Chicago (IL) - Sharp has introduced a line of scalable 1800 lumen LED-based lighting fixtures appropriate for permanent outdoor use (roughly the same illumination as a traditional 250 Watt flood light per head). While two of the three models introduced are traditional AC power units which would sit atop utility poles, one model can operate on either AC power, or DC from power stored by an included solar panel and battery assembly.
Light arrays include dual-head and larger units affixed on a pole, or designed to mount to an existing pole. Center image shows solar panel, light and battery assembly. LED lights produce 1800 lumens per bulb. As assembled, luminosity runs as high as 9600 lumens per fixture (the equivalent of five traditional 250 Watt flood lights using a maximum of 184 watts). Prices vary in the range from $8271 - $12,407 (Left) to $10,339 - $14,992 (Middle) to $517 - $775 (Right).
The solar panel models LN-LX1, LN-LXH1, LN-LSX1 and LN-LXHS1 include a dual-head light fixture, battery assembly and overhead stationary solar panel. According to sharp, these provide LED light while emitting "no CO2 whatsoever", storing energy during the day to release all night. These models sell for $10,339, $12,407, $12,924 and $14,992, respectively. Ouch!
The other two lines include DL-E40VA and DL-E20VA which are dual-head or single-head light fixtures which operate off of traditional AC power. They sell for $775 and $517, respectively; along with DL-E240N, DL-E24SN, DL-E140N and DL-E14SN which include dual-head or single-head light fixture, as well as a 4.5 meter (14'6") mounting pole for stand-alone outdoor lighting in any area, and sell for $10,856, $12,407, $8271 and $9822 respectively.
Sharp is manufacturing these products in Japan with a very low initial run of only 12,000 solar powered units, 36,000 units that mount on existing poles, and 6,000 units with poles. However, this may be due to its extremely high price which, while quite shocking, is targeted primarily at cities and municipalities where permanent outdoor lighting can save significantly on annual electrical bills.
The LEDs used in these products are 30% more luminous efficient with a lens dispersing light over a broad area. They can be installed in public places at a distance of 32 meters per pole, compared to 12 meters for 40 Watt mercury-vapor lamps.
Solar powered lights provide illumination from "Sunset to sunrise (all-night light with energy-saving mode)". It also includes a seismic detector which switches the light on automatically when any Magnitude 5 or greater quake is registered (on Japanese seismic scale). The battery pack consists of three 12 volt, 38 Amp-hour batteries, providing 114 Amp-hours of power. The unit weighs 131 kilograms (290 pounds) and operates from -15C to +40C.
The DL-E40VA and DL-E20VA models consume 39 Watts (2400 lumens) and 17 Watts (1200 lumens) respectively, and are mounted on an existing pole. They are light-weight devices weighing only about 6.5 pounds. The DL-E240N and DL-E24SN consume 184 Watts and produce 9500 lumens at 127 pounds (including the pole, which is in excess of 100 pounds). The DL-E140N and DL-E14SN models are similar in weight and product 4750 lumens on 92 Watts.
To achieve 9500 lumens using traditional 60 Watt incandescent bulbs would require 720 Watts of power for 12 bulbs. An equivalent incandescent annual expense with 12 hours of daily operation would be $315.58, compared to an annual expense of $80.65 for the LED lights (a savings of $234.93 per year). Considering that these models cost $8271 to $12,407 (compared to under $300 for bulbs and fixtures for the 60 Watt solution), it would take between 34 and 51 years to justify the expense in money. It would take 63 years to justify the expense for the solar powered version, assuming the batteries and solar panel itself never failed -- or the pole, come to think of it.
Going green makes no sense until these prices come down. Given this rate of disparity in expense between traditional power-consuming lights, and LED-based products (even those which are 30% more luminous efficient than previous models), I can see no justifiable reason to go green in this instance. At least not for 5- to 10- more years when the prices will finally come down to reasonable levels.
In addition, silicon-based solar cells are basically made by refining sand. Isn't it possible that some company could produce a 15% efficient or higher silicon-based solar cell that is extremely cheap? I would think it would be a Chicken and the egg kind of thing. First, you build enough solar panels to completely power your plant. Then, from that point forward the only expenses you'd have would be shipping, equipment maintenance and employees.
Surely this is doable for some ingenious company out there?UPDATED:March 31, 2009 - 01:45am CDT
The article's annual electricity expense calculations and amounts have been updated.