A broking firm says a 10 per cent reduction in power prices could be achieved in the current electricity market - meaning the Labour-Greens proposal is unnecessary.

A protest which halted a mining giant's oil exploration on NZ's high seas and prompted a controversial law change cost taxpayers nearly $1.7 million, documents show.

The war of words over the Opposition's electricity market reform plan has flared again as political opponents traded fire over the plan's economic impact.

Mighty River Power expects it would take at least five years for the Labour and Green party's new electricity policies to be enacted, and John Key says it won't happen.

Labour's proposed shake-up of the energy sector could slash up to 20 per cent off the value of Mighty River Power although analysts rate the chances of the Opposition's plan going ahead at less than 50 per cent.

Political commentators have been quick to point out that New Zealand voters now have a real choice, writes Liam Dann. Sometimes it seems we have two poor choices.

Matt McCarten looks at the plans of Labour and the Greens to set up an electricity agency, NZ Power, if they are elected next year.

The Labour-Green proposal to cut Kiwi householders' power prices through radical market reform has been given the thumbs-up by consumer groups, but energy sector commentators are divided on the plan.

Labour and Greens want Crown-owned single buyer to set electricity prices for generators.

The Government says Labour and the Greens are trying to sink the Mighty River Power share float with a hastily drafted threat to impose Soviet-style intervention on the electricity market.

Labour and the Greens are promising a major intervention in the retail power system in a bid to lower residential power prices if they win next year's election.

Petrol prices are heading down towards the $2 mark with BP announcing a 3c price cut today as international oil prices tumble.

Brokers and analysts are predicting a strong take-up of Mighty River Power shares as the offer opens to the public today.

Mighty River Power directors are to get a 73 per cent pay rise, it has been confirmed ahead of the release of offer documents for the company's partial float tomorrow.

When people like the PM talk of an orderly transition to a post-smelter environment, they are talking about the scrapping of generating capacity, writes Brian Fallow.

New Zealand's largest solar installation has been put on top of the refurbished Shed 10 on Auckland's waterfront.

The first bite of autumn will be felt over much of the country in the next few days as rain sets in over the South Island.

German carmaker Audi is undertaking an interesting experiment: at one specially equipped parking garage the cars park themselves.

Prospects of keeping the Tiwai Pt aluminium smelter open in the long-term are grim, with Meridian Energy saying it is still in the dark.

The Government and its flagship asset sale programme will not be held hostage by Rio Tinto over the mineral giant's threat to close the Tiwai Point aluminium smelter, Prime Minister John Key said yesterday.

Rio Tinto isn't going to get a deal out of the Government and is likely to shut down the Tiwai Pt aluminium smelter potentially at the cost of thousands of jobs over the next five years.

"Why don't John Key and David Parker come up with a common front towards Rio Tinto to send a message to the Tiwai Point owner?" asks Fran O'Sullivan.

Rain will bring some relief to drought-stricken farms this week, but the seasonal outlook is for dry conditions to linger well into autumn.