Retired Europeans can generate big incomes selling power back to energy suppliers - but not New Zealanders.

Malcolm McAll, an eco-house developer who is using an $820,000 Whangaparaoa house north of Auckland to showcase energy efficiency, says New Zealand is well behind the international scene.

Last week, McAll of Ecos Homes, promoted his new 280sq m house at 62 Arden Ave in Stanmore Bay as being an electricity profit centre, making more power than it used.

He sold $127.75 of power back to Meridian Energy over a two-month period, and Rebecca Johns of Meridian in Christchurch said this was becoming more common because houses were fitted with import-export metres which allowed them to sell excess power.

But McAll claimed far more money could be generated.

"A retired couple in a small two-bedroom home with $60,000 spare cash could generate an income of about $600-$800 a month to supplement their pension," he said, citing European examples where people owned electric cars, had no fuel bills and generated an income.

Mike Scaife of Wellington challenged the claim, saying it was impossible to achieve an income level this high. "My evidence is simple maths and knowledge of solar installation prices and costs," he said, predicting the European experience would never be available to Kiwis.

"A large percentage of the power generation here is owned by the Government which stands to potentially lose income if this ever takes off.

"Any failure to lower power costs to the public just boosts their coffers.

"I have 3.6Kw of photovolatic panels to install at my house and feed power into the grid. This amount is calculated to be just enough to break even averaged over a year, so hopefully our net power charges will be zero.

"I am not doing this because of any incentives, but just to stick my finger at the power companies and their ever-increasing charges; 90 per cent of our hot water is already supplied by DIY solar hot water panels I made over four years ago," Scaife said.

McAll said he was citing European examples and that the present disincentives in New Zealand did not yet permit this level of income.

But he wants to change this and highlight energy-saving housing components here.

"It is possible, in some European countries where Governments and power companies are working together to promote micro-generation. We are trying to encourage people here to recognise the possibilities and demand changes to the current situation in terms of grants and better tariffs," McAll said.

"After all, when homeowners are paying for the cost of the generating infrastructure, the power companies don't have to.

"We are already seeing great advances in micro-generation, which will continue to reduce the cost of installations and improve their efficiency.

"When you also factor in the ever-increasing cost of power, the fuel savings from running an electric car and the reduced power consumption through the use of low energy appliances, such as those featured in our showhome, the future is very promising," McAll said.