Solar Power Systems

A Brief Introduction to Solar Power

Solar panels, also called "photovoltaic" (photo = light, voltaic = electricity) modules are comprised of a group of photovoltaic cells connected together in a single frame. These cells are made of special semiconductive materials, the most common of which is silicon. Typically, these silicon cells are manufactured in 6-inch disks that produce approximately 1/2 volt per cell. These disks are then cut into 4-inch squares (and for our applications are cut into still smaller strips) and strung together in series to generate the required voltage for our products.

When the photons of sunlight strike each photovoltaic cell, a certain portion of them are absorbed into the silicon; in other words, the energy of the sun is transferred to the semiconductor. This energy releases electrons in the semiconductor, enabling them to flow freely. All solar cells have one or more electric fields that force these freed electrons to flow in a certain direction, which is called a current. When metal contacts are attached on the top and bottom of each photovoltaic cell, this current can be drawn off for external use. When combined with each cell's voltage, the current defines the power (in Watts) that the photovoltaic cells can produce.

Photovoltaic cell technology has progressed significantly in recent years. Cost reductions, improved energy efficiency (the ability of the cells to transform sunlight into usable energy) and higher production rates mean solar power is now available for an increasing number of applications - from solar calculators to large solar power stations.

A Comparison of Solar Panels

Not all solar panels are created equal! There are large variations in durability, performance and price. The solar panel used by a manufacturer defines the capabilities, reliability and physical appearance of a solar-powered product. However, there is a fine balance as solar panels providing only slightly more charging power often show a significant increase in price - resulting in solar-powered product too expensive for market expectations.

Carmanah's Solar Power Systems

Carmanah performed a great deal of research prior to selecting the solar panels used in all of its products. The company's efforts were focused on maximizing the durability, quality and performance of its solar power systems while minimizing cost, thus ensuring it has superior reliable products that are priced competitively with other solar and even non-solar alternatives.

Carmanah chose a monocrystalline solar panel technology as the basis of its solar power systems. Originally designed for the U.S. armed forces, this technology has been thoroughly tested under extreme environmental conditions and is more efficient (up to 14%) than the polycrystalline or amorphous (6-7%) solar panel technologies typically used in consumer grade solar-powered products. Carmanah's solar panels are also custom-made to match the specifications of the battery system used in each of its products.

Carmanah's Proprietary Solar Panel Dome

Carmanah manufactures its products with a solar panel fully encapsulated in a patented polymer dome design. This dome provides a number of benefits:

• It increases the solar panel's effectiveness at drawing in light. Typically, a solar panel should be installed facing the sun at an angle of 15� plus latitude for optimal efficiency.

  With Carmanah's proprietary dome design, the solar panel does not have to meet these installation requirements in order to draw the energy it needs for charging.

• As the solar panel is sealed in the polymer, it is very well protected. The polymer is extremely shock resistant, UV resistant, and will not crack or fade in the sun. The solar panel is therefore much more durable than those used in other solar products (commercial or consumer), and can take a great deal of abuse.

• The shape of the solar dome is a deterrent to birds, as they find it more difficult to stand on the dome than on lights with flatter surfaces. In addition, the polymer used is non-porous, very smooth and self-cleaning. It either eliminates the need for cleaning or extends the interval between cleanings significantly.

• The shape of the solar dome eliminates the need for a bird spike, which would cast a shadow and deteriorate the solar panels ability to function.

• The overall benefit, of course, is that Carmanah's products can be used in far more applications than typical solar-powered products and require no real technical knowledge of solar power for proper installation.

Carmanah's Solar Powering Process

As explained above, the solar panels used by Carmanah collect light energy from the sun and convert it to electrical current, which in turn creates power which is stored by the product's battery system.

How quickly the solar panels will recharge the battery system is affected by:

1. How sunny it is outside (or the amount of overcast).
2. How much dirt or grime is covering the solar panels.
3. The outside temperature, as the battery systems and solar panels perform differently under various temperatures.