 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Windmills : Disassembly of F&P washing machine?
  Page 2 of 2 |
|||||
| Author | Message | ||||
| KiwiJohn Guru  Joined: 01/12/2005 Location: New ZealandPosts: 691 |
I see what you mean! This is the way I see it, you need so many Kwh per annum and for that you need so many litres down your 'penstock'. To keep that going you need so many litres pumped to the upper tank when you only have an average of (he says looking by eye) 3 kilometres per hour of wind. I think this means you need a wind generator that can drive a pump that can lift enough water to drive a turbine that can drive a generator(alternator) to drive the load and the wind generator must be able to do this with about 3Kmph of wind. If your tank could store enough water to run the hydro power for about 5 hours and you drew most of your load for only 16 hours of each day then a wind turbine able to pump enough water for about 2/3 of the load would be sufficient (I think). The lead acid batteries would still be there to handle those heavy short duration loads that the hydro could not support alone. I think you mis-understood what I was saying about transferring windmill power down the hill by way of high pressure water, but it was a silly idea anyway. There seems to be a huge variation in efficiencies of micro-hydro generators, do you have enough head to run a real turbine rather than something like a pelton wheel? Taking into account the lower efficiency of lifting and storing water compared to the lead acid batteries which would pan out cheapest in the long term? |
||||
| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Yup, that's about the size of it. What the graphs don't adequately show is that sometimes we go for days with little or no wind. Fortunately, most of those days we have moderate to good sun so the PV works well, but this winter just gone, we've had days on end with fog. No wind, no sun, nothing. Boo, hiss. Some days however (like middle of last week) I got a near-constant 500W from the wind turbine, up to close to 900W for short bursts. That day, the generator barely needed to run! Yup. I can see what you're getting at, but the relatively short run-time of the water and high (energy) cost of "recharging" the tank makes the batteries look like a more viable solution, sadly. Yes, this was always my intention. I guess I was just off chasing "hairbrained ideas" myself. Sounded good though. I didn't look into it in too much detail until I worked out the broader picture. If it's going to cost me more to recharge the tank, than a similar energy in storage cells, what's the point? If they were CLOSE, then doing away with the large, expensive, limited-life batteries makes sense, but not with a 5 or 6-fold difference in efficiency! At this stage batteries still look to be the answer. I'd need a lot more water storage, and/or a lot more fall (head) to make the water option really viable. I'm pulling about 13 KWH/day at the moment, which would *JUST* work with a 500W constant source of base power. For example, if I had an extra 2KW of PV that I could rely on to move water back up to the top tank during the day, then the hydro could provide enough power overnight to reduce the discharge on the batteries to an insignificant amount and thus really extend their life. Against that, there'd be what, $5K in a hydro, 30 odd solar panels, so we're talking no change out of $25-30K. I could buy a largeish bank of cells for $10K, which should last for 10 years, invest the remaining $15-20K over 10 years and perhaps have earned enough to pay for their replacements when they're needed! Why can't renewable energy sources be more reliable?! I mean, it's THERE, and when it works, it's beaut, but I live too far from the sea to use tidal (>300Km), solar is here for at best 40% of the day, but sometimes nothing useful for a week at a time. Wind is certainly better output per dollar of investment, but it too is unreliable. And we just don't have a good, reliable, cost-effective way to STORE power when times are good. (This all came about from wanting to "bank" surplus energy, and moving water seemed an interesting possibility - but sadly, its watts-per-cubic-metre isn't very good. With 50m head, it's about 140 watt-hours/m^3 compared to something like a Trojan 220AH/6V battery which works out at over 110,000 watt-hours/m^3, so batteries have over 800 times the energy density of my tank of water! Back to the drawing board, me thinks! |
||||
| KiwiJohn Guru Joined: 01/12/2005 Location: New ZealandPosts: 691 |
It been great yarning with you Ross even if I didnt contribute much at all to the solution! I worked at a place once that had a 600Kw hydro (Pelton wheel) driven from a 500' ft head. It was just a little thing really but it drove everything in a moderate sized hotel including heating, houses and my stuff at the airport. Such a no-fuss machine I have always had a soft spot for hydros wherever possible but they are not so attractive if you have to pump the water up to them! 
I would love to try a micro-hyrdo using car turbo charger rotors, I may be way off track but I think with the density of water they would produce useful power at quite low RPM. One last point on the subject of banking surplus energy, I think it might still be worth while even if the efficiencey is only, what 15%?, still better than wasting it. Cheers John |
||||
| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Sounds wonderful! Wish I had permanent waterflow here like that. Heck, I'd be monsterously happy with 1KW! Yes, I think that would probably be good to play with, but you'd want a fairly high flow rate (probably more suited to high flow, low pressure) - but I suppose it would depend on how much power you expected to extract! Yes and no. The idea is sound, but if it costs me a heap to set up for arguably very little return, it probably isn't worth doing it. The worst part (could) be using the water from the top tank, and then having to actually run the generator to get water back up the top for showers etc a couple of days later if there wasn't any "free" energy to pump it back up! Anyhow, I'll sit and think on it for a bit. I contemplated using renewable energy to (slowly) lift a large weight, thus storing the power as potential kinetic energy, and getting it back out later somehow, but thats an even bigger engineering feat than the water. (My tank weighs over 120 tonnes when full, it'd take a lot of engineering to store a useful amount in "dead weight") Cheers John |
||||
russelcat Newbie  Joined: 12/11/2010 Location: AustraliaPosts: 4 |
still trying |
||||
| russelcat Newbie Joined: 12/11/2010 Location: AustraliaPosts: 4 |
My battery room is underground, 2m x 5m roughly. The north, west and east walls are concrete-filled besser blocks, the remaining wall is just standard besser block. The floor is a 150mm thick slab, and the roof is a 200mm thick slab. I have the batteries sitting on a "plinth" made from yet more besser blocks, 2 deep to make a 400mm deep shelf for the batteries to sit on. I'll try to find some photos. Hi i like the shed and that battery bank would be a dream. The only thing I would do is put some sort of material under the batteries a sthey dont like sitting on concrete or cement as for some reason it shortens thier life , beleive me i lost 12 deep cycle batteries in 2 years from sitting on concrete , but a brilliant setup just the same . still trying |
||||
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Its a myth mate, see here:batteries on concrete You better start looking for the 'real' reason your batteries died  Klaus |
||||
| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
For the record - if you go back and look closely, you can see a 3/4" sheet of styrene foam on top of the concrete blocks, and a 1/8" sheet of high density plastic sheet on top of that and the batteries sitting on that. This was partly for the "myth" about batteries self-discharging excessively on concrete, but mostly to level out the small imperfections in height so the batteries could be safely bolted together. The battery bank as posted way back then was sadly destroyed by the idiot contractors during construction (long story). Here's the current state of play (including 19mm MDF the batteries are sitting on): 
 |
||||
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
[quote]was sadly destroyed by the idiot contractors during construction (long story). [/quote] I like a good long story. That would have been 1 costly idiot mistake. Nice setup Ross. Pete. Sometimes it just works |
||||
| RossW Guru Joined: 25/02/2006 Location: AustraliaPosts: 495 |
Well I don't have time for a full recital but the short version is that the cells originally photographed were 2V/300AH hawkers which had been removed from service because they were scheduled for replacement on time. They'd been shipped to me but I wasn't ready to install them immediately (construction delays, inverter delays etc). They went in as photographed but had been in storage for a while - they really needed the kid glove treatment to bring them back. I'd planned on gradually letting them soak up charge as often as I could manage to run the generator. (No power on site, nowhere near enough PV to do anything etc). Anyhow, I had to go out of town for a week. There were several trades on site that week - but all had been told NOT to use the batteries for anything except the two floodlights I had provided (100 watt high-pressure sodium lights), and to run the genset daily (which should have put power into the batteries). Anecdotally, it appears they completely ignored my instructions and lived it up. They were using their own 1500 watt halogen flood lights. Their electric kettle was used repeatedly for their various tea/coffee breaks. They even used a hot air gun to help dry off paint where they'd had to touch-up several damaged areas! The batteries would sag and the inverter would shut down on low volts (it's log told me this). They found that if they turned the inverter off, then back on, things would work again. They did this all week! Finally the inverter wouldn't turn back on and they just ran their stuff off the generator - but unplugged the lead to the inverter/charger because it was inconvenient, they needed another cable!! The final straw was that the temporary water pump (which ran off DC) was running off the batteries too, with no LVD - so once the cells were flat enough the inverter wouldn't run, the water pump discharged them even further. By the time I got back the cells were pretty much beyond recovery. The blame-game started, everyone who was on site denied it was them and blamed someone else. Without proof, what could I do? (What I *WANTED* to do was shoot them all and bury the bodies before anyone missed them). |
||||
| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
[quote] What I *WANTED* to do was shoot them all [/quote] I dont blame you feeling that way......but hell the cost of bullets and all, just aint worth it for something as dumb as goat droppings. Pete. Sometimes it just works |
||||
| VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539 |
Hi Ross Real nice setup now, on your old batteries, mine came in a similar condition and with the use of desulphators they have come up to capacity, took about three months but would have been quicker if I had more desulphators on them, I have found that with the ones I am using 1 unit for 250 amphr is about right, I leave them on all the time as they are not a high intensity unit, even though they are rated at 1000 amphr its better at 250. They have rescued some wet cells that where to zero volts and sitting at that fo nearly 12 months, I saved 4 out of five batteries. I found in Victoria in cold weather the batteries lost capacity sitting on cold concrete, a piece of wood under them was enough to normalize, I never noticed any die from the concrete but the capacity was down, with the old 32 volt systems I serviced in the early days it was a requirement to put them on a wood base and insulation from cold with a timber box. Maybe old wives tales with new batteries now due to a bit different plate construction. Love your setup I wont send a picture of mine because you would shame me. All the best Bob Foolin Around |
||||
| Page 2 of 2 |
|||||
 Print this page |
