Floating on water, a large solar power array offers a look into a more sustainable future.

A large floating solar 'array' capable of producing enough power to run 200 New Zealand homes for a year is soon to be floating on top of the Rosedale wastewater pond on Auckland's North Shore.

The one megawatt installation will be the first of its kind in New Zealand, according to Colin Daly, CEO of Vector Powersmart, the company delivering the project.

He says this is both because it will float on water (it will take only three per cent of the pond's surface) rather than take up valuable land and because its generation capacity of 1MW will be at a scale not seen in New Zealand before.

"Watercare (the utility company) had the good fortune to have a lot of surface space on the pond, so we will be able to create a very large solar installation on the water," Daly says.


But far from being a one-off, Daly believes the demand for alternative energy solutions like the array will increase as large energy users realise how solar and battery storage technology gives them new options.

"Business is where the big mobilisation is going to take place (in renewable energy)," he says. "We want businesses to know they can come to us and by putting their needs at the forefront we can develop sustainable solutions.

"These could mean zero carbon solutions, electrifying transport fleets, providing security of supply, fixing and lowering energy costs or any combination of these; these are options providing real energy independence."

Daly says Watercare had been looking at ways to be more energy efficient and self-sufficient at the Rosedale plant. It will use the electricity generated by the array for pumping in aeration at the plant, allowing natural bacteria to break down waste as part of the treatment process.

Aitutaki tour of the array
Aitutaki tour of the array

He says Vector Powersmart's work in the Pacific helping island nations offset diesel generation with renewable, clean solar power is another example of how solutions can be tailored to unique needs.

"A few weeks ago we opened a solar, battery and management system in Aitutaki (in the Cook Islands) that is estimated will provide almost a quarter of their energy needs and save 243,000 litres of diesel from being burnt."
Daly says Vector Powersmart is committed to working with its larger customers to formulate solutions for future power needs, taking the guesswork out of power cost projections.

These costs can be variable, but as solar solutions can be delivered for a fixed capital cost, power costs will no longer be an unknown quantity over the life of the systems – typically around 25 years for solar panels.

He says for those wanting to avoid an upfront cost, solutions can be designed where customers only pay for the solar electricity a system produces, not for the system itself.


"This lowers businesses' exposure from the energy cost perspective as it means they are effectively paying a fixed rate for their power," says Daly.

The customers come first in this process: Vector Powersmart sits with them to establish what they want to achieve before diving deeper into developing innovative solutions.

Daly says the projects being delivered by the company are just the beginning of a transformation to 100 per cent renewable energy in New Zealand and he believes the end goal - where customers can buy, sell or share power they produce themselves through a peer-to-peer network – is ambitious and paradigm shifting.

"In the United States community solar (where communities have access to local solar farms) is growing fast. Over the last year alone enough community solar was installed to power nearly 300,000 homes and we can foresee a time when the same will happen here."

He says given trends like this, solar is an energy form whose time has come – and Vector Powersmart is excited to be at the forefront of this revolution.
"In the face of challenges [like climate change] it can be reassuring for businesses to know they have a trusted partner who can create bespoke solutions for them."