Lake Onslow storage scheme could be a winner

THE Greens propose putting solar panels on all state houses, at a cost of about $10 billion.

Since these would produce zero power on cold winter evenings, when demand is highest, they suggest batteries could be added.

The Lake Onslow pumped hydro scheme, at a cost of about $4 billion, would store as much electricity as all the batteries Tesla's gigafactory could produce in 300 years.

It would also last much longer than a battery, and would not need any new solar panels or wind turbines built to charge it — it would use spring runoff from the Clutha and Waitaki, running through the power stations we already have.

The South Island has the cleanest power on Earth, but the North

Island has almost the same emissions per watthour as Britain, even with a fraction of the population density.

They stopped burning coal — so should we.

John O'Neill

Roslyn

Predators v prey

PETER Foster bemoans predators (Letters, 16.7.20). He cites ‘‘introduced’’ trout eating indigenous whitebait and he claims possums eat birds.

Does he not understand predator/ prey relationships are the norm?

Native falcons eat native tui, and native kiwi eat native worms. Trout are preyed on by native eels, and eels prey on native whitebait.

Native shags prey on trout, and so on.

Nature develops predator/prey relationships so all is in equilibrium to a fair degree.

Man stuffs the balance with wholesale 1080 drops. Research shows four years after a 1080 drop, superbreeder rat numbers soar to four times the number at the time of the drop.

Obsession with ‘‘introduced’’ species and predators ignores that we’re now in a 21stcentury, evolved ecosystem.

Most New Zealanders do care. If only we could let common sense prevail.

Grant Macgregor

Oamaru