Metrolight, which has just received $9 million in a third round of funding from Gemini Israel Funds and Richard Branson's Virgin Fuels, has been riding a surge of demand for its high-frequency electronic ballast, a device for controlling high-intensity discharge (HID) lights--those bright lights used for illuminating department stores, large interior spaces and freeways.
The system effectively provides the same amount of light as more traditional magnetic or electromagnetic systems, but requires less overall power, the company says. Additionally, the HID lights can be dimmed when no one is present or, if the light fixture is connected to the Internet, dimmed by a utility to prevent a. Some customers have seen their electric lighting and maintenance bills drop by around 50 percent, according to Metrolight.
"There are 150 million HID sockets in the U.S. and each one is a candidate for our product," says Randy Reid, Metrolight's executive vice president of sales.
The company has been selling systems since 2002, but in the past two years revenue has accelerated with rising electricity prices, Reid says.
Other companies make similar products, but Metrolight is gaining a reputation.
"It's pretty state-of-the-art as far as electronic ballasts are concerned," says Ed Hammer, a retired lighting engineer from GE.
Lighting consumes 22 percent of the electricity generated in the U.S., according to the Department of Energy, and HID lights account for around 22 percent of the total electricity generated for lighting. Light fixtures in general could stand some improvement. The vast amount of energy directed toward incandescent bulbs turns into heat, not light. Typical light bulbs only get about 15 lumens per watt.
HID bulbs, by contrast, are somewhat efficient in terms of lumens per watt: commercial HID lamps can get 90 lumens per watt. Unfortunately, they remain quite power hungry, consuming 400 watts or more of power. Older HIDs are also controlled by magnetic ballasts. In many cases, it takes significant voltage and a few minutes for the magnetic ballast to flip on the light.
The older ballasts also splatter tungsten onto the walls of the lamp, blackening the surface and reducing the lifespan. Mercury in the lamp causes the tungsten to splatter, says Hammer.
"If you can reduce the sputtering, you can reduce the darkening," Hammer says.
By contrast, Metrolight's electronic ballast controls the lamp with a constant train of electronic pulses. The lamp lights quicker, sputtering is minimized, and lower energy consumption and longer life for the bulb results.
"We are starting the lamp very gently and easily," he says. "Instead of using a 400 watt bulb (par for the course for metal halide HIDs), you can use a 250 watt bulb."
Magnetic ballasts also don't have dimmers. Metrolight can dim, which can lead to considerable savings. In warehouses, a dimmer can be used to lower the lights in areas when forklifts or employees aren't present. The dimmer can then flip the lights on automatically when someone or some vehicle passes a sensor.
The company's technology also complements many of the new lighting technologies gaining momentum. Some companies, for instance, are touting systems that. Since the sun doesn't shine all of the time, building contractors are considering combining systems with an HID system powered with Metrolight's dimmers. The lights hooked to the lamp/fiber systems are actually HIDs anyway, so they are tailored for the dimmer.
LEDs compete with HID systems. LEDs are increasingly popular in buildings. The city of Raleigh, N.C. is replacing sodium HIDs with LEDs in