Hon Dr MEGAN WOODS: What we know is that renewable sources of generation are a lower cost than generation by fossil fuels, but they don't provide reliable round-the-clock supply, and therefore our system is currently reliant on expensive fossil fuels when the wind isn't blowing or the hydro lakes are low. A pumped hydro scheme works like a battery, where renewable energy is stored in an upper reservoir and is released back down into a hydro power station to generate electricity when demand is high. It is then pumped back up to the reservoir when demand is low and prices are low. This would drive down prices for consumers by removing the reliance on fossil fuels in the system and support more renewable energy generation.