I know there are various ways to go down from 220v to somethng else, i just dont know what is energy efficient and what is not.
At home i have a 300 watt halogen lamp, to light-up my room.
if a heatsync is required then how can such a solution be energy efficient ?
While those Philips light are nice, they are expensive. $150 to replace a $5 bulb. I know this is not really green thinking, but here electricity is about $0.09 per kWh, so it would take (150/0.09)*(1000/(300-66)) = 7122 continuous hours of running those Philips bulbs before they even begin to pay off. If we assume an average of 4 hours of usage each day, that's more than 4.5 years before a return on investment is realized.Now that I've done the math, there may be some merit to this as long as the LED bulbs last as long as promised. Something that has never been delivered with the CFL bulbs. They last only about 1/4 as long as they are advertised to.
$150 to replace a $5 bulb