The US roadway system is sprawling, covering over 150,000 miles all the way from Maine’s rocky coastline to the great redwoods of California. If you’ve traveled by highway outside of major cities, you’ve probably noticed that some of them are lit at night closest to the cities they travel through.
The US roadway system is sprawling, covering over 150,000 miles all the way from Maine’s rocky coastline to the great redwoods of California. If you’ve traveled by highway outside of major cities, you’ve probably noticed that some of them are lit at night closest to the cities they travel through. These roadway lamps use mercury bulbs to light highway systems for about twelve hours daily.
Given the energy efficiency of newer technologies, like LED lighting and solar paneled lighting, there’s considerable untapped potential for savings in our nation’s roadway lighting. The upfront costs could be significant, however. Let’s consider some of the risks and benefits associated with solar powered LED lighting for roadways.
Replacing mercury lamp bulbs in our nation’s roadway lighting with solar powered LED lighting provides a number of promising solutions. For one thing, LED lighting saves about 75% more energy than the mercury lamps widely used in roadway lighting across the US. Energy savings on that scale yields tremendous cost savings over time. Overall, considering energy savings is essentially a consideration of financial savings too. Energy technologies that are more efficient, reliable, and longer lasting inevitably yield significant savings associated with energy production and risk.
In 2009 a group of researchers tested the economic feasibility of solar powered LED lighting units for roadways compared to grid powered LEDs and the traditional mercury lamps. They tested the three different system’s costs and benefits for a 10 km highway with 2 lanes.
In the study, the installation cost for the sample stretch of highway was valued at 22 million USD for LED powered by grid power and 26 million USD for solar-powered. The total installation cost of conventional mercury lighting was 18 million USD. So clearly the LED systems are both more costly upfront. But, the costs of power generation and electrical transmission can be greatly reduced with both of the LED systems, since about 75% energy is saved for LED compared to mercury bulbs.
The payback time for the excess investment of the whole lighting system is 2.2 years for LED using grid power and 3.3 years for LED using solar powered. The LED fixture lifetime can exceed 10 years. Therefore, the roadway lighting using high-power LED either by grid power or solar power is economically feasible in considering the payback time and the lifetime compared to the current mercury bulbs in roadway lighting across the US1.
Solar lighting has been commercialized for some time, which dispels some risks that would be involved with any technology in an experimental phase. In terms of reliability, grid power cannot reach the most remote roadway areas in the US. Solar LED lighting station would effectively eliminate the need for transmission, and therefore eliminate the energy loss that occurs during transmission.
Seems like it’s time to switch bulbs!