Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

GENERATION OF UNLIMITED ELECTRICAL POWER WITHOUT USING HYDRO-CARBONS OR NUCLEAR ENERGY 2

Status
Not open for further replies.
There were reasons for that. Since 2009, a combination of factors converged to produce a wave of coal plant retirement announcements by plant operators. These factors included:

1. The continued aging of the coal fleet, in which the median generating station was built in January 1966. Since their efficiency is lower than newer plants, older plants are typically run less often and have poorer economics.

2. New and proposed EPA regulations, including the proposed Clean Air Transport Rule, the proposed Coal Combustion Residuals rule, the proposed Tailoring Rule (covering greenhouse gas emissions), the Ozone NAAQS (National Ambient Air Quality Standards), the forthcoming National Emission Standard for Hazardous Air Pollutants (NESHAPs), and cooling water regulations under section 316(b) of the Clean Water Act.

3. Low prices of power from natural gas plants.

This study is predicting a minimum of 153 shutdowns and a maximum of 353 shutdowns.

 
Ah, I see, you are just talking about the US and its political situation. This is an international forum.
 
The only place in the world that is investing in coal generation is China. And it is estimated that China will use up its coal reserves in 35 years.
 
Following is a graphic
RiverTank_ryfspx.jpg

The topology of Southwest Wisconsin, the Mississippi River, and Red storage tanks.
Theoretically, each tank represents a capacity of a cylinder, 1 mile in diameter, and 1 mile deep.
From a practical point of view, each tank is actually a small damed up valley between river bluffs on the banks of the Mississippi, maybe 400 ft deep.
Wind Generators, river water pumps, solar collectors are used to fill the tanks with water borrowed from the river.
SlideRuleEra indicated a staggering number of wind turbines would be needed to just fill one tank in five years.
Construction costs of a small dam at the head of a valley should be minimal.
Not looking to dam the Mississippi and create another Grand Coulée dam, just a few small dams that, as a whole might approach the Grand Coulee as a whole.
 
hokie66 said:
If coal is not an economical fuel, what is?

The fuel of choice today, for environmental, economic, and reliability reasons is natural gas. Over the past thirty years, or so, both the size (Megawatts output) and efficiency of combustion turbines has been increase dramatically. Additionally, the waste heat from the turbine is now used in a "HRSG" (Heat Recovery Steam Generator) to drive a steam turbine which is the prime mover for a second electric generator. These units are called "Combined Cycle". Overall efficiency is well over 50%. The combustion turbine / generator provides about 2/3 of the electrical power produced. The steam turbine / generator the remaining 1/3.

bimr - Thanks for the link to the report by the Union of Concerned Scientists. I read the Executive Summary and plan to continue with the full report. As the Corporate Senior Civil / Structural Engineer , Generation (Now Retired) for a mid-sized electric utility I've had a lot of first hand experience with multiple aspects of assorted coal, hydro, oil, and natural gas stations - old and new. Will be interesting to see how this report presents the situation.

wannebeSE - Thanks for your link. I looked at some of the generation sites addressed in that project. Many are pumped storage hydro. Pumped storage is great for one reason, and one reason only - rapid response short term peak power. There are really only four commercially available, meaningfully sized, ways to quick provide peak power:

1. Hydro.

2. Open cycle combustion turbines - grossly expensive to operate and inefficient.

3. Electrical grid interconnections to neighboring utilities - expensive, and somebody, somewhere has to generate the needed power quickly, but a last resort in an emergency.

4. "Spinning Reserve" - often a load-following coal fired station running at synchronous speed (60 Hz, in the USA) and connected to the grid but NOT contributing any power to it. Efficiency = 0%, that's one of the prices of paid for society not to have frequent blackouts.

Pumped storage allows a utility that does not have suitable geography for full scale hydro reservoir to use a smaller reservoir for peak power. It buys time, say a couple of hours, for the utility to bring online efficient load-following stations, which have been on standby, to meet demand indefinitely. A great way to minimize use of "spinning reserve".

[idea]
[r2d2]
 
dwbarlow

Regarding "Determine how much, if any new energy, could offset the reduced use of hydro-carbon fueled electricity generation."

Your propsed project will have a net loss of energy. Pumps are only 60% efficiency.

As SlideRuleEra stated, pumped storage projects are only constructed to avoid the expense of a power station that is only used at peak times. Pumped storage eliminates capital costs while increasing inefficiency.

Have you ever heard of a dam project where the water was recycled back to the dam? You would only be able to recycle 60% of the water because of the pump's ineffiency.

To fill up the basins, you would have to shut off the river for 8 months and then permanently reduce the flow of the River to keep the basins filled.
 
The pumped storage thing as a battery is pretty cool, and used in a lot of different places.

The Mississippi is a pretty terrible place to do it though. The idea works best when you have several nearby reservoirs in series in a mountainous region.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -
 
Natural gas is great where you have it, but that is not an option everywhere. In Australia, we are starting to use (and export) coal seam gas, but the extraction process certainly has its problems and environmental concerns.

In a pumped storage scheme, the pump efficiency is largely irrelevant, especially when powered by nuclear, as SRE's "spinning reserve" is used.
 
Spinning reserve and the power to drive pumped storage are not the same thing.

A plant operating in spinning reserve mode is usually a utility's second tier (of efficiency) units which are used for load following. The plant is burning just enough fuel to operate its own internal power requirements, usually about 8% to 10% of its gross rated capacity. No power is being delivered to the grid or to any of the utility's other units. When peak power is needed this unit is poised to quickly ramp up fuel consumption and begin feeding the grid to supply (paying) customers.

Power to drive pumped storage comes from first-line, base loaded plants that would have to cut back on output (but not go off line) because of reduced customer demand. This is usually at night when industrial customer demands are low and residential use is minimal. Say this plant had been operating at 90% capacity during the day. At night, it "could" be cut back to say 70% capacity... but efficiency would drop. Instead, the plant may continue at 90% with 70% going to customers and 20% driving the utility's reversed hydraulic turbine / generators as pumps.

[idea]
[r2d2]
 
Thanks for clarifying that. But with nuclear plants, like at North Anna, isn't it still capacity which would otherwise be unused that drives the pumps?
 
North Anna is definitely a pair of base load units. Dominion Generation would take steps to maximize the operation of those two. As a routine anticipated power peak passed, first they would take less efficient units (at other locations) off line - while North Anna continues at its maximum efficiency output. As the peak continues to fall, North Anna would continue with output unchanged. What would change is that power from North Anna would be split - whatever is needed by customers is first priority, remaining power is sent to power pumped storage.

A utility's management of its generating resources is a very sophisticated operation. Skilled "dispachers" using special software maintain 24/7 control of exactly how a utility uses its generating mix. They balance cost, reliability, and redundancy to "keep the lights on". I have a lot of respect for them.

15720.jpg




[idea]
[r2d2]
 
A system of systems and subsystems, with redundant capabilities. Existing USA electrical generation is already a system of subsystems and some redundancies exist. I've got that.

Looking back, there showed have been a green line connecting storage tanks. I left out the networking capability. The networking capability consists of a pipeline to allow all storage tanks to keep close to full potential.

I do not understand the concept of net-loss described above. Wind, solar, and existing river current energy are driven by just a few factors: energy from the sun, gravity potential, and atmosphere. They exist outside anything engineers can create. However, these sources of energy can be harnessed and converted to energy sources. The energy sources are free, the effort to harness and convert is not. So far, I don't have to pay for my daily requirements of oxygen and water. Could a day come, where those simple needs are no longer free?

So, I look at possible alternatives, that will help ensure that the basics, oxygen and water, remain free for humanity and all life that is dependent on humanity's choices.

Someone mentioned that a pump storage system would only provide a few hours in the case of a failure of other energy generation systems. I completely disagree with that. A networked pump storage system with a capacity of the Grand Coulée (GC) dam and reservoir would certainly supply more then just a couple of hours of essential needs if a national black-out were to occur, wouldn't it? Maybe the GC in the west and the Tennessee Valley Authority (TVA) system in the east. What is wrong with keeping a few fully charged energy batteries in reserve? What is wrong with using some of that excess charging capacity of a pump storage system to feed back into the grid?

I don't want to see another GC system cover and hide anymore of the national resources which we still have. In todays political environment that is not likely to happen anyway.

Back to the main theme, humanities need of energy has outgrown the natural capacity of current energy consumption. Artificial systems are needed to supply humanities need of energy, while these artificial systems are being engineered to be more efficient. Are there natural systems that have yet to be harnessed if for no other reason then to supplement artificial systems and provide a significant reserve capability?

 
Fascinating discussion though most far over my head - when I saw the "efficiency" discussions of energy storage, for whatever reason I immediately thought instead about some sort of massive flywheels. There is an interesting site at that in places now talks about some quite impressive technology (and some obstacles), beyond the flywheels most of us grew up with. It claims, "Conversely, flywheels with magnetic bearings and high vacuum can maintain 97% mechanical efficiency, and 85% round trip efficiency.[16] ". It incidentally refers also in another place to the Joint European Torus used for fusion research, "JET has two 775 ton flywheels that spin up to 225 rpm. Each massive flywheel stores 3 GJ.[31]" Per , I saw there each of these machines is reportedly capable (along with the grid) of delivering at least bursts of 400 megawatts peak power to the JET coils. Wikipedia also states that some sort of flywheels or arrays are actually being tested out west for energy storage on a demo project for the California Energy Commission.
While I'm sure the technological hurdles and the cost of these wheels and the environment containment structures to house same are immense, and perhaps now of such magnitude that only governments can love, I guess if same or something better could be made feasible at least concretemasonry would still be able for a while to wade the ripples or and dunk a crawfish in the eddies behind the bolders for the smallies (like I was also fortunate to do in the same general part of the country many years ago);>)
 
I though about this while sleeping. Personally, I was a little disappointed to come to the realization that on a large scale, this idea is not practical. But I also realized that if a small community with the right geography, could put it to use on a small scale on a fairly reasonable budget.

It's kind of spooky that "rconner" brought up flywheels though, because that relates to next idea I wanted to flush out. The 80,000 pound dragster. Since this is more of classical physics and modern mechanics problem I'm going to go to a more appropriate forum.
 
You can tell this is an engineer's forum. Look at what a basic idea to store wind energy has turned into.
 
Flywheels are a neat idea, rconnor. I'm going to have to look into that further.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East -
 
pumped storeage is only effective if using off-peak supply.
The unit in North Wales , Dinorwig, is rated at 1.8 GW with a run up time of 10 secs and was designed to be 75% efficient, with a 600m head 10m diameter main shaft.

Cheers,
Chris
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor