A solar lantern is well-known example portable stand alone solar electric system. It consists of all necessary components required for a standalone solar electric system in a single casing except the solar PV module. It is consists mainly a lamp, a battery and an electronic control circuit in a single casing. The solar module is a separated past of the lantern. This PV module has to be connected with lantern’s battery terminals for charging purpose. Now days solar lantern are very popularly used for both indoor and outdoor purposes.
Casing of a solar lantern may be mode of either metal, plastic or fiberglass. Battery, charging and control circuit are placed inside the casing with proper memer, so that inside space of the casing can be properly used. On the top of the casing there is a lamp holder mounted at center. One CFL of required rating is attached with this holder.
The lamp is covered from all sides by transparent glass or fiberglass. This cover is transparent from all sides, hence solar lantern can emit light in all directions i.e. 360o of light illumination. The top of the transparent hollow cylindrical lamp cover, there is one top cover which is not transparent and generally made of some material by which casing of solar lantern is made. Hanger of the lantern is filled with the top cover. There is a plug point and charging discharging (ON) indications on casing.
For changing purpose, wire with socket comes from solar module which placed under sunlight is plugged to the plug point on the casing. There are different models of solar lantern, but normally battery capacity of a solar lantern is 12 V 7 Ah. CFL lamp used in this system is normally either 5W or 7W. The PV module used for charging solar lantern is from 8 Watts peak to 14 Watts peak.
A table showing different configuration of solar lantern as per MNRE specifications is given below
|Model||Lamp (CFL)||Battery||PV Module|
|I-A||5 W||12 V, 7 Ah at 20oC||8 to 99 Watts (Peak)|
|I-B||5 W||12 V, 7 Ah at 20oC||8 to 99 Watts (Peak)|
|II-A||7 W||12 V, 7 Ah at 20oC||8 to 99 Watts (Peak)|
|II-B||7 W||12 V, 7 Ah at 20oC||8 to 99 Watts (Peak)|
The lumen output is generally in the range of 230 ± 5 % for 7 W CFL.