There are a number of reasons why it is advisable to use LED drivers with high efficiencies.
The first, of course, is the cost benefits of high efficiency drivers. The less energy that is required to provide the desired luminous output, the less it costs to power the fixture. Since one of the main reasons for switching to LED lighting is the accompanying cost saving, it makes sense to use a driver with a high efficiency to maximise these cost savings.
Secondly, the energy that is dissipated in a power supply is dissipated as heat. This heat can reduce the lifespan of the critical components of the supply. A more efficient driver will therefore have an improved product life and MTBF. For example, the power dissipated in a 90% efficient driver is half that dissipated in a 80% efficient driver. Doubling the heat dissipated in the driver will greatly increase component temperature. This is of particular concern with regard to electrolytic capacitors, where a 10 degree increase in temperature can lead to a 50% decrease in component life. These electrolytic capacitors are generally the weakest link in LED drivers, and any improvement in their lifespan will also improve the driver’s lifespan.