The Green Party is calling for an independent umpire to regulate buy-back prices set by power companies, after a major supplier slashed its rate for new customers generating solar or wind power.
Users of renewable energy - such as solar or wind - use the electricity to power their home or business, and can sell back any excess electricity to their supplier to be used on the national grid.
Contact Energy announced on Friday it was cutting its buy-back rate for new customers by over half, dropping from 17c to 8c.
Green Party energy spokesman Gareth Hughes said the move showed electricity companies had all the power in setting terms, contract length and buy-back rate for exporting surplus energy.
"It is high time New Zealand established an independent umpire to set fair and non-subsidised rates for surplus energy with greater contract certainty," he said.
Many New Zealanders were looking to gain greater energy freedom by installing solar panels as power prices rose, and Contact customers looking to invest in solar would feel "disappointed and powerless," Hughes said.
Contact chief executive Dennis Barnes said the new buy-back rates signalled the company's desire not to favour one particular form of renewable electricity over another, and was in line with the cost of purchasing new forms of renewable energy.
"Contact is a huge supporter of renewable generation - last financial year almost 70% of our total electricity generation came from our five geothermal power stations and two hydro power stations."
The new buy-back rate was the first in over five years, and was competitive with other energy retailers' rates which ranged upwards from 3.5c, he said.
Contact's price change only applies to new customers to distributed electricity generation, although the buy-back rate for all customers generating renewable energy was subject to change with 30 days notice.
Hughes said the 30 day notice period further showed it was the electricity companies who had all the power, and a "fair, reasonable rate" should be set in New Zealand in line with Australia, Germany and the United States, among other countries.
Different companies had different rates and different terms to pay people feeding their surplus power back into the grid, and in the absence of guidelines or regulation, it was entirely at the power companies' discretion.
A tariff set by an independent umpire such as the Electricity Authority would give greater certainty to people who had invested thousands of dollars in solar panels for their home or business, Hughes said.
The sustainable energy industry was "going gangbusters", recording a 30 per cent growth rate for the last year in March.
"The Green Party wants to make it easy for families to generate their own clean power and to receive a fair payment for it."
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