To recap:
I have access to a stream which would generate 280w continuously 24hrs... To equate to a solar panel install, how much kWh/day is this... 24x280=6,720... Is this then a 6kWh equivalent?
How do I calculate batteries when output is so low, but 100% solid...
PhantomNVD: I already run a very energy efficient home. Wood burner (free wood) and gas califont and oven/hob ($50-70/month depending on wife's baking)
PowerShop tells me I use 5kW/day summer, and 14 in winter, so 6kW/day is all my use in summer and nearly half in winter.
My base load then IS nearly 300W, so I'd definitely need some panels to perk up the battery bank for night/winter use, though that's also when they're least/not productive :(
It looks to be $22000 to connect to 'the grid' after "development costs" so the battery bank
At 300W/h 24h/day I'd still cut my power bill in less than half annually, and pay off the micro hydro investment in a medium timeframe... even if I got $0 payback from the grid, so perhaps grid connected is simply a choice between battery bank vs grid use?
As I see it then (in my case) for such a small system, if I worked out how to run the base load directly from the hydro, the grid would just be factored against 'solar and battery' use at peak, vs grid fees, especially if grid connect >= solar install
AFAIK I'd need the battery bank to service a load greater than the <300w output, but as it runs 24/7 I should easily be able to replace this overnight and through the day when away and only running my base load?
Also, I only have 40m of the stream passing through my backyard and a 2m head, so dam would be
a)unlikely to be feasible, and
B) not really useful unless the head raised considerably to facilitate a higher power output?
Solar PV maths:
raytaylor:280 watts continuous is 6.7kwh of power a day
A 2kw solar system will provide 2.5kwh to 15kwh of power a day
PhantomNVD: Quick update... I just got an off-grid quote for my 10kW/day at 50,000 for Solar, and $55k if I used the mini hydro in the mix(!)
Apparently $35k for the base hydro install, and another $20k for solar to supplement for winter needs.
When the turbine is $2000, the piping $800, plus around $3000 for a good regulator, and $2000 to cable... Have to do it myself to make the numbers add up favourably I guess...
and another case example:
nutbugs: @PhantomNVD. A couple of comments about my experiences. (I probably should create a new thread about all this as someone suggested a while back - time is short and the todo list is long! It is on it though :))
We elected to install a second turbine and reduce the battery bank capacity so that we could cover a larger base load. We have plenty of flow rate in our stream so this wasn't an issue - simply installed a larger size pipe. We actually have capacity in the feed pipe to run three turbines. The excess generation is dumped into a hot water cylinder so we can have lots of outdoor hot baths :)
As per PM's - I will dig out our logic for battery bank sizing etc and get that to you.
The batteries are the weakest link overall when you consider the maintenance and cost. We are 6 or 7Km from the nearest grid point across unfriendly terrain so a grid tie is not an option. If it was - I think I would go that way. The downside obviously is that if the grid is down so is your alternative power! Not sure how they manage the Hydro connections - it will need a load somewhere I think?
We have 16 x 6v 225AHr batteries.
We are running 48v - so that is two banks of 8.
We really wanted to cover peaks above 1KW or so - of which there are not many - we keep everything very efficient - and a few hours outage. This has seemed to work well enough so far.