Meridian has jumped on the 'Solar Promise' bandwagon. 'Bandwagon' may carry a few negative connotations, so let's just call it a wagon.
What does the Solar Promise wagon promise, then? It promises to allow individuals and companies to promise to get their friends, family, and customers to promise to take a serious glance at installing solar heating.
Jokes aside, it's actually an initiative begun by the Nelson City Council, et al, to make solar energy more affordable; and they've done this by introducing a rates-based financing scheme (that should give one cause for further investigation), and waiving solar resource consents; well, I certainly like the last one!
Being the calculating type - don't frown like that: I meant the type that likes to do calculations - I liked that they included a few figures on the website, that is:
1. that power bills have risen by 78% in the last 8 years; and,
2. that solar water heating can reduce the costs of hot water heating by 75%.
Now, for the calculations: from 2, then, you would end up saving about 21% on the overall bill (assuming 29% of the bill goes to hot water heating costs). So, if you've got a power bill of $200 per month, you'll be saving $42 per month.
Seeing that a hot water heating system costs between $4,000 - $8,000, it'll take between 8 - 16 years to recoup the cost on a money-saved-because-we-don't-have-to-heat-so-much-water basis alone - provided the power bill stays the same.
If, however, the power bill goes up another 78% in 8 years, at a rate of 9.75% a year, the cost'll be recouped within 7 - 10 years.
So, is it worth it? Well, I'm not your accountant. But, if I was, I'd say that it depended on what your goals were, and what kind of term for fulfillment you'd be happy with. Aside from that though, a solar hot water heating system would add a bit of resell value to the house.