How a Solar Energy System Works

Solar energy is radiant light and heat that can be harnessed to produce electricity. It also provides thermal energy for heating buildings and generating hot water.

Solar systems are sized based on the expected electricity usage of your home or off-grid dwelling, and there are online calculators to help you determine this.

Solar Energy

The sun’s light and heat can be harnessed to create renewable or “green” energy. Solar panels, also known as photovoltaic cells, are a familiar sight in power stations and on homes and businesses. When sunlight hits a photovoltaic cell, it loosens electrons from atoms inside the cell’s semiconductor material. The free electrons flow through metal contacts within the panel and generate electricity.

Solar energy can be used by itself or in combination with other forms of energy. When used alone, solar energy produces no pollutants and has minimal environmental impact.

When combined with storage technologies, such as batteries, solar power can provide reliable electricity even during times of peak demand. Peak power usage typically occurs on hot summer afternoons and evenings, when electricity is needed to cool homes and run appliances.

Solar energy systems vary in size and cost, and the amount of electricity they produce depends on how much sunlight the area receives. To determine how large a system you need, consult your local meteorological data, or ask the utility company about average electricity consumption in your area. It’s also helpful to have copies of recent utility bills on hand to compare the power your solar system produces against how much electricity you consume. Once you’ve applied for connectivity to the grid, a bi-directional meter is installed to track your electricity use and solar production.

Solar Panels

Solar panels convert sunlight into electricity to power homes and businesses. Solar energy also produces heat to heat homes, water and commercial buildings, or is used for large-scale power generation.

Solar power is a renewable, sustainable resource. Solar panels generate electricity through the photovoltaic effect, a process that occurs when particles of sunlight called photons knock electrons free from atoms in the panel, creating a flow of electricity. The more electrons that are captured, the more electricity that is produced. Solar energy is the most cost effective, environmentally friendly way to produce clean, renewable electricity.

There are several types of solar panels, including crystalline silicon, thin film and SOLAR ENERGY SYSTEM amorphous silicon. The best type of solar panels for your home will depend on your location, electricity consumption and peak power demands.

For the simplest deployment, solar panels are attached to a support frame or rack known as a fixed mount and are tilted to face south (in the Northern Hemisphere) or north (in the Southern Hemisphere). More advanced systems include motor-driven tracking mounts that reorient themselves based on the daily and seasonal movement of the sun.

When combined with a smart inverter, your solar system can monitor and adjust its energy use to maximize your production. This is particularly important if you participate in a net metering program with your local utility company, which credits homeowners for sending excess electricity back to the grid.

Solar Thermal

Solar thermal energy can be used to generate electricity or for industrial applications such as pasteurization, curing, drying, and distillation. Thermal energy storage can be incorporated to increase dispatchability and lower the levelized cost of electricity (LCOE).

Concentrating solar-thermal power (CSP) technologies use mirrors to concentrate sunlight onto a receiver that’s mounted on a tracker, or parabolic trough. The concentrated sunlight heats a fluid, usually water, to high temperatures. The hot fluid is then used to spin a turbine or engine to generate electricity.

The solar energy that isn’t converted to electricity is stored in a thermal energy storage system. This allows CSP plants to operate during night and overcast conditions, displacing fossil fuel- or nuclear-powered plants. Using storage also reduces LCOE by increasing the utilization factor of the plant.

Several different thermal energy storage systems have been developed, including the molten salt system employed in the Andasol 1 power plant near Granada, Spain. Another is a modular solar steam-generator power plant designed by Solar Millennium, which has a prototype near Barstow, California.

Commercial concentrating solar power (CSP) was first demonstrated in 1985 at the 354 MW SEGS solar complex in the Mojave Desert of California. Commercial plants are built with either a parabolic trough design or a solar power tower. The Ivanpah solar power facility uses trough technology without thermal storage, while the Ouarzazate solar power station uses both trough and tower technology with several hours of energy storage.

Solar Batteries

Solar batteries add a solar water pump for home new dimension to solar power systems, enabling homeowners to store energy for use when the sun isn’t shining. This reduces reliance on the grid and makes a solar system more reliable — especially in regions with variable sunlight.

Batteries are available with different capacities and voltage options to suit specific solar energy needs. The type of battery chemistry is also important, as some work best for short periods and others for longer. Some common chemistries include lead-acid, lithium ion, nickel cadmium and flow batteries.

Regardless of the type of battery, solar energy storage systems require an inverter to convert DC into AC electricity for the home or the electric grid. This is a key part of the technology and helps ensure that solar energy storage can deliver high levels of reliability, efficiency and cost-effectiveness.

Solar battery brands like Generac PWRcell and Tesla Powerwall are known for their durability and integrated design, blending seamlessly with solar panel systems. Their built-in inverter reduces components, lowering system costs and optimizing performance.

In general, a battery in self-consumption mode will maintain a low state of charge (SOC) each day, charging during the sun’s peak hours and discharging through a home’s electrical consumption at night. During an outage, the battery will provide backup power to essential appliances and keep them running for as long as necessary.

What Type of Solar Energy System is Right For Your Home?

Solar power systems generate electricity from sunlight. They can be grid-tied or hybrid.

Solar energy has many benefits over other sources of electricity. However, it has certain environmental impacts.

Solar technology has a long history. It all started in 1839 when French physicist Edmond Becquerel discovered the photovoltaic effect.

Solar Photovoltaic (PV)

A PV system uses solar panels to convert sunlight directly into electricity. Sunlight is made up of different colours of light, each with a specific energy level (also known as wavelengths). Some of this spectrum is reflected and some cannot be converted to electricity (for example infrared SOLAR ENERGY SYSTEM and ultraviolet). Solar photovoltaic cells are designed to capture the sunlight with the most amount of energy and generate the highest voltage.

The most common semiconductor material used in PV cells is crystalline silicon. The crystal lattice of silicon atoms gives the cell an organised structure that helps convert sunlight into electricity efficiently. Thin-film solar technologies use a range of other materials, such as cadmium telluride and copper indium gallium diselenide, which offer a lower cost than traditional crystalline silicon cells.

A solar PV system is usually connected to a battery, which stores excess power and can be drawn upon when demand is high. In stand-alone systems, the battery is located as close to the modules as possible, which minimises power losses. In grid-connected systems, an electronic device called a maximum power point tracker can optimise the DC-AC voltage conversion.

Many Australian states and territories offer incentives, such as interest-free loans or higher feed-in tariffs, to improve the financial return on a PV system. Choice recommends working with accredited installers and retailers when installing a new PV system.

Solar Thermal (CSP)

Concentrated solar power (CSP) systems focus sunlight through a series of mirrors, concentrating it to achieve high temperatures. This heat can then be used to drive a traditional thermal power plant or engine for electricity generation. CSP plants can also be coupled to thermal energy storage to improve dispatchability during cloudy or nighttime hours.

The primary CSP technologies are parabolic trough and solar power tower plants. While both systems have been proven at commercial scale, the CSP industry is currently focused on trough technology due to its low capital cost and efficiency compared to tower. Crescent Dunes, a 550 MW CSP project in the Mojave Desert, is a good example of trough technology.

Large CSP projects require a large amount of land. For example, a 100 MW plant will need five to ten acres per MW of capacity. CSP plants also need to be located in areas with high irradiance, as they use large mirrors to concentrate sunlight on a receiver to generate heat. The NREL has a tool to help determine the solar potential of a site.

Energy storage is an integral part of CSP, as it enables the system to provide flexible, dispatchable power. Current commercial projects use liquid molten salt as the storage medium, although new options for storage are being investigated including gases like air and liquid metals and solids like ceramics.

Solar Water Heating

Solar Water Heating (SWH) is a very efficient way to use the sun to heat your home’s water. This reduces your utility bills and also helps to lower carbon emissions. In many parts of the country, SWH can even be used to offset your electricity or gas usage.

The basic principle is that sunlight passes through a collector’s glass covering and strikes absorber plates within the collector. These plates are designed to capture the solar energy and convert it into thermal energy. The heat is then transferred to a storage tank or to the home’s water supply via a heat exchanger. Insulation materials are also crucial, reducing heat loss and ensuring that the heat is retained in the system.

There are two main types of solar water heating systems: passive and active. Passive systems are very simple, and work by positioning a hot water tank directly over or above the collector. As the tanks’ water gets warmer, it naturally rises into the collector. Active systems use a pump station and system controller that monitors temperature data to determine when the collector is hotter than the tank and to start the pump accordingly.

Both types of systems require regular inspection and maintenance to ensure optimal performance. Unless you are comfortable working on ladders, walking on roofs or performing soldering or hot work, it is important to hire a qualified technician for inspections and maintenance.

Solar Hot Water

Solar hot water (SWH) systems use the sun’s energy to heat your home’s water, cutting heating costs. They have been in use for centuries, but today’s technological advances make them suitable for virtually any climate.

The key components of SWH systems include solar collectors, a storage tank, a heat transfer fluid, a backup water heater, pipes and controls. A pump station or system controller solar water pump for home uses temperature data to manage the system, ensuring maximum performance. The heat transfer fluid is either potable water or a mixture of potable water and antifreeze, depending on the type of system. The antifreeze allows the system to operate in regions with freezing temperatures.

A solar storage tank is sized to match peak household hot water demand and the SWH’s production capabilities. It also contains a pressure relief valve and air vents at high points in the piping to prevent overheating. Indirect circulation systems are best for climates with frequent freezing conditions, while direct systems can be used in areas that don’t experience freezing weather.

SWH systems are relatively simple and inexpensive to maintain. O&M costs are generally less than 1% of the initial system cost, making them a smart investment for homeowners and businesses. The DOE’s Solar Water Heating website features a list of system types and a wealth of tips on selecting and maintaining a system.

How a Solar Energy System Works

Sunlight contains radiant energy that can be harnessed to produce heat and electricity. There are a number of technologies that can do this.

Solar photovoltaic (PV) systems convert sunlight into electricity by passing it through a semi-conductor surface. Solar thermal systems are less sophisticated and involve directly heating a working fluid, usually water.

Solar cells

Solar cells convert sunlight into electrical energy. They are made of semiconductors that strongly absorb visible radiation and are layered together into a single unit. These units can be arranged in large groups called arrays to function as central electric power stations or placed on rooftops to provide an alternative to traditional electricity sources.

When sunlight hits the cell, it causes the free electrons to break apart, leaving behind holes. The electric field then transports the holes to the p-type layer and the electrons to the n-type layer.

To make this happen, the silicon atoms in a SOLAR ENERGY SYSTEM solar cell are purposely mixed with a few atoms of another material — usually phosphorus. The phosphorus adds one extra electron to each of the silicon atoms, making them have five instead of four. While we typically think of impurities as undesirable, this one is essential to the solar cell’s operation. The additional electrons help fill the holes created by the missing ones, creating a current that can be directed by metallic contacts to a power grid for use.

Solar panels

Solar power is a clean, renewable resource that doesn’t create harmful greenhouse gases. It’s also a great way to save money on electricity bills and reduce dependence on fossil fuels.

The sun constantly releases tiny packets of energy called photons. If we could capture just a fraction of this energy, it would meet all of the world’s energy needs. Solar panels convert this light into usable electricity by using photovoltaic cells. They are usually arranged in an array on a roof or other area with unobstructed sunlight.

Each panel consists of 36 solar cells laminated to glass within an aluminum frame and wired together. There are two types of solar panels: monocrystalline and polycrystalline. Monocrystalline panels use a single pure form of silicon, while polycrystalline panels use multiple silicon fragments that are more cost-effective.

The silicon isn’t a good conductor of electricity on its own, so it’s treated with boron and phosphorus to improve its performance. These additions help create a layer of n-type silicon with an excess of electrons and a layer of p-type silicon with a deficit of electrons.

Solar furnaces

Solar furnaces generate heat by concentrating sunlight on a target area. This heat is then converted to useful energy. These systems are designed to operate at higher temperatures than electric furnaces, and they can avoid the carbon electrodes that cause problems in traditional coal-based industrial furnaces. These systems are currently being researched for a range of applications, from high-value products like fullerenes to commodity products such as cement.

The solar furnaces are used for material heating, metallurgical processes, and for research. They can also be used to produce hydrogen fuel. They are a great source of clean energy and help reduce the use of fossil fuels.

Solar furnaces can be used to provide power and heat for a variety of purposes, from cooking food to operating a Stirling engine. They are also a great way to save money on your utility bills. This is because the sun is a renewable energy resource that can be used to replace traditional fuels, such as oil or gas. Solar furnaces work by focusing sunlight on a target area, such as a crucible. The target area is then heated to a temperature up to 3500°C.

Solar power towers

A solar power tower is a type of solar thermal energy plant that uses mirrors to focus sunlight on a central receiver at the top of a tall tower. The heat from the mirrors is used to heat a working fluid that then turns to steam, which powers a turbine generator to produce electricity. Solar power towers use a large number of flat, sun-tracking mirrors called heliostats to accurately follow the sun’s movement across the sky each day.

Each heliostat has computer controlled sun tracking mechanisms that direct the sun’s rays towards a blackened heat absorbing receiver at the top of the tower. The heat-transfer medium in the receiver can be a variety of liquids and gases including water/steam, molten salts, oil, or air.

The molten salt used in the most recent solar power tower plants is preheated in storage tanks to a high temperature before being pumped through the receiver where it absorbs the concentrated solar radiation. This high-temperature molten salt is then cooled to a liquid state and used as a heat transfer medium.

Solar batteries

Solar batteries are a key component of any residential solar system, whether they operate in self-consumption mode or critical backup mode. When in self-consumption mode, solar batteries charge and discharge on a regular basis (cycles) while providing power to household appliances.

In critical backup mode, solar batteries provide energy after the solar energy system supplier sun goes down or during a grid outage. Both modes increase the reliability of a solar energy system and reduce its dependence on the electric grid.

Like the lithium-ion batteries in your cell phone, laptop, TV remote and other devices, solar battery technology is based on a chemical reaction. When you place a solar panel in direct sunlight, it generates electricity through a semiconductor made of silicon that absorbs the light and knocks electrons loose.

The free electrons then travel through a metal contacts on the top and bottom of the panel, creating an electric current that powers appliances in your home. This DC current is sent to an inverter, which converts it into AC electricity that can be used by your household appliances.

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.