PESWiki.com -- Pure Energy Systems Wiki:  Finding and facilitating breakthrough clean energy technologies.







    

Directory:Advanced Power Generation

From PESWiki

Jump to: navigation, search

Contents

Advanced Utility-Scale Power Generation

Advanced utility-scale power generation technologies are being developed that have the potential to nearly double the energy conversion efficiencies of existing coal, oil and natural gas power generating plants to 60% (from the current average efficiency of around 35%). This development is very significant because if it is deployed nationally it would mean no new dirty power plants would have to be built for decades to deliver the electricity we need (and by then perhaps these dirty technologies will be replaced by emerging clean energy technologies). Another advantage this technological advancement offers is the fact that it allows heavy metals and other pollutants to be captured more easily in the stack, since the final exhaust heat is much cooler.

The idea is to use the waste heat from the power generating process, that is currently exahusted into the atomosphere, to run a secondary power generation loop, thus doubling output from our current power plants. There are a number of different technologies and methods that could be used to capture waste heat and re-use it for electrical generation, including the following:

Propane Vapor Method of Using Waste Heat

Propane vapor, which has a much lower boiling point (-44 Degrees Fahrenheit) than water (212 F), could be run through a secondary power generation loop, called a Cascading Closed Loop Cycle (CCLC) or Integrated Gasification Combined Cycle (IGCC) (in a similiar design). The secondary power generation cycle would theoretically double the output of an existing power plant without requiring additional raw materials such as coal or oil at the front end of the process. It's a simple concept to grasp: same amount of raw materials in, twice the power output. It's just a matter of using the raw materials in a much more efficient manner by running them through a secondary power generation cycle.

Stirling Engine Method of Using Waste Heat

Discharging any heated fluid (air, water, etc.) into the environment is like floating dollars up a smoke stack or out a waste water pipe. Stirling engines can run on any heat source, including waste heat; it is only natural to consider using a Stirling engine to recover power from industrial waste heat sources. A system can be designed to use waste heat to run a Stirling engine and produce electricity from the waste heat. Same raw material input costs, more electricity generated on the output side of the equation. In other words, Stirling engine technology can be used to increase the efficiency of any industrial process that has waste heat output, especially electric power generation.

The german company SUNMACHINE has developed a power unit for homes; its stirling motor is driven by a wood pellet burner. It produces approx. 3 kW of power and a thermal power up to 10 kW with an overall efficency of nearly 90 %; a new technology called "upside-down-burner" makes it possible to burn the pallets nearly without consumption residue.

More at SUNMACHINEand American Stirling Company

Articles About Advanced Utility-Scale Power Generation

A system designed to capture waste heat from industrial smokestacks and turn it into electricity could significantly boost the efficiency of power stations, drastically cutting carbon emissions, its inventors claim. It could also reduce the amount of toxic pollution released into the atmosphere.

The key to the efficiency of the heat-scavenging system is that it uses propane vapor rather than steam to turn a turbine and drive an electricity generator. This allows it to be driven by low-temperature waste heat. System converts smokestack heat to electricity



New coal utilisation technologies are being developed. One of the more promising of these is Integrated Gasification Combined Cycle (IGCC) power generation. This gasifies coal, using a high-pressure gasifier, and uses both a gas and a steam turbine to generate power. Pressurised Fluidised Bed (PFB) combustion and gasification is another new coal utilisation technology for power generation.

Typical thermal efficiencies of conventional pf-fired power stations are about 37%. Demonstration power generation facilities using integrated gasification combined-cycle systems are achieving thermal efficiencies of approximately 47%. It is believed that efficiencies of more than 50% are possible using current or nearly available technologies. With new gas turbine concepts and increased process temperatures meaning that possible efficiencies of more than 60% are being targeted. Advanced Power Generation (using coal)


Advanced Nuclear Power Generation Designs

Nuclear power is certainly not the most popular energy source amongst free energy and alternative energy enthusiasts. Many would like to move beyond nuclear power in our quest for clean renewable power. However, it would be irresponsible not to mention a far safer and more efficient nuclear power technology that has been in development for decades called the Pebble Bed Nuclear Reactor. It is worth mentioning because it is far more efficient than the present Light Water Nuclear Reactors in use today.

Instead of water, the Pebble Bed Nuclear Reactor uses an inert or semi-inert gas such as helium, nitrogen or carbon dioxide as the coolant, at very high temperature, to drive a turbine directly. This eliminates the complex and potentially dangerous steam coolant and power generation system from the design, and increases the transfer efficiency (ratio of electrical output to thermal output) to about 50% (from 30% in the steam reactor design).

The Pebble Bed Nuclear Reactor is also designed in such a way that as the temperature of the reactor rises the nuclear reactions diminsh, until they completely stop around 1,600 C, thus allowing the reactor to cool on its own, well below the 2,000+ C melting point of the graphite balls used to contain the uranium in the reactor. This inherent safety feature is one of the reasons the Pebble Bed Nuclear Reactor is far safer than the conventional Light Water Nuclear Reactors that can potentially go into nuclear meltdown if the water/steam coolant system fails.

Certainly, if nuclear energy is going to be implemented once again in the U.S., the Pebble Bed Nuclear Reactor design would be preferable because of its inherent safety features and more efficient electicity generating capabilities.

The Chinese are planning on building the first commericial version of the Pebble Bed Nuclear Reactor (a 200 MW generation station) starting in 2007: Let a Thousand Reactors Bloom


Using H to Store Off-Peak Generation

An idea to utilize excess electricity generated from utility power generation stations during off-peak hours.

We don't need anything more than to capture the 'Off-Peak' Amps that are generated in excess every night, using utility scale batteries or Hydrogen to store the excess Amps for other uses. These Amps/Watts are currently simply run to ground (wasted), as any Generation Systems Engineer will tell you.

The excess Amps could be used to generate Hydrogen even by the crudest, most rudimentary method, electrolysis. The Hydrogen could be compressed into tanks for distribution, or be burned the next day as a supplement to the primary fuel being used at the generating facility, or perhaps be used to run a fuel cell to produce electricity.

>Paraphrased from Jef4ers comments<


Other Ideas for Storing Off-Peak Generation

'Off-Peak' Amps are already generated in excess every night, even by our current antiquated and highly inefficient power generating facilities, and run to ground (wasted). [Note: This statement is fundamentally incorrect. Energy Management Systems closely match actual generation to actual load. Generators are scheduled on and off line as needed throughout the day by Unit Commitment algorithms. Generation is closely matched to the power demand on the grid on a minute by minute, hour by hour basis by Automatic Generation Control systems operating in near real time.] If the Advanced Utility-Scale Power Generation schemes outlined on this page are actually implemented, we'll have even more excess 'Off-Peak' Amps to deal with during off-peak times.

In order to operate our electric grid in the most efficient way possible, these abundant excess 'Off-Peak' Amps will have to be captured and stored for later use. As outlined above, one method of capturing these otherwise wasted Amps is to convert them into Hydrogen for later use. But, certainly there are plenty of other ways these excess 'Off-Peak' Amps could be captured for later use on the power grid. Large power storage technologies that have long been in development and are finally becoming technologically feasible for storing massive amounts of electricity include: Utility Scale Batteries, Flywheels, and Ultra Capacitors.

Any move towards Advanced Utility-Scale Power Generation schemes will have to be accompanied by a serious effort to capture excess 'Off-Peak' Amps for later use in the electric grid. This would maximize the efficiency of our electric generating capacity. Which would be very important in a world where oil is running low and electric alternatives become increasingly important for transportation.

  • Energy storage coming to a power grid near you - Technology optimists say that wide-scale energy storage will change the face of the transmission grid and make wind and solar power more compelling economically. (Green Tech Blog; June 27, 2008)

Combined Power Plants

  • Das Regenerative Kombikraftwerk - The Combined Power Plant optimally combines the advantages of various renewable energy sources. Wind turbines and solar modules help generate electricity in accordance with how much wind and sun is available. Biogas and hydropower are used to make up the difference: they are converted into electricity as needed in order to balance out short-term fluctuations, or are temporarily stored. Technically, there is nothing preventing us from 100 per cent provision with renewables. (YouTube; Dec. 18, 2007) (BioPact; Dec 18, 2007)

See Also


- Other "Directory" listings
- PESWiki home page

Personal tools

Departments
Sponsored Links

Support
Toolbox