Grid-tie is now hugely popular in Europe, North America, China and Australia. This is due to the availability of grants to reduce the installation costs, the ability to earn money through feed-in tariffs and the opportunity to sell electricity back into the electricity companies.
In a grid-tie system, your home runs on solar power during the day. Any surplus energy that you produce is then fed into the grid. In the evenings and at night, when your solar energy system is not producing electricity, you then buy your power from the electricity companies in the usual way. The benefit of grid-tie solar installations is that they reduce your reliance on the big electricity companies and ensure that more of your electricity is produced in an environmentally efficient way.
One disadvantage of most grid-tie systems is that if there is a power cut, power from your solar array is also cut. By itself, you do not have additional energy security by installing a grid-tie solar energy system. Grid-tie can work especially well in hot, sunny climates, where peak demand for electricity from the grid often coincides with the sun shining, thanks to the high power demand of air conditioning units. Grid-tie also works well where the owners use most of the power themselves.