Hi, I'm interested in a run of the river scheme with a potential of at least 300kW. It consists of a 2m head, 45 degree straight concrete weir with flat river banks. Assuming 75% total efficiency, this means a flow of 27 cumecs would be needed through a turbine (the scheme would be capital rather than flow limited, such that 300kW should be possible for most of the year, apart from flood conditions causing the head to drop/disappear).
Looking at various studies on the net, the assumed cost/kW for microhydro schemes vary considerably from less than �1000 ($1750) to over �3000. This isn't very helpful, so I would appreciate any figures the group could suggest for the breakdown of a typical low head scheme. I know its an impossible question (how long is a piece of string!), but perhaps someone can offer some typical breakdowns between the civil works/turbine/trash-racks/generators and controls/management and consultancy for this type of scheme. (I can get estimates for grid connection costs). I'm assuming that lower cost fixed pitch propellor turbines would be appropriate rather than expensive kaplans given the capital rather than flow limitations. Also being in the UK my understanding is that fine pitch screening would be required (don't want the cormorants to go hungry!) - given the capital limitations I'm assuming a manual rather than automatic trash rack cleaning solution would be appropriate). I am assuming that the civil works costs are likely to dominate - particularly for a low head scheme, and probably the hardest to estimate. Obviously a site survey would help considerably but I'm only at the stage of considering if this is remotely feasable. In this case I expect that access and excavation conditions should be benign (clay/shale - no rock) so I'm guessing that a large part of the cost would be for sheet piling to prevent water ingress into the excavation. Is this a reasonable assumption? What about possible solutions avoiding the need for sheet piling - eg. (please don't laugh too violently - I'm not a mechanical/hydraulic engineer!) dropping precast channel sections into a flooded excavation and pumping mass concrete underneath? How big a channel would be required to be excavated for the head and tailraces and turbine for that 27 cumecs flow? I'm assuming that a .1m (5%) head loss might be reasonable, but as I'm not a hydraulic engineer, any suggestions? Thats quite enough for one post, so please accept my thanks in advance for any suggestions/advice/well-deserved-ridicule you may wish to offer, Splynk ------------------------ Yahoo! Groups Sponsor ---------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/FGYolB/TM ---------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
