Correction: The original copy and headline of this report stated the solar panel reduced the family's power bill to $1.50 a year, which is incorrect. In fact, the panel costs the family $1.50 a year to run.
A Northland family's DIY hack has been labelled as "ingenious" and "achievable" after cutting their electricity bills by hundreds of dollars a year.
Terry Johnson and his partner Mel McMinn created their own solar panel heating system using just aluminum cans and spray paint.
Johnson and McMinn collected more than 270 cans, building their project over a few weekends before documenting their progress on blog site Frugal Kiwi.
Initially, the project cost about $500 in materials, but the long-term savings could help be beneficial to families.
"We had it for about 18 months. A large part of the cost went into buying a sheet of polycarbonate. We could have used cheaper materials but we would have saved hundreds of dollars a year or at least a dollar a day if we chose to run an electric heater," Johnson told the Herald.
"The two little fans within the unit cost $1.50 per year to run.
"In broad terms, the energy out of the unit on a sunny day would be the equivalent to about $1 worth of power per day, saving us a couple of hundred dollars a year on heating."
So how did Johnson create his own solar heating panel?
He cut the top of the cans to form baffles and glued them in columns of 16.
The cans were spray-painted black to absorb as much heat as possible and then fitted to a plywood frame.
A clear polycarbonate side was fitted to the plywood frame allowing light to shine on the cans.
Two holes were cut at the top and bottom to allow airflow and the entire panel was fitted to the eastern side of the house for maximum sunlight.
An intake and an exhaust fan were fitted on the inside wall to get a result he claims heats his house by 4-7C which was enough to cut his electricity bills to almost zero.
Johnson told the Herald the concept wasn't entirely created to save money, but instead provide a cleaner environment to live in.
"Over the year you're only wanting that benefit over the cooler months. The concept worked well during winter but you wouldn't need it during summer.
"The idea isn't entirely to cost cut, but the benefit is to have a more liveable house. You have less mould, less condensation and you have a much more comfortable home to live in compared to just turning a heater on for warmth.
"Waking up in the morning to turn the heater on and having to remember to turn it off, you're creating more work for yourself where you just want to have the place nicer already."
How well did the concept work? According to McMinn on The Frugal Kiwi, the experiment was a success.
"The heat from our panel, spread across our great room, didn't immediately feel like a huge boost when it came on," McMinn explained. "What did happen was that the thermal mass of the whole large space was lifted by several degrees.
"The panel got up to about 60 or 70C, and the air came out of it in the 50s."
Johnson and McMinn's solar panel story has gone viral and attracted responses from around the globe, including the US, Mexico and Australia.
"This is absolutely incredible. I can't believe that just a couple of soda cans can be made into a solar panel," a fan from the US wrote. "And at $1.50 a year! I could be saving so much money during the very long winters of Utah!"
Another wrote: "This is a really incredible DIY! I can't believe you're able to get that effect with cans."
While Johnson and McMinn are proud of what they've achieved, they say they've received mixed reaction but can see the lighter side of any negative comments.
"A lot of people have called us geniuses and said it's a brilliant hack that they're looking at trying. It seems to have captured the imagination of people even overseas.
"People have pointed out that the heater won't work at night, which we already knew. People say we're either geniuses and inspirational, we didn't think it up ourselves, or that we live in Northland so don't know what the term cold means!
"But we see a lot of Scandinavian countries implement these types of heating ideas. It goes to show these things can work in 0-degree temperatures and still put out 50-60 degree air."
Should you give it a go in your own house?
While everyone has a different skill set, Johnson believes there are many other options available to heat your home for a small price.
"Having the confidence to experiment on your own house takes a fair bit of intestinal fortitude but there are other methods, such as cheap double gazing, to heat your home and reduce the power bill.
"I'd do it again in the right house. The house we had didn't have much in the way of window space. It had not been built to take advantage of the sun. There weren't a lot of options. But in the right house you could utilise the solar panel."