This morning, Cree announced a new high-output streetlight designed to replace the 400-watt HPS and cut energy usage in half. It’s called LEDway HO Roadway Luminaire. Yesterday, we were given a briefing on this product. The luminaire has many features one would expect such as tool-less entry and 10KV protection, but the exciting part is the 50% increase in lumens/dollar.
Another benefit is that it can switch to nine different light levels, from 100% down to 61%, about 25,000 lumens to 15,000 lumens, or 274 total system watts to 136. Now one fixture can solve many needs.
When I talk to utilities, one reluctance to any new technology is based on their truck configuration. With 50 years of experience, they beam with pride as they explain how their crews have mastered the correct mix of lamps, ballasts, starters, capacitors, and sockets needed. They want to fix 99% of the fixtures on the first call. Now with one luminaire, they can address most situations in the target market of freeways, expressways and major arterial roads—without all those components.
The math seems to work. Let’s say you want to design a road with 30-foot poles to 1.7 average foot-candles, which is the minimum standard in IES RP8. According to the example Cree provided, if a 250-watt HPS were chosen, the luminaire would consume 295 system watts and only provide 1.59 foot-candles—not meeting the spec. Normally, the utility would step up to a 400-wat HPS, which consumes 460 total system watts and provides 2.66 average foot-candles—which is well over the spec. Wasted light. With the new HO luminaire, the utility would simply dial back the wattage, in this case to 214 total system watts, which would meet the 1.7 foot-candle requirement. Therefore the spec could be met with a 214-watt fixture instead of 460 watts. However, as your humble editor continues to point out, this example will now drive the light levels uniformly to the lowest common denominator. However, I am constantly reminded that today’s technology allows for luminaire manufacturers to deliver any light level the customer desires. Our hope is that with new technology, the industry will not always design to the lowest level.
Another important feature is cost. There have been great LED fixtures that were complete flops because they were not cost viable. We are told that a city or utility should expect to pay about $500 to $600 for the LEDway HO base model in typical quantities. This is a competitive price and thus their claim of a 50% increase in lumens/dollar.
At an average cost of $550 and $0.07 per kWh, it equates to about $75 per year just in energy savings. This savings does not reflect the huge maintenance reduction. Two men-and-a-truck can add $10 to $50 per year in maintenance savings. More if they are unionized. Even more if they are in Chicago with their three men-and-a-truck policy (One to do the work, one to drive the truck, and one to sit in the portable lawn chair.)
In August of this year, Cree launched a $99 LED cobrahead replacement. Cree seems to have most bases covered even though they have only recently entered, and disrupted, the former oligopoly of street lighting.