Department of Solar Technology

Objective:

To develop a centre of excellence in the area of solar energy and its applications in line with requirements of rural world.  Continued learning to improve knowledge management system to act as an efficient backup unit of technology. Carry out research and extension works which will benefit the in situ installation, operation and maintenance of solar systems.

Faculty:

         Sri. Muralidhar .K, Deputy Director (Solar Energy)
         Smt. Shanthi .G, Assistant Director (Solar)

Areas of research:

  • Roof Top Photovoltaic Systems operating in Islanded mode and Grid connected mode (net metered).
  • Solar Photo Voltaic Water Pumping Applications.
  • Remote Village Electrification using micro grids / nanogrids.
  • Solar based Hybrid Systems for power generation.
  • Evaluation of Solar PV cell technologies used in power generation.
  • Solar Thermal Applications viz. Water heating Systems, Dryers.
  • Solar based Applications for Rural Environment.
  • Field studies on installed Solar Energy Systems.

Consultancy:

  • Installation of Roof Top SPV systems
  • Electrification of unelectrified areas through solar technologies
  • Deliver Guest lectures in areas of Renewable Energy

Subjects:

Realizable solar potential in India is 110 GW to 144 GW by 2024.

About MGIRED
Assessment of Solar energy moderated potential in Karnataka is around 10,000 MW.

Revised Solar Potential as on 24/11/2014

State wise Estimated Solar Power Potential
Total Solar Power in GWp: 748.98 GWp
State
Solar Potential (GWp)
Andhra Pradesh
38.44
Arunachal Pradesh
8.65
Assam
13.76
Bihar
11.20
Chhattisgarh
18.27
Delhi
2.05
Goa
0.88
Gujarat
35.77
Haryana
4.56
Himachal Pradesh
33.84
Jammu & Kashmir
111.05
Jharkhand
18.18
Karnataka
24.70
Kerala
6.11
Madhya Pradesh
61.66
Maharashtra
64.32
Manipur
10.63
Meghalaya
5.86
Mizoram
9.09
Nagaland
7.29
Orissa
25.78
Punjab
2.81
Rajasthan
142.31
Sikkim
4.94
Tamil Nadu
17.67
Telangana
20.41
Tripura
2.08
Uttar Pradesh
22.83
Uttarakhand
16.80
West Bengal
6.26
UT
0.79
Total
748.98
 
The Ministry of New and Renewable Energy (MNRE) is the nodal Ministry of the Government of India for all matters relating to new and renewable energy.

The Karnataka Renewable Energy Development Limited (KREDL) is an organization working under the purview of Energy Department, Government of Karnataka. The KREDL works through various Governmental Agencies, Private Organizations, NGO's and Accredited Energy Auditors.

Consequent to the announcement of the National Action Plan on Climate Change in June 2008, the Government of India has approved “Jawaharlal Nehru National Solar Mission” (JNNSM) which aims at development and deployment of solar energy technologies in the country to achieve parity with grid power tariff by 2022.

As a part of this mission the government has initiated a subsidy scheme to help individuals and organization to procure these solar energy systems at reduced capital costs. The scheme is being implemented by IREDA through NABARD.

GRID CONNECTED ROOFTOP SOLAR PV SYSTEM AND NET ENERGY METERING-THE FUTURE OF CLEAN ENERGY
While the Jawaharlal Nehru National Solar Mission (JNNSM) opened up the solar electricity sector in India, the focus has primarily been on large-scale grid-connected power plants. With the drastic fall in prices of solar photovoltaic (PV) modules and balance of systems (BOS), Roof top PV(RTPV) systems can offer substantial benefits in terms of providing peaking supply of power, reducing T&D losses, improving tail end voltages, and creating local jobs. Roof top PV system is ideally suited for India. It is sustainable (through the use of solar PV, a renewable resource in the grid-connected mode, thus avoiding the use of batteries). Here, we will discuss the need for and advantages of emphasizing rooftop PV with net-metering as a self-consumption power source in India, especially in large cities.

Renewable energy resources have attracted public, governmental, and academic attention due to the global energy crisis. An important technical challenge is the integration of renewable resources into the existing utility grid such that reliable power is injected without violating the grid codes and standards. There is an increasing focus on the development of solar energy in India for a variety of reasons, including our limited conventional energy reserves, their local environmental and social impacts, energy security, and climate change and energy access. Rooftop PV (RTPV) systems are PV systems installed on rooftops of residential, commercial or industrial premises. The electricity generated from such systems could either be entirely fed into the grid at regulated feed-in-tariffs, or used for self-consumption with the net-metering approach. A net-metering mechanism allows for a two-way flow of electricity wherein the consumer is billed only for the ‘net’ electricity (total consumption – own PV production) supplied by the BESCOM. Such RTPV systems could be installed with or without battery storage, and with one integrated net meter or two separate meters (one for export to grid and one for consumption).

Solar energy, therefore, has great potential as future energy source. It also has the advantage of permitting the decentralized distribution of energy, thereby empowering people at the grassroots level". Based on this vision Jawaharlal Nehru National Solar Mission was launched under the brand name "Solar India”. India is endowed with abundant solar energy, which is capable of producing 5,000 trillion kilowatts of clean energy. Country is blessed with around 300 sunny days in a year and solar insolation of 4-7 kWh per Sq. m per day. If this energy is harnessed efficiently, it can easily reduce our energy deficit scenario and that to with no carbon emission. In near future Solar energy will have a huge role to play in meeting India’s energy demand.

PV'S ON BUILDINGS:
For commercial buildings, the use of PVs may significantly influence the geometry, positioning and orientation of the building to maximize their viability. For domestic properties there is normally a part of the building, usually the roof that lends itself to the location of PVs. However, if the opportunity exists it is worth thinking about the building design where it can be influenced to maximize the potential of PVs wherever possible. This is especially true where solar thermal panels are also being considered as there may be a limited amount of space suitable for mounting the panels. PVs need to be considered as an integral part of the energy strategy of the building and of its functioning. The integration of PVs with the other building elements is critical to success, as ever appearance and aesthetics are especially important. The use of PVs should be part of the overall energy strategy for the building. Reasons to use PV include Energy costs, Environment, Security of supply, Demonstration / Education purposes, Architectural design / feature.

PV's are worth considering if the following key factors are right:

  • Location: The solar radiation at the site is important and the building on the site needs to have good access to it.
  • Demand: The PV installation should be sized so as to optimize (in practical and economic terms) the amount of electricity which can be contributed to the overall electrical demand, e.g. Storage or stand-alone system, grid-tied system.
  • Design: PVs will affect the form and aesthetics - the community, the client and the designers all need to be satisfied with the result.

WHAT DIFFERENCE DO PVS MAKE TO A BUILDING?

The main points to address are:
  • Orientation
  • Footprint
  • Facade
  • Section

A building orientated to the south for delighting, passive solar gain and free of over shading is eminently suitable for PVs. Similarly, a footprint with the long axis running east-west thus giving a large south-facing wall area and potentially a large south-facing roof is advantageous for PVs. The façade of a building is more complex. It is important to remember that PV can be wall mounted as well as roof mounted, but can still be very beneficial in terms of contribution to the overall energy requirement of a building. A similarity can be drawn to a window, which is a very simple “passive” element of a building, which provides free energy gains to a building (heat and light). Firstly, in construction terms, building-integrated PV systems need to play the same role as the traditional wall and roofing cladding elements they replace. Consequently, they must address all the normal issues, for example:

  • Appearance
  • Weather tightness and protection from the elements
  • Wind loading
  • Lifetime of materials and risks and consequences of failure
  • Safety (construction, fire, electrical, etc.)
  • Cost

There are a number of more particular aspects, often associated with being able to use the Electricity produced, namely:

  • Avoidance of self shading
  • Heat generation and ventilation.
  • Provision of accessible routes for connectors and cables
  • Maintenance

TYPES OF PHOTOVOLTAIC SOLAR PANELS

There are three main types of photovoltaic solar panels for both commercial and residential use. They are: Monocrystalline, Polycrystalline and Amorphous Silicon also called "Thin Film".All three types of solar panels have both advantages and disadvantages depending on the end user's budget, the size and type of environment where they are used and the expected output of the system to name a few:

Monocrystalline Photovoltaic Solar Panel: Made from a large crystal of silicon. Monocrystalline solar panels are the most efficient and most expensive panels currently available. Because of their high efficiency, they are often used in applications where installation square footage is limited, giving the end user the maximum electrical output for the installation area available.


Polycrystalline Photovoltaic Solar Panel: Characterized by its shattered glass look because of the manufacturing process of using multiple silicon crystals, polycrystalline solar panels are the most commonly seen solar panels. It is little less efficient than monocrystalline panels also less expensive.


Amorphous Silicon "Thin Film" Photovoltaic Solar Panel: These panels can be thin and flexible which is why they are commonly referred to as "Thin Film" solar panels. Amorphous silicon solar panels are common for building integrated photovoltaic (BIPV) applications because of their many application options and aesthetics. They are cheaper and are not affected by shading. Drawbacks are low efficiency; loss of wattage per sq. ft. installed and heat retention. They are manufactured using silicon, copper indium di selenide (CIS) or cadmium telluride (CdTe)


Comparison of Different Types of PV Modules

Cell material
Module efficiency
Surface area needed for
1 kWp
Advantages
Disadvantages
Monocrystalline Silicon 15-18 % 7-9 m² - Most efficient PV Modules
- Easily available on the market
- Highly standardised
- Most expensive
- Waste of silicon in the production process
Polycrystalline Silicon 13-16 % 8-9 m² - Less energy and time needed for production than for monocrystalline cells (= lower costs)
- Easily available on the market
- Highly standardised
- Slightly less efficient than monocrystalline silicon modules
Micromorph tandem (aµ-Si) 6-9 % 9-12 m² - More space for the same output needed
Thin film:
Copper indium diselenide (CIS)
10-12 % 9-11 m² - Higher temperatures and shading  have lower impact on performance
- Lower production costs
- More space for the same output needed
Thin film:
Cadmium telluride (CdTe)
9-11 % 11-13 m² - Higher temperatures and shading have lower impact on performance
- Highest cost-cutting potential
- More space for the same output needed
Thin film:
Amorphus silicon (a-Si)
6-8 % 13-20 m² - Higher temperatures and shading have lower impact on performance
- Less silicon needed for production
- More space for the same output needed
 

Third Generation Solar Cells
Currently there are solar cells based in different new technologies in the way to market maturity, for example the high efficiency cells:

Thin film III-V solar cells:

  • Union of the semiconductors from the third and the fifth group from the periodic table.
  • Efficiency of 20-25%
  • A variety of possible combination increasing price while increasing efficiency
  • Most common connection: gallium arsenide (GaAs)
  • Application: Power supply of satellites

Multi-stack thin film:

  • "Stacking" III-V solar cells or silicon cells
  • Efficiency up to approximately 37% Each cell absorbs a certain wavelength, and then the stack can absorb more from the solar spectrum
  • The top cell material has the highest band gap and covers the highest absorption area. Underlying cells absorbs the section of the solar spectrum with smaller wavelengths.
  • Series connection of the overlying cells
Other names for multi-stack solar cells (depending on the number of layers) are: Tandem, triple, or multiple cascade cells.
 

Concentrator photovoltaics (CPV): CPV are based on lenses or mirrors which focus direct sun light on solar cells. These cells consist of a small amount of highly efficient, but expensive, PV-material (silicon or III-V compounds, generally gallium arsenide or GaA). At present concentrating intensities vary from a factor of 2 to 100 suns (low concentration) to 1000 suns (high concentration). Commercial module efficiencies lay in the range of 20 to 25 percent, although efficiencies of 25 to 30 percent could have been achieved with gallium arsenide. An efficiency of 41. 1 percent has been achieved in the laboratory by the Fraunhofer Institut für solare Energie systeme, Germany (concentrating intensity: 450 suns) .

In order the course of the sun Concentrator modules are mounted on a 2-axis tracking system. In case of low-concentration-PV there exist 1-axis tracking systems and less complex lenses.


Fig. Concentrator Photovoltaics Panel
 

TYPES OF PHOTOVOLTAIC SYSTEMS

1. Off grid system: The term off-grid refers to not being connected to a grid, mainly used in terms of not being connected to the main or national electrical grid. In electricity, off-grid can be stand-alone systems (SHS) or mini-grids typically to provide a smaller community with electricity. Off-grid electrification is an approach to access electricity used in countries and areas with little access to electricity, due to scattered or distant population. It can be any kind of electricity generation. The term off-the-grid (OTG) can refer to living in a self-sufficient manner without reliance on one or more public utilities. Off-the-grid homes are autonomous; they do not rely on municipal water supply, sewer, natural gas, electrical power grid, or similar utility services. A true off-grid house is able to operate completely independently of all traditional public utility services.



2. Grid-tied system: A grid-tie inverter is a power inverter that converts direct current (DC) electricity into alternating current (AC) with an ability to synchronize to interface with a utility line. Its applications are converting DC sources such as solar panels into AC for tying with the grid. Inverters take DC power and invert it to AC power so it can be fed into the electric utility company grid. The grid tie inverter must synchronize its frequency with that of the grid (e.g. 50 or 60 Hz) using a local oscillator and limit the voltage to no higher than the grid voltage. The inverter has an on-board computer which will sense the current AC grid waveform, and output a voltage to correspond with the grid. However, supplying reactive power to the grid might be necessary to keep the voltage in the local grid inside allowed limitations. Otherwise, in a grid segment with considerable power from renewable sources voltage levels might rise too much at times of high production. Grid-tie inverters are also designed to quickly disconnect from the grid if the utility grid goes down. The grid tie inverter will shut down to prevent the energy it transfers from harming any line workers who are sent to fix the power grid. Properly configured, a grid tie inverter enables a home owner to use an alternative power generation system like solar or wind power without extensive rewiring and without batteries. If the alternative power being produced is insufficient, the deficit will be sourced from the electricity grid.

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3. Net metering system: Net metering allows residential and commercial customers who generate their own electricity from solar power to feed electricity they do not use back into the grid. Net metering is a billing mechanism that credits solar energy system owners for the electricity they add to the grid. For example, if a residential customer has a PV system on the home's rooftop, it may generate more electricity than the home uses during daylight hours. If the home is net-metered, the electricity meter will run backwards to provide a credit against what electricity is consumed at night or other periods where the home's electricity use exceeds the system's output. Customers are only billed for their "net" energy use. On average, only 20-40% of a solar energy system’s output ever goes into the grid. Exported solar electricity serves nearby customers’ loads. Electricity delivered to the grid can be compensated in several ways. "Net metering" is where the entity that owns the renewable energy power source receives compensation from the utility for its net outflow of power. So for example, if during a given month a power system feeds 500 kilowatt-hours into the grid and uses 100 kilowatt-hours from the grid, it would receive compensation for 400 kilowatt-hours. Another policy is a feed-in tariff, where the producer is paid for every kilowatt hour delivered to the grid by a special tariff based on a contract with distribution company or other power authority.



GRID CONNECTED ROOF TOP SOLAR PV SYSTEM
In recent years solar PV systems became viable and attractive. Available roof-top area on the buildings can also be used for setting up solar PV power plants, and thus dispensing with the requirement of free land area. The electricity generated from SPV systems can also be fed to the distribution or transmission grid after conditioning to suit grid integration.
 
The roof-top solar PV systems:
  • Area easy to install and maintain
  • Have long life of 25 years

Grid-connected solar photovoltaic (PV) systems are expected to proliferate over the coming decade and higher penetration levels will put a premium on achieving optimal performance and reliability. A PV solar plant is a plant that uses solar cells to convert solar irradiation into electrical energy. PV solar plants consist of solar modules, an inverter converting DC into AC and transformer conveying the generated power into the grid net. It has been shown in practice that the energy efficiency of PV solar plant decreases from 0.5-1% annually. The real lifetime of silicon-made PV modules is expected to be at least 25 years. Since there are no moving parts in the system and it requires only minimal attention. But depending upon the dust level, the system requires periodic cleaning.

ADVANTAGES:
The grid connected roof top solar PV system would fulfill the partial / full power needs of large scale buildings. The following are some of the benefits of roof top SPV systems:

  • Generation of environmentally clean energy.
  • Consumer becomes generator for his own electricity requirements.
  • Reduction in electricity consumption from the grid.
  • Reduction in diesel consumption wherever DG backup is provided.
  • Feeding excess power to the grid.

BASICS OF SIZING A SOLAR PV SYSTEM
The most important thing that one needs to know before sizing a PV system is the energy requirements of a setup.
(Along with all the electrical values mentioned in article mentioned above) A few things that can help are:
Wattages and counts of all the appliances that need to be run on solar PV.

If you do not have wattages then you can look at the current requirement (in amperes) of the appliances and calculate wattage with this simple formula:

Watts = Ampere x 240 (voltage)

Electricity bills of the setup. Used to check the monthly electricity units used in a setup. Daily units can be obtained by dividing month units by 28/29/30 or 31 (depending on the number of days in the month for which the bill is generated)
Daily usage of each appliance in hours. This is required if you do not have a sample electricity bill. This helps in calculating the number of units of electricity used in a day using the formula below:

Units = (Watts x Hours) /1000

Two things are absolutely essential are: Total wattage of appliances (which denotes the instantaneous electricity requirement of a setup) and Total Units (which denotes the total electricity used in a day).
Sizing a PV panel

To size a PV panel, the most essential thing to know is the Total Units consumed in a day by the appliances in a setup (unless it is a direct connected system or a grid connected system for which details are mentioned here). The size of PV system should not be less than the one that can generate total units consume in a day. Every PV panels has a peak wattage (Wp) mentioned on them.  A 1 kWp (or peak kilo watt) system would generate 5 to 7 units in a day. Thus the right size of PV system (in kWp) should be estimated by dividing maximum daily usage units divided by 5.

You can buy a bigger system if you are going for a grid connected system where extra electricity produced will be sold back to the electricity provider (or BESCOM). In such cases you can optimize the size of PV system based on the space that you have for installing PV panels .

Sizing Batteries for PV system: If you are not going for a grid connected system or a direct connected system, you need batteries to store the energy generated using PV panels. Along with sizing of the PV panel, it is important to size the batteries as well. Because if you purchase more batteries then they will not get fully charged, if you buy fewer batteries, you may not be able to get the maximum benefit out of the solar panel.

Most big PV systems use deep cycle (or deep discharge) batteries that are designed to discharge to low energy levels and also to recharge rapidly. These are typically lead acid batteries that may or may not require maintenance. In case of solar mobile phone chargers or other small chargers the batteries may be Lithium Ion, etc.

Batteries have energy storage ratings mentioned in Amp-hour (Ah) or milli-Amp-hour (mAh). They also have a nominal voltage that they generate (typically deep discharge batteries are 12 V batteries, cell phone batteries are 5 V batteries, etc). To calculate the total energy a battery can store you can use following formula:

Units = (Volt x Ah) / 1000 or (Volt x mAh) / 1000000

We have already talked about how to calculate the total units required in a day and also the sizing of the PV system. Batteries should be sized in such a way that the units of energy generated by the PV system should be equal to the number we have calculated above.

So assuming we have a 1 kWp system and we assume that on an average it generates 6 units a day and if we have to buy 12 V battery for it, the Ah (or storage) of battery required would be:
(6 x1000) /12 = 500 Ah

Sizing Inverter for a Solar PV system: A power inverter or inverter is a system that converts Direct Current (or DC) to an alternating current (or AC). A solar panel produces DC current, batteries also generate DC current, but most systems we use in our daily lives use AC current. Inverters also have transformers to convert DC output voltage to any AC output voltage. Depending on the type of system (grid or off-grid) various types of inverters are available.

Sizing of inverter depends on the wattage of appliances connected to it. The input rating of inverter should never be lower than the total wattages of the appliances. Also it should have the same nominal input voltage as that of the battery setup. It is always better to have inverter wattage about 20-25% more than that of the appliances connected. This is specifically essential if the appliances connected have compressors or motors (like AC, refrigerator, pumps, etc), which draw high starting current.

Most inverters available in market are rated on kVA/VA or Kilo Volt Ampere/Volt Ampere. In ideal situations (power factor of 1) 1 VA = 1 Watt. But in real power factor varies from 0.85 to 0.99. So one can assume 1.18 VA = 1 Watt. So if you have a setup where the total wattage of the system is 1000 Watts, it means your inverter size required is more than 1180 VA or 1.18 kVA (add some extra to be on a safer side).

The higher the VA of an inverter, more is the number of appliances it can support, but more costly it would be. So it is important to size it right while buying. Also for a grid-tied system, as there are no batteries connected, the size or VA of the inverter should match the wattage of PV panel for efficient and safe operation.

COSTS OF SOLAR PV SYSTEMS AND INCENTIVES FROM MNRE
As a part of JNNSM the government has initiated a subsidy scheme to help individuals and organization to procure these solar energy systems at reduced capital costs. The scheme is being implemented by IREDA through NABARD.
Under NSM, a Solar PV module comes with a warranty of 25 years from the date of supply.
A good 5 kW system for a home would cost approximately Rs 5-7 lakhs to setup with a design life of 25 years.
MNRE provides 30% capital subsidy on capital expenditures for rooftop solar systems for both commercial and residential entities for systems up to 100 kWp.  
The government also provides loans at 5% per annum for 50% of the capital expenditure for 5 years tenure for both commercial and residential entities. Commercial entities can claim either capital or interest subsidies.

Sl No. Category Capacity State NABARD
1 Solar power packs/ SPV Power Plants (with battery bank @ 9.6 VAh/Wp) Up to 300 Wp Rs. 75 Rs. 100
>300 Wp to 10kWp Rs. 45 Rs. 45*
>10 kWp to 100 Wp Rs. 39 NA
2 SPV Power Plants (Without Battery) Up to 500 kWp Rs. 24 NA
3 Street Lights through SPV power Plant Up to 100 kWp Rs. 75 NA

*Capital subsidy limited to 1 kWp system through NABARD

Project proposals shall be submitted to the MNRE in the prescribed formats for small capacity systems, stand-alone SPV power plants and Mini-grid SPV power plants. For lower capacity systems, this would be operated in programme mode.
The Government of Karnataka has announced a programme for installation of Grid connected Solar Rooftop PV System on the Rooftop of the Residential/Commercial/Educational/Industrial organizations.

SURYA RAITHA SCHEME FROM KREDL: In an effort to harness solar energy for those who till the soil in the State, the State government of Karnataka announced the launch of the ambitious Surya Raitha program. Grid connected solar irrigation PV pumps under small PV Plants on Net metering basis. Under this SURYA RAITHA scheme state govt is providing subsidy up to 10HP pumping system.

Central Finance Assistance (CFA) in Rs /HP for Solar Photo Voltaic Water Pumping System as on 3/11/2014

Sl No. SPV Pumps Capacity State NABARD
1 DC Pumps Up to 2 HP Rs. 43200 Rs. 57600
>2HP to 5HP Rs. 40500 Rs. 54000
2 AC Pumps Up to 2 HP Rs. 37800 Rs. 50400
>2HP to 5HP Rs. 32400 Rs. 43200
>5 HP to 10 HP* Rs. 28800 Rs. 38880

*SPV water pumping system over 5HP may avail subsidy under State Government Schemes while MNRE subsidy is limited to 5 HP only.

SOLAR COOKER

A solar cooker is a device which uses sunlight to cook. They use solar energy as fuel and they cost nothing to run .it is smoke free, cuts down energy cost and the food cooked is rich with vitamins. Solar cookers are used in outdoor cooking especially in situations where there is abundant solar energy.
Box type costs around Rs. 2500 and Dish type approximately costs Rs. 7500.

SOLAR LANTERN

Solar Lantern is a portable lighting device consisting of a PV module, battery, lamp, and electronics. Battery, lamp, and electronics are placed in a suitable housing, made of metal or plastic or fibre glass. The Solar lantern is suitable for either indoor or outdoor lighting, covering a full range of 360 degrees.

Cost of the Solar Lantern is approximately Rs. 1500.



SOLAR LIGHTING & STREET LIGHTING

Solar home lighting systems approved under NSM (National Solar Mission) are required to have a certain level of efficiency. The   CFL based solar systems are required to have module efficiency of 14% and above and a  LED based solar system  is required to have module efficiency of 12% and above.

A solar home lighting system (with inverter) comes with a warranty of 5 years .The batteries if sealed maintenance free come with 2 years warranty and lead acid flooded type battery comes with 5 year warranty.

 
Solar Street Lighting Components
  • Solar panels
  • Solar controller
  • Batteries- lead-acid batteries, Ni-Cd batteries, Ni-H batteries
  • Light source - LED light source, long life, up to 1,00,000 hours, low voltage, the inverter does not needed, a
    higher luminous efficiency
  • Lamp and lamp shell

12W + 40 AH Battery + 40 Watts PV Solar Panel + 17.5 Feet Pole + 9W LED light =  Approximately 18,000 - 20,000

SUBSIDY SCHEMES UNDER MNRE : Central Finance Assistance (CFA) in Rs /Wp for Solar Photo Voltaic Lighting System as on 3/11/2014

Sl No. Category   Capacity State NABARD
1 Solar lighting System- street lights, home lights, lanterns CFL Upto 74 Wp Rs. 75 Rs. 100
2 LED Upto 40 Wp Rs. 120 Rs. 160

SOLAR PUMP

Two types of Solar pumps are Surface water pumps and Deep well pumps.

Types of Solar Pumping Systems and Applications:
A solar pumping system consists of an array of Photovoltaic (PV) panels mounted on a fixed or tracking mounting structure, connected to an Alternating Current (AC) or a Direct Current (DC) motor, suction and delivery pipes and electrical switchgears. A DC pump could be driven by a brushed or brushless permanent magnet DC motor. In case of an AC motor, an inverter or a Variable Frequency Drive (VFD) is used to convert DC power from the solar array to AC power required by the pump. The versatility and robustness of solar pumps make them suitable for practically all types of conventional pumping applications. Thus besides irrigation solar pumping systems can be used in a urban and rural municipal Services, residential applications amongst various other applications

Grid Connected Pumping

In many places, solar pumps can be installed where pump is being driven by electricity grid. Irrigation needs are intermittent, between 200 to 250 days in a year, leaving most of the days with additional power available. In collaboration with electricity authorities and local utilities, it could be encouraged to connect solar pumps to feed surplus power back in the grid.

Solar Pump Mini Grid

There is current trend in rural electricity grid to separate irrigation pumping from rural residential homes. A dedicated transformer is connected to a cluster of irrigation pumps supplying power for fixed number of hours. This has created an opportunity to introduce high efficiency electric pumps coupled to a transformer based solar PV plants. Each transformer could have PV plant ranging from 25 KWp to 500 KWp jointly in a people, public and private ownership. The PV plant will feed power to the cluster of pumps. In case surplus power is available, PV plant will feedback power to the grid. Pumps could act as reliable anchor loads in case of off-grid mini grids.

Diesel Pumps

In many areas that are not grid connected or if the power supply is not reliable, farmers are incurring high cost for diesel pump and recurring costs for diesel, making small and marginal farming economically unviable. Additionally, most of these diesel pumps are highly inefficient. A programme that replaces diesel pumps with solar PV pumps would also help in reducing pollution besides immensely benefiting the farmer.

Community Solar Pumps or Water as a Service

In some states, farmers with electricity/diesel connection also sell or barter water with neighbouring farmers who do not have a pumping system. In these situations, either solar pump (along with panels) needs to be portable or water as a service needs to be encouraged. The pumps would thus be owned by large farmers or community and the service of providing water to other farmers shall be provided. This could help to develop Local enterprises increasing local employment opportunities.

Micro Solar Pumps

In some cases, farmers grow vegetables on a very small size plot largely using manual irrigation methods like swing bucket, hand pumps or treadle pumps. A small micro solar pump with less than 75 Wp to 500 Wp with 0.1 HP to 0.5 HP pump of power needed could do a similar function as a manually operated pump. Most of these farmers have no access to electricity. There are applications of micro solar pumps even in rural schools,health centres and drinking water.



  • A solar-powered pump is a pump running on electricity generated by photovoltaic panels or the thermal
    energy available from collected sunlight as opposed to grid electricity or diesel run water pumps.
  • A system with 1800 watt PV array capacity and 2 HP pump can give a water discharge of 1.4 lakh liters per
    day from a depth of 6 to 7 meters. This quantity of water is considered adequate for irrigating about 2-3 acres
    of land holding for several crops.
  • SUBSIDY SCHEMES UNDER MNRE : Central Finance Assistance (CFA) in Rs /HP for Solar Photo Voltaic
    Water Pumping System as on 3/11/2014
Sl No. SPV Pumps Capacity State NABARD
1 DC Pumps Up to 2 HP Rs. 43200 Rs. 57600
>2HP to 5HP Rs. 40500 Rs. 54000
2 AC Pumps Up to 2 HP Rs. 37800 Rs. 50400
>2HP to 5HP Rs. 32400 Rs. 43200
>5 HP to 10 HP* Rs. 28800 Rs. 38880

*SPV water pumping system over 5HP may avail subsidy under State Government Schemes while MNRE subsidy is limited to 5 HP only.

  • SURYA RAITHA SCHEME FROM KREDL: In an effort to harness solar energy for those who till the soil in the State, the State government of Karnataka announced the launch of the ambitious Surya Raitha program. Grid connected solar irrigation PV pumps under small PV Plants on Net metering basis. Under this SURYA RAITHA scheme state govt is providing subsidy up to 10HP pumping system.


Salient Features of Solar Water Heating System

  • Around 60 deg. – 80 deg. C temperature can be attained depending on solar radiation, weather conditions and solar collector system efficiency.
  • Solar water heaters (SWHs) of 100-300 litres capacity are suited for domestic application.
  • A 100 litres capacity SWH can replace an electric geyser for residential use and saves 1500 units of electricity annually.
  • Life -15-20 years.
  • Approximate cost: Rs.15000- 20,000 for a 100 litres capacity system and Rs.110-150 per installed litre for higher capacity systems.
  • Payback period: 3-4 years.