the amount of money you think your saving really isnt that much by turning your lights of for an extra 2 hours for flower then 4 hours for veg.. your probably saving 1 or 2 dollars a month.. unless your running multiple 1000w bulbs then the savings are insignificant and the risk of hermie outways the cost much more..
http://en.seedfinder.eu/growing/energy-costs-calculator/
you can go there to use the energy cost calculator, just get your most recent energy bill and input the cost per killowatt hour (its in euros so ull have to convert dollars to euros)..
and then it will tell you how much evrything will cost the fans, the lights, all of it per day/month/entire grow... then convert it bak to dollars..
i have a closet grow so it only cost like 30 bux for the whole shabang...
this is what the end result will look like i have two 150w magnetic ballast, two cpu fans, one regular cirulation fan, an air purifier, and a t5 for cloning station. i did the calculation for 90 days of both sides on... and it only costs 50 bux USD.. $.22 cents a day...
EURO
Illumination all together: 405 kWh 22.64 EUR
into the growth: 243 kWh 13.59 EUR
into the bloom: 162 kWh 9.06 EUR
Costs for the circulating air ventilation: 102.6 kWh 5.74 EUR
div. Consumer #1: 135 kWh 7.55 EUR
div. Consumer #2: 81 kWh 4.53 EUR
All together: 40.46 EUR ($57.71 USD)
Costs per month: 6.69 EUR
Costs per day: 0.22 EUR
TO CONVERT FROM EURO TO US DOLLAR
http://www.google.com/search?q=usd+to+euro&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a