The Newmans ran the numbers and found that for a 'normal' household, the total payments over 20 years would be $26,400. My colleagues in the eco-design field came up with similar numbers, and determined the equivalent system could be purchased today for half that.
In effect, signing a contract for the solarZero programme would be similar to taking out a loan to pay for solar panels and paying it off over 20 years. In both cases, economically savvy and fiscally prudent people would decline, and instead invest in products and strategies with much better financial returns.
This was essentially the same conclusion reached by researchers at the University of Canterbury Electric Power Engineering Centre, which I wrote briefly about last week.
Those researchers found grid-tied solar electricity systems were financially viable only for households that could pay cash upfront for the panels and that use lots of electricity during daylight hours. In other words, rich people who use heaps of power - fine for them, but not aligned with the theory and practice of eco-thrifty renovation.
Over the course of 500 home consultations, I have never recommended installing photovoltaic (PV) panels as one of the top 20 (or more) suggestions that are proven to be cost-effective for creating warm, dry, healthy, energy-efficient homes.
In response to those who protest loudly, and insist PV is cost-effective, I have said for years: "Show me the numbers."
No one has come forth, yet the protests remain - hell hath no fury like an environmentalist scorned.
Last week I also shared research showing household PV panels have a much greater carbon footprint than wind or geothermal power, and I'm sure I ruffled feathers among those still clinging to dogmatic beliefs.
I have found it immensely amusing and ironic that I've been black-listed by local greens at the same time as being thanked and praised by Federated Farmers. Makes me wonder which group is more open-minded.
Please bear in mind this column is written by someone who owned an off-grid home powered by PV for eight years, and who presently has a stack of panels ready to mount on the roof. But that's another story.
In the meantime, here are some other suggestions for fun, easy and cost-effective ways of using solar energy: grow a vegetable garden, make a solar cooker, air your washing on a line outdoors.
Personally, I am immensely grateful for the sun - and the rain, and the soil - for contributing to a record crop of the World's Best Garlic this year. Like the mighty All Blacks, this year's crop of Allium sativum has truly outdone itself - available at the River Market for the next four weeks only.
-Nelson Lebo is an eco design professional specialising in new residential building, renovation, and healthy homes - 022 635 0868; 06 344 5013; theecoschool@gmail.com
