What does a Grid Tie Inverter do?

A Grid Tie Inverter is a piece of equipment used in renewable energy systems, such as solar or wind power domestic systems. They are sometimes known as synchronous inverters or grid interactive inverters. The inverter is required to run and appliances and if the system owner is planning to sell excess energy back to the National Grid.

This is part of how solar PV system owners earn feed in tariffs from domestic systems, alongside the generation tariff. It converts direct current (DC) electricity created by the system into alternating current (AC). In the UK, all appliance run on AC. The Grid Tie Inverter must synchronise its frequency with the National Grid.

Using an inverter means a householder can use the energy produced by solar PV panels without having to rewire their house. It allows the householder to receive power from the National Grid if the system is not producing sufficient power.

How do they work?

Grid Tie Inverters can use a number of different technologies to convert the current. They can use high or low frequency transformers or even not use a transformer. Transformers work by converting the the DC generated to high frequency AC then back to DC and finally back to the AC at the required voltage.

Inverters without transformers are more efficient than those using transformers and are increasing in popularity. Transformerless inverters use a different type of cable than transformer based inverters.

How much do they cost?

The cost of Grid Tie Inverters varies hugely depending on the model chosen. Some inverters can cost from a few hundred pounds going up to several thousand. The cost of the inverter needed for your system will be dependent upon the size and requirements of the system.

To establish the Grid Tie Inverter required for your system contact a specialist supplier who will be able to advise you and provide an accurate quote. It is worth contacting several suppliers to get the best quote for the inverter you require.

Do I need a Grid Tie Inverter?

Whether or not you need a grid tie inverter will depend very much upon the size of the system you have installed. If you have installed a small scale system with just a couple of PV panels you will probably use battery storage. If this is the case, then you can by an ordinary inverter which does not allow you to resell to the National Grid.

These inverters vary in price from as low as £10 up to several hundred pounds depending on the size of your system and your personal requirements. Inverter suppliers will be able to give prospective purchasers advice on which type of non Grid Tie Inverter will be needed for your system.