One in five WA households now have solar panels in a bid to keep power bills to a minimum.

So is it time to consider the next step and invest in a battery to store your solar energy?

It will take about ten years to get a return on a household battery which can cost up to $20,000.

So when's the right time to buy one and what do you need to know about them?

Dozens of questions are answered in this Focus discussion with Craig Donohue, Managing Director of Clean NRG Solar and Professor Ray Wills, owner of Future Smart Strategies and board member of Horizon Power.