Strong demand for shares in Genesis Energy saw the public pool heavily scaled back yesterday, raising the ire of investors who missed out on getting their desired levels of stock but also reflecting the offer's popularity.

Home electricity bills rose by $63 on average in the 12 months to February, with the biggest increases generally occurring in some smaller cities and their large rural hinterlands.

The Treasury would have liked more "Mum and Dad" small investors to have bought shares in electricity generators Mighty River Power and Meridian Energy.

If the price is set too low, money is left on the table and assets can be sold off at a discount, writes Christoph Schumacher and Sasha Molchanov. This is neither desirable nor efficient.

The average power bill for a family of four will rise by 2.4 per cent this year, Energy and Resources Minister Simon Bridges said yesterday.

Over the past couple of weeks, households have been receiving nasty surprises in the mail.

Households will be socked with power bill increases of as much as 24% next month and power firms and network operators are blaming each other over who is responsible.

Investors wanting more certainty around Labour-Greens policy for overhauling the electricity sector before the election appear to be out of luck.

Mighty River Power remains on track to meet forecast full-year profit for the year but is wary of falling lake levels feeding its central North Island hydro dams.

New Zealanders are switching to cheaper power companies in droves with help from Government-sponsored campaign.

The biggest barrier to new products is the complexity of 29 separate monopolies owning the country's electricity networks, says Contact.

International mining giant Rio Tinto said the outlook for the metal was positive despite a 9 per cent fall in spot prices over 2013.

The Government will loan households up to $15,000 at low interest rates to help them install solar power if the Greens are elected.

Today's generators never paid enough for the assets to entitle them to charge consumers what the authority now says is reasonable, writes Geoff Bertram.

Setting electricity prices based on historical costs could increase costs for consumers rather than reduce them, says the Electricity Authority.

Feel you're paying too much for electricity? Not according to a new report, which says consumers never actually paid the full cost of building NZ's power stations.

Meridian Energy sold more electricity in the first six months of the current financial year than in the previous year, but prices achieved were significantly lower.

A Labour-led government will make good on its promise to regulate the electricity industry and stamp out 'super-profits', deputy leader David Parker says.

The Govt has revised the estimate of how much it expects to receive from its partial asset sales down to between $4.6 to $5b.

NZ lighting technology has saved the Countdown supermarket chain's owner almost $500,000 a year in energy costs in two of its buildings.

Investors who took up shares in newly listed Mighty River Power and Meridian will take little comfort from PwC's latest report on the electricity sector.

The decade-long surge in big wind farm building in New Zealand is nearing an end with no new projects in the pipeline as the sector booms around the world.

Parts of Waikato will be without power today as urgent repairs are carried out on the Transpower network.

The Government, fresh from the sale of shares in Mighty River Power and Meridian Energy, faces a harder sell when it comes to divesting a 49 per cent stake in the third and final power generator.

Hundreds of thousands of Transpower customers lost power today when backup measures failed to kick in while the company simulated a "catastrophic power failure".

Meridian Energy's instalment receipts have continued to hold firm, helped by buying interest from Bank of New York Mellon Corp, through its London-based subsidiary, Newton Investment.