Check out this manufacturer of EM Lighting Inverters. There is a tipping point on the number of EM ballasts where a lighting inverter becomes the least expensive solution to comply with code. From the website at Crucial Power:
Crucial Power offers the most diversified Central Lighting Inverter product line on the market today. Standard features include:
n Latest technology, Double Conversion “no-break” transfer of power
n Pulse Width Modulated (PWM) design for true Sine Wave output
n Compatible with fluorescent, incandescent and HID lamps
n Small footprint, modular design enclosures
n Sealed maintenance-free lead calcium batteries
n Advanced self-testing and monitoring systems
n Listed to UL 924, UL924A and UL 1778UPS by CSA
Crucial Power leads the industry with many exclusive products, including:
n EconoSine – the most compact (28” x 24” x 15”) self-contained 500VA to 3000VA Inverter available
n EconoSine Super Charged – new 2.1KW and 3KW model with multiple voltages and expanded capabilities
n Wave Riderรค family – full range of latest design Inverters in 3kVA to 62.5kVA sizes, wide array of options, single and three phase models
n HEU – the only outdoor and hostile environment Inverter on the market, built for remote, vandal-prone and harsh weather locations
n Monitoring – from basic local monitoring to advanced systems for remote monitoring and reporting via phone, fax, e-mail, pager or the internet worldwide
Crucial Power Inverters are in operation throughout the U.S. in a wide range of applications, including retail stores, schools & universities, office buildings, hospitals, restaurants, banks, movie theaters, hotels & motels, airports, railroads, subways & tunnels, prisons, military bases, shopping centers and manufacturing plants.