Domestic Efficient Lighting Programme (DELP) or Unnat Jyoti by Affordable LEDs for All (UJALA) scheme

Bachat Lamp Yojana

• “Bachat Lamp Yojana” was a launched in 2009 to reduce the cost of compact fluorescent lamps (CFLs, i.e., energy saving lights) sold to consumers.
• Implemented through the Bureau of Energy Efficiency (BEE) in India’s Ministry of Power, the program’s goal was to deliver CFLs at the cost of normal lightbulbs.
• The difference in cost will be covered by the sale of Certified Emission Reduction(CER) Units (Carbon Credits) under the Clean Development Mechanism of the Kyoto Protocol.
• The Ministry of New and Renewable Energy stopped the subsidy on CFL-based solar lighting system to encourage the use of the LED version.

DELP

• DELP replaced the ‘Bachat Lamp Yojana’ [Energy Efficient Lighting Programme (EELP)] – Scheme to offer CFL at the price of Incandescent bulbs.
• DELP encourages the people to use LED bulbs in place of incandescent bulbs, tube lights and CFL bulbs.
• DELP sold 9 crore LED bulbs at subsidized prices reducing the energy cost by 50 billion rupees.
• DELP scheme is implemented by Energy Efficiency Services Limited (EESL) – Ministry of Power.

EESL

• EESL is a Joint Venture company of four Central Power Sector undertakings viz. NTPC Ltd, PFC, REC, and Power Grid.
• EESL was set up to create and sustain markets for energy efficiency in the country.
• EESL works closely with the Bureau of Energy Efficiency (BEE).
• It is leading the market related activities of the National Mission for Enhanced Energy Efficiency (NMEEE), one of the 8 national missions under National Action Plan on climate change.

Comparison: Light Emitting Diodes (LEDs) – Incandescent Light Bulbs – Compact Fluorescents (CFLs)

Tungsten Lamp or incandescent light bulb

• In an incandescent light bulb, a wire filament (tungsten) is heated to a high temperature by passing an electric current through it until it glows with visible light.
• The hot filament is protected from oxidation with a glass or quartz bulb that is filled with inert gas.

Why tungsten?

• Pure tungsten has very high melting point (3400 °C) [An electric current can heat the filament around 2000-3000 °C, which stays below the melting point of tungsten].
• It has very low vapor pressure, and greatest tensile strength out of all the metals.

CFL

• Compact fluorescent lamp is a fluorescent lamp designed to replace tungsten lamp.
• Compared to incandescent lamps, CFLs are highly energy efficient.
• Like all fluorescent lamps, CFLs contain toxic mercury.

Fluorescent lighting

• A fluorescent lamp is a low pressure mercury-vapor gas-discharge lamp.
• Electrons that are bound to mercury atoms are excited to states where they will radiate ultraviolet light as they return to a lower energy level.
• This emitted ultraviolet light is converted into visible light as it strikes the fluorescent coating on the bulb (phosphor coating).

LED lamp

• An LED lamp is a light-emitting diode (LED) product which is assembled into a lamp.
• LED lamps have a lifespan and electrical efficiency which are several times longer than incandescent lamps, and significantly more efficient than most fluorescent lamps.

Light-emitting diode (LED)

• A light-emitting diode (LED) is a two-lead semiconductor light source.
• It is a p–n junction diode, which emits light when activated.
• When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons.
• This effect is called electroluminescence, and the color of the light corresponds to the energy of the photon.

Comparison: Light Emitting Diodes (LEDs) – Incandescent Light Bulbs – Compact Fluorescents (CFLs)

Type	Light Emitting Diodes (LEDs)	Compact Fluorescents (CFLs)	Incandescent Light Bulbs
Life Span (average)	50,000 hours 40X	8,000 hours 7.5 X	1,200 hours X
Power used	7 watts X	14 watts 2X	60 watts 9X
Brightness in lumens	600	540	800
Annual Operating Cost	X	2X	10X
Contains the TOXIC Mercury	No	Yes	No
Carbon Dioxide Emissions    (The bulbs don’t emit CO2. Power generation emits CO2.) Lower energy consumption decreases: CO2 emissions, sulfur oxide, and high-level nuclear waste.	X	2X	10X
Turns on instantly	Yes	No – takes time to warm up	Yes
Heat output	Low	Medium	High
Heat sensitive	No	Yes	Yes
Moisture sensitive	No	Yes	Yes
Durability	Very Durable – LEDs can handle jarring and bumping	Not Very Durable – glass can break easily	Not Very Durable – glass or filament can break easily

Source: http://goo.gl/255fPE and Delp Scheme.

Insulated gate bipolar transistor (IGBT)

• A transistor is a semiconductor device.
• It forms the basic component of all electronic devices.
• It is used to amplify or switch electronic signals and electrical power.
• IGBT replaces analogue power control with digital power control with a massive increase in efficiency.

IGBT applications

• A CFL lamp needs a switch. IGBT plays the role of a switch in a CFL.
• IGBTs is also used to generate the (mercury) gas discharge, which lights up the bulb.
• The IGBT’s other advantage is that it can fit in a small volume.
• IGBT are also used in electronic components of various household appliances ranging from space heaters to refrigerators.
• They are also used in medical products (X-ray, CAT, MRI).

Jayant Baliga

• Inventor of the insulated gate bipolar transistor (IGBT).
• Alumnus of Indian Institute of Technology, Madras.
• He won the global energy prize in 2015.