MICRO SOLAR DOME
For Lighting up Households in Slums and Rural Areas
A low-cost and energy-efficient device has been developed to capture sunlight and light up households, particularly in urban slum or rural areas which lack electricity supply. Micro Solar Dome (MSD) has been developed by the Department of Science and Technology in collaboration with N B Institute for Rural Technology. The device has a semi-spherical upper dome made of acrylic material that captures sunlight. It passes through a sun tube which has a thin layer of highly reflective coating on the inner wall of the passage. It also contains a lower dome made of acrylic. There is a shutter at the bottom of the lower dome which can be closed if light is not required during the day.
The device is leak proof and capable of working throughout the day. After sunset, it can work for four hours. The product has been tested at Electronics Regional Test Laboratory (ERTL), which has paved the way for its acceptance on pan India basis. The micro solar dome was also tested for select parameters at IITBombay, Mumbai; TERI University, New Delhi; and Indian Institute of Engineering Science and Technology (IIEST), Kolkata. On up-scaling the photovoltaic-enabled MSD device will cost `1,200 and non-PV MSD will cost `500. However, these prices are expected to come down over a period of time. The PV-integrated micro solar dome has been included as a product for off-grid solar lighting applications by the Ministry of New and Renewable Energy (MNRE) and is eligible for subsidy.
Types of Micro Solar Domes
Micro solar dome is a unique device that captures light from various directions and concentrates it inside the house, brightening it enough to ease the tasks of cooking, cleaning, reading, and other day-to-day activities. It can be fitted in any type of roof, viz., GCI sheet, asbestos, clay tiles. There are three types of micro solar domes:
Normal Micro Solar Dome: Dome type day-lighting device has a transparent semi-spherical upper dome made of acrylic material which captures the sunlight and the light passes through a suntube having a thin layer of highly reflective coating on the inner wall of the passage. The light output varies from 3 W to 15 electrical equivalent Watt from morning to evening. Suntube with highly reflective coating; upper dome; and lower dome are the components of a normal micro solar dome.
PV Integrated Micro Solar Dome: It is the latest version of the micro solar dome. The integrated PV module fitted in the dome charges a battery during day time which in turn provides light during night time from the micro solar dome for about 4 hours through LED fitted in the lower dome. Components of PV integrated micro solar dome include: Suntube with highly reflective coating; upper dome; lower dome with LED fitted; PV panel; battery; and controller circuit
Non-PV Filtered Micro Solar Dome: In both these types of domes, sun filter is used to reduce illumination during summer.
Micro solar domes can be installed on that part of the GCI/asbestos/ clay tile rooftop which gets the maximum sunlight. Before installation the roof should be checked properly particularly in respect of durability. It should be ensured that a person can work on the roof to fix up the dome.
source: Akshay Urja Magazine