Residential solar panels
Residential solar panels continue to be one of the largest trends in green building and energy conservation. Solar panels are quickly becoming one of the most affordable ways to lower utility costs for the homeowner.
Homes connected to the utility electrical grid are known as grid-tied homes or on-the-grid systems, while off-grid homes rely on batteries and need to be a safe distance from power lines. Most homeowners choose to work on the grid due to the added security from the utility company.
Residential solar energy systems still function on cloudy days by drawing upon backup electricity from the utility company (for on-the-grid systems), and the same is true during night hours. For off-the-grid systems, the panels are usually connected to a battery storage system as the backup power source and will extract energy if there is a deficiency that day.
Solar Cells
Solar panels are made up of number of solar cells. Solar Cells, or photovoltaic cells, are arranged in a grid-like pattern on the surface of the solar panel. These solar voltaic cells collect sunlight during the daylight hours and covert it into electricity. Sometimes the term solar cell is reserved for devices intended specifically to capture energy from sunlight, while the term photovoltaic cell is used when the light source is unspecified. The field of research related to solar cells is known as photo voltaic.
Solar electric panels contain many photovoltaic cells electrically connected and packaged behind glass for mechanical protection and electrical insulation. The modules are usually connected together in an array and with other components such as a mounting frame and an electrical inverter (for on grid) or a charge controller and batteries (for off grid).
In addition to solar panels, a photovoltaic (PV) system requires a mounting structure to tilt panels toward the sun, an inverter to convert panel-generated direct current (DC) into appliance-friendly alternating current (AC), battery storage to compensate for unfavourable weather conditions, and a charge controller to regulate battery operation.Two Forms of solar cells
There are two main forms of solar cells in existence today, and these are; "solar electricity panels" and "solar hot water panels". The two different technologies allow us to either generate electricity for our homes or to heat the water we use.The combination of a solar hot water panel with other renewable energy technologies, such as solar panels, or a home wind turbine can work quite well together in providing a source of cheap, clean, and renewable energy for our homes.
Solar Panel
Solar panels consist of modules that contain solar cells and convert sunlight into direct current (DC) electricity. An inverter within the panel converts the DC power into alternating current (AC) electricity that is used to heat and cool the home, and also operate any home appliance or device.
Solar Panels are a form of active solar power. The term solar panel is used to describe two completely different technologies, both of which generate energy from sunlight, and both of which are packaged in the form of panels:
- a photovoltaic module is used to generate electricity
- a solar thermal collector is used to generate heat (generally hot water)
Solar panels are typically constructed with crystalline silicon, which is used in other industries (such as the microprocessor industry), and the more expensive gallium arsenide, which is produced exclusively for use in photovoltaic (solar) cells.
Other, more efficient solar panels are assembled by depositing amorphous silicon alloy in a continuous roll-to-roll process. The solar cells created from this process are called Amorphous Silicon Solar Cells, or A-si. Solar Panels constructed using amorphous silicon technology is more durable, efficient, and thinner than their crystalline counterpartsFor very important solar projects, such as space probes that have to rely on solar energy, very-high efficiency solar cells are constructed from gallium arsenide by a process called molecular beam epitaxy. Solar cells constructed by this process have several p-n junction diodes, each designed to be maximally efficient at absorbing a given part of the solar spectrum. These solar panels are much more efficient than conventional types, but the process and materials involved make them far too expensive for everyday applications.
The newest solar panels function on the molecular or quantum level, and represent an exciting new technology coming into play. These solar panels are created by implanting carbon nanotubes or quantum dots into a treated plastic. Unlike silicon-based solar panels, these solar panels do not have to be constructed in a clean room, and therefore production costs are somewhat diminished.
Power production
In direct sunlight at the surface of the equator, a maximally efficient photovoltaic cell about 1/5m in diameter creates a current of approximately 2 amps at 2 volts, however, due to the Earth's atmospheric interference, terran solar panels will never perform as well as solar panels exposed directly to the sun's rays.
Solar hot water panel
Solar hot water panels are a means to harness the sun's energy in a unique way. Like traditional solar panels, solar hot water panels are placed in direct sunlight, oftentimes arrayed on rooftops. A solar hot water array often referred to as a solar hot water heater, uses the energy from the sun to heat a fluid, which is in turn used to move heat generated in the array to a heat storage vessel. The process starts by heating a body of sanitized water and storing it in a hot water cylinder. Next, solar hot water panels would be installed on the rooftop, each with a darkly-coated absorber plate complete with water circulation tubes.
The tubes carry the heated water from the solar water heater to a place where it can be used or stored. A heat exchanger released heat and circulates the cooled water back to the solar hot water array to be reheated. This cycle of heating, energy utilization, and cooling is begun anew with each sunrise and lasts throughout the day for the effective life of the solar hot water heater. These arrays are especially useful for businesses that utilize large quantities of hot water, such as the pictured Laundromat.
Solar hot water heaters are composed of a several hot water panel units, and can be fully automated systems.