Greenpeace list targets Mercury

The halo around Mercury Energy customers in television advertisements may lose some shine with the launch of an online "clean energy guide" by environmental group Greenpeace.

Mercury is the retail brand of state owned Mighty River Power, which is trying to re-fire the mothballed Marsden B power station using coal, earning the ire of climate campaigners.

Greenpeace's new guide is designed to give consumers a way of ranking electricity companies according to how they make their power, both currently and according to future plans.

Climate campaigner Vanessa Atkinson said consumers had "been in the dark for years about where their electricity comes from".

The new guide, due to go online today, is designed to help consumers "make the switch" to companies that used renewable energy. It gives more importance to future plans since these developments will "determine our energy future".

Greenpeace says the rankings are not an endorsement of any company and only take into account effects of climate change.

Mighty River's fellow state-owned enterprise Meridian Energy has been given the top "Green" ranking by Greenpeace, since it generates all power from renewable sources - wind and hydro.

While Greenpeace backs Meridian's wind-farm expansions, it is not so supportive of its national transmission grid upgrades, or its past plans for expanding hydro-electric generation on the Waitaki River.

"Electricity companies should take their customers' preference for clean energy into account and stop investing in outdated, fossil fuels like coal and instead invest in renewable energy like wind and solar," said Atkinson.

Mighty River and Greenpeace have both appealed to the Environment Court about resource consent being granted for Marsden B to be fired up with coal. Mighty River is appealing against the conditions imposed.

Mighty River general manager external affairs Neil Williams said the company had to consider many options.

"At the end of the day, no one fuel ultimately is the solution to New Zealand's future energy requirements. It's important there are options there if they're required."

Mighty River's primary focus was on new geothermal power generation, but it was also looking into wind and small-scale hydro stations and was exploring for gas fields.

The ranking

* Greenpeace has ranked NZ power companies, according to how they make electricity.

* Top ranked "green" company is state-owned hydro and wind generator Meridian.

* Bottom is Mighty River Power, also state-owned, which sells electricity under the Mercury name.

* Other "red companies" include Genesis/Energy online and Contact/Empower

* "Orange" companies, include Trustpower.

* Burning coal to generate electricity emits more CO2 than gas, so earns a worse ranking from Greenpeace.