An electricity company's offer of free power has given one Carterton family a bit of a shock.
Steve and Maria Cretney took up Mercury’s "free power day" three times, a promotion offering a full 24 hours of free electricity.
The first two times, they say, they used power like any other day. But the third time the free power day was offered, the family decided to really make the most of it.
"In the morning, I left a note out for the kids saying, 'Don't forget there's free power. Do what you want. Have your heaters on, do some baking'," Maria said.
So the heat pump went on. Their kids, Abigail and Mark, indulged in long, hot showers, and played endless video games, and six loads of washing went on. Steve put on a roast and even water-blasted the house.
But when the bill came in, they were surprised to find their third free power credit for that day was a similar amount as their previous credits, even though they'd used significantly more power.
"I compared it to the other two bills and thought, 'How could it be just a couple of dollars different when we'd done so much more?'" Steve said.
Upon contacting Mercury, the couple found that because of the type of electricity meter installed at their house, there was no way for the company to calculate their free power day.
The majority of Mercury's free power days are calculated on smart meters, which can track and send exactly how much electricity a household is using every half hour. The Cretneys, however, have an analogue meter, which requires a meter reader to visit and record the amount of electricity used since the last read.
Mercury said the Cretneys' power credits had to be calculated based on an exaggerated estimate of their usage – by multiplying their most recent available usage by a factor equivalent to the difference between the usage of other Mercury customers who live near them on free power days, compared to non-free power days.
Mercury said that they had to agree to these terms and conditions before redeeming the offer.
"This is the fairest way usage for customers on analogue meters, and the only option we have beyond excluding these customers from this reward entirely, which we feel would be unfair and disadvantage these customers. Every year we credit tens of thousands of customers with free power days," said Kevin Angland, general manager of retail and digital for Mercury.
"Free power days are an opportunity for us to give back to our customers and thank them for their loyalty. More than 90 per cent of Mercury's residential customers have smart meters, which allow us to calculate precise free power day credits based on actual data."
But the Cretneys say the terms and conditions were too easy to miss, and Sue Chetwin from Consumer NZ agrees.
"It might be in the terms and conditions, but people don’t usually read the terms and this is such a critical part. It's an impossible calculation that only Mercury can make, and I just don’t think that’s fair."
The Cretneys were given an extra $15 dollar goodwill credit by Mercury, but they still believe they ended up spending more money than they had intended.
"When you've been told, 'You've got a free power day, use as much as you want,' everyone's going to jump at that chance, aren't they?" Maria said.
While the best things in life may be free, they're not always so easy to come by. So when the offer of something for nothing comes up, it's worth checking what that actually means.