Code No:TMS066Price:1000Category:Energy: Generation
Summary:The scope of the study is to assess the viability of various technology options available to India in photo-voltaics for rural applications and assess their market within existing constraints.
The various technological gaps observed and the recommendations are given. Also the action plan for bridging the technological gaps among implementing agencies is recommended.
Year of Publication : 1993
Table Of Contents :
- Executive Summary
- Product Profile
- SPV systems
- Current Technology Status
- Current Support infrastructure
- Problem Areas
- PV Technology Evaluation
- PV Market Prospects
- Recommended Action Plan
Sources of Information.
CURRENT TECHNOLOGY STATUS
Cells : There are currently 7 alternative solar cell technologies that are under development internationally. These can be categorized into non thin film and thin film. The non thin film will include concentrator, wafer silicon, grown silicon sheet and deposit silicon sheet. The thin film category includes single junction amorphous silicon, multi junction amorphous silicon and poly crystalline thin film based on cadmium and copper indium diselinide.
Spectacular developments have taken place in solar cells over the year resulting in increased efficiency and lowering of cost internationally. Out of the various technologies crystalline silicon (single crystalline and multi crystalline) and amorphous silicon have been commercialized.
The developments in single crystalline have reached a stage where efficiency of 24% have been achieved on small area cells. The most advanced developments is in the form of PERL (Passivated emmiter rear locally diffuse) cell. The other promising developments relate to the concept of laser grooved buried contact cells. On commercial scale, the cell efficiencies of 14% and above are routinely attained internationally. Against this the developments in India have achieved commercial efficiencies upto 11 to 12%.
In the multi crystalline cells, the highest efficiency achieved till date is of about 17.8 % (2x2 cm area) using high quality cast sub strates. In India multi crystalline cells of acceptable quality are not yet manufactured.
Amorphous silicon technology developments have revolved around quality manufacturing technology, low cost production and improvements in cell reliability. High film production type of machines have resulted in almost continuous feed throughs of the substrate materials. Single junction cells have reached efficiencies of 12 to 12.5% in small areas and 10.5% (on 30 x 40 cm). multijunction devices have reached efficiencies of 13.7% and large sub modules have surpassed 9% efficiency levels. Currently starting efficiencies of 10% after degradation can be realized on stacked cell structures. Panel efficiencies on commercial scale are available with stable efficiencies of 6% . In India the module efficiency on pilot scale have indicated efficiencies of 5%.
In poly crystalline thin film cells, the most advanced candidates at present are cadmium telluride and copper indium diselinide. The highest total area efficiency of 13.6% (1.08 sq. cm) has been achieved on cadmium telluride internationally. In the case of copper indium diselinide the highest active area cell efficiency of 14.1% has been reported (3.5 sq. cm). in India the developments are in very nascent stages.
For concentrator cells research results have indicated efficiencies of 34% for mechanically stacked GaAs-On-GasSb cells operated at 100 X. In silicon concentrator cell development, stable efficiencies of the order of 26%have been achieved at 100x (1x1.2 sq.cm) important progresses have been made in the development of concentrator components. The latest developments is in the design of point focused concentrator modules. In India the researches in concentrator cells have been minimal upto now.
Tremendous advances have been reported in tandem cell structures with noticeable efficiency improvement compared to their single junction counterparts with efficiency increase of above 15 to 17%. One of the new developments reported is in the area of spheroidal solar cells which may result in low cost cell. Current efficiency achievements are reported at11.3% efficiency.
BALANCE OF SYSTEMS : the most important BOS (Balance of systems) in SPV is electronic BOS. Internationally very reliable electronic BOS are available based on solid state circuitry and programmable microprocessor based systems with several features. The Indian electronic BOS are most prone to failures due to unreliability of component quality, lack of proper design features and poor tolerances.
STORANGE SYSTEM : In batteries, internationally various new kinds are being developed with minimum of 10 years life time, total maintenance free operations, high energy efficiency and deep discharge characteristics. These technologies are in the advanced stages of development. In India the use is mostly made of lead acid storage batteries. Some manufactures have recently come out with deep discharge tubular plate industrial battery version for PV applications. However, these do need frequent maintenance. Back
The current total international PV market is estimated at approx. 46.5 MW with an average annual growth rate of 15% during the last couple of years. The percentage contribution by different countries is as follows :
% Share by countries
The major contribution in others category came from the two Indian manufacturers constituting 36% of its total share.
Single crystalline PV based modules constitutes the major share. The share by various technologies is as follows :
% Share by Technologies
|Ribbon and concentrator||0.2|
The market for single crystalline silicon though currently maximum has declined countinually over the years. On the other hand, the market for multi crystalline cells have increased during the same period. The market for amorphous silicon seems to be saturating at the current level.
Among the countries, USA has dominated single crystalline module market by making almost 44% contributions to the global shipment whereas the amorphous silicon market have mainly been dominated by Japan accounting for over 73.5% of the total shipment.
Currently stand alone PV applications constitute the largest market share among various applications in USA where as in case of Japan, the consumer market have a major share of 56%. The Government sector demand accounts for less than 8% of the total demand both in USA and Japan.
In India the current total off take of PV systems is around Rs. 50 crores constituting almost 1.2 MW. Over the last 3 to 4 years the market has remained virtually stagnant. Almost 100% market share is for single crystalline based technology. The current market is dominated by demonstration market rather than commercial or consumer market. The Government’s sponsored projects constitute the major application of PV systems constituting almost 75% of the total requirement or even more. Most of the PV applications in India are for stand alone systems for rural areas basically for rural electrification, water pumping, domestic street lighting and decentralized consumer power packs. The consumer segments of PV market has so far been neglected.
CURRENT SUPPORT INFRASTRUCTURE:
Majority of the solar cells are being manufactured by public sector organisations in India, namely, Central Electronics Ltd., and Bharat Heavy Electronics Ltd. The current total capacity is 2.5 MW for crystalline silicon cells. Several private organisations have now moved in areas of cells, modules, system integration, installation and commissioning of PV systems. BHEL has recently set up a pilot plant facility for manufacturing amorphous silicon cells with a capacity of 500 KW peak per shift per annum.
In the case of storage batteries, there are 3 major private sector lead acid storage batter manufactures who have now started offering tubular plate lead acid batteries for PV applications. There are also 2 or 3 nickel cadmium cell manufactures in India.
In the area of BOS a number of small and medium scale private sector firms are involved but they lack considerably on technical grounds particularly in electronic BOS.
In case of raw materials about 70% of crystalline wafers are imported. In addition, poly silicon CZ ingots are also imported to an extent. Metkumn is the major raw material supplier in India with a current capacity of 60,000 wafers per month.
Number of module materials are also not manufactured in India including EVA, toddler, high transitivity glass, crane glass, interconnects and consumables for wafers and cell manufactures.
For modules and system tests there is no uniform criteria followed at present. BIS has initiated the activity of establishing standards for PV covering the entire field including soalr cell, the modules and its interface with electrical systems to which energy is supplied. Among the several product development activities that have been incorporated include small size modules, foldable modules, compact flouroscent lamps, use of maximum power point, tracking system, improved module packing densities and use of high efficiency submersible pumping systems.
There is big programme sponsored by Government for demonstration of PV application in rural areas. The programme is monitored by DNES and its supporting agencies.
PROBLEM AREAS :
The major problems in widespread diffusion of PV technologies can be summarized as follows :
1. Lack of commercial viability for various applications.
2. Far too small a semi-conductor industry leading to small production capacities of poly silicon and thus higher prices.
3. Lack of infrastructure for module materials, leading to lower efficiencies of cells and modules compared to western countries.
4. lower average yield
5. Poor quality and reliability of BOS systems components.
6. Lack of site specific approach to the engineering design of SPV systems
7. Small product range offered by Indian manufacturers compared to international range.
8. Lack of uniformity in testing and monitoring of most of the PV systems in India.
9. Use of sub standard components leading to unacceptable performance in the field.
10. Poor commercial marketing network base
11. Near negligible after sale service set up.
12. Poor coordination between various agencies etc. Back
TECHNOLOGY EVALUATION :
By Cells Types : The present supremacy of singe crystalline silicon based solar cell technology in Indian context is beyond any doubt. For various technical, economical and commercial reasons, it appears that the single crystalline silicon based solar technology is going to remain dominant in India for quite some years to come. The multicrystalline technology may be able to act as a stong supplement to single crystalline technology.
The promising area of amorphous silicon solar cell is still to solve many scientific and technical problems associated with its use. For all other technologies, not much work has been done in India upto now even though they hold lot of potential.
By applications : The major applications for PV systems in rural areas can be categories into :
1. Pumping - irrigation and drinking water supply
2. Lighting - Street lighting and domestic lighting etc.
4. Small scale industries
5. Health - refrigeration and health centers
7. Consumer applications
8. Central power supply
9. Other miscellaneous
the viability of PV system in comparison to other sources of power (both conventional and non conventional) on various technical, economical, social and institutional is described in detail in the report. Broad conclusion are summarized in the table.
TECHNO-ECONOMIC EVALUATION PV SYSTEMS –RURAL APPLICATIONS
Readiness for PV
PV systems cost effective for loads upto 2.5 KWh/day for most location. PV/diesel hybrid may be effective upto 10 KW/h day.
|First choice in
|The overall cost per dose is cheaper for the PV refrigerator even when the initial capital cost is 3 to 4 times higher. Also it is highly reliable compare to kerosense.||First choice in circumstances.|
|Drinking Water||HAND PUMP DISEL PV ANIMAL||
PV systems are economical in remote areas
a) 15 meter water table with population of 1000 or to break
|First choice in many circumstances. Close to break through in large markets.|
|Small lighting-Lanterns||PV KEROSENE||Based on life cycle cost per kilo lumen hr. the solar lantern can be 30% more economical than kerosene lamp at the current price.||First choice in many circumstances|
|Stand alone Domestic power||PV
|Economically viable on long terms cost benefit analysis in areas which are difficult and inaccessible for diesel supply.||First choice in many circumstances.|
|Irrigation Pumping||DIESEL, ELECTRICAL, BIO GAS/DUEL FUEL, PV, WIND, SOLAR THERMAL||PV pump is competitive with diesel in remote areas where the volume head trouble is less than 1000m4. Quite suitable for trickle irrigation or low water crops like fruits etc.||
First choice only in some circumstances Break through shall need few years development
|Centrlalised Village Electric Supply||GRID
|Generally too expensive for large scale implementation cost now to come down by 50% to below acceptable. PV is economical for loads upto 3 KW at a distance of 6 to 20 kms from substation. For larger loads (10 kw). PV is economical at a distance of 60 kms.||First choice in some circumstances|
MARKET PROSPECTS :
The market prospects for PV is not easy to determine. The main factors influencing the market are as follows.
1. World wide technology / price trends, its impact on prices and its diffusion in India.
2. Government motivation / incentives /financial support.
3. local manufacturing capability base available in cells as well as systems and raw materials.
4. institutional development support in terms of technical development / regulatory aspects training and information feed back.
5. Market infrastructure and application engineering support
6. Comparative system viability and reliability aspects
7. Users perceptions, attitudes and adoption trend
8. Growth in rural economic structure.
Based on the estimates available by studies carried by expert groups, the world market forecasts are available for two different price scenario (high and low). The expected world market will be as follows:
PROJECTIONS OF PHOTOVOLTAIC PRICES AND
SALES 1987-2000 (1987 US$)
LOW PRICE SCENARIO
HIGH PRICE SCENARIO
INDIAN MARKET PROSPECTS
The share of Indian shipment in the world shipment has generally been in the range of 2.5% to 3.5% in the past several years as indicted in the table in the next page.
From out understanding of the various market influencing factors we can come to one clear conclusion that in India at least in the 8th Five Year Plan (1992-1997) we would not see a very rapid improvement in the present situation despite ambitious targets and proposals.
Based on the assumptions as discussed in the report it is expected that Indian shipment would be around 2.5 MW in 1995 and 6.25 MW in 2000 AD (assuming the high price scenario and share of 2.5% in the world PV market). The low price scenario which is most unlikely in case of India may result in a requirement of 7.5 and 125 MW by 1995 and 2000 AD respectively.
INDIAN SHIPMENT VS WORLD SHIPMENT
|YEAR||WORLD SHIPMENT MW||LOCAL SHIPMENT KW||% SHIPMENT|
The actual demand will depend upon coordination and active participation of number of key players including industry, researchers, users, investors, policy makers etc.
REAL MARKET POTENTIAL – INDIA
The actual market potential for PV technology is substantial which is not obvious from what we have projected above. An idea of actual market potential can be had from the actual power need requirement of the rural areas which is not reflected in the above estimate. The market potential for various rural applications is summarized in table below. The actual market will depend upon the penetration that PV would be able to make to get its share in the total power requirement. It is expected based on market evaluation studies that the penetration of PV would be maximum for telecommunication applications followed by refrigeration and provision of clear drinking water for rural areas etc.
MARKET POTENTIAL AS IT WILL EXIST IN (1992-1997)
Total* S.No. Application 1992-97
Potential (MW) prices
|penetration at current|
|1. Village street lighting||80||0 – 2 %|
|2. Irrigation pumping||12500||0 – 2 %|
|3. Drinking water||8||2 – 5 %|
|4. Domestic connections||600||0 – 2 %|
|5. Village industries||1000||0 – 2 %|
|6. Refrigeration||4||5 – 10 %|
|7. Rural health centers||20||0 – 2 %|
|8. Rural telecommunication||1670- 80 %|
|9. Solar lanterns – Households||355 – 10 %|
|10. Evaluation -lighting||7.5||0 – 2 %|
* only penetration will create demand Back
1. Need for providing continuing long term support in terms of technical development, R & D, information and dissemination, training, demonstration, financing and market support etc.
2. Establishment of appropriate organisation structure and coordination linkages between various agencies.
3. Implementation of innovative long term finance-cum-leasing support for the use of PV systems in rural areas.
4. To review the policies and programmes of rural electrification through reflecting the real cost of providing electricity.
5. Need for reforms in the methods of granting subsidies.
6. Creation of favorable business environment through direct marketing approaches.
7. Need to change the system of Governments promotion effort by prompting the nodal agencies to buy complete system from one agency.
8. To organize financial arrangements of PV systems similar to hire purchase schemes.
9. Need to put in vigorous R & D & technology development in multicrystalline solar cells.
10. Setting up of a pilot plant for polycrystalline thin film cells.
11. Expansion of research and development in the end use devices.
12. Need for correct site specific approaches to the engineering designs.
13. Need to improve the quality of BOS and other components.
14. Ensuring a satisfactory after sale service.
15. Disemination of procedures for routine maintenance among actual users.
16. Laying down of minimum standards for various PV systems.
17. Establishment of National PV Test center.
18. Institutionalizing systems for feed back from users.
19. Removal of import duty o module materials.
20. Equal emphasis on both rural and urban markets.
21. Scutinise the PV products based on long term life cycle cost concepts.
22. Introducing in order of priority the following PV systems
3. Drinking water