The following are a few solutions that are available on the market today to aid in the running and switching of various light sources. As technology improves and the demand for more energy efficient lighting increases the traditional wire wound ballast is becoming a thing of the past.
Dimmable Smart Ballasts
If you wish to future proof a luminaire you can install a smart ballast with a standard photocell. You can set up a dimming/switching profile for the ballast to follow and if at a later stage you wish to Network the Luminaire you can simply replace the photocell with the node which relates to your ballast.
Photocells & Part Night Photocells
The market has seen an increasing number of photocells which can now aid in energy saving, ranging from varying the LUX levels at which they are activated/deactivated to actually switching off a luminaire between set times. These are stand alone systems and do not have the ability to be managed externally.
There are products on the market, mainly by Philips Lighting such as the LumiStep which when used in conjunction with a dimmable ballast and a photocell will give single step dimming down to 50% for either 6 or 8 hours giving an energy saving of upto 25%.
Another product called the Dynadimmer which uses the same concept as the LumiStep provides multi-step dimming which can result in energy savings of upto 40%.