With the impending huge escalation of electricity charges people are looking for solar energy once again.
To help anyone interested, I am giving some facts and figures needed for establishing off-grid small scale cheaper illuminating system.
Solar panel :
New 40 Watt panel is sufficient for lighting purposes of a normal house.
Price is around 7,500.00 Rupees.
If you can go for 2 x 40W = 15,000/- you can run 12 V fans for few hrs after sunny daytime.
A normal car battery is OK. If you can find a battery removed from a vehicle with some charging capacity try it without buying a new battery.
You have to fix a controller between the solar panel and the battery to protect overcharging. Price : around 3,000/-
Do not connect the panels directly to the battery for more than one hour. In a sunny day it may get fully charged within few hrs and then start killing the battery.
LED is the best. 12V CFL also can be used if your kid prefers to study under CFL than LED.
Locally made LED bulbs are available at lower cost.
A bulb with 24 LEDs is around 350 rupees with 6 month warranty.
Remember to buy 12 Volt type (230 V is made for mains current)
IMPORTANT fact about LED Bulb ( LED Bulb = series of connected LE Diodes)
There are 2 types in the market.
One with heat sink and other without heat sink.
If the bulb is with a heat sink that means it generates lot of heat and very less power is saved.
Hence DO NOT buy bulbs with heat sink if you want to save energy and money.( for 12V or even 230 v)
Some local bulb manufacturers use low quality material and life time is less.
Hence, be careful when buying LED bulbs. Keep your warranty papers safely.
I buy fair quality make from “Shine Bulb” Kandy. 072 2 653 406
Their make is available at Welco elect. 1st cross st. Pettah . opp. peoples bank. .
30 LED 12V is around 450/- If you buy more than 10 ask wholesale price.
Solar panels are now available everywhere you can Google or papers to find nearest.
I bought from JLanka . Pahalawela road, ( Japan friendship road near the parliament , Battaramulla 077 831 4973. jlankatech.com
40W panel was 11,000/- now the price has come down to 7,500/-
Solar panels give power for about 15-20 years with a slight correction each year after 10 years of time. I have used a pair over 25 years . They died due to weathering of plastic like material.
LED bulb with Heat sink use power to generate unnecessary heat
Another heating type bulb .
Non heating LED bulb without Heat sinks : save more energy .
Another non heating LED
I posted some commercial address to help only. I have no contacts with them. There may be better places near you.
Note2: Do not connect 12V bulbs to 230 V !