MNRE invites comments on White LED (W-LED) based ‘Solar Study Lamp’ Specifications

MNRE invites comments on White LED (W-LED) based ‘Solar Study Lamp’ Specifications

solar W-LED lightMNRE has invited comments on White LED (W-LED) based Solar Study Lamp specifications. Point wise comments can be sent by 19th June, 2016 to Sh. Tarun Singh, Scientist-C through [email protected]. The specifications are placed for information of stake holders.

Solar Study Lamp consists 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.

PV module converts sun light into electricity, charges the battery which powers the luminaire. Luminaire consists of White Light Emitting Diode (W-LED).


The broad performance specifications of a W-LED light source based Solar Study Lamps are:

  • PV Module- 2Wp under STC
  • Battery- Lithium-Ferro Phosphate of 3.2V, 2000mAh (or requisitecapacity) OR

NiMH or Lithium ion (of requisite capacity)

  • Light Source -1 Watt W-LED luminaire, dispersed beam, soothing to eyes with the use of proper optics and diffuser
  • Light Output – Study lamp should deliver minimum of 150 Lux at over an area of 1.5 feet Diameter. [Minimum 150 Lux when measured at the periphery of 45 centimetres diameter from a height of 30 centimetres.]
  • Duty cycle- 4 hours a dayunder average daily insolation of 4.5 kWh/ sq.m.on a horizontal surface.



(i) Indigenously manufactured PV modules should be used in the Solar Study Lamp.

(ii) The PV module should have crystalline silicon solar cells, and should have humidity, freeze, thermal cycling and damp heat tests certificate conforming to IEC 61215 Edition II / BIS 14286 from an NABL or IECQ accredited Laboratory.

(iii) The PV module must have a minimum of 2Wp at an appropriate voltage for charging of battery used, under the standard test conditions (STC) of measurement.

(iv) There should preferably be an arrangement (stand) for mounting the module at an optimum angle in the direction facing the sun.

(v) A foil/ strip containing the following details should be fixed inside on the module so as to be clearly visible from the front side:-

a) Name of the Manufacturer and/ or distinctive Logo

b) Model and/ or Type No.

c) Serial No.

d) Year of manufacture

(vii) A distinctive serial number starting with NSM will be engraved on the frame of the module or screen printed on the tedlar sheet of the module.


(i) Lithium-Ferro Phosphate of 3.2V, 2000mAh (or requisitecapacity)


NiMH or Lithium ion (of requisite capacity)

(ii) Battery should conform to the latest BIS/ International standards.


  1. The light source should be 1.0 Watts (max.) luminaire based on White Light Emitting Diode (W-LED).
  2. It should be dispersed beam, soothing to eyes with the use of proper optics and diffuser.

III. The colour temperature of W-LED(s) used in the system should be in the  range of 5500oK –6500oK.

  1. W-LED(s) should not emit ultraviolet light.
  2. The light output from the W-LED should be constant throughout the duty cycle.


  1. Efficiency of the electronic system should be at least 85%.
  2. Electronics should have temperature compensation for proper charging of the battery throughout the year.

III. The idle current should be less than 1 mA

  1. The PCB containing the electronics should be capable of solder free installation and replacement.
  2. Necessary lengths of wires/ cables, switches suitable for DC use and other protections should be provided.
  3. The system should have a USB port for mobile charging


  1. Adequate protection is to be incorporated for “No Load” condition, e.g. when the lamp is removed and the Solar Study Lamp is switched ON.
  2. The system should have protection against battery overcharge and deep discharge conditions.

III. The load reconnect should be provided at around 80% of the battery capacity status.

  1. Adequate protection should be provided against battery reverse polarity.
  2. A fuse should be provided to protect against short circuit conditions.
  3. Protection for reverse flow of current through the PV module should be provided.

VII. During the charging, lamp cannot be switched “ON”.


  • The system should have two indicators, green and red.
  • The green indicator should indicate the charging under progress and should glow only when the charging is taking place. It should stop glowing when the battery is fully charged.
  • Red indicator should indicate the battery “Load Cut Off” condition.


  1. The complete Solar Study Lamp will be warranted for five years.
  2. The battery should be warranted for a period of 5 years.

III. The Warrantee/ Guarantee Card to be supplied with the Solar Study Lamp must contain the details of the system supplied.


An Operation, Instruction and Maintenance Manual, in English and the local language, should be provided with the Solar Study Lamp. The following minimum details must be provided in the Manual:

  • Basic principles of Photovoltaics.
  • A small write-up (with a block diagram) on Solar Study Lamp – its components, PV module, battery, electronics and luminaire and expected performance.
  • Significance of indicators.
  • Type, Model number, Voltage, capacity of the battery, used in the system.
  • The make, model number, country of origin and technical characteristics (including IESNA LM-80 report) of W-LEDs used in the lighting system.
  • Clear instructions on mounting, operation, regular maintenance and trouble shooting of the Solar Study Lamp.
  • Instructions on replacement of battery.
  • DO’s and DONT’s.
  • Name and address of the contact person for repair and maintenance during the warranty.

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