WIND ENERGY

1.         Can Wind mills be set up in any place for power generation?

            No, Wind mills can be installed only at specific locations which have adequate wind potential. The relevant indicators are mean wind speed of 18 kmph or above and mean wind power density of 150 W / m² at 30 m height or 200 W/m² at 50 m height

2.         which are the potential locations in Tamil Nadu ?

41 potential locations have been identified in 8 districts in Tamil Nadu so far through wind resource surveys.

3.         Are there different  types of wind mills?

            Yes, There are two types of wind mills

1. fixed speed asynchronous induction generators and

2. variable speed synchronous machines.

The latter is particularly suited for Indian wind regimes and site conditions.

There is also another classification which are as follows :

1. Wind mills with Horizontal axis

2. Wind mills with Vertical axis

The most common types of wind mills are horizontal axis.

4.         What are the various capacities at which wind mills are available ?

The wind mills with following capacities in kW are at present in the manufacturer’s range : 225,250,350,400,500,600,750,800,950,1000, 1250, 1650 and 2000 kW.

5.         What is the investment required for 1 MW ?

            Investment required for 1 MW is Rs 4.50 – 5.00 ( approx ) including cost of land.

6.         What is the extent of land required for a wind mill ?

            The land requirement is 20 to 25 acres per MW depending upon the capacity of wind machine i.e. smaller capacity machines need more land while large capacity machines will need lesser extent of land.

7.         Can the power generated from wind mills be sold to TNEB or used for Industries?

            The power produced from wind mills in potential areas may be fed to TNEB grid or can also be used for captive purpose by Industries in locations within Tamil Nadu by paying wheeling charges of 5 % to TNEB. The power produced during a year could also be used by industries till March under banking facility for which additional 5 % is payable.But for captive use, the power generated can be used within the financial year (upto March ) by paying banking charges.

8.         Can the power be generated throughout the year ?

       No, power could be generated only for 5 - 6 months in a year depending upon location.

9.         Are there wind mills suitable for smaller power loads ?

Small aerogenerators upto 30 kW are available which can be used as stand alone type generator to produce electricity for captive use. It can be installed in places where the wind speed is in the range of 15 to 18 kmph and more.

10.       Can wind mills be used for other than power generation ?

Wind mills can be used directly for pumping water without the need to produce electricity and run the motor & pump. Two types are available – Gear type which can operate even at a wind speed of 9 kmph and the other, non-gear type will operate better at higher wind speeds of about 18 kmph.

SOLAR  ENERGY

SOLAR WATER HEATING SYSTEMS

1.         What is a Solar water heating system & how does it work?

            The system that converts cold water into hot water making use of heat energy from sun is called solar hot water system ( SHWS ). The metal tubes absorb thermal energy from sun and heat up the water. This water lesser in density moves up while cold water rushes down to fill metal tubes. The heated water moves up wards and gets collected in the storage tank.

2.         What is the maximum possible temperature which could be attained in  SWHS ?

            It could attain a temperature of  60^°  to 80^° C. The rise in temperature however depends on the extent of solar radiation, weather conditions, efficiency of solar collector system etc.

3.         Can we install the system anywhere?

            Yes, it can be installed any where in the building such as roof tops, terraces, open grounds etc. without shades.

4.         How should the system be installed ?

1. South orientation of the collectors for better solar radiation

2. Collector tilt should be 15^° over latitude.

3. The Over head tank for cold water should be above SHW system for smooth flow of water.

5.         Does it generate hot water on all days and in all seasons of the year?

            It generates hot water on all clear sunny days. On partially cloudy days, it can reach moderate temperature except rainy or heavily overcast days. It can be used on an average of 300 days in a year.

6.         Can we use any type of water such as treated water, bore well water or  tank water?

1. it is desirable to use soft and potable water

2. Hard water can also be used with heat exchanger arrangement

7.   Are there different types of SWHS in use?

• There are presently two types of systems in use- one based on FPC (Flat Plate Collectors) and the other on ETC (Evacuated tube Collectors).  The life of FPC based system is generally 15-20 years.  ETC based systems are relatively new and more useful in colder regions.  The life of the system may be less since the collectors comprise glass tubes which are fragile.

8.      Are there different types of solar collectors? If so, how to select the best  one ?

• Yes, good solar collectors are made of high quality materials for a longer life,  say 10 – 15 years with good workmanship      

• Good collectors should have high efficiency of conversion

• Improved glazings are used for better transmittivity ( 92 % )

• Black chrome selective coating over copper absorber / fins is essential to achieve higher temperature and better efficiency. As ISI standards are available, collectors with ISI markings are better than others.  

9.         How many days in a year can hot water be obtained and how about the          rest of the days ?

            Every SHWS can give hot water for about 300 days. These systems are provided with electrical back up heating systems to cater for during inadequate solar radiation period

10.         Are there any government incentives, subsides, loans etc., ?

MNRE provides the following:

1. Soft loans from IREDA and other banks/ financial institutions can be availed

2. 80 % accelerated depreciation for profit making companies, if soft loan is not availed

3. Equivalent capital subsidy available for registered institutions and commercial establishments not availing the loan

11.       What is the initial cost of a solar hot water system & how about maintenance cost ?

a) Domestic System  ( 100 LPD at 60^° C)                                  : Rs 12 500 /- to 15 000

b) Non domestic System   ( Temperature range 60^° C to 80^° C )  : Rs 120 /- to 140 per LPD

            Maintenance is minimal since the system requires only periodic cleaning of the glass sheet and checking for leakages and functioning of valves.  

 SOLAR COOKERS

1.         How do the Solar Cookers work ?

Solar Cookers absorb the heat by reflecting or concentrating the solar radiation directly for cooking or by producing steam which is used for cooking on large scale.

2.         What are the advantages of solar cooker ?

1. No fuel is required and thus saves on recurring fuel cost

2. Hygiene and quality of the food is maintained

3. There is no fire hazard nor damage to vessels.

3.         What are the various types of solar cookers available ?

1. Box type for cooking upto 5 persons

2. Dish type for cooking for 10 to 15 persons

3. Scheffler model for about 50 persons

4. Solar Steam model to cater for any number of persons

4.         What is the probable saving in the use of solar cookers ?

            The saving interms of LPG normally used for cooking, will be in the range of 20 to 40 % depending upon the type of cookers used.

5.         Whether all types of food items can be cooked in a solar cooker ?

            In the case of Dish type ( Scheffler model ) Solar cookers, all items can be cooked including roasting, frying and boiling where as in box type cooker all items except frying or chapati making can be cooked.

6.         What is the time required for cooking ?

In the case of Dish type and scheffler model, 1 to 1½ hours will be required for cooking a meal time. For Box cookers, 2 to 3 hours will be required. 

7.         What can be done during rainy days ?

            In the case of Box cooker, a back up electrical heater can be provided inside. In the case of others, conventional cooking system, oil fired boiler / conventional steam generation system should be available on hand to meet the requirements during rainy days.

8.         Is any subsidy available for Box type cookers ?

            No capital subsidy is available. However interest free loans are made available through select nationalized banks.

9.         What assistance is available for other types of cookers ?

           30 % subsidy subject to a maximum amount is provided by MNRE for Dish type and other bigger models for which the subsidy will be sanctioned on case to case basis.

10.       How the above assistance can be availed ?

            The user may contact any one of the manufacturers as per MNRE list given in this website, who after study of your requirements will make the proposal for suitable type of cooker with his consent / commitment to meet the balance cost. They will send the proposal to TEDA, who after scrutiny and examination will recommend it to MNRE for sanction of assistance. On receipt of sanction, it will be communicated to the user.

SOLAR AIR HEATING SYSTEMS (SAHS)

1.         What is a solar air heating system and how does it work ?

The system consists of an absorber plate and metallic plate or glass cover. The air flows through the gap between them, when it gets heated up while the absorber plate absorbs the heat. The hot air is drawn through the plates with a blower which is operated electrically.

2.         What will be the temperature of the hot air from the system ?

It will be in the range of 60 to 80°C depending upon solar radiation. The hot air could be used for total energy delivery for low temperature applications while it could be used as partial energy delivery or preheating for higher temperature.

3.         What are the possible applications / uses ?

1. Drying of agro and allied products, food items like fruits, vegetables, chillies, tea-leaves, fish, salt etc.

2. Drying of processed leather, ceramic, chemicals etc.

3. Hot air required for process heat applications in industries.

4.         What are the advantages of using SAHS ?

1. Can save in fuel cost to the extent of 25 % or more depending upon the nature of fuel replaced.

2. Can ensure uniform heating, better quality of dried products and get better price

5.         What is the cost of the system ?

The system with a collector area of 100 sq.m costs about Rs. 6.00 lakhs. The saving can be in the range of Rs. 1.5 lakhs to Rs. 2.5 lakhs per annum depending upon the fuel replaced and intensity of solar radiation and the duration of sun shine at site.

6.         How are the systems installed ?

            The systems will have to be designed based on the site conditions and the heating requirements of the products and maintained as per the instructions of the supplier

7.         What are the purposes for which SAHS have been used so far ?

            SAHS have been installed so far for the following purposes :

1. Preheating of air for tea drying

2. Chillies drying

3. Coriander seed drying

4. Fish drying

5. Coffee beans drying

6. Leather drying

7. Salt drying

8. Cloth drying

9. Dal processing

10. Fruits and Vegetables dehydration

8.         Is there any problem in the operation of the unit ?

No problem has been reported so far.

9.         What is the potential available for solar air drying / heating ?

The SAHS can be used in many industrial activities ( drying / heating ) such as chemical, pharmaceutical, bulk durg, limited areas of textiles and hosieries, tannery, edible oil etc.

10.       Is there any financial assistance available for installation of SAHS ?

At present subsidy is given by MNRE upto 50 % cost for non- profit institutions and 35% cost for commercial and industrial organisations subject to a maximum limit.The availability and other details regarding subsidy will vary from time to time. The correct details may be obtained by contacting TEDA office.

SPV LIGHTING SYSTEMS

1.         How does a solar lighting System work ?

A solar lighting system consists of a photovoltaic module, which converts solar radiation into DC electricity, a battery where power is stored and an inverter which converts power as AC electricity and the loads such as lights or fans.

2.         What are the different applications and its cost ?

1. Solar lantern – a portable light and costs about Rs. 3,000/-

2. Home lighting system - a fixed, indoor lighting system - Available in various configurations, namely, 1 light, 2 lights, 1 light + 1 fan, 4 lights, 2 light + 1 fan Costs vary from RS. 7,000/- to Rs. 25,000/- depending upon the model.

3. Street lighting system – for outdoor use – costs about Rs.22,000 to 25,000/-

3.         How many hours can it be used ?

Solar lanterns and home lighting system  can work for about 4 hours daily, and  street lighting systems with automatic ‘ON’ and ‘OFF’ can work for 10-12 hours daily if the battery is charged regularly.

4.         Will the systems work in rainy days ?

The system is designed to work with 3 days autonomy, i.e., when charged fully, it can work for 3 days without fresh charging. However, in cloudy / rainy days, modules can absorb diffused light and can charge the battery which can serve for lesser hours.

5.         Whether the rain water will affect the module ?

            Modules are fixed in the open since they have to face the sun. But rain water will not affect the working of the module, since the actual conversion of sunlight into electricity is done by the solar cells placed inside the module which is sealed and made water proof.

6.         How should the solar module be fixed in the open ?

            The solar module should be placed in an open area, preferably on the roof top, slightly inclined and facing north / south. The module is connected to the battery through a cable of about 5 metre length or as may be required.

7.         What type of battery is used ?

The batteries used are of tubular, deep discharge, electrolyte, low maintenance battery for home lights and street lights unlike car battery, which is designed for low discharge. In the case of lantern, the battery is provided inside and sealed and so it is called maintenance free battery.

8.         What is the proper system of maintenance ?

            Maintenance is very negligible except for topping of the battery periodically using distilled water once in two months in the case of tubular battery. The module may be cleaned with a wet cloth to remove the dust once a week to ensure proper charging of the battery.

9.         What are the uses of solar PV lights ?

Solar lights could be used for a variety of lighting purposes in houses, offices, factories, gardens, parks, streets etc. They are also very useful in remote places for domestic lighting where grid (EB) supply is not available.

10.       Is there any subsidy available for installing the solar PV lighting system ?

Subsidy upto 50 % of specified cost has been provided by Ministry of New and Renewable Energy  subject to a maximum limit.

SOLAR PV PUMPS 

1.         What is a Solar Photovoltaic ( SPV ) water pump ?         

            A solar PV Water Pump consists of a Photovoltaic array mounted on a stand, and motor pump set compatible with the photovoltaic array:

As the sun’s rays falls on the solar module D.C electricity is generated and is used to run a D.C motor pump set or an A.C motor pump set. AC motor requires an inverter.

2.         What are the different types of solar pumps  ?

The different types of pumps are  :

(a)     D.C. surface centrifugal pumpset

(b)     D.C. submersible pumpset

(c)      D.C. floating pumpset

(d)     A.C. submersible pumpset

(e)     Any other type of motor – pump set, as approved by MNRE 

3.         What are the advantages of solar pumps ?

            Solar pumps operate on solar energy available free with nature, and thus save expenditure on diesel or electricity.

• The cost of operation and maintenance of solar pumps is negligible

• Useful for water pumping in remote areas without grid power.

4.         What are the capacities at which solar water pumps are available and what is the average discharge ?

            Solar Water Pump are available with a Photovoltaic array capacity upto 3000 Watts (2 hp). The capacity of the PV array (Watts) and the pump (hp) will be decided based on the depth of water table at site and the quantity of water required for use. The average discharge rate that can be obtained for different capacities are given below :

·       Discharge from the pumps will vary depending upon the intensity of the sun rays from morning till evening. It would be maximum around noon time and if the depth of water table is low.

5.         How much area can a system irrigate ?

            Solar water pumps of 900 Wp capacity, can irrigate the following extent of land for different crops :  

 

7.         Is there any loan facility available?

            Yes, soft loan is available ( upto 2004 – 05 ) @ 5 % interest per annum through Indian Renewable Energy Development Agency Limited ( IREDA ). The maximum amount of soft loan available will be upto 90% of the unsubsidized part of the SPV water pumping system. The loan is channeled by IREDA through their intermediaries such as TATA BP Solar India Ltd., Bangalore. In case MNRE financial assistance ( subsidy ) is not availed, the loan amount can be upto 90% of the sale price of the system.  The principal with interest is repayable in 10 years ( Including one year moratorium).

8.         Is there performance guarantee for the solar pumps ?

            Yes, PV Arrays are supplied with performance guarantee for a period of 10 years.  Motor pump sets and accessories are supplied with a guarantee for a period of one year only. Users can enter into AMC thereafter for pumpsets and accessories.

9.         Will the solar pumps work during cloudy days

            The pumps will run even when it is cloudy but the discharge will be less depending upon solar radiation at the site; but if it is dark due to thick clouds, the water discharge may be very poor.

10.       How do we ensure proper maintenance ?

            SPV panels have to be cleaned periodically to remove the dust on the surface once in 2 or 3 days so that the sun’s radiation could be fully utilised. Maintenance of the pump should also be taken care of and Annual Maintenance Contract ( AMC ) may be entered into with the supplier for trouble-free service of the pump after the initial guarantee period.

Minimum amount of spare parts for the pumps and other systems are also supplied along with the solar water pumps for trouble - free operation for a period of 3 years.

BIOENERGY

POWER GENERATION FROM BIOMASS

1.         What are the different ways of power generation from Biomass ?

Power is generated from biomass mainly in two ways viz.,

1. Bagasse based co-generation ( in sugar mill )

2. Combustion based power generation

2.         What are the feed materials required ?

Biomass is broadly classified into the following three main categories.

Field level residues          - Paddy straw, stalks of various crops etc.

Plantation crop residues  -  Coconut residues like fronts, stems, polmyrah tree residues etc.

Agro industry residues    -  Rice husk, coconut shell, groundnut shell etc.

3.         Is there any assessment study carried out on the availability of Biomass  materials in Tamil Nadu ?

Yes, TEDA carried out detailed surplus biomass availability studies in 49 Taluks based on which the total potential is 228.8 MW. The district level biomass assessment study has also been carried out for the entire state of Tamil Nadu. The draft report is under finalization by MNRE.

4.         To what purpose biomass based power projects can be set up ?

The biomass based power project can be set up either for investment purpose by exporting to TNEB the entire power produced or for captive use in industries at lower cost than fossil fuels.

5.         Where are the Biomass based power projects in operation in Tamil Nadu ?

5 Projects with total capacity of 72.5 MW are in operation in the State.

6.         What action has been taken to set up more biomass based power projects    in Tamil Nadu ?

Govt. of Tamil Nadu have formed Standing Committee on Biomass based power projects headed by Chairman and Managing Director, TEDA.  Based on the recommendations of the committee 15 projects of total capacity of 126 MW are in the progress and 12 more (125 MW) in the pipeline.

7.         What is co-generation ?

Generation of steam at high pressure for power generation in turbines and subsequent use of the same at lower pressure for process heating applications is termed cogeneration.

8.         What is the present capacity of power from co-generation in Tamil Nadu ?

The total installed capacity of co-generation of power in 3 co-operative and 16 private sugar mills in Tamil Nadu is 337 MW as on 31.3.2007. The exportable surplus power capacity to the grid is 194 MW, which is about 30 % of the capacity in the country. 

9.         What is the cost of Co-generation plant  and how much power can be             produced from a typical sugar mills ?

            The tentative cost of co-generation plant is Rs. 3.5 to 4 crores / MW.

            A sugar mill of 2500 TCD can produce 15 MW of power.

10.       Whether the surplus power can be sold to TNEB ?

            Yes, the surplus power can be sold to TNEB and earn additional revenue for the sugar mills.

WASTE TO ENERGY

1.         How wastes are generated and which of them are suitable for energy recovery ?

Generation of wastes both in the solid and liquid form is associated with industrial and other activities. Solid wastes include household wastes, city garbage and industrial wastes. Liquid form includes domestic sewage and effluents from community, institutional and industrial activities. Organic wastes, MSW, Sewage wastes, industrial wastes etc. are suitable for energy recovery.

2.         What are the processes used for recovery of energy from wastes ?

The processes used are

1. Biomethanation and

2. Combustion

3.         What types of wastes can be effectively treated through Biomethanation ?

1. Organic Wastes   -    segregated from Municipal Solid Wastes (MSW)

2. Sewage water, which poses a major problem of disposal, can be used in combination with organic wastes

3. Industrial waste water containing high levels of BOD / COD

4.         How energy is recovered by Biomethanation process ?

The segregated organic wastes are digested under anaerobic conditions to produce methane gas which in turn can be used for power generation.

5.         When combustion process is used ?

Combustion process is used for producing steam from MSW that contain high amount of organic non-biodegradable matter and low moisture content. The steam so produced is used for power generation through conventional turbines.

6.         Is the Government providing any financial assistance ?

Yes. MNRE provides financial assistance for waste to energy projects at the rate of Rs.3.00 crores / MW subject to certain basic criteria. Further details may be obtained from TEDA office.

7.         Is a Detailed project report (DPR) is required ?

Yes. DPR is mandatory for availing loan from financial institutions, for obtaining statutory clearances and incentives from MNRE, Govt. of India.

8.         Who will prepare the DPR ?

A consultant from the list given in this website may be contacted who will visit the site and after study, will prepare the DPR.

9.         Is the power generated from wastes can be sold to TNEB and under    what condition ?

Yes, the power generated from wastes can be sold to TNEB. The present tariff rates normally applicable for all Bio energy projects are given below :

(i)                 Purchase of power at Rs.3.15 per unit with annual escalation of 5 % subject to a maximum of 90 % of HT Tariff for industries. 2 % towards the time loss will be deducted form the energy generated form the power plants.

(ii)               Concessional wheeling charges of 3 % for distance upto 25 km and 6 % for distance beyond 25 km for captive use.)            

10.       Are there plants in operation ?

The following projects have been taken up in Tamil Nadu

(i)	Effluent water from sago processing unit at Mallur,  Salem District	:	200 kWe (Thermal)
(ii)	Effluent water from sago processing industry at Pappireddipatti,  Dharmapuri District	:	500 kWe (Electrical) (Dual Fuel)
(iii)	From Poultry litter at Sarkaruduppam,  Namakkal District	:	1500 kWe (Electrical)
(iv)	From Poultry litter at Senguttaikadu, Namakkal District	:	2500 kWe (Electrical)
(v)	From vegetable wastes at Koyambedu Market, Chennai	:	230 kWe (Electrical)

BIOMASS GASIFIER

 1.         What is Biomass Gasifier system ?

Biomass gasifier system is a closed vessel, normally, cylindrical in shape, in which solid biomass material such as wood waste, agro residues, branches and twigs of plants etc. are subjected to partial combustion in the presence of a limited supply of air. This process is called ‘Gasification’ and the gas produced is known as ‘producer gas’.

2.         What are the different types of gasifier ?

The gasifiers are classified as updraft, downdraft and cross draft.

3.         Which are the most widely used types ?

The most widely used gasifier types are updraft and downdraft. In updraft gasifier, fuel and air flow are in counter current fashion, fuel coming down from top. In the downdraft gasifier, fuel and air flow are in co-current fashion from top to bottom.

4.         What are the main applications for which the gasifier is used ?

The gas from updraft gasifier is more suitable for heating ( thermal ) applications. The downdraft gasifier producers a relatively clean gas with less tar and hence is more suitable for power generation.

5.         What are the potential uses of Gasifier ?