Systems Explained

Basic Solar PV installations

Solar PV systems, that turn the sun’s rays into useable electricty are basically quite simple and vary from application to application depending on the user’s needs.

In a nutshell, the solar pv panels turn the sun’s energy into DC electric current. This is then sent to a unit called an ‘inverter’ that converts it to AC electricity (the 240v electricity that people often refer to as ‘mains’ electricity). This then goes into the main fuse box of the house/business premises which then distributes it out to the plugs and lighting system of the building.

At its simplest it works like this:

1. Off-grid
For example:
A caravan in a remote location
A stable block or workshop too far from a house to warrant running a cable
A boat out at sea.

Imagine a completely, stand alone, off-grid system. No national grid mains connection. The system produces electricity during daylight hours and powers the location’s appliances.

However, at night there will be no electricity produced! In such a case a battery storage system would be used (more on this later).

2. On-grid system
Example: Family home, office block, industrial unit, school, shop etc

More often than not, a solar pv system is installed where there is already mains grid electricity and helps to reduce bills. The solar pv powers the house or business during the day. But should it be a dull, gloomy day the system uses mains/grid electricity as a back-up supply. During the night, when the panels don’t produce anything, the house or business premises uses mains/grid power.

But what if it’s a blazing, sunny day and the panels are producing at full capacity and the house is empty or the business is closed for whatever reason? Any electricity produced by the panels that is not used is sent directly into the national grid for which the system owner gets a payment for. It’s called the Smart Export Guarantee (SEG) details of which can be found here:


3. On-grid system with battery storage
Example: Family home, office block, industrial unit, school, shop etc where occupants are out during the day. Or somewhere that needs elctricity at night.

The rate you get for exporting a unit of power under the SEG will likely be much less than the amount you pay for a unit of power from your electricity company. So, if you produce more electricity than you use during the day, you may therefore feel that you will save more by not exporting it, and saving it for later, to avoid paying for electricity at night. In this case storage batteries are installed which would help power the building at night.  This option makes you become even less dependent on electricity from the grid. But if you need more power at night than you have stored in your batteries, the system uses mains/grid electricity.


In case you were wondering and wanted to ask:

How long do pv solar panels last?

All our Solar PV Panels have a:
12 year product guarantee
25 year performance guarantee.

Solar panels lose about 0.6% efficiency every year.  Therefore a 25 year old panel will produce 15% less power than a new one. But a dirty panel is even less efficient! Therefore an annual clean is advised although they do tend to be self cleaning due to being out in the weather.

Inverters – 10 year standard guarantee which can be extended
Batteries – 10 year standard

Workmanship – 2 year insurance backed with IWA insurance – which can be extend to 5 years.

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