They may be charged from the same source, but solar panels are not made the same. Solar powered devices and charging units are making an impact in the consumer electronics sector, but there’s much that needs to be known about the different products. Expert Craig Adam of Secur gave a brief education on what to look for.
Solar charging products seem like a no-brainer but have yet to significantly take off. What are the issues involved?
The main problem with small portable solar chargers has been in disappointing performance. The small inefficient solar panels that have been introduced in the past can take days to charge a large lithium battery. Users have been very disappointed with the long charging times.
What aspects and features should a consumer look for in solar charging solutions?
The key is matching the solar panel output to the size of the battery. There is a fairly simple formula to determine the normal charging time based on the rated output of the solar panel and the size of the battery. In many cases, a large lithium battery will require a larger solar charging surface than would be practical on a small handheld device.The other alternative is to go with a very high efficiency solar cell. This is the approach we prefer in our solar chargers.
What is the life expectancy of solar charging products compared to other portable charging units?
Typical solar panels will last about 7 years before the output start to degrade. However, the high efficiency panels Secur uses are rated to last 30 years. Some types of batteries have a very limited number of charges and discharges during their life time – especially lead acid and NiMH batteries which are used in low cost charging systems. All Secur Products use Lithium Ion or Lithium Polymer batteries which offer up to ten times the number of charges compared to the lower costs batteries.
Are all solar products made alike?
No. There are several basic types of solar panels that have vastly different charging efficiencies:
- Amorphous Panels – 6% – 8%
- Thin Film Panels – 9% – 10% efficiency
- Polycrystalline Panels – 13% to 15% efficiency
- Traditional Monocrystalline Panels – 15% – 18% efficiency
- Sun Power Panels – 24% efficiency
Another main factor that determines the actual output of a solar cell is how much of the light spectrum is used to generate current. Most solar panels require direct sunlight that depends primarily on the infrared spectrum. Once the direct sunlight is not available the output drops dramatically – given you very few hours of high out charging in during a typical day.
The Secur Sun Power panels are based on a patented technology that uses a much broader range of the light spectrum. Thus, you can charge from sunrise to sunset or under overcast skies.
Another factor is the reflective surface the solar panel. Many popular solar panels have a shiny plastic or glass surface that reflects much of the sunlight and reduces output. The Sun Power panels have a special mat finish which absorbs a much higher percentage of the available than most other solar panels. These factors will result in the actual energy output in an average day being up to twice that of traditional monocrystalline solar cells. It will be up to four times greater than flexible thin film solar panels.
What does Secur bring to the sector and what innovations are on the horizon?
Sun Power Solar Cells with up to four times the output of other portable solar panels; Built-in solar controller than greatly reduces accidental discharge and extends battery life; High capacity, light weight Lithium Ion batteries; and Multi-function solar powered products which include smartphone charges, lighting and radios.