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 isn’t overly complicated, isn’t difficult to operate and maintain, has longevity, and is often more cost-effective than any other form of renewable power.
Although we’d 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 dad’s 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 turbine’s 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 utility’s meter now turns backward when our plant supplies more power than we consume.
How many hoops did they have to jump through to get permits for zoning, excavation, disruption of "wetlands", don't step on this beetle, utility easements, etc. These are the real cahllenges to a project of this type. The technical part is simple!
Still trying to understand the ROI if I do have a creek without that nice dam the guys had to work with. Thanks to my beavers ... I've got some 3 foot drops (some of the year) and good volume (but not 40 cubic feet per second). I also have an issue that the creek is a good distance from the house and/or grid. Would love to see more detail from the perspective of implementation.
This is a great DIY project, but it probably doesn't scale well to similar sized commercial applications. I'm thinking mainly because of labor costs involved. It sounds like the two brothers did most of the work, with no costs associated with their time. Labor costs alone can be a very significant cost in projects like this. Many applications may also require the design services of professional engineers (structrual, electrical and mechanical), another significant cost.
Incentives (and hardware requirements) vary from utility to utility, also. Sounds like these guys got the best of both worlds...simple grid-tie in requirements and very attractive buy-back rates for surplus power. In some areas its exactly opposite. Very expensive equipment required for grid connection and buy back rates less than what you typically pay as a consumer.
And even a 100W generating system may require the same level of automation and control of this 20kW system. This means that there is really no way for the 2 gpm / 2 ft. drop system to have ANY payback if you want to make it grid-connected. But, if all you want is a stand alone system to charge up your cordless drill, you're off the races. A simple water wheel and a DC motor will get you up and running without even needing a dam.
I don't mean to be a pessemist, but there are real technical and regulatory barriers to this kind of thing. The real success story in this applciation is the amount of time and effort (the perspiration) that these two guys put into the job. Kudos to them.
If you are interested in small hydroelectric installations, spend some time on the internet and following some of the other links provided by the other post'ers (is that a word??).
I did a short analyisis on a similar system for my brother who has a trout farm down south - he has a fair amount of water flowing (the details are buried away someplace on this computer) and he thought that maybe he could make some money from that by selling (or at least 'replacing') electrical power. Unfortunately, from the information I could find, the ROI was clearly NOT in his favor even for a mainly DYI system.
The author's system is impressive - very impressive. But I doubt if it makes economic sense IMHO.
I read the article as saying that technically you CAN generate electricity with as little as 2 gpm and only 2 feet of head. This doesn't necessarily mean it is economically attractive, or even that much of a benefit. I gather that in this application they have 10 feet of head and run close to 320 gpm, when generating 20KW. It sounds like the lake does not always have enough flow to permit continuous generation at this rate. The use of three 15 HP motors is to adequately load the 50 HP turbine.
This was an interesting article. I have been very interested in low rise lakes for storing wind or solar photovoltaic energy. When you have wind or sun, you can drive pumps to pump up to a reservoir/lake/tank from a lower lake or river. Then you can generate hydroelectric power when you need it, or when the peak load gives the best payback to feed the grid. The "potential energy" of gravity on water may be more cost effective than batteries.
Indeed. I did a quick check. First, I assume the typo of minutes vs. seconds. 2 gallons per sec is about 16 pounds per sec over a 2 ft drop is 32 pound-ft/sec is about 43 watts at near 100% efficiency.
The basic premis is all wrong. You can't do a whole lot with 40W but it might be better than nothing in some circumstances.
My 20 year old analysys of low-head hyrdo didn't come up with a service period that equalled or exceeded the payback. Power companies are notably fickle about allowing any frequency other than 60HZ, so generating AC, converting to DC, then back to 220VAC/60.00HZ was a significant expense. Older turbine water wheels had adjustable 'vanes' that kept speed constant independant of load but their accuracy was unacceptable; most newer wheels use a 'throttle' plate to control input flow which greatly reduces the efficiency of the set-up, though if flow can be held constant, speed can be controlled varying the field to control load. Finding and rehabing a hundred year old bronze 20-50HP turbine was the best economic solution, though these are few and far between. In Maine, fish are more important than electricity, so we're tearing down 100 year old hydro dams in hopes there is a 100 year old salmon who may want to come home to spawn. Several of my fellow hyrdo co-conspirators genrate DC and use that to run resistive heat, controlling indoor temperature by opening or closing windows. Assuming you own a dam which will supply minimum flow, can find an old turbine wheel, can cludge-up the necessary controlls to meet the grid requirements, can meet the environmental concerns, can do most of the labor yourself, you still have to be aware that the government in all its wisdom will change the rules and remove the requirement that the power company must pay you at their 'cogeneration' rate, rather than some other contrived rate. Like electric cars, the analysis of the economics for hydro power is more emotional than economic. I congratulate the writer on an apparent successful installatioin, other than the typo of water flow, the research looks good, though I don't see how he controlls frequency to meet the grid requirements.
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