Why isn’t Hydro electric Generating used to the max ?

I’ve been wondering this for awhile, and I was reminded of it again today when I was at the nearest local reservoir .
Here in central Ohio we have a few good sized reservoirs, with some pretty large dams holding them back. The one I was at today, Hoover, (In Ohio, not out west) has (2) 5ft. or so conduits going through it, blasting water 24/7/365. It is impressive to look at but I always wonder why no one has hung a generator or two on those conduits. Now a do not know a whole lot about large commercial generators, but I did look up the specs of Hoover (this time the one out west) and it’s generators do about 110MW each. If you hooked just one generator to one of these smaller dams that did, lets say, a mere 25MW, and sold the juice for $.04 per kWh, wouldn’t that be like 9 million annually in revenue? I gotta think it would be worth it.
So why isn’t it done? Is it political? Are we not striving to be as environmentally friendly as we could be?
Anyone know?

Hydroelectric power isn’t generated by sticking a generator in front of pressurized water, it’s generated by water falling into turbines which spin generators. Because of this, you need to have a tall dam for hydroelectric power. And those things cost a pretty penny to build, so you’d better be making a lot of money from the power it generates.

You get electricity by converting potenial energy into kenetic energy. Potential energy is basically heigth times mass. To get a lot of electricity, you need to get a lot of heigth difference from the top of the water level to the point it comes out of the bottom of the dam.

It’s really economics. No energy confersion is perfect, so there is a certain height difference need to even produce electricity. After that it is just cost. Does the cost of all of the equipment, offset by the amount of electricity produced, make the electricity cheaper than that produced by another source.

You can make electricity from just tidal flow. But if you have other source for power available, you could make electricity cheaper from, say coal.

There’s more to it than that. Hydroelectric power is very environmentally unfriendly - you drown an entire valley! - and for this reason very little new hydroelectricity is being planned in the US (though in other places with weaker environmental politics hydroelectricity is doing more).
You can build hydroelectric plants in places with only a small elevation difference, by the way. The available energy is flow times height, and in some places a huge flow is available so even with a small height the energy is worth harvesting. Tidal energy is a great example - the height difference being exploited is only a few feet, or tens of feet at the very most.

On the Ohio River, at the Hannibal Locks and Dam, the local utility company attached a hydroelectric station to the end of the dam a few years ago. It has two horizontal turbines, and generates a s***load of electricity from a water level change of about 15 to 20 feet. The dam is a standard rollerdam for maintaining a navagation pool in the river. There are (or were)plans in the works to install another station at the Willow Island Dam on the Ohio, and at the Summersville Dam, not sure what river. These are all in West Virginia.

I worked as an engineering technician for a number of years, involved with the siting and preliminary design of hydroelectric generating facilities, as well as the management of actual projects under construction. My company was located in southern Ohio, and I was peripherally involved in the construction of the plant at the Greenup Locks & Dam, on the Ohio River near Greenup KY.

A$ to the OP, the an$wer is $imple. Can you gue$$ what it i$? Compared to more traditional types of power-generating stations, hydro plants are extremely capital-intensive in terms of up-front costs. Even though, once in place, the plants can operate very cheaply (no fuel to by, for one thing) and generally last in service much longer than other types of generators – most of which rely on turbines that utilize steam at high temperatures and pressures – the initial cost of hydro facilities and the resultant high debt service requirements conspire to render hydro uneconomic compared to, say, a coal-fired steam turbine/generator. For example, in the early Eighties, when Greenup went on line, the initial cost of building that generating capacity was around $1650/kw, at least double the cost of steam generators then. Sure, you don’t have the burden of buying fuel with hydro, but, in the case of Greenup, the owners had to come up with around $115 million to build a relatively dinky station with a maximum generating capacity of 70 megawatts.

Another factor to consider (and again, this relates to money) is the simple fact that, unlike coal or nuke plants, hydro generators depend heavily on the weather, a notoriously unreliable thing. The supply of water is dependent on rainfall. No rain, no juice. Oddly, most low-head generating stations (the Greenup facility, with 30’ of head max, and the Hannibal facility are definitely “low-head”) suffer more often when there’s too much rain. All hydro facilities lose some head (pressure) when there’s a lot of rain because of the rise in the tailwater level, but with low-head plants, there’s very little to lose. IIRC, the Greenup plant had to shut down when gross head across the turbines dropped below about 12 feet, a thing that happened several times a year.

There are other reasons for the lack of hydro, including environmental and institutional obstacles. High-head facilities, typically in the western states, are rightfully considered to be “fish-grinders,” and that taint has been (wrongly) carried to all types of hydro. As far as inundating valleys, little of that sort of thing has taken place in the U.S. for forty years, at least for the sake of generating electricity. Most hydroelectric stations built in my lifetime have been installed at existing dams, where the valley has already been flooded for other reasons.

In addition, hydroelectric power is heavily regulated by the Federal Energy Regulatory Commission (“FERC,” pronounced by those in the industry “furk”), which oversees a variety of permitting and licensing schemes. The cost of obtaining a license to build a hydropower plant can easily exceed a million bucks, and that’s money paid out before the first earth is moved. The demands of state- and local-level governments, which are shamelessly coddled by FERC, can literally add many millions of dollars to the cost of any hydro plant. A typical hydropower proposal in the Midwest must satisfy the “concerns” of FERC, the Army Corps of Engineers, the U.S. Fish and Wildlife Service, the USEPA, the state’s own EPA and wildlife agency (if a waterway is located in two states, as the Ohio River is, multiply this factor by two), any and every historical society, city and county planning agencies, individual members of the general public, and on and on and on…

I worked on a proposal to build a hydropower plant at the Belleville Locks & Dam in the mid-Eighties, located at a point on the Ohio River primarily regulated by the State of West Virginia. The site was totally desolate and undeveloped, seldom used by anyone for anything, nothing around for miles, save a few dilapidated houses on stilts. The cost of satisfying the “concerns” of a single government agency – the West Virginia Department of Natural Resources, a collection of folks who know a cash cow when they see one – was over $3 million, mostly in the form of recreational facilities. Unfortunately, the WVDNR is considered by FERC to be the lead agency in the state, and is responsible for issuing the “401 permit,” without which FERC cannot, by law, issue a license. The cost of satisfying these “concerns” (read “extortion”) literally broke the back of the project, which would have been marginally profitable.

Yeah, I’m windy, but I think I answered the OP’s question. Didn’t I?

Yup, you answered it quite well, and I thank you! I figured the reasons that this resource is left untaped was due to start up cost and politics, but I also figured there were reasons I didn’t think of. I appreciate the information from someone such as yourself who is involved in the industry.
It’s still kind of a bugger to see a facility such as Hoover in NE Columbus, that is seems would be relativly easy to have it generating power, but all that energy just flows down the creek.
Thanks again TBone2.

The massive Snowy Mountains Hydroelectric Scheme was hailed as a breakthrough when it was built in Australia in, IIRC, the 1950s. It certainly was an incredible feat of engineering. However, it involved redirecting water flow on a large scale, and this was done in an era when the environmental results were not considered.

The result? In some places, beautiful valleys have been flooded (there are now ghost towns underwater), and once mighty rivers have been reduced to a pathetic trickle.

The total power output into the grid is still very small compared to the coalfired power stations.

I think tidal technology might be the way to go.

Well, I was at the Hoover Dam (the big 'un) just last Sunday, when someone in our tour group asked a similar question: “Why don’t you have all the turbines running” (of the eight turbines on the Nevada side, only three were running that day) “to take care of that California energy crisis?”

The guide’s answer boiled down to this: The Hoover Dam is in the water business, not the electricity business. It’s there primarily to provide irrigation and flood control to California. To run more turbines, they’d have to increase the flow of water through the dam.

“Sure,” he said, “California *could[i/] have all the electricity it needs, but your head of lettuce would still cost $5.00 because of the big drought they’d have to go with it.”

Made sense to me, though I’d never have thought of it before.