Solar

Solar energy has gained a significant share of the energy market in the last decades. This is due in large to the reduction in the component cost, escalating energy costs, easy and simple installation and similarly to wind solar, has zero-cost at source. Solar has both disadvantages and advantages, some of which are as follows:

• Easy and quick installation.
• Reasonably cost effective.
• Dependence on solar emissions.
• Large surface area required for panels.
• Lifespan of components.
• Poor installation practices.

Solar Energy can be divided into two specific areas:

Energy for the heating of water

Energy for the generation of electricity

The use of zero cost energy sources such as solar and wind in view of dwindling fossil fuels is increasing the requirement for alternate energy sources.

Solar has become increasingly more important in areas such as Southern Europe, South America, Australia, Asia, and Africa. In these areas solar radiation offers a relatively low cost,” quick fix” solution to energy restrictions. The other aspect to going “off-grid” in many areas is accessibility and cost viability. In many remote areas that are for example used for mining and agricultural purposes supplying utilities such as water and energy is not feasible due to distances and cost parameters. The focus in this section of the webpage will be dedicated in greater detail to the Southern African region. Africa due to its large arid areas could supply most of Europe with its energy requirements. However geopolitical differences have largely prevented this, one of the exceptions is the solar facility in Morocco which supplies energy to Spain via an undersea cable. Solar energy can be obtained via either the use of photo-voltaic materials or concentrating the energy via the use of mirrors. The latter apart from the cost factor has an implication that the mirrors must continuously rotate/move in accordance with the location of the sun.

One of the other main challenges is that the sun is not continuously available, similarly to wind. The sun and the wind face similar challenges where the requirement for energy is not constant. Conventional nuclear and fossil fuel energy generators could “power” down or up as demand requires. Wind whilst not constant can generate energy twenty-four hours a day. The trade-off with solar energy, whilst having a zero-cost basis requires storage facilities for the “off” periods such as when the sun is obscured by clouds or at night. If cost calculations are performed on a quality solar energy installation, the payback period is generally in the thirty-six-to-forty-eight-month range. This makes the case that solar is viable as energy costs from fossil fuel sources will continue to escalate as they become scarcer. Other aspects to be taken into consideration when considering a solar installation whether commercial or domestic is the “green footprint” remaining because of the manufacture of the components and also their lifespan.

The installation of PV systems is generally simple however there are certain non-energy considerations to be aware of, some of the are as follows:

• A PV installation effectively becomes a component of the house, factory etc. and the cost implications regarding the value of the entity must be considered.
• Many Insurance suppliers and city/town councils may have to be informed of the installation or require approval and may also specify certain component manufacturers that must be used.
• The cost of any installation may require financial input via a loan facility. In South Africa this is normally a function of the home loan division of the bond holder of the property. The repayment period is over sixty months, however, interest rates can fluctuate meaning potentially higher monthly repayments. It is important to avoid one particular aspect of the solar industry that exists in the US whereby a financier or solar supplier can take a lien on a property prior to it being sold.
•  It is critical for a registered contractor to install the PV system, as a COC certificate is required by the loan supplier and insurer. Due to the simplicity of the installation some installers have resulted in sub-standard installations becoming a physical liability. There is a green card system although not a necessity can enhance the reputation of an installer.

Prior to examining the potential for the installation other cost-effective measures for the generation of energy can be considered, these include the use of rechargeable LED light globes, external solar spotlights and the conversion of cooking facilities to LPG (liquid petroleum gas). Industrial energy generally requires large amounts of current (Amps). This can only be supplied by large diesel generators or large PV installations. The same criteria that apply to urban solutions also apply to industrial concerns. Once low-cost solar considerations have been examined, solutions of a more permanent nature can be studied. Depending upon the size, a PV installation can be expensive. The largest domestic energy consumers are cooking appliances, geysers and air conditioners. An alternative approach may be to plan for ultimately going of the grid with an initial position of installing solar generating units which are more economic.

Solar geysers could be a logical starting point. Solar Geysers are generally divided into two categories: low and high pressure. Characteristics of both are as follow:

• Generally low-pressure geysers are used in rural areas where water resourses in terms of pressure is low. Urban water pressures are generally higher due to water being stored in tanks high above ground levels.
• Solar geysers have a reasonably short payback period.
• Zero nighttime radiation, cloudy weather and rain can reduce the reliability of solar geysers.
• Conventional electric geysers require power inputs of 2-3kW.
• Solar geysers are reasonably easy to install.
• Precautions against freezing conditions must be taken into account, hail and sudden extreme rain, paying attention to roof drainage facilities as panel will effectively create a sheet which existing guttering may not be designed to accommodate.

If a solar geyser is to be installed ensure that the manufacturer is reputable in terms of supply of spare parts. Depending upon the size of the household or weather conditions, solar geysers may not be able to supply hot water on a continuous basis, so it is recommended that the main geyser remain connected to the main utility water supply and also the main electricity supply, be it the grid or a PV system. A real time relay can be used to overcome this type of situation whereby the grid/PV source is activated when there is a shortage of hot water. Photo-Voltaic (PV) systems have started to become more popular, however prior to making some comments on the subject it is necessary to state in terms how these systems are sold in terms of magnitude of output.

Unit of Current           Ampere (A) or (I)

Unit of Voltage           Volt      (V)

Unit of Power             Watt     (W)

The relationship between these three quantities is:

Power = Amps x Volts or P=IV     (watts)

The easiest way of explaining this is to imagine a pipe with water in it, the water equates to Amps, the pressure to move the water are the Volts and the work done to move the water is the Power. (Scientifically this is not entirely correct as the system would involve work and force).

Many PV systems are sold using some of the following ratings, AH, KVA and KWH These are explained as follows:

• Ah is Amps per hour and relates to battery capacity (i.e., it is the number of amps that can be drawn from a charged battery per hour).
• KVA is Kilovolt Amps and relates to the power output and KWH is Kilowatts per hour which is also the power output. Often there is a power correction factor that leads to the result that 1KVA does not equal 1KWh.
• Before investing in a PV energy roof power generating system, it is essential to be aware that technology is continuously evolving, and components may change in both size and improved performance.