This is going to be a very interesting project. I have been doing a bit of a deep dive on the figures, and also getting historic weather conditions for decent Corbiere Vintages. So I now know I will be running the lighting to a peak of a 15 hour day. This alters the figures a little, perhaps I may have had some dodgy workings, so lets look at it all again.
VINE – £24 – £4.80/yr
I have depreciated this over 5 years, which is what i have given the pot, it may be possible to transplant, but I thought it would be more prudent to assume that they are viable for 5 years. I am fully aware that they will go for 40+ years though.
AQUAFARM POT – £90 – £18/yr
I didn’t really shop around and regretted this to the tune of about £10 when I found it cheaper elsewhere for around the £80 mark. I have assumed it will last about 5 years. It is extremely efficient though, only using 2 watts of electricity an hour.
LIGHTS – £58 – £58/yr (!)
OK, there is definitely a better option out there, but to reduce heat, and for practical reasons, like energy efficiency, I thought I was doing the right thing by choosing to go down the LED route… They are guaranteed for 5000 hours though, which means they are depreciated over a year. In reality you would scale up some how, especially on this item.
TRELLIS & 4 GANG SOCKET – £10 – £2/yr
Utter bargain, parents had an old steep triangular trellis, whack it up upside down and now I have a support for the vine. I have also managed to acquire a 4 gang socket in the process An arbitrary £10 later, depreciated at £5 a year, we have all we need.
DEPRECIATION TOTAL: £82.80/yr
0.09 kWh x 15 hours x 365 @ 15p/kWh = £73.91/yr
0.002 kWh x 24 x 365 @ 15p/kWh = £2.63/yr
RUNNING COSTS TOTAL: £76.54/yr
TOTAL COST PER ANNUM
This is £30 or 25% higher than expected. This does not account for any nutrients, it also doesn’t really matter as a figure until we find out what the yield will be.
Planted normally a vine can bare anywhere between 7lbs and 30lbs of fruit. At 7lbs that would be £22.86/lb, whereas at 30lbs that would be £5.33/lb.
A metric tonne of Cabernet Sauvignon grapes would sell for around £2k a tonne in the UK. Or roughly £1/lb… it seems like there is no value in this project.
But what may save the proposal, in true dragons den style… Is that I believe you can either shorten the annual life cycle. Or even potentially triple harvest each vine each year.
When budburst occurs, should one bud not flower another two buds are kept in reserve. Imagine the unnatural… Three summer’s and a spring… Or it may be spring, summer autumn, summer autumn, summer autumn. 3 harvest seasons in 21 months. Better then 1.5 seasons a year. Our £5.33/lb might now cost less than £4.