Here is what I can tell you mathmatically based upon my experience with one size cage only. First off there are many factors that will contribute to the possible savings you may experience like the temperature you keep the room the cages are in, the materials that the cages are made of, etc. Each situation is unique and you may not experience the same results as others. Also RHP may not work in all situations based upon cage height and size and the animal you are heating. Every animal has different needs.I used to keep my ball pythons in glass 40 breeder size tanks. I was using a 16 watt uth and a 100 watt infrared bulb to heat the cage. The infrared was on 24/7 at 100% power and the uth was running at about 50% to maintain temps ( based upon the reading my herpstat was showing so I can say on the average I was using 108 watts per hour every hour to heat that style cage. I switched to 4'×2'×2' wooden cages using just an 80 watt RHP. AFTER the initial heating period time it took to acclimate the cage my panels are running at 46% (again based upon the reading from my herpstat) so based on that im using 40 watts an hour. 108wph down to 40wph, thats about a 64% savings per cage and I changed 7 cages over so that is a pretty significant savings at the end of the years , but again that is based upon my conditions so you may not see the same results.