Question

in addition to power output light bulbs should also be labelled with the rate at which they emit visible light ​

Answer 1

Answer:

While the energy label tells you about the energy performance of the light bulb you have bought, it does not say anything about its impact on the environment.  You will find out a little more by checking whether the bulb carries an ecolabel (a blue and green flower with star-shaped petals).

This European label guarantees products that have less of an impact on the environment and which are safe and reliable to use.  N.B.: This labelling is voluntary, which means that the product fulfils the ecological criteria set but is not necessarily the most environmentally friendly on the market (other products that do not carry the label may be equally or even more environmentally friendly).