What is Solar Photovoltaic (PV)?

The sun provides energy in the forms of light and heat. Photovoltaic panels convert the sunlight into electricity.
How do Solar PV Panels Function?

Solar PV is the conversion of light energy, normally from the sun, into electricity. Solar PV panels produce direct current (DC) when exposed to the sun, which is later converted into alternating current (AC) using an inverter. The conversion into AC is necessary because most household appliances are designed for AC and it also allows current to be fed back into the utility grid.

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What are the different types of PV Panels?

1. Are more efficient than Polycrystalline or Thin-film, making it a better choice for space-constrained properties (like roof-tops) as you get a higher yield.
2. Cost about 20% more expensive than Polycrystalline.
3. Monocrystalline is aesthetically more pleasing than Polycrystalline.
4. Performs better than Polycrystalline in hotter and low-light conditions. It is important to note that hotter conditions reduces the output of a panel and therefore the power yield and the same is true of low-light conditions.

1. Approximately 8% less efficient than Monocrystalline panels.
2. Ideally suited for installations with unconstrained installation space.
3. Minimises upfront capital cost.
4. Avoids producing excess power.

Thin Film:
1. Less efficient that Monocrystalline and Polycrystalline.
2. Perform better in high temperatures and shaded environments.
3. Can be made physically flexible, which makes it suitable for various applications.


Types of Solar PV Systems

There are two main types of PV systems, these are:

Grid-connected PV systems
Grid-connected installations are cheaper as no batteries are required and they are common in urban areas. They typically consist of a PV panel array, an inverter and a bi-directional meter that measures current flowing to and from the utility grid. Grid-connected PV systems supply electricity to the grid when it is producing more electricity than the internal demand of the building it is supplying. Electricity from the grid is used when the panels cannot generate enough electricity to meet the demand.
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Off-grid PV systems
Off-grid (battery linked) PV installations are typically used in areas not connected to the electricity grid. During sunlight, the installation supplies electricity to the building and charges the batteries that supply electricity at times when the sun is not shining or the PV system cannot meet the demand of the building. Batteries are expensive and thus off-grid systems are more expensive then grid connected systems and also require more maintenance. 
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