UTILIZING SOLAR PANELS FOR STREET LIGHTING

UTILIZING SOLAR PANELS FOR STREET LIGHTING


The rising cost of power consumption as a result of dependency on diesel, gas and petrol with uncontrollable, sky rocketing price changes, couple with the fact that the mains supply is grossly inadequate, has necessitated the research into various other ways to generate power supply and dependency on the various prime movers. One of the success stories from such research is the generation of power supply from renewable energy technologies Solar Panels.

SOLAR LIGHTING CONCEPT

The concept works with the sun as the direct source of energy. Using renewable energy technologies, we can convert energy into electricity.

Solar powered lighting is a relatively simple concept. In a basic way, the system operates like a bank account. Withdrawals from the battery to power the light source must be compensated for by commensurate deposits of energy from the solar panels.

As long as the system rate of deposits exceed withdrawals on an average daily basis, the battery remains charged and light source is reliably powered.

1) The sun provides a direct source of energy to the solar panel.
2) The battery is recharged during the day by direct-current (DC) electricity produced by the solar panel.
3) The light source is powered by the battery each night.
4) Electronic controls are used between the battery, light source and solar panels to
Protect the battery from and overcharge discharge, and to control the timing and
The light period.


How Does Solar Power Work?

In principal, it’s simple. A solar panel converts light to electricity. During daylight, even on cloudy days, this “solar generator” (solar panel) charges long-life batteries, which store the energy until needed. Thus, the energy of the sun is harnessed to product power.
In practice, of course, solar outdoor lighting is a little more complex. In addition to large
capacity batteries and solar panels, the system also incorporates sophisticated
proprietary charge regulators, which stop the flow of solar generated electricity when
the batteries are fully charged, and then resume charging when more power is needed.
The key to solar outdoor lighting is the solar power pack, which houses photovoltaic
solar panels, a proprietary microprocessor control system and batteries. It is attached
to specifically designed lights having super reflectivity and high energy ballasts.



How dependable is Solar Powered Lighting?

Very dependable. For one thing, it’s never too cloudy to collect solar energy. In fact,
if there’s enough sunlight to see reasonably well, there’s enough to collect and store
energy – even if it’s raining. The system can be configured to store enough energy to operate five or more consecutive days without sun. What’s more, solar powered outdoor lighting is virtually maintenance free, especially with dry batteries which require no water or other regular service.

What Advantages Does Solar Power Have?
Solar Power systems provide unmatched convenience, reliability and efficiency. Each Solar Powered Lighting has its own “power plant” – so you don’t depend on far away generating stations, transmission lines, substations, switches and transformers. Since each solar electric light operates autonomously, every light is programmed through its
own control system, to turn on and off as needed.

in the unlikely event that an individual solar outdoor light fails, no other lights are affected. Solar systems Outperform traditional wired systems hands-down. In a solar installation, initial costs are incurred for the self-contained energy collection and storage system. But after that, the energy itself is free! When compared to the traditional system
cost for cable, trenching, metering equipment and construction – plus electric bills
Continuing forever – the solar system’s advantages can be dramatic and immediate.

Benefits of Solar Powered Lighting
• No trenching, no metering, no wiring
• Cost savings from day one due to ease of installation
• Lighting works well to deter crime
• People feel safer when areas are illuminated
• Can be installed in the most remote locations
• No cost for daily operation
• Free energy once installed – no electric bills.
• Not connected to grid power – will work even when electric power is out
• Will turn on even after cloudy days
• Reach beyond commercial power lines
• Immune to black outs
Benefits of SOL (SOLAR OUTDOOR LIGHTING)
• CCFL Bulb – provides 30,000 to 40,000 hours with 5 year warranty
• LED technology – provides 100,000 hours
• Max-Lite Reflector in fixtures is specially designed to maximize light output
• No maintenance gel cell batteries
• Batteries located in vented battery box at top of pole







How To Size (Solar Outdoor Lighting)

The solar powered system must be “sized” to determine the appropriate size for the solar panel array before the system can be specified and its price can be determined.

To size a system, we need the following information:

Geographic Location

Different geographic locations have different average sunlight intensity, which determines the size of the required solar panels.

Lighting Application

Different applications require different intensities of illumination.
Preferred Bulb
1) Cold Cathode (CCF)
2) Compact Fluorescent (CF)
3) Low Pressure Sodium (LPS).

Run Time (Duration of the Load)

Run Time is the number of hours that you need the lights to be on each night.
Examples of Run Time are: Dusk to Dawn, 12 hours, 6 hours, and split Run Time hours after dusk and 2 hours before dawn).

Fixture Model

We have a variety of standard fixtures available.
Solar Panel Angle: Flat or 45-Degrees
Solar panels on our SL systems are mounted flat (not inclined). This allows our systems, which are generally used within 23 degrees of the Equator (in the to have a lower EPA (Effective Projected Area) and withstand a higher wind velocity.
Solar panels on our PM systems are mounted at an inclined angle and are generally more cost effective outside of the tropics because they are positioned directly towards
the sun. After you provide the information listed above, we determine the following:
Sun Hours (based on your geographic location)
We determine the sun hours from the sunlight intensity for your geographic area.
Bulb Size
We determine the bulb size from the amount of light you need for your particular
Application or from your specific foot-candle requirements.
Solar Panel Size
Solar panels are available in a variety of sizes. We always calculate a reserve and
deliver a solar panel that will assure reliability.
Model
Based on your requirements, we will recommend the model that is most cost effective.
Size and Number of Batteries
The battery size that is required depends on the wattage of the lamp and the number
of hours the lamp must operate each day. We include sufficient battery backup so system will operate properly after up to five dark or cloudy days. Additional battery Back-up will be included if needed or requested.

In conclusion, it is necessary to point out here that this design concept is relatively new and expensive and cannot be short term. Therefore, effort to ensure that the client gets the right value when the option is adopted is key to effectiveness and efficiency of the system.

Reference: www.solarlighting.com


Azimuth Angle


Azimuth angle (ß)and tilt angle (α).
Illustration: Heindl Internet AG
In order to most effectively use Solar Radiation, a PV Module or Collector of a photovoltaic system and Solar Heating System, respectively, is aligned to absorb or collect as much of the radiation as possible. The radiation's angle of incidence, the tilt angle of the module or collector, and the azimuth angle all play roles in achieving the greatest possible power production.

The azimuth angle ((ß) in the picture at right) specifies how many degrees the surface of the module or collector diverges from the exact south-facing direction. The tilt angle (α) specifies the divergence from the horizontal.

Experiments show that photovoltaic systems operate most effectively with an azimuth angle of about 0° and a tilt angle of about 30° . Of course small variances in these values are not at all problematic: with the system oriented towards the south-east or south-west, about 95 % of the highest possible amount of light can still be absorbed. Large systems with arrays are fitted with electric motors which track the sun in order to optimise output.

See also: Tracking Systems