4 plants how much light?

Ok im thinking of going to holland and renting a flat for 3/4 months and growing 8 plants...im trying to keep the eletric bill low but just want to know how much light will i need for each four? And what type of light is best?

Depends entirely on how big you want to grow the plants, what method you intend to use and how much yield you want per plant. Give as much info as you think is slightly relevant, you'll get good advice here.

That would depend on how long you have them in the vegetative state. Also that would depend on your yield expectations. Depends also on if you want a factory to do SCROG or SOG or perhaps just enough for personal smoke. I currently use a 600 W HPS to flower 10 plants. I plan on decreasing the number to 3-4 and veg them longer and placing in another 600W HPS in the flower room. My electricity bill is around $ 109 for the following...a 400 W MH for vegetative growth..around 110 W of flourescents for cloning and seeds or to add more light to the existing mother plants...a 600 W HPS for vegging..2 fans on timers 1 in vegetative room and 1 in flower room..an exhaust fan moving about 650 cfm 12 hours a day..an intake moving in about 225 cfm 12 hours a day..a humidifier that runs about 12 hours a day..thats about it for now.