CHP is by far largest currently cost effective source of renewable energy

[philb]

cogeneration systems can achieve efficiencies as much as 80% while the separate systems have combined efficiencies of only 30 to 45% (1).
Because use of CHP can reduce total fossil fuel consumption, emissions to the atmosphere are reduced. It can result in reductions of up to 50% in CO2 emissions compared with conventional sources of heat and power as well as reduced emissions of sulphur dioxide and particulates (2).



Approximately 56,000 (MW) of CHP electric generation is in operation in the United States and is widely used in the chemical, petroleum refining, and paper industries. More recently, light manufacturing industries, commercial buildings and universities have adopted this technology. In 1999, CHP plants accounted for 7% of U.S. electricity generation capacity and generated 9% of all electricity produced in the United States. A typical system efficiency was 68%. In Denmark and the Netherlands, more than 40% of electricity is obtained from CHP systems (4).



topping cycle cogeneration systems are:

(1) An gas turbine or diesel engine producing electrical or mechanical power followed by a heat recovery boiler to create steam to drive a secondary steam turbine. This is called a combined-cycle topping system.

(2) The second type of system burns fuel (any type) to produce high-pressure steam that then passes through a steam turbine to produce power with the exhaust provides low-pressure process steam. This is a steam-turbine topping system.

(3) A third type employs hot water from an engine jacket cooling system flowing to a heat recovery boiler, where it is converted to process steam and hot water for space heating.

(4) The fourth type is a gas-turbine topping system. A natural gas turbine drives a generator. The exhaust gas goes to a heat recovery boiler that makes process steam and process heat (3).

References:

1) American Council for an Energy-Efficiency Economy
2) COGEN Europe
3) Energy Efficiency and Renewable Energy Network: Cogeneration
4) American Council for an Energy-Efficiency Economy


Combined Heat and Power Systems(CHP)

A typical electric generation facility may achieve up to 45 percent efficiency in the generation process, but with the addition of a waste heat recovery unit, can achieve energy efficiencies in excess of 80 percent. http://www.naturalgas.org/overview/combinedheat_powersystems.asp



I. 4 types of 'topping cycle' system, where the system generates electricity first, and the waste heat or exhaust is used in an alternate process. Four types of topping cycle systems exist. The first, known as a combined-cycle topping system, burns fuel in a gas turbine or engine to generate electricity. The exhaust from this turbine or engine can either provide usable heat, or go to a heat recovery system to generate steam, which then may drive a secondary steam turbine.

The second type of topping cycle systems is known as a steam-turbine topping system. This system burns fuel to produce steam, which generates power through a steam turbine. The exhaust (left over steam) can be used as low-pressure process steam, to heat water for example.

The third type of topping cycle systems consists of an electric generator in which the engine jacket cooling water (the water that absorbs the excess emitted heat from an engine) is run through a heat recovery system to generate steam or hot water for space heating. The last type of topping cycle system is known as a gas turbine topping system. This system consists of a natural gas fired turbine, which drives a generator to produce electricity. The exhaust gas flows through a heat recovery boiler, which can convert the exhaust energy into steam, or usable heat.

II. 'bottoming cycle' systems. This type of system is the reverse of the above systems in that excess heat from a manufacturing process is used to generate steam, which then produces electricity. These types of systems are common in industries that use very high temperature furnaces, such as the glass or metals industries. Excess energy from the industrial application is generated first, and then used to power an electric generator second.



III. fuel cells may also be used in a CHP system. Fuel cells can produce electricity using natural gas, without combustion or burning of the gas. However, fuel cells also produce heat along with electricity.



Combined Heat and Power Applications

CHP systems have applications both in large centralized power plants, and in distributed generation settings. Cogeneration systems have applications in centralized power plants, large industrial settings, large and medium sized commercial settings, and even smaller residential or commercial sites. The key determinant of whether or not combined heat and power technology would be of use is the nearby need or purpose for the captured waste heat. While electricity may be transferred reasonably efficiently across great distances, steam and hot water are not as transportable.

Heat that is generated from cogeneration plants has many uses, the most common of which include industrial processes and space and water heating. Those facilities that require both electricity and high temperature steam are best suited for CHP systems, as the system can operate at peak efficiency. There are many industries that require both electricity and steam, for example the pulp and paper industry is a major user of CHP systems. Electricity is required for lighting and operating machines, while the steam is useful in the manufacturing of paper.

Many commercial establishments also benefit from CHP systems. Universities, hospitals, condominiums, and office buildings all require electricity for lighting and electronic devices. These facilities also have high space and water heating requirements, making cogeneration a logical choice. For example, the University of Florida has an on-campus 42 MW gas turbine cogeneration facility that produces electricity and space and water heating for the campus. For more information on this cogeneration system, click here.

CHP systems are also available to serve smaller sized facilities. In this type of facility, these smaller, 'modular' cogeneration units can generate anywhere from 20 kW to 650 kW, and produce hot water from engine waste heat. It is most common to install a system based on the hot water needs of the establishment. For facilities like restaurants or medical facilities, which require hot water year-round, cogeneration makes an economic and environmentally friendly option. In terms of household sized CHP systems, it is possible to install a small system that can generate up to 10 kW, and fulfill all of the household heating requirements of an average home. However, these types of systems are not common. Fuel cell manufacturers are expected to target these small sized cogeneration units once the technology is perfected and it is economical for a household to install such a unit.

To learn more about CHP systems and explore other internet resources, visit the United States Combined Heat and Power association here.

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Industrial Technology Research Institute(ITRI)

Waste Heat Electricity Generation Technologies

rankin cycle- below 300 degree
sterling cylce- above 600 degrees
heat exhangers
http://int.erl.itri.org.tw/eng/research/thermofluids/coretechnology7.jsp?tree_idx=0100

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CANMET Energy Technology Centre’s Pyroelectric R&D Consortium to investigate

the conversion of low-grade waste heat to electricity.

Benefits of Pyroelectric Conversion

• 3 to 5% of a waste heat stream can be converted to electricity;

• electricity could be generated at between 3-5 ¢/kWh using pyroelectric

conversion, with capital cost amortized over 20 years;

• pyroelectric conversion units could be installed at between $1200 and

$1300/kW;

• reduced cost of cooling the low-grade heat waste streams before

discharging;

• substantial CO2 reductions in emissions are expected.



Georgia TechÕs Industrial Assessment Center (IAC) provides energy, waste, and productivity assessments at no charge to small and mid-sized manufacturers.(CHP & Energy Audits)

http://www.poweringthesouth.org/articles/static/1/1012841496_1012401156.html

Center for Energy Efficiency and Renewable Energy (CEERE)

Industrial Assessment Center: CHP http://www.ceere.org/iac/iac_combined.html

An MIT scientist and a colleague have invented a semiconductor technology that could allow efficient, affordable production of electricity from a variety of energy sources--including waste heat--without a turbine or similar generator.

The new device is twice as efficient as its closest commercial competitor.

http://web.mit.edu/newsoffice/2001/electricity-1205.html

Partnership for Innovative Technology in Housing http://www.toolbase.org/techinv/techDetails.aspx?technologyID=220

Fuel Cell: Combined Heat and Power (CHP)



UC/Cal State project promotes using waste heat from power generation to heat and cool buildings http://www.berkeley.edu/news/media/releases/2003/09/18_power.shtml

CHP for the food & beverage processing industries Oak Ridge Natrional Laboratory

http://www.sentech.org/CHP4foodprocessing/emergingtechnologies.htm

Cogeneration Planning LLC, Cogeneration and Waste Heat to Energy Systems

http://www.cogenplan.com/

[Coastie for Truth]

1. Memories of my mis-spent youth

I remember "primitive" combined heat and power systems from my Engineering Design course (43 years ago). Popular in any manufacturing processes where you had a lot of heat (steel making, petroleum refining).

There were companies (okay 2 or 3 companies) in the "steel valley" that made boilers that "recaptured" the "waste heat" from the open hearth shop and used it to run a steam turbine to generate electricity.

The family that endowed the theater in the student union where I went to college was in that business.

[OffWithTheirHeads]

2. California Highway Patrol?

I know they consrve energy but WTF?

[Dead_Parrot]

3. Figures. Who needs air con...

when you can look this cool?



(seriously, thanks philb - some nice systems in there...)

[phantom power]

4. These are very efficient, but they aren't renewable, per se.

It's a way of making the most out of a fuel, but it doesn't really say anything about whether that fuel is renewable or not.

[philb]

7. Think of it this way

If you have a generator that every month produces electricity from a fuel source at 35% efficiency, you can add
a process to also use the waste heat and are operating at 60% efficiency. Then each month that the generator is in
service you are getting an additional renewable and continual 25% energy benefit that you would not be getting otherwise.
Its satisfying a continuous energy need in continuing manner from a source of energy that requires no additonal fossil fuel
input. I think that is the definition of renewable.

But I wasn't the one who first called CHP a source of renewable energy.
And it doesn't really matter what terminology is used. The point is it likely represents the biggest source of
untapped clearly cost effective technology for satisfying a huge amount of energy needs without additional use of fossil fuels.
It serves a similar purpose as renewable fuels whatever you call it.

[Strelnikov_]

5. Another Idea From The Late 70's That Was Overrun By 'Morning In America'

I am disappointed that the ethanol plant being built east of town is going to be coal fired stand alone plant.

They could have located the plant 4 miles further west, adjacent to the coal fired municipal electric plant, and made use of the waste heat in the ethanol production process, thus increasing the EROEI of the end product. One other benefit, the municipal plant burns refuse (resource recovery). Therefore, byproducts from the ethanol processing that could not be marketed could be burned for process energy.

As a previous poster noted, though, co-generation has nothing to do with renewable energy.

[LiberalEsto]

6. This "waste heat" can also be used to recharge

desiccant wheels in desiccant dehumidification systems.

Desiccant dehumidification (DD) is a very effective but costly-to-install way to remove moisture from the air. It's often used in buildings that have serious mold problems, such as schools. It's also used in operating rooms where the surgeons' need for very cold room temperatures can cause unsanitary condensation of moisture.

Capturing the otherwise-wasted heat from existing air-conditioning or power-generating systems to recharge the revolving lithium bromide desiccant wheel make using a desiccant dehumidification system much more cost-effective.

A large part of my job involves writing case studies of CHP and DD installations.

[philb]

8. Gas Research Institute has developed effecient and reliable dessicant

dehumidifacation systems and chillers for applications like Food Store chillers as well as other industrial and
business dehumidification applications. One could likely find more about them by search.

[LiberalEsto]

10. I actually work indirectly for GRI

I write case studies for the Energy Solutions Center which is connected to GRI. I've written a number of case studies on desiccant dehumidification applications including schools, hospitals, manufacturing and supermarket applications.

I also do case studies on cogeneration, absorption cooling, and other natural gas-related technologies. I'm not an engineer or a technie, but I can see how much energy gets wasted and how much could be saved with better heating and cooling equipment.

[AZCat]

9. Standard 90.1-2004 requires exhaust air energy recovery for...

individual fan systems w/5,000 cfm or greater and a minimum outdoor air supply =< 70% of total supply (surgeries, as you mentioned, fall in this category).

Here in Southern Arizona we're more worried about recovering "waste cooling" than waste heat, but the principle is the same.

[philb]

11. CHP for utility distributive power, business & industry applications

Capstone MicroTurbines at RI Natural Gas Co. Surpass 45,000 Operating Hours; Innovative Power Generators Have Operated Nearly Non-Stop for More Than 5 Years



Capstone Turbine Corporation(R) (www.microturbine.com) (Nasdaq: CPST), the world's leading manufacturer of microturbine energy systems, announced that two of its 30-kilowatt microturbines currently operating at New England Gas Company in Rhode Island surpassed a milestone of more than 45,000 hours of near continuous operation.

"New England Gas Company, which serves more than a quarter-million customers in Rhode Island and Massachusetts, was an early supporter of distributed generation," said Capstone CEO John R. Tucker. "Their two Capstone C30s have been running nearly non-stop for more than five years, accumulating more than 45,000 hours of operation thus far."

"We are elated with the performance of these Capstone MicroTurbine(R) systems at our Cumberland facility," said New England Gas Company CEO Thomas C. Robillard. "We believe that this product, and its proven reliability, enhances the viability of distributed generation. I'm also pleased to see Capstone now leading the charge here in the Northeast for energy conservation using clean, efficient distributed generation."

The gas utility's two C30 systems create power 24/7, reducing demand on the local utility grid. "We're focused on seeing how far we can push the two little beauties we've been running here since 2000," said New England Gas Company Technician Bob Tousignant.

Capstone MicroTurbines are very low emission, very high efficiency generators of power and heat used to reduce energy costs and increase energy security at a variety of businesses and public facilities. With only one moving part and no need for oil, lubricant, coolant, other hazardous materials or even water, Capstone MicroTurbines are most often deployed in combined heat and power (CHP) applications in which the exhaust heat is used to heat water or to drive absorption chillers - which create cold from heat energy instead of electric energy - in combined cooling, heating and power (CCHP) applications.

Several examples of Capstone's CHP and CCHP installations will be featured at the US Department of Energy's Microturbine Applications Workshop (www.ms.ornl.gov/maw06/default.html) being held next week in San Francisco. In addition to several end-user presentations, the workshop will feature a tour January 19 of a utility site in Oakland that operates an array of ten C60 Capstone MicroTurbines as well as a tour highlighting four 60-kilowatt Capstone-made systems driving an OEM CCHP installation at the San Francisco Ritz-Carlton Hotel.

[philb]

12. US Department of Energy Provides $310,000 Grant to ThermoEnergy for CHP

The US Department of Energy Provides $310,000 Grant to ThermoEnergy to Begin Development of Zero-Air-Emission Industrial Power Plants
LITTLE ROCK, Ark., Jan 17, 2006 -- BUSINESS WIRE
ThermoEnergy Corporation (OTCBB:TMEN) today announced the start of a $310,000 federally funded project to develop compact zero air emission power plants for medium to heavy industry. Commonly referred to as Combined Heat & Power (CHP) plants, these systems would allow main-stream industries to switch from natural gas to lower priced alternative fuels to supply their energy needs. Switching fuel sources could allow many companies to save hundreds of millions of dollars in energy costs, reduce air pollution, keep their US based plants operating, and lessen dependence on imported energy resources.
These CHP plants will be based on the Company's advanced patented zero air emission power plant design known as TIPS; an acronym for ThermoEnergy Integrated Power System. TIPS eliminates the atmospheric emissions of NOx, SOx, mercury, and particulates from power plants that run on coal, oil, natural gas or biomass. In addition, TIPS captures and recovers carbon dioxide (CO2) in pressurized liquid form for sequestration or beneficial reuse. With TIPS, harmful air emissions from power plants, which endangers the environment and human health, will become a thing of the past.
Currently, most heavy industry in the US relies on fossil fuel, in the form of natural gas, to supply its energy needs - a commodity that has gone up almost 600% in the past five years. A significant percentage of these facilities are situated in 'Non Attainment' areas; meaning that the local air quality does not meet minimum US EPA clean air standards. In order to change fuel sources, the new source must be as clean as or cleaner than natural gas. Currently no conventional power plant design in the 50Mw to 100Mw range will allow them to make such a switch. Hence the critical need for a reliable, cost-effective zero air emission power plant design. The need for such power plants is even greater in countries that are part of the Kyoto Treaty.
Joining ThermoEnergy on this project will be CANMET, the Canadian energy laboratory, and Reaction Systems Engineering of Kent, UK. "These two entities represent some of the most respected international experts in the field of advanced power generation systems," said Dennis Cossey, CEO of ThermoEnergy Corporation. "We are both fortunate and pleased to have people of this caliber involved with our project," added Cossey.
"We are very excited to be part of this team and to add our expertise to develop this process which has a high potential to play an important role in the next generation of clean power generation systems," said Bruce Clements of CANMET.
This project is the second of three separate US government grants, authorized by Congress in 2005, to get underway. A third grant, totaling $1.5MM, will focus on the development of TIPS as a cost-effective upgrade for existing coal-fired power plants designed to convert them to zero air emission facilities. This project is expected to get underway in the near future.