Thanks Eilrem Your information is very informative. I think now I have learnt as much as I can by looking at websites and asking a few questions on relevant groups.
Think the next step for me is to buy some books, think there was one recommended at the site than is used to link to this group.... Yes I know the site and yes I can find the book... I will be fine on this,, do not need a reminder.. It is good to know where I stand and to have some basic information if I attempt a microhydro project. I now think I have some idea of what I am up against. However I am not stupid enough to start any project without getting a lot of detailed information from books and from experts. Thanks N. Peter Evans --- In [email protected], Eilrem Fernandez <[EMAIL PROTECTED]> wrote: > Hi Peter, > > Assuming that the resource is not in question, a 2kW system is not ideal for DC system operation. > 1. Typical DC alternators are rated below 500W, so you might have to operate several units in parallel, which is not practical. > 2. If the total simultaneous load does not exceed 2kW, you will be better off just using 220VAC direct generation without a battery bank. Typical 3kVA/220VAC synchronous generator costs $150 here in the Philippines. > 3. Low cost inverters are notoriously inefficient and you still have to maintain a battery bank to operate it. An inverter needs a stable DC supply for proper operation. An alternator generates pulsating DC: some AC harmonic contents are present. > 4. DC appliances are usually more expensive than AC appliances. > > A 300W system is more suited for DC operation with battery bank. > 1. It could generate a total of 300Wx24h=7.2kWhr every day, more than enough for typical household use in a third world country. > 2. A 200Ah/12V battery (about $120) could serve as storage. > 3. It is more cost effective, more convenient, and more efficient to use a good medium sized inverter (500VA - 1kVA, about $50 - $100), except for direct heating applications. > 4. You can use for penstock the ordinary 2" - 4" diameter uPVC pipes used for water supply (blue color), a little bit more expensive than drainpipes but a lot tougher, as long as the head does not exceed 30meters gross head. Plastic uPVC pipes for watermains are rated up to 100psi, equivalent to about 70m gross head. I have even used the ordinary 2" BI tubes on one installation (20m head, 200W). > > It is ok to use temporary materials for the weir and canal, based on my experience. However, I don't recommend using wood and sheet metal in making a runner. Scrap metals of the proper dimension for fabricating the turbine could be bought from scrap dealers in 3rd world countries. You might spend $200-400 for a complete turbine, including labor and materials, assuming that your hydro site is ideal for the crossflow turbine. > 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/
