Learn About Solar
Solar Water HeaterSolar Water PumpSolar Power PackSolar Microgrid
Solar Lighting
Whether it is a solar street light, lantern or wall light, a solar lighting system follows the same process. A small
solar lighting system is ideally suited for a house of 4 people, lighting 2-4 lamps for up to 4 hours daily. Such a
solar home lighting solution can help save approximately Rs 7200 worth of kerosene while saving carbon
emissions equivalent of burning approximately 240 litres of kerosene.
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When the sun’s radiation falls on a solar photovoltaic (PV) panel, current is generated.
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The current produced from the PV panels is controlled and regulated by an
inbuilt/standalone charge controller/inverter. The inverter sends the current to charge the
battery.
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When the connected appliances are switched on, the charge controller/inverter also helps
regulate the current from the battery, sending it to the output appliance to provide light and
energy.
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Solar Water Heater
Solar thermal systems use sunlight to heat water — for domestic use, swimming pools and more. A typical direct
solar thermal system consists of collector, pipes and an insulated tank.
A typical 100 LPD (litre per day) system is sufficient to provide approximately 100 litres of hot water at an
average temperature of 65°C every day on all sunny days. This helps save approximately 4 units of electricity
daily (equivalent energy consumed by an electrical geyser) offering cost benefits of approximately Rs 4,000 per
year. TPS solar water heaters are available in scalable multiples of 100. Large scale installations, for special
applications involving heat transfer can also be engineered.
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When the sun’s rays fall on a solar water heater collector, made of either an Evacuated
Vacuum Tube system (EVT) or Flat Plate Collector system (FPC), the solar radiation heats
up the water present in glass tubes (in EVT) / metal tubes (in FPC) due to high
transmittance of the covering glass medium.
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The heated water, now less dense, rises in the various tubes eventually reaching the tank
at the top.
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The relatively colder and denser water in the tank descends into the tubes, in turn getting
heated — this cycle continues. The Thermosiphon effect ensures the movement of hot
water upwards into the tank because of difference in density, eliminating the need for an
external pump. The insulated tank ensures that the hot water remains hot for a long time.
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Solar Water Pump
A solar water pump has a mini power house at its heart and consists of a calibrated and matching solar array of
modules – tuned with the equivalent power of pump for that particular application. The solar water pumping
system is capable of running all types of electrical water pumps with applications varying from irrigation to
household demands. Irrigation pumps such as submersible, surface or deep well can also be coupled with drip
irrigation systems to enhance the returns from this configuration.
A typical solar water pumping system is known by the sum total of solar array size that is required to run the
attached pump. A 1000 Wp solar water pump is capable of drawing and pumping approximately 40,000 litres of
water per day from a source that is up to 10 meters deep. This is sufficient to irrigate about 2 acres of land with
regular crops. A 1000 Wp solar water pump helps save up to Rs 45,000 when compared to equivalent use of a
diesel-operated pump over a year.
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Each solar array has a number of solar modules connected in parallel or series. Every solar
PV panel generates current by converting solar radiation to electrical energy.
The electrical energy from the entire array is controlled, tuned and directed by the inbuilt
controller in DC pumps or through the Variable Frequency Driver(VFD) and enables the
connected pump (may be submersible or surface) to draw water and feed the delivery
pipelines.
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The water thus drawn from ponds, rivers, bore wells or other sources by a solar water
pump is pumped to supply water as required. It can be stored in tanks from where it is later
channelled to fields or the supply from the pump may be coupled with drip irrigation
systems to provide optimised water to fields directly.
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Solar Power Pack
Today households need continuous and regular access to power for various needs. Solar power packs are
designed to provide electricity in homes with intermittent or no grid electricity. The power packs being modular in
construction can be customised to generate and provide solutions for individual needs.
Solar power packs can begin at about 100 watts, going up to a few kilowatts. A typical 4-person semi
urban/urban home can have a good mix of solar power and grid power balance by choosing to install a 1 KW
solar power pack. A 1 KW power pack can help save Rs 8,250 per year (compared to using grid electricity).
When used as power backup in grid-constrained locations, it saves fuel costs of up to Rs 56,000 per year
compared to the equivalent use of a 1 KVA gasoline generator.
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A power pack is composed of a set of solar PV panels connected together to generate
electricity by converting solar radiation into electrical energy.
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The electrical energy generated from the array of panels is transmitted to the household
load or battery bank storage through a controller or smart inverter. The inverter is a
seamless connection between grid, solar array, house load and the battery bank. It
constantly interacts with these 4 inputs to always utilise solar energy to the maximum –
choosing to utilise it against the load first and directing excess generation to storage in the
batteries, reserved for use when solar power is not there.
The battery bank stores power that cannot be utilised directly by the household load – to be
used when requirement of household load is more than what the solar PV is providing at a
particular time or when power from solar energy is not available, thus reducing the
consumption of power from grid and saving on electricity bill.
Solar Microgrid
Villages can now have access to electricity by investing in their own microgrid power plant. The size of a solar
microgrid depends upon the number of solar panels and wattage comprising the solar array. The requirement
and size of a microgrid is calculated by adding the power needs of individual homes in the village that will be
connected together.
A typical solar microgrid can range from 1 KW to several megawatts. A typical rural house requires
approximately 2 units of electricity and so, for a village of 100 homes, a 4 KW microgrid is sufficient. A 4 KW
plant helps generate electricity worth Rs 33,000 per year.
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Every solar PV panel connected in the array generates electricity by converting solar
radiation into electrical energy. All PV panels are connected in a particular order of parallel
and series combinations to provide the required voltage. The electricity generated from the
array of panels is transmitted to a central controller called the Power Conditioning Unit
(PCU), which is, in simple terms, a large power inverter. The PCU is connected to the
Distribution Box (DB) on one hand and the battery bank on the other.
The PCU controls, regulates and directs the electrical energy transmitted from the array,
and supplies electricity directly to homes, shops, offices, street lights etc.
During the day if the power generated is not used or surplus power is generated, the PCU
directs this to the battery bank which stores power. This power can then be used at night
(after the sun sets). The microgrid and battery bank are connected to a computer for local
power usage monitoring. With the addition of a modem, this information can be accessed
from a remote location, eliminating the need for local manpower to monitor the system.