Microhydroelectric power is making a comeback in electricity generation for homes, farms, and small businesses. This trend is fueled by factors including favorable regulation, rising energy prices, and advances in automation. And do-it-yourselfers worldwide are diving in.
The only requirement to generate electricity is access to a stream with a two-foot drop in water level and two gallons of flow per minute. A hydroelectric system isnít overly complicated, isnít difficult to operate and maintain, has longevity, and is often more cost-effective than any other form of renewable power.
Although weíd never built such a system before, we did so by using low-cost components and free technical support, both supplied by AutomationDirect.
In 1980, my father, Arno Froese, began investigating the potential for generating hydroelectricity on his property. The land is situated near the dam of a 64-acre communal lake, allowing access to the 10-foot height differential between the lake and the tailwater on the other side of the dam.
My dad measured the water flowing over the spillway and determined that an average of 40 cubic feet per second flowed through the pond, making it a marginally feasible hydroelectric project. In 2004, my brother Simon discovered our dadís research and decided to move forward.
This microhydroelectric power plant generates 20kW of power, controlled by equipment from AutomationDirect.
In March 2004, Simon began excavation. For two years, the project was a challenging and sometimes disappointing excavation site, requiring us to dig 17 feet below lake level for the foundation while groundwater and mud continuously seeped into the hole. By the end of 2006, the underwater portions of the plant had been built, a four-foot aluminum pipe through the back of the dam was in place, and a temporary cofferdam was removed. We then installed a refurbished 50hp Francis turbine. Testing determined that the turbineís optimal speed would be 150rpm.
The hydroelectric system is powered by water draining from the lake that flows through a turbine, which drives three generators via a belt and pulley system. The generators are three Baldor Electric model L1177T 15hp single-phase induction motors.
Driving an induction motor at higher than normal speed generates electricity. Output from the three motors was tied into the local electric grid via the same transformer that formerly only provided power to the property. The utilityís meter now turns backward when our plant supplies more power than we consume.
I applaud this project from a technical and ingenuity standpoint.
However, I tend to agree with the pessimism on the regulatory stuff. Here in NY, the environmental hurdles as well as the federal & state energy commisions/authorities and utilities would make it nearly impossible. The thousands you would have to spend on attorneys, permits, fees, and political contributions to make it happen legally could buy you electric power from the utility for a hundred years or better. I think in this state the only thing attempting such a project would get you is legal trouble and the related fines and attorney fees.
The idea may or may not be impractical, but the comments are entusiastic. Those who comment on the Design News site are passionate about their views. I think that's very clear in this thread as well as the other comment threads.
Design News asked for people to moderate and presumably add comments to their web site. You had to make a certain number of posts to remain in the system and to receive a stipend or whatever it was called. I get the feeling that this thread is more about maintaining a posting record than making real comments about an idea that is impractical in almost every state.
You are absolutely correct. There's little more than .001 hp available from water @ 2 GPM dropping 2 feet. If this was able to produce 20 Kw we'd have ourselves a nice perpetual motion machine! I think that the heading of the article is misleading. The article itself is worthy.
This is a very good work! I wonder if this is affordable for developing countries like Mexico or Latin America where there is good potential for micro hydroelectric generation, how expensive is the system and where can I purchase one? Thanks
I have yet to connect our Micro Hydro to the grid. Except for a few hours of testing, when I discovered what 'absolute value' metering meant, we have been running autonomously since commissioning 2006. I used pumps as turbines and 3 phase motors as single phase generators to cut costs. I don't think I gave up any efficiency at all since I'm getting a bit more than my initial calculations indicated. NY just passed the net-metering law for under 25kW hydro, so we'll be hooking up soon.
Syncing induction generators of a few tens of KW to each other or the power-line is not a problem as long as they are within a few RPM or Hz of each other.
Thank you, renuengineer for that explanation of how induction generation works; I couldn't have done it better!
Re: FERC, they don't involve themselves with individual installations this small. In South Carolina, our department of Health and Environmental Control does regulate dams & reservoirs, but our lake had already been in existence for over 100 years. The utility company was satisfied with some cursory drawings and assurance that we were entirely induction-based. The only official inspection was that of the county building department.
NASA and Boeing developed a huge, carbon composite cryogenic fuel tank for deep space missions, and started testing it last month. The 18-ft cryotank will enable heavy-lift launch vehicles to send both humans and robots into deep space.
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