to rise further resulting in further reduction in PV Project costs.
The bottomline - Solar Photo Voltaic is truly affordable. It may have already been affordable in some areas where grid power price is quite high. Or for some of the Industries or Commercial Complexes where DG set is being used. As the Government subsidy is quite attractive any incentive or subsidy should be considered a boon for the project maximizing returns and minimizing payback period.



What is Solar Energy?


Solar Energy is one of the most talked about Energy sources in the Global Energy scenario especially in European and North American regions. A Solar-rich Country like India cannot be far behind and the interest is certainly picking up.

The term Solar Energy is frequently used to refer to Solar PV Power Projects. Although Solar Energy is a broad term and consists of Solar Thermal Energy and Solar PV Energy. Amid all the discussions, curiosity, hypes, myths etc. the attention or focus is generally more on the negative aspects and doubts on Solar Energy especially on Solar Photo Voltaic and its applicability. In this post we attempt to answer some of the most Frequently Asked Questions (FAQs) on Solar Energy especially on Solar Photo Voltaic. (You are free to post your queries or views in the comments section below).

(a) Can Solar Energy work across all the locations in India?
Yes, Solar Energy is suitable for most parts of India as can be seen in the Solar radiation map. The main focus is on Solar radiation for which GHI and DNI figures are used. As can be observed in the Solar radiation map these figures for India ranges from 4.0 to 6.5 or more and is thus much better than global average. The output (kWh / Units) for Solar Energy Power Project will vary  from location to location but is in general very good and hence Solar Energy is certainly a workable option across India.
 See the solar system installed at tribal boys Ahram Chendradadar, Block- Bodla, District- Kabirdham by CREDA. This system was sanctioned in year 2010-11 by the BRGF scheme of Govt. of Chhattisgarh.

Battery Bank Installed at control Room
Rating voltage of each battery - 02 volt, 600 AH
system design at 48 volt 

SPV Modules Installed at roof
Cap. of Solar Power Plant- 03 KW.
Cap. Of each Module- 300 Wp.

 (b) Can Solar Energy work without a battery backup?
Yes, Solar Energy can work without battery backup. Batteries are not necessarily needed for backup unless the Photo Voltaic project is used for feeding power to a setup or a complex or households in a rural area which have no grid connectivity at all. As such Solar Energy is a broad term and if it refers to Solar Thermal energy Power Project then backup for thermal energy storage is needed. It is no wonder that Solar Photo Voltaic is gaining more popularity than Solar Thermal due to its simplicity, ease of operations and excellent life (25-30 years).


(c) Can Solar Energy work in the rain or foggy conditions?
Yes, Solar Energy can work in the rain. There are 2 types of radiations that Solar Photo Voltaic works on - Direct Radiation and Diffused Radiation. During the rainy season or foggy weather diffused radiation is still available although direct radiation would be reduced. During such times the output may marginally drop a bit. In fact Kawardha (Chhattisgarh) which receives good annual rainfall is where CREDA has installed 49 no.  of  Solar power plants in Remote villages whose total cap. is 57.5 kw. as well as CREDA has installed 56 no. of Solar power plants in Tribval/ Ahram /  Hostels , 14 in Primary health centers and many more solar pumps ( 62 no. of 900 wp cap & 13 no. of 1800 wp cap. ). as well as many systems of various capacities have been installed in urban areas also. It indicates that at every season importance of solar power is much needed. And the beneficiaries are also going to interact with solar and other renewable energy sources.


(d) Is Solar Energy really affordable?
Solar Energy - specifically Solar Photo Voltaic is indeed quite affordable. Primary reasons are significant fall in Photo Voltaic Solar prices and consecutive increase in grid prices.




(e) Does Solar Energy require a huge area?
Not really. Area required for Solar Photo Voltaic Power Project varies from 3.5 Acres to 7.5 Acres per MW of Installation depending on Technology. Considering the fact that Solar PV does not require active involvement or water for operations the sites can be in far-off locations. There is indeed a huge availability of arid land which is otherwise un-utilized and can be effectively utilized for PV Solar Power Projects. In case of Industrial plants huge rooftops can be utilized for installation of PV Solar Panels.


(f) Does Solar Energy using PV technology rely on temperature for operations?
Solar Photo Voltaic works on Light energy of the Sun i.e. when Photons strike the Cells within the PV Modules - they let the electrons loose which then flow in one direction generating electrical power in the other direction. It is depicted in the diagram in this post. Hence PV does not rely on temperature for its operation. However depending on technology the output may vary a bit at extreme temperatures.
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