Solar Panels For Sale
We wish to provide you and the rest of the world with sustainable energy and one of the most efficient ways of extracting clean energy from nature is by using solar panels to harness the power of the sun. So here are some of the products we recommend.
What Is Solar Energy?
This is power derived from direct sunlight. This section will provide extensive solar energy information.
How Does Solar Power Work?
Solar power for homes can be used for lighting, cooking, drying, and heating or for powering household devices. Solar power can also be used in thermal energy sources for passive or active heating or cooling. Solar power systems work in two ways; Solar PV modules convert solar radiation directly to electricity while thermal systems focus solar radiation to produce steam which is used to turn turbines (solar power generator) to generate electricity.
The photovoltaic technology can be traced back 150 years ago but significant progress was made from the year 1954 with the development of silicon photovoltaic cells. The performance of PV modules has been improving over time paving way for reduced cost of solar power generation. The current PV technology involves use of photovoltaic panels that consist of solar cells that are protected by a glass sheet. The system contains a solar inverter that converts direct solar current (DC) to AC (alternating current) which is then transmitted over the power grid. This is how solar panels work. A photovoltaic panel is made of photovoltaic cells. Pv cells are made from semiconductor material that reflect, absorb or transmit photons from sunlight. The absorbed photons are the ones that are used to produce power. For better efficiency Pv panels are ideally installed facing the sun directly.
Presently, annual global PV module production is over 150 MW, which translates into a more than $1 billion/year business. The present day performance, efficiency and cost of photovoltaic systems have made them suitable for most grid-isolated and grid-connected power systems globally.
Solar pv is steadily gaining a larger market share in electricity generation. In fact, statistics from REN21 show that “In 2014, solar PV marked another record year for growth, with an estimated 40 GW installed for a total global capacity of about 177 GW. China, Japan, and the United States accounted for the vast majority of new capacity”. There is also an increase in the number of solar powered devices today. The cost of electricity generated from photovoltaic systems is still higher than from other competing technologies, but these costs are set to decline steadily over time.
Solar Thermal Systems
These are advanced solar power systems that concentrate sunlight for heating or cooling. The first ever thermal power system was installed in Sahara in 1910 to run a steam engine. Thermal systems can be classified into low, medium or high temperature collectors. They can also be designed as active or passive thermal systems. Solar heat concentration is a form of active thermal system.
The low temperature collectors are simple flat plates used for smaller applications like heating water in swimming pools or showers and air heating in offices or homes. The flat plates are mechanically simple consisting of the absorber, a collector box, heat insulation and a transparent cover. The absorbed energy is converted to thermal energy which is then transferred to the absorber sheet then to the absorber pipes and finally to the fluid.
Medium temperature collectors also use the same beam and diffuse radiation mechanism as the flat plates. The difference is they produce more thermal energy and are therefore used for commercial heating systems where larger areas are involved like water distillation or drying of wood products for either processing or construction.
High temperature systems focus energy onto small areas using lenses and mirrors and can generate up to 3000C/20 bar pressure as CST (Concentrated Solar Thermal) for industries or as CSP (Concentrated Solar Power) for electric power grids. The most outstanding advantage of CSP is the ability to efficiently store thermal energy allowing the supply of electric power up to a period of 24-hours. These systems only use the beam component of solar radiation which means its benefits are limited to a certain geographic range. The collectors are tracked according to the position of the sun because they utilize direct solar radiation. There are three different technologies used to concentrate rays to a point. The IPCC categorizes them as follows;
– Parabolic trough concentration
– Line –focus/linear Fresnel systems
– Dish or central receiver systems
The parabolic system utilizes parabolic trough-shaped mirrors to focus heat to receiver tubes that contain an intermediary fluid (usually oil) for heat transfer. The fluid is heated to 3900C and transferred through numerous heat exchangers to produce steam that powers an electricity-producing turbine. Parabolic reflectors track the sun’s movement and concentrate irradiation to a heat collection element mounted along its focal line. These systems are commercially available.
The linear Fresnel systems use long parallel mirrors as the concentrators with a linearly fixed receiver. The heat transfer mechanism is similar to the parabolic system.
Commonly known as the power tower system, the central receiver system makes use of a circular array of large individually- tracking reflectors (heliostats). Each mirror tracks the sun on double axes and focuses it towards a point on a tall receiving tower. The receiver may consist of tubes containing the fluid or a fixed inverted receiver cavity.
Passive systems are commonly integrated into the building at the architectural design level. A passive solar house plan may involve designing large areas of the house with solar thermal masses like stones, tiles, glasses etc. that consistently absorb heat, store it and later dissipate it to keep the house interior warm. Passive house plans are designed by architects to allow for optimum heat storage throughout the year.
A typical passive house.
Solar panels are the most common solar energy systems. A solar panel is combination of solar cells (photovoltaic devices). The solar cell converts solar energy directly to electricity. The traditional use of solar power has been solar panel (usually pv panels) installations on the roof of residential for small scale domestic use. Solar electricity is common in areas with no connection to the national electricity grid. Space stations make use of solar arrays (thousands of solar cells) to produce electricity. However, solar panel technology is still inefficient in converting the sun energy to electric power. Ordinarily, silicon solar cells generate electricity with an efficiency of up to 18% while those made from gallium arsenide exhibit efficiencies of up to 27%. Photovoltaic panels also have a life span.
Choosing A Solar Panel
Choosing the best solar panels involves more than just the price consideration. A solar panel’s price is pegged onto a number of factors. It is determined by the wattage, size, durability, brand and materials used. Its size should correspond to the area it is to be fitted. Choose a solar panel with greater conversion efficiency with low temperature co-efficiency with a longer guaranteed life span. Solar cells made from monocrystalline silicon have greater conversion efficiency than all other types of solar cells. The wattage will be determined by the number and nature of operations the system is intended to support. The panel should display very minimal light-induced degradation (LID) and potential-induced degradation (PID).
Solar panel kits are purchased with installation manuals. It is however recommended to involve a qualified solar technology expert to make proper installation. The expert will recommend ideal positioning of the solar panel. Solar panels for sale come in various sizes and capacities. For small scale purposes, DIY solar panels or portable solar panels are among the cheap solar panels that can be purchased from any solar energy companies and used with very simply.
Facts About Solar Energy
s Solar energy is measured in kWh.
s The kWh is used to determine the capacity of solar panels power production. The cost of solar panels is consequently determined by the wattage.
s Solar energy is free and inexhaustible.
s About 30% of incoming solar energy is reflected back to space. The rest is absorbed by land masses, clouds and water bodies.
s The uses of solar energy are multiple. This means that solar energy can easily substitute most conventional energy sources. According to the Corpus SCP, solar is the fastest growing energy technology in the European Union region.
s We use solar energy in our everyday life in a number of ways. Solar energy supports a number of physical and environmental flows on which humans depend.
s Approximately 1,000W of solar power reaches the Earth’s surface per hour/m2. This varies with the geographical location and the terrain,
s The fossil fuels used today are a form of stored solar energy.
s Solar energy is green energy; it is non-polluting. Solar power production does not produce any noise.
Facts About Solar Power
Here are some of the solar power facts;
s The use of solar power is on the rise. Solar water heaters are used in majority of homes. Solar hot water is a common feature in recent residential property.
s The solar power industry has advanced greatly and is creating jobs for hundreds of thousands of people around the world.
s Solar power plants transform sun energy to electricity either through concentration of irradiation or through photovoltaics.
s The Ivanpah plant is the largest solar power plant in the world and is located in Mojave Desert in California. The solar plant generates a large percentage of the world’s commercially produced solar power (almost 400MW) using concentration technology. The largest PV plant (Solar Star) generates up to 579MW and is also located in California.
Advantages Of Solar Energy
– Solar energy is a clean energy.
– It is abundant in supply.
– It can be used anywhere from both small scale to large scale industrial and commercial purposes. There is increasing use of solar generators worldwide.
– It can be used together with other forms of energy. Solar thermal technologies can be used together with conventional power systems to enhance efficiency. “Because these technologies involve a thermal intermediary, they can be readily hybridized with fossil fuels and in some cases adapted to utilize thermal storage. The primary advantage of hybridization and thermal storage is that the technologies can provide dispatchable power and operate during periods when solar energy is not available. Hybridization and thermal storage can enhance the economic value of the electricity produced, and reduce its average cost” (Herzog et al., 2001).
– It is sustainable energy; it will never be depleted.
– Solar energy panels require minimum maintenance
– Solar energy is free
– Solar technology allows for energy storage even at small scale level. Solar energy storage systems include use of batteries that store electricity in DC form.
– Solar installation capital costs are high
– The efficiency of solar energy varies with changing weather conditions
– Solar energy storage technologies are expensive to install
– Harnessing of solar energy uses up a considerable amount of space.