Solar Power Technologies
The Sun gives us energy in the form of electromagnetic radiation. Solar power technologies capture and transform this radiation into electricity and heat.
The most familiar is photovoltaic (PV) technology, used in solar panels. When the sun shines on a PV cell, it creates electric charges that flow, producing electricity.
Solar Panels
Solar panels generate electricity from the sun, reducing the amount of fossil fuels and traditional power sources needed to run homes and businesses. The panels are made of layers of special semiconductor materials arranged in positive and negative sides (similar to batteries) which create an electronic flow when exposed to sunlight. Wiring connected to the positive and negative sides of the panel harnesses this energy and converts it into alternating current electricity that can be used in appliances, lights and electric vehicles.
Solar energy works on sunny days and cloudy days but it is more effective during the hours of daylight closest to the equator. In fact, many households can expect to realize significant energy savings just from upgrading or replacing old household items like light bulbs and thermostats with more efficient alternatives.
The most common type of solar panel is crystalline silicon (c-Si) which accounts for 84% of the US and global market, but there are other types as well including copper indium gallium di-selenide (CIGS), thin film amorphous silicon and cadmium telluride. The most important feature of a solar panel is its efficiency, and panels lose only about 2% of their effectiveness per year, so they are a long-term investment better suited to home owners rather than renters.
All solar panel manufacturers follow strict quality standards and inspection of the manufacturing process may include visitation, assembly checks, material testing supervision and Non Destructive Testing (NDT). Module electrical connections are made with wires sized according to the current rating and fault conditions and often include in-line fuses. Blocking and bypass diodes are often incorporated into the modules to deal with partial array shading in order to maximize output.
Inverters
The inverter is the heart of a solar power system, converting direct current (DC) electricity from your panels into alternating current (AC) that the grid SOLAR ENERGY SYSTEM uses. It then sends your AC energy to your fusebox or power board for use in your home. Excess electricity is either returned to the grid or sent into your battery storage system if you have one.
Depending on the size of your solar system, you may have a single inverter or multiple inverters. Inverters with DC Optimiser technology offer an even more efficient solution by allowing you to connect your high energy consuming appliances, like electric hot water systems, air conditioners and pool pumps, to start operating when there is surplus solar energy produced. This reduces electricity usage from the grid and also saves you money on your power bills.
An inverter is a large device that accepts the DC electricity from many solar panels and transforms it into AC electricity to be used in your home or sent back into the grid. They generally employ Maximum Power Point Tracking (MPPT) to maximise solar energy production.
Batteries
Batteries are the energy storage component of solar power systems. They store the excess energy generated by PV panels to be used later in the day or at night when sunlight is not available. This allows homeowners to maximize their use of renewables and reduce or eliminate their reliance on the grid.
A battery is a collection of voltaic cells that produce electricity through chemical action between the electrodes and electrolyte. Each cell consists of two half-cells connected in series: one includes an electrode to which electrons (negatively charged ions) migrate from the cathode, and another including an electrolyte to which metal cations (positively charged ions) migrate from the anode. The electrodes are separated by a membrane that allows ions to migrate between them.
There are a number of different lead-acid solar energy system supplier batteries that can be used with solar panels, including flooded, absorbed glass mat (AGM) and valve regulated lead acid (VRLA). Lead-acid batteries have a deep-cycle capacity with a safe depth of discharge (DOD) of about 40%. They also have a moderate energy density and are relatively inexpensive.
Other types of batteries can be used for solar power storage, including lithium ion and sodium nickel chloride. Lithium ion batteries are increasingly popular due to their low cost, high efficiency and longevity. Lithium-ion batteries are a good option for homeowners who want to utilize their solar energy system at night and/or during periods of low sunlight.
Controls
The solar charge controller controls how much power is generated by the PV array and transferred to the battery system during sunlight. It also prevents the reverse flow of current from the batteries back to the solar panels during low sun irradiance and night time.
The most important function is voltage regulation. It does this by continuously monitoring the panel and load voltages and opening the circuit, halting the charging, when the battery voltage ascents above the overvoltage limit. The controller may also monitor the battery state of charge and indicate when the battery is fully charged.
It has electronic protections to guard against the effects of nighttime reverse current drain on the batteries, short circuiting, high temperatures and excessive battery discharge. It incorporates disconnect switches for the battery, PV array and the load to prevent connections from being reversed during disconnection or system maintenance.
Some charge controllers use pulse width modulation (PWM) technology to control the current and voltage from PV modules while others have advanced maximum power point tracking (MPPT). The MPPT controllers identify the best working voltage and amperage of a solar panel array and match it with the electric cell bank. This allows for an extra 10-30% more power out of the solar panel array compared to a PWM controller. Choose a manufacturer that uses the more sophisticated MPPT controllers for better performance and increased ROI of your solar LED lights.