LED light bulbs
LED bulbs save almost 80% of electricity charges. They have a long lifetime, works on 100% already from the switching on. The LED bulbs are resistant to repeated switch on/off. LED bulbs have a variety of colour temperatures, indicated as a number of Kelvins.
from 2700-3000 Kelvins - warm white - suitable for relaxation, use in living room, bedroom
from 4000-6000 Kelvins - neutral white - suitable for work, use in study, office
more than 6000 Kelvins - cold white - mostly decorative lighting, not suitable for private interior