What is Solar PV?

Solar photovoltaic systems commonly referred to as solar PV systems, convert sunlight directly into electricity. This is different from the solar thermal collectors for solar water heaters. A solar PV system can help reduce carbon emissions and your electricity bill by producing sustainable electricity from the sun instead of burning fossil fuels.

Solar PV first appeared in niche markets in the 1950s and slowly became more mainstream as it was used in off-grid applications.

Most electricity is distributed through an electrical utility provider, the company that produces and/or distributes electricity to consumers. The electricity from a variety of sources is distributed along the electrical grid and can span hundreds of miles from the power plants to homes and businesses. This grid network is not always reliable due to overloading, severe weather, and maintenance or upgrades. Installing a PV power system allows you to create your own electricity to supply your entire home or business and can potentially eliminate the issues associated with large utility grids. The amount of electricity generated is dependent on several factors: the size and arrangement of the PV power system, the PV module type, the available sunlight, and the efficiency of the electrical components used to convert solar energy into electricity usable by your home or building.

Definition of Solar PV

Solar Photovoltaic (PV) is a technology that converts sunlight into direct current electricity by using semiconductors. When the sun hits the semiconductor within the PV cell, electrons are freed and form an electric current.

Solar PV technology is generally employed on a panel (hence solar panels). PV cells are typically found connected to each other and mounted on a frame called a module. Multiple modules can be wired together to form an array, which can be scaled up or down to produce the amount of power needed.

How Solar Panels are made?

PV cells can be made from various semiconductor materials. The most commonly used material today is silicon but other materials, such as the ones listed below, are being tested and used to increase the efficiency of converting sunlight to electricity.

Monocrystalline Silicon

Polycrystalline Silicon

Amorphous Silicon

Cadmium Telluride (CdTe)

Copper Indium Gallium Selenide (CIGS)

Almost 90% of the world’s PV technologies, today, are based on some variation of silicon. Monocrystalline is referred to as single-crystalline, these solar panels consist of one crystalline structure, given them deep dark shading. Monocrystalline cells have the most noteworthy energy efficiency at around 15%-21%, which means they convert 15%-21% of the absorbed solar energy into electricity. It is considered the highest quality of the types of material.

A Polycrystalline cell is referred to as multi-crystalline cells. It has more silicon impurities than monocrystalline panels. This makes it less efficient, normally converting around 13-16% and more affordable.

Thin-film solar panels are made by placing a few thin layers of photovoltaic over one another to makes the module. There are a couple of various kinds of thin-film solar panels, and the way by which they differ from one another comes down to the material utilized for the PV layers. The sorts are as per the following:

  • Amorphous silicon
  • Cadmium telluride
  • Organic PV cells
  • Copper indium gallium selenide

These solar panels are considered the least expensive solar panels and these panels have very low energy efficiency.

The major difference between the technologies is the material used to generate electricity out of sunlight. Each type of material has different attributes, resulting in different applications and efficiencies. In general, the efficiency of solar PV technologies varies, ranging between 6-18% at the moment.

How PV Systems Work

Grid-connected PV System

The grid-connected solar photovoltaic (PV) system is a common and cost-effective option to reduce electricity bills and emissions. It consists of PV modules, a grid-connect inverter, associated mounting hardware, and electrical cables and safety devices. You can generate your own renewable energy on site, and supplement your electricity needs from the local utility grid when the PV system is not supplying enough energy. You can also export excess electricity back to the utility company when the PV system is generating more electricity than you need. The way this exported electricity is metered and the rate of financial return varies by country, state and utility provider. The downside of this system configuration is that you are still connected to the grid. Depending on local regulations the system will automatically shut down if the grid becomes unavailable, meaning you will not produce any solar power during this time, and would still experience blackouts. You would also only use solar power during daylight hours with good solar irradiation, so at night and on cloudy days you would still draw power from the grid and pay an electricity bill.

Grid-connected PV System with Batteries

A grid-connected photovoltaic (PV) system with batteries gives you the best of both worlds. The PV modules can be used to charge a battery bank during the day, and then provide this electricity to your home or business whenever it is needed (day or night). Maintaining a connection to the grid also allows for electricity to be supplied during periods of high use or when the weather is bad for extended periods. Depending on local regulations and government incentives, you may be able to export electricity from your battery bank at times when the utility provider needs it most, and attract a higher rate of return for that solar power. This system could also be configured to supply DC loads from the battery bank.

Off-grid PV System

The off-grid solar photovoltaic (PV) system can be extensively applied in remote locations, and other areas not covered by the main power grid. The PV modules generate electricity that is used to charge batteries during sunlight hours. This can then power DC loads directly or be provided to the AC load through the inverter. This system configuration provides independence from the utility grid however there are limitations on the days of autonomy and the size of the loads that can be supplied by batteries and inverters on their own.

For some applications where small amounts of electricity are required, like emergency call boxes and UPS systems, PV systems are often cost justified even when the grid is accessible. When applications require larger amounts of electricity and are located away from existing power lines, PV systems can in many cases offer the least expensive and most viable option.

Advantage of Solar PV

  • PV panels provide clean – green energy. During electricity generation with PV panels, there is no harmful greenhouse gas emissions thus solar PV is environmentally friendly.
  • Solar energy is the energy supplied by nature – it is thus free and abundant!
  • Solar energy can be made available almost anywhere there is sunlight
  • Solar energy is especially appropriate for smart energy networks with distributed power generation – DPG is indeed the next-generation power network structure!
  • Solar panels cost is currently on a fast reducing track and is expected to continue reducing for the next years – consequently, solar PV panels have indeed a highly promising future both for economical viability and environmental sustainability.
  • Photovoltaic panels, through the photoelectric phenomenon, produce electricity in a direct electricity generation way.
  • Operating and maintenance costs for PV panels are considered to be low, almost negligible, compared to the costs of other renewable energy systems.
  • PV panels have no mechanically moving parts, except in cases of sun-tracking mechanical bases; consequently, they have far fewer breakages or require less maintenance than other renewable energy systems (e.g. wind turbines).
  • PV panels are totally silent, producing no noise at all; consequently, they are a perfect solution for urban areas and for residential applications.
  • Because solar energy coincides with energy needs for cooling, PV panels can provide an effective solution to energy demand peaks – especially in hot summer months where energy demand is high.
  • Though solar energy panels’ prices have seen a drastic reduction in the past years, and are still falling, nonetheless, solar photovoltaic panels are one of the major renewable energy systems that are promoted through government subsidy funding (FITs, STCs, other tax credits, etc.); thus the financial incentive for PV panels make solar energy panels an attractive investment alternative.
  • Residential solar panels are easy to install on rooftops or on the ground without any interference to residential lifestyle.

 

In this article, we’ve discussed solar PV- Overview of solar PV, how solar PV is made, how solar PV works, its advantages, etc. If you want to protect the planet by cutting back on your dependence on nonrenewable energy and reduce your monthly electric bill, then get your free solar quote today!

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