Hi all,
I'm looking to into making a hydropower system at my new home. The stream falls about 30m (~100ft) and I'm estimating the flow at between 5 and 20litres/sec (~60-240GPM) over the winter - I suspect it'll be a trickle in midsummer.
Having used powerspouts' calc I think there's potential for 0.5-2kw give or take.
Having used H-hydro's s/sheet I've got a net head of 43psi, and a Vjet of 24m/s = spoon velocity U of 12m/s, which for h-hydro's smallest (presumably cheapest) turgo wheel gives a shaft speed of 2700rpm.
I was hoping to do this as cheap as possible so I was planing on getting h-hydro spoons (or maybe a whole wheel) and making a genny myself.
1st question: are my numbers in the right ball-park?
2nd Q: how do you figure no. / size of jets? (powerspout calc does give no. (1 or 2) and size, but I don't know how they figure it). Is it better to have more jets or one big one?
3rd Q: do you think an axial flux PMA similar to hugh piggot wind turbine is a good choice for efficiency? (I was thinking something with smaller mags and higher rpm - though 2700 rpm might be a bit too high. possibly use a larger dia. wheel? but that's more $$$
As an alternative, I do have a 2Kw 1PH (cap start) induction motor which I could use but don't really want to re-wind or fit permanent magnets, and I wasn't sure how easy it is to get it to self excite.
4th Q: If I have a system sized to provide 2kw when the water's there, how low will it go before shutting down? (if I have to choose, I'd rather have 0.5kw for 6-8 months than 2kw for 1-2 months).
Thx
Mab
PS. Has anyone every tried using actual spoons (like teaspoons) to make a turgo? I can get those really cheap.