AHC/WI: More Heat and Power Cogeneration

Delta Force

Banned
Thermal power stations generate electricity by using heat to drive steam and/or gas turbines (combined cycle uses both). After going through the process, there is still a lot of thermal waste heat left over that isn't suitable for electricity generation. Cogeneration facilities harness this energy to provide space heating or process heat for industrial applications.

Cogeneration facilities can achieve very high efficiencies. Edison built a cogeneration facility in the 1880s that achieved a thermal efficiency of nearly 50%. By comparison, the best modern single cycle systems achieve efficiencies in the mid-30% to mid-40% range, combined cycle plants achieve over 50%, and modern cogeneration facilities can achieve thermal efficiences of nearly 80%. In other words, Edison was achieving thermal efficiences comparable to and in many cases better than those achieved by modern central grid utility power stations with his small power station.

The benefits of cogeneration were realized and it was extensively used on early power stations for electric companies and industrial users. However, as the electric companies grew into utilities and expanded beyond urban areas, power stations weren't always in a location where cogeneration was practical, and eventually it became uncommon.

Electricity demand was growing 7% per year (doubling every decade) between the 1890s and 1973, but demand for heating shouldn't grow that rapidly, and when electricity demand outpaces local supply the needed power can be supplied by the central grid.

A consequence of this is that there would probably be less demand for coal gas/natural gas and petroleum heating, because electric companies would be providing the heating instead. The market for stoves might not be lucrative enough to justify a coal gas/natural gas company. That might slow the expansion of natural gas use, but it could leave more of it for utilities to use in power stations from the 1960s onwards. Maybe some of that natural gas could even be burned in urban cogeneration facilities, where it would produce energy with less health and environmental consequences than coal or petroleum power stations.

Without abandoning the centralized grid approach to things, which has a lot of advantages, could cogeneration have remained popular, at least in some areas? Would this lead to an earlier expansion into natural gas for utilities?
 
What about if it was used in major buildings that require huge centralised heating systems, perhaps like hosptials? Major buildings have huge boilers or gas heating systems with consequnt huge waste heat outputs, if these building generated their own electricity as part of the process they could get more output per unit of gas or boiler oil input. But I don't know how much one of these things costs as oppsed to a simple heating system and elctrical connection.

As a possibly relevent aside, until recently people who installed solar panels on their roof were gettiong huge feed in tarrif rates from power companies as an incentive. But now that these FIT incentives are ending people are re-setting their solar systems so that instead of pumping power into the grid they use the power in their home first and only afterwards does it fdeed into the grid. Perhaps cogenration could benefit from such FIT subsidies, feeding power into the grid (while heating the building) at a high rate and buying cheap power from the company and thus making money off the scheme. When the industry is up and running the FITs will reduce or end and the result will be a healthy cogeneration industry.
 
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Delta Force

Banned
What about if it was used in major buildings that require huge centralised heating systems, perhaps like hosptials? Major buildings have huge boilers or gas heating systems with consequnt huge waste heat outputs, if these building generated their own electricity as part of the process they could get more output per unit of gas or boiler oil input. But I don't know how much one of these things costs as oppsed to a simple heating system and elctrical connection.

As a possibly relevent aside, until recently people who installed solar panels on their roof were gettiong huge feed in tarrif rates from power companies as an incentive. But now that these FIT incentives are ending people are re-setting their solar systems so that instead of pumping power into the grid they use the power in their home first and only afterwards does it fdeed into the grid. Perhaps cogenration could benefit from such FIT subsidies, feeding power into the grid (while heating the building) at a high rate and buying cheap power from the company and thus making money off the scheme. When the industry is up and running the FITs will reduce or end and the result will be a healthy cogeneration industry.

I'm not sure how much the various systems cost. I've only looked at this from the electric power side of things, in which case you are adding district heating systems to an electricity generating unit. It doesn't cost that much to do, but a lot of the systems you need are already there. A unit that only generates thermal output would still need a boiler or turbine.

The only references I've seen for adding electricity generation to a system producing thermal power is for an urban geothermal system currently used only to provide heat, and for adding steam turbines to a military nuclear reactor to harness the waste heat to provide power (N-Reactor).
 

Delta Force

Banned
What about exporting electricity while using waste heat to drive local chemical factories?

That could work. Either way, it's easier to import or export electric power than heat. Electricity suffers some losses as it travels, but not nearly as much as heating.

A cogeneration project would probably need to have some capacity that only provides heat to meet peak heating demand. If it's a temperate climate that needs heating but doesn't need cooling, the heating needs will outstrip electricity needs at some point in the year. In hotter climates the electricity demand would peak in the summer to run fans, air conditioners, and other forms of cooling.
 
Cogenaration

Ways

Some tax incentives

Making gas pipes more prevalent thus Enable Combined cycle + Heat more widespread.

More safe and cheap nuclear reactors - SMR +MSR is way.
 

Delta Force

Banned
Ways

Some tax incentives

Making gas pipes more prevalent thus Enable Combined cycle + Heat more widespread.

More safe and cheap nuclear reactors - SMR +MSR is way.

Maybe there could a program for utilities, where they could convert homes, businesses, and factories near a cogeneration facility to thermal power. The costs are lower than gas or petroleum heating, so there would be immediate savings. People could pay for the conversion outright, or perhaps the utility could offer a loan that is paid each month with the utility bill.

Nuclear reactors probably aren't ever going to be placed in cities to provide heat or power. Work is being done on long distance heat pipelines though, so maybe they could provide heat to cities and communities further away from the power station.
 
There's an awful lot of district heating & cogeneration in eastern europe and scandinavia. Even the UK came close to adopting it after WW2 in London (dropped due to lack of money). Expanding that for air pollution reasons (the UK driver) doesn't seem too hard - it's a hell of a lot easier to clean up one power station than hundreds of open fires.
 
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