View source for Basic stand-alone PV system components/en

[[Category:Basic concepts]]
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Stand-alone PV systems, regardless of where one is at in the world, share the same basic components. This article will give a high-level overview with links to more detailed information on each component. To understand how power flows between key components see [[Power flow between components]].

[[File:Components of a pv system201108.png|frame|center|'''Components of a stand-alone system with an inverter:'''<br />''(1)'' PV source ''(2)'' Charge controller ''(3)'' Energy storage ''(4)'' Inverter '' (5)'' Power distribution ''(6)'' Mounting system ''(7)'' Conductors ''(8)'' Overcurrent protection/disconnects ''(9)'' Grounding system ''(10)'' Physical wire protection ''(11)'' Loads/appliances]]

===PV source===

A PV system has a [[:Category:PV source|PV source]] - one or more PV modules - that converts the energy of the sun into electrical current. Solar PV modules use the photovoltaic (PV) effect to generate electrical current upon exposure to light. If there are multiple modules in the system, they are mounted together and connected into an ''array.'' The term array may be used for simplicity even if there is only one module in the system.

===Energy storage===

A stand-alone PV system requires some type of [[:Category:Energy storage|energy storage system]] in order to provide energy at night or during periods of bad weather. The most common form of energy storage for stand-alone PV systems is batteries. There are many different kinds of batteries that each carries advantages and disadvantages. If there are multiple batteries in a system, they are arranged together into what is referred to as a ''battery bank.''  The term battery bank may be used for simplicity even if there is only one battery in the system.

===Charge controller===

A [[:Category:Charge controller|charge controller]] or [[:Category:Inverter|inverter-charger]] is essential as batteries have specific charging requirements and proper charging is  essential to ensuring that they have a long life. A system may have multiple parallel solar charge controllers or even incorporate other power sources.

===Inverter===

In order to power alternating current loads, it is necessary to have an [[:Category:Inverter|inverter]] in a stand-alone system. The battery bank provides a stable voltage and current to the inverter, which it can then convert into stable alternating current to supply AC loads.

===Power distribution===

A stand-alone PV system requires some type of [[:Category:Power distribution|power distribution]] - a load center or busbars - to be able to distribute electricity safely to loads.

===Mounting system===

PV modules must be anchored to some type of [[:Category:Mounting system|mounting system]] to ensure that their production is maximized with the correct orientation and angle relative to the sun, but also to ensure that they are not damaged by weather.

===Conductors===

All of the different electrical components of a system are connected together with [[:Category:Conductors|conductors]] - wire and cable - that must be appropriate for the voltage, current and conditions to which they will be subjected.

===Overcurrent protection/disconnects===

All equipment in a PV system - conductors and all components - have a maximum amount of current that they can handle and should therefore be protected from currents that could exceed their maximum rated current. Otherwise, an electrical fire can result. Devices that protect equipment from excess current are called [[Overcurrent protection|overcurrent protection devices (OCPDs)]], the most common of which are breakers and fuses. Additionally, in any system it is necessary to isolate all components of a PV system from all potential power sources in order to be able to work safely for maintenance or troubleshooting. Both of these functions can be often be performed by an [[Overcurrent protection|overcurrent protection device]], but a seperate [[Disconnects|means of disconnection]] may be necessary for various components. For all articles on OCPDs and disconnects see [[:Category:Overcurrent protection and disconnects|overcurrent protection and disconnects]].

===Grounding system===

A properly built [[:Category:Grounding|grounding system]] ensures safety for users and protections the system equipment against damage from lightning. Small PV systems often do not incorporate a grounding system due to cost, but the benefit of proper grounding increases as system size and cost increases.

===Physical wire protection===

If a conductor could potentially be damaged by the conditions in which it is installed, weather, rodents, building occupants or any other source, it is necessary to provide [[:Category:Physical wire protection|physical wire protection]]

===Loads===

The purpose of an off-grid PV system is to be able to provide power for [[:Category:Loads|loads]] or lighting and appliances. There are important considerations that go into choosing lighting and appliances for use with an off-grid system.