Originally Posted by
72andsunny
Aberdian, have your calculations been as good as promised so far? It doesn't get much sunnier than Hawke's Bay; we really would like to put in a system if it made any sort of financial sense.
They've only been in a couple of weeks so all we have to go by is the word of the installer (who is a family friend so hopefully he'll not lie too much) and my back of a fag packet calculations - luckily the two methods seem to come up around the same value, installer says payback in 7 years, my numbers reckon about 8. Bear in mind that we'll be a net exporter to the grid based on our usage pattern and the size of array we've put in.
Looking at our numbers, we'll only have a deficit in June and July when the inversion layer is in and the sun's hidden - not a huge one, we don't have heat pumps or electric ovens to run and the vineyard bore is switched off so it's just appliances and lights etc.Bear in mind that I tend to be VERY conservative when it comes to numbers, I'm reasonably confident(ish) that I've got a good handle on how much power we should be producing......ask me in a year if that's true!!
Apart from the money, the great thing about it is that it makes me feel righteous....