Batteries on a grid connect solar system

Due to rising electricity prices and the current lack of a regulated feed-in tariff (in NSW), we are getting a lot of inquiries to 'get off the grid'

There are two possible reasons why you might want to use batteries on a grid connected solar system.

1) You might want to do something for the environment, save money and /or wish to disconnect from the grid for philosophical reasons. The truthful answer is that these goals are difficult - and expensive - to achieve.

Over the last few years solar panel prices have decreased substantially while battery prices have increased a lot. An off-grid solar system is now two to three times the cost of the same sized system connected to the grid. For example, a $5000 grid connected solar system would cost approximately $15,000 if it was not grid connected, with the batteries costing several thousand dollars. Batteries are around 85% efficient - so some 15% of the power you produce is effectively lost. Additionally, batteries need periodic replacement, typically every 10 years.

Off the grid solar systems start to become cost effective only where a new grid connection will cost you more than $15,000.


2) You might want battery back up where you have concern that the grid power may fail for a prolonged period. Prolonged loss of power can lead to food spoilage, loss of water for drinking, stock and for bush fire suppression etc. In some cases there can be business losses, communications and infrastructure failures. You may also be concerned that grid failures will increase in the future due to climate change- eg hotter weather increasing air conditioning loads to breaking point and an increased frequency and severity of cyclones.

We can design and supply back up solar power systems to meet your needs; for example you may want your whole house to be backed up or you might want a more economical system to run a few lights, your fridge or a computer system.

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