Old Solar Panels: What to Know About Solar Engery

what to know about solar engery

Solar energy is a source of energy that can be extracted for a number of human uses. It is generated by nuclear fusion that takes place in the sun.

The energy of sunlight is converted into electrical energy either through photovoltaic (PV) panels or through mirrors that concentrate solar radiation. This energy can then be used to generate electricity or stored in batteries for use later.

Photovoltaic (PV) panels

Photovoltaic (PV) panels capture solar energy and transform it into electricity. They can power a household or be used to supply a utility-scale electric grid.

PV modules are made from different materials which influence their performance and efficiency. The most common types of PV panels are monocrystalline and polycrystalline silicon.

They can also be amorphous or thin film. Thin-film cells use materials such as cadmium telluride or copper indium gallium diselenide, layered on glass or plastic.

These are less expensive than crystalline cells, but they don’t convert as much sunlight into electricity and have lower efficiencies.

The location of the PV module can also impact its performance. If it is cladded on the roof, this can make it susceptible to high temperatures, especially in areas of very high solar irradiation such as Far North Queensland and Northern Territory.

A PV system can be grid-connected, meaning that it can produce electricity when the sun is shining and sell excess electricity back to the grid when you don’t need it. Or it can be off-grid, which means that it doesn’t have any connection to the power grid and needs a battery or generator to provide electricity when the sun isn’t shining.

Concentrating solar-thermal (CSP) systems

Concentrating solar-thermal (CSP) systems are a type of renewable energy that generates power using the sun’s heat. They are used in utility-scale solar power plants, but can also be applied to water desalination and process heat in industrial facilities.

CSP technology uses mirrors or lenses that concentrate a large area of sunlight onto a small area. The concentrated light then is converted into heat to drive a steam generator or engine.

There are many types of CSP technology, including trough-shaped solar receivers and towers. Typical systems have several mirrors that focus sunlight to a heat absorber tube, called a solar receiver.

The solar receiver absorbs the sun’s energy and transfers it to a fluid, typically thermal oil or molten salt, that is heated to 1,380degF or more. The fluid is then used to spin a turbine or an engine to generate electricity. The energy can be stored in thermal energy storage devices, which allow CSP plants to continue producing electricity day or night until needed.

Batteries

Batteries are a form of storage that allow you to pull power from your solar system when the grid supply is less dependable or during times when utility rates spike. They also reduce demand charges and help you avoid high utility prices that can drive up your electricity bills.

Batteries come in a variety of sizes and performance levels, but their primary purpose is to store chemical energy and convert it into electrical energy. They work by using redox reactions between the electrodes (anode and cathode) and a liquid or solid electrolyte.

They are made of two half cells, each connected in series by a conductive electrolyte that allows the electrons to flow from one electrode to the other.

Battery types include lead-acid batteries, lithium-ion batteries and nickel-cadmium batteries. Lithium-ion batteries are a popular choice for solar engery because they have a long lifespan, good specific energy and low self-discharge.

Inverters

In solar engery, an inverter is the device that changes raw direct current (DC) power from a solar panel to alternating current (AC) electricity. Until an inverter is in place, the solar energy you’ve generated can’t be used to power any devices that consume AC electricity like a table lamp.

Inverters can be very simple, such as those that use a single switch to produce a square wave that is close enough to AC for many devices. These inverters can reduce total harmonic distortion (THD) to a level that meets technical standards for commercial grid connections.

More complex inverters use more than two voltages to form a multiple-stepped approximation to a sine wave that can further reduce THD and voltage and current harmonics. However, such inverters require additional switching components which increase cost.

Smart inverters can also be designed to respond to changes in voltage and frequency to provide grid services like automatic generation control. This allows the inverter to keep on generating even when the grid goes out of sync, or to change its output in response to a signal from an operator to change its power output.