The EPI platform merry-go-round allows many children to ride while a few take turns pushing. The generation train starts with a hub bearing to which the entire deck of the merry-go-round is attached. A drive shaft from the hub connects to a helical gearbox operating as a speed-increaser. The high-speed output shaft then turns a permanent rare earth magnet windmill generator. The efficiency of this generator is over 70%. The electricity generated by the merry-go-round and all other play equipment in the EPI system is carried by underground wires to a power enclosure, created by Goal Zero, where it is converted to direct current and used to charge a large AGM deep cycle battery (much like those found in golf carts). In the enclosre, a state-of-the-art MPPT (maximum power point tracking) power controller effectively manages the charging and discharging of the storage batteries, protecting against drainage and ensuring long battery life.
Energizer Battery Corporation, an EPI sponsor, has developed and currently supplies the “smart” LED lanterns used in EPI systems. This custom-designed lantern has a nickle-metal hydride (NiMH) battery pack capable of providing children’s studies with over 40 hours of bright light between recharges. One specific thing that sets the EPI smart LED lanterns apart from other such lanterns is the chip found within each that manages recharging from the large storage battery, as well as power to the LED bulbs. The lantern service life is expected to be greater than five years. You can donate a lantern here!
A solar panel is also connected to the power enclosure for educational purposes and to prevent battery discharging during school breaks. The CIGS (Copper Indium Gallium Selenide) solar panel provides additional system energy when school is in session.