Heating In a Nuclear Powered Society
April 24th, 2008
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On this site we’ve talked about nuclear energy as a means of providing emission free energy in a scalable and economical way. Nuclear energy can, of course, provide ample energy for electrical generation. For transportation, the topic of electrified vehicles or hybrids has come up as a means of transitioning to nuclear energy as the bases for transportation energy. There is one other aspect of energy use which has not been addressed as much here and that is building and space heating.
We don’t often consider the amount of energy needed to heat our homes and other buildings, primarily because most of it does not come from electricity, but in terms of actual energy end use, the amount of energy required is enormous. In the US, buildings account for the largest end users of energy and space heating is an enormous contributer. In In the US, the average office or commercial building uses about 15% of the energy consumer for space heating, but this represents a huge variance from place to place. In the southern US, heating may only be needed on a few chilly nights, while in the North East and Midwest, it an easily account for more than 50% of a building’s energy use.
In Ontario Canada, where winters can be long and harsh and summers are generally mild, an average home uses up to 81% of energy on building heating and hot water. This is not unusual however, in fact many US states and many countries in the world use considerably more of their energy for heating. Despite the reputation of the United States for being an energy gluten, a quick check of the international rankings of energy use per capital shows some countries you might not expect near the top. Of course, they all have one thing in common: Long, harsh winters.
So why not heat everything with electricity?
The most obvious method for reducing the use of oil and gas, as well as firewood, coal or other dirty fuels for heating is to move toward more electric space and water heating. Indeed, when powered by nuclear energy, electricity can be an emission free method of heating both hot water and structures. In some areas, it is quite common and electric hot water heaters are common even in areas which use gas or oil for other heating needs.
However there are some problems:
Providing heat for a structure can take enormous amounts of energy. Electric heat is easy to install, simple to operate and has an inexpensive upfront cost and for this reason it’s a very popular way to provide secondary heat for workshops, small buildings and so on, where only a small amount of heat is needed. It is also a common way of heating homes and businesses in areas such as the American South. In these areas, heating is only required for a few cool winter nights or the occasional cold front. Therefore, large powerful heating systems are not required.
But in areas like Canada, the northern parts of the United States, as well as the Rockey Mountains and Northern Europe, electric heat is limited to the occasional space heater to keep a drafty room warm. In these areas, a small house will require a minimum of about 75,000 BTU’s per hour to maintain a comfortable temperature. For larger single family homes, 150,000 BTU per hour may be in order. And for small apartment buildings, one 500,000 BTU’s per hour is not unusual. This does not even include hot water!
To match a 75,000 BTU/Hr furnace with electricity heat would take about 22 kilowatts of power when running at full capacity. 500,000 BTU/Hr which would require about 150,000 kilowatts to replace with electric heat. A large office complex, shopping mall or other commercial establishment can easily require several megawatts of energy to heat or more. That is a LOT of electricity. For a place like Canada, with a relatively large population and bitter cold winters, heating all homes and businesses, or even a significant percentage of them with electricity would be far beyond the capacity of the current grid and generating systems, perhaps by more than 200% Even temperate countries like the UK or Germany would have difficulty with electric heat as the primary source of structure and water heating.
Why on-site fuel is common:
When this much energy is needed for heating, there is a good reason why on-site burning of oil or gas is the choice over electricity. It’s far more effecient. To understand this we simply need to take a look at how electricity is generated. In most cases this is done with heat, such as from a reactor or burning material. The heat is used to drive the turbine of a thermal engine and then turn a generator. Much of the heat is lost, and only the best combined cycle power generators can even claim to break the 50% mark on the generating effeciency versus energy lost as heat. Additionally, energy is lost in the process of transmitting the electricity to your home. Thus, when you run a heating element on electricity, it actually has taken three times or more fuel to provide heat than if you had burned the fuel on site.
The fact that energy is lost when generating electricity is accepted because it’s an unavoidable result of thermodynamics. Whenever you generate electricity you have to pay Carnot his due. This is true whenever any kind of energy is derived from heat. There would be no advantage to generating the electricity locally because the reductions in line loss would be offset by the lost effeciency in using smaller systems with poorer conversion effeciency. We consider electricity to be more valuable than heat because it can be used for more things and is easy to regulate and convert.
But why pay Carnot if you don’t have to? Since all you really want is heat, there’s no reason to go to the trouble of the heat->steam->mechanical energy->electricity->transmission->back to heat process. It’s much more effecient to burn the fuel on site and just use all the heat without converting it. This is why it’s so much cheaper and more common to have a gas or oil burning furnace.
So how does one reduce the need for fossil fuel heat in a nuclear-powered society? There are a few methods.
Electric Heat - As mentioned, electric heat has limitations due to the need for very large amounts of electricity. However, it has advantages too and works well for certain applications. Electric heat is extremely simple to install and has almost no upkeep. It can be used in a number of rolls including baseboard heat, blowers, portable space heaters, radiant floor heating and infrared heaters, which work well outdoors or in workshops where raiding the ambient temperature is not practical. For hot water, electric hot water heaters may be the most economical choice for when only relatively small amounts of hot water are needed.
Electric heating is well suited to environments where only occasional warming is needed or where temperatures rarely drop by very much. It also can work alongside other heating methods and improve heating while reducing emissions. For example, radiant floor heat from electric heating elements can improve the feel of warmth in a room. In temperate areas, it can be installed along side other heating methods and used for primary heating on cool spring or fall days. A larger oil or gas system would therefore only be needed on the especially cold times during winter. This can achieve some reduced emissions without overburdening the power grid.
Heat Pumps – Heat pumps use electricity, but should not be confused with standard electric heating. With a heat pump system, heat is moved from one location to another and therefore the thermal energy is not completely derived from the electricity used to run the system. A heat pump is basically like a standard air conditioner working in reverse and some air conditioning systems can actually double as a heat-pump system. While an air conditioner will cool the inside of a building and expel heat from an outdoor condenser, a heat pump derives heat from cooling the outside unit, which becomes the evaporator rather than the condenser. When used in favorable environments they can require as little as one fourth the energy of a comparable electric heating system.
There are two kinds of heat pumps: Air sourced heat pumps are the simplest. They have an outdoor unit which simply derives heat from air circulation. These work well in areas which are generally hot and need air conditioning to maintain comfortable temperatures indoors. In these cases, the unit can work as an air conditioner most of the time and only switch to working as a heat pump during colder than normal time periods. However, air sourced heat pumps work very poorly when the outdoor air is extremely cold. For this reason, they are not an option for areas where there are very cold winters and the temperature commonly drops bellow freezing.
The second kind of heat pump is a geothermal heat pump (Not to be confused with geothermal energy as in power generation). These units do not simply use air as the source of heat but instead use underground piping to collect heat. The advantage of this is that they are able to operate when the temperature is low by using the thermal mass of the ground as the heat source. However, because of this they tend to be a lot more expensive to install and maintain and leaky collector pipes can be a major headache. There are also limits to how much energy can be drawn from the ground in a given area, especially in colder climates. The use of the heat pump can actually have the effect of cooling the area of ground, depleting the thermal energy avaliable.
One novel method of increasing the heat avaliable from a geothermal heat pump is to put heat into the area of the collector when excess heat is avaliable, effectively making it thermal mass storage medium. The most common way is to use the heat pump in reverse for cooling during the summer months and then heat in the winter. Other methods use solar thermal heating to add heat to the ground on warm sunny days, or to dump waste heat such as from refrigeration into the ground.
However, despite these factors, geothermal heat pumps do not generally work very well in areas with long, extremely cold winters and the problem of underground piping and potential leaks also makes them unappealing to many situations. Drbuzz0’s cousin in Ireland really likes geothermal heat pump/solar thermal collection systems like this, but that’s probably because Ireland is the kind of place where conditions are optimal for heat pumps. It gets cold in Ireland frequently, but it never gets *that* cold.
Hydrogen Enriched Gas and Synthetic Gas – Municipal gas service is already avaliable in much of the world. Indeed, natural gas is one of the most common fuels for heating of homes and buildings and producing hot water. In areas where gas service is not avaliable, many heat (and cook) with compressed gas, stored and delivered on site. For city gas service, natural gas is used which is primarily methane (CH4) it burns very cleanly, producing two parts water for every one part carbon dioxide emitted. It also produces very little soot or smog-causing compounds. However, for areas where gas is stored on site or in smaller reserves, propane and occasionally butane are the preferred gases to use. These gases, often referred to as LPG (Liquid Petroleum Gas) are less present in natural gas but they require less pressure to liquefy and have a slightly better energy density. Propane (C3H8) also burns cleanly but part-per-part produces slightly more CO2 than methane.
Methane and other light hydrocarbons are relatively simple to synthesize using nuclear energy and doing so could increase their availability and therefore reduce price. This would help reduce pollution by encouraging methane use over other fuels like oil or wood burning (which is making a big comeback for home heating). Using nuclear-sourced methane can not only reduce the burden on fossil-fuel sources, but also improve the overall emissions footprint. In addition to the greenhouse gases produced when methane is burned, drilling for methane and transporting it by pipeline over long distances inevitably results in some of the gas leaking or being vented. Since methane is 25 times as potent a greenhouse gas as CO2, this is a significant source. The synthesis of methane with nuclear heat and in closed and controlled vessels can be far less prone to venting and leaking than drilling.
The CO2 can be further reduced by enriching the gas provided by services with hydrogen, produced by nuclear energy. Existing natural gas systems deployed in many areas and the furnaces and heaters which burn the fuel can be used without modification to burn a blend of hydrogen and methane. Many areas once actually used “town gas” to provide for gas heating and lighting service and some still do. Town gas is a synthetic gas mixture of up to 50% hydrogen, but will burn fine in most equipment designed for methane or LPG. Switching to 100% hydrogen in existing gas systems is probably not practical as it would require a much larger volume of gas moved and equipment might not function properly on it. However, a mixture of methane, enriched with hydrogen, generated by nuclear thermochemical means, could reduce the emissions (of both CO2 and NOx compounds) and cost of gas service while still allowing equipment to function properly. One concern about using hydrogen in the existing natural gas grid, without major modification, has been that it would cause an increase in leakage, however large scale trails have been conducted with up to 40% hydrogen blends and have not found unacceptable increases in leakage. In practice,this amount may be too high for use without modification to gas metering equipment.
District Heating - District heating is the method of heating multiple buildings with a central heat system. The heat can be delivered by means of steam, hot water at just bellow the boiling point or by pressurized hot hot water delivered at well above the normal boiling point of water. District heating is not new and has been deployed in North America, Europe and elsewhere. Many district heat systems are powered by “combined heat and power” stations which produce both electricity and steam or hot water for heating. This can add greatly to the effeciency of a power plant, since much of the heat for a district heat system can be derived from what would otherwise be waste heat, thereby increasing the overall effeciency of the power plant to well above what can be effectively achieved with thermal engines alone. It is also a far more efficient method of delivering large amounts of energy for heating when compared to electricity. Fast-moving fluids in insulated pipes can travel several miles with only minimal loss of temperature.
In the past, district heating systems have been deployed in many large cities and are often referred to as “city steam” service. Large systems are no longer as common in North America, although some large systems such as the Vancouver BC heating system and the Con Edison New York Steam System remain in service, providing energy for heat and hot water to thousands of buildings. Wide-scale district heat is more popular in areas where fuel prices are higher or where large amounts of waste heat are avaliable. These include Russia, Germany, Sweden and Norway where several cities have large district heat systems, many of which are which are more modern and effecient than those in North America, which have generally been in operation for decades. The reduction in fuel use can be dramatic, the city of Växjö, Norway has already reduced the use of fossil fuels by 30% in buildings and is aiming at a reduction of 50% by increasing the use of district heat.
Of all countries where district heat is utilized, Iceland leads the way where an amazing 95% of structure and hot water heating is accomplished by heat distribution systems. The reasons for this are two fold: first the obvious cold temperatures make effecient heating a necessity and secondly large amounts of waste heat are avaliable from the countries geothermal power stations. Iceland is also unique in that district heating systems are not confined to densely populated areas like cities, but have been deployed into more suburban areas where the service is delivered by a combination of underground and above ground pipelines. The system is used for heating of hot water, normally through a heat exchanger, as opposed to direct use of the hot water as well as heating of homes and businesses. After the hot water has been used for heating of water and structures it then retains enough heat to melt ice on streets and sidewalks. The system is open-ended and the water is finally discharged after being used for heating. In a few unique examples, the final use of the water is to provide heated swimming in the winter.
Another benefit worth mentioning is that district heat systems are frequently used to provide power for cooling and air conditioning needs. This is done through the use of absorption chillers, sometimes referred to as “heat powered air conditioning,” which use a series of steps to dry and cool air through the use of heated water and salt solutions.
While district heating presents a high capital investment in cities and large geographic areas, it has proven to be extremely cost effective on smaller scales, where the investment is paid off more quickly. Common examples of smaller district heat systems include college and university campuses, large apparentness and condominium complexes, military bases, office parks and other such complexes. These systems are actually quite common and in a few cases utilize the waste heat of local power plants for part or all of the heating needs. In cases where a dedicated heat plant is used, there are still benefits over individual heat systems due to higher effeciency and the ability to provide better flue gas treatment in a single location. Of course, the enviornmental benefits would be even greater if nuclear energy were used as the heat source.
Deployment of district heating systems in areas like North America, where few exist outside of a few cities, represents a challenge, since the large scale systems require a great deal of construction and a high initial investment. Newer systems, however, since as closed-loop superheated water systems along with better insulation and systems which can utilize hoses and smaller diameter pipes may reduce this cost. Newer systems also offer lower maintenance and better effeciency than older steam-based systems. The benefits of deployment of nuclear based district heating, however, has numerous benefits. Not only does it offer the opportunity to expand the use of nuclear energy in place of fossil fuels, but the availability of low cost heating can enable such luxuries as ice melting on streets and sidewalks, as is done in Iceland. It may also have the benefit of reducing thermal discharges from nuclear power plants.
One method by which deployment of district heating could be achieved in an economical manner involves a stagged deployment where a system is first established by connecting pre-existing heating systems or facilities with large heating needs to nuclear reactors. Due to the large expenditure on fuel by such facilities, extension of a system to these locations would have a high initial ROI, especially in areas which are located near to power plants. The next step of such a system would involve connecting smaller customers, even individual homes, which are already located near pipelines to the system. Larger scale development of these systems could eventually lead to dedicated heat plants using relatively small reactors to deliver thermal energy for heating, hot water and process heat needs.
The following map shows a theoretical initial deployment around a nuclear power plant. The blue lines represent above ground large throughput pipelines, situated along railroad tracks, transmission line right of ways or other existing paths. The dark red lines represent underground pipes in more populated areas or for the final delivery of the heat to the customer. The development of the system begins with connection of the existing district heating systems, such as in a college or office complex, followed by large customers, such as apartment buildings and then smaller ones which are located near the pipeline. Later small businesses and homes may be connected to such a system.
In practice, it is likely that if nuclear energy is deployed widely for both electricity and heating, it will be by a combination of methods. For large heating needs and in areas where nuclear heat is avaliable, district heat may make sense. In areas where heating needs are not as great, electric heat or heat pumps may fit the bill. Methane and hydrogen enriched gas service is less than perfect but may be the best option for systems which already exist. In areas where heating oil or LPG systems are already in place, electric heat may be able to reduce, if not eliminate the use of fossil fuel for heating on site.
This entry was posted on Thursday, April 24th, 2008 at 11:58 am and is filed under Enviornment, Good Science, Nuclear. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
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April 24th, 2008 at 12:46 pm
Actually, heat pump based heating is a very effective way to heat electrically. Solar water heating in areas with enough sunshine is about the only sensible and cost effective way to use solar.
Where I live, heating is really only needed on winter nights. Even on most days in winter there’s enough sun to heat water. I am experimenting right now with latent heat storage, where during the day the hot water from the roof mounted solar water heater is used to melt an (isolated) tank full of paraffin wax (candlewax). During the night that latent heat reservoir is cooled back down, solidifying the paraffin wax. I am using that heat energy to heat the house.
A friend of mine has modified his air-conditioning system to dump the heat extracted from his house into his swimming pool. During the swimming season in summer, the pool is very comfortable. At night he dumps excess heat via roof mounted pool heater panels.
In the winter he also heats the pool with the roof mounted solar panels during the day, but extracts heat from the pool at night via the airconditioning system, run in reverse.
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April 24th, 2008 at 1:58 pm
Passively safe reactors like pebble beds(which can safely suffer a complete LOCA without SCRAM or any other intervention at all by operators) could be built under a city and used for district heating.
Another approach I find really neat(but may not necessarily be cost effective or low maintenance) is seasonal heat store. You collect thermal energy, either using solar heat collectors or by running pipes under asphalt(for instance in a parking lot) whenever the temperature is high enough. You circulate some heat transfer medium(e.g. water+anti-freeze) through the tubing and down into an underground tank of water or large block of insulated earth and boreholes so that it can be stored for winter. That’s definetly not cost effective if you’re going to have one heat store for each person, but if you have one big heat store for an entire block of flats or for a small block of suburban homes that might just be doable if the system can be built with enough reliabillity to not need a lot of upkeep.
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April 24th, 2008 at 2:31 pm
Heat pumps ARE actually quite popular in Canada. Lots of people have holiday homes that they only use during the +- 6 months of the year when they’re not frozen(in some mountain areas of BC, it’s more like 4 months), suring the rest of the year they have to make sure that there is enough heat in the house, or the pipes will burst. Heat pumps are a very cheap(about $30/month) way to keep the temperature of a house just above zero.
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April 24th, 2008 at 2:48 pm
Yeah heat pumps are great for certain applications and are considerably better than standard electric heat in terms of effeciency in general. If you only need heat on cold winter nights then they would work great for that or if you just want to keep the house enough above outdoor temperatures to keep the pipes and stuff from freezing.
They would be great for a lot of areas or as part of a system in areas with harsher climates. They have limitations though. For example, I lived in upstate New York and I actually knew someone who had a heat pump as the primary heat source for a small home. They regretted putting it in the first winter. It got down well under freezing and the heat pump was running like crazy and not doing very much to heat the place. In that area you can get a few days in a row of temperatures around 15 F. Right now I live in Connecticut and the houses here are generally heated by oil. I suspect a heat pump would not get the job done here either.
Then you have to consider that they are somewhat limited for certain applications like large buildings or high rises in cold cities. You wouldn’t really be able to have an air-sourced heat pump in some place with really cold weather, even occasionally. You would need a lot of ground for a heat sink for a 20 story building or a big complex and in a city there’s not enough ground space to go around.
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April 24th, 2008 at 3:14 pm
drbuzz0 said:
It’s all about the temperature difference between inside and outside. If you want to heat the inside so that it’s comfortable for people, the forget about it., but if you want the inside to be juuuuuuuuuuust warn enough that the pipes don’t burst, it’s ideal.
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April 24th, 2008 at 3:52 pm
There was a heat pump system available for a while in Europe that ran on heating oil. I don’t know if it is still available. Basically it’s a small Diesel engine (1 Liter, adapted from a VW car engine) drove a heat pump. The cooling water and exhaust heat of the engine was also used. It saved about 25-35% of oil compared to a straight oil burner. But not cheap though.
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April 24th, 2008 at 4:06 pm
KLA said:
Interesting concept. I guess that kinda makes sense if you could burn oil for both heat and to run the heat pump to draw in more heat. 25% savings would not be that much though if the capital cost is high because then there would be a long time to offset it. Also, would it need much maintenance? Changing the oil and that kind of thing might mean not as much return.
Sounds like it might have potential though if there were a way to add an electric motor to it then it could be a kind of hybrid system. Use it on electric in the summer for air conditioning. Then use it as an electric heat pump in the fall and spring and that kind of thing and fire up the oil burning/dieseling kind of thing when it’s real cold and use that to kick in a little more heat.
I think heating is a worthy consideration as an application of nuclear energy. I agree that doing it with electric heat is probably not realistic in all circumstances. It might work in the mild areas with some cold nights but it needs too much electricity for big applications.
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April 24th, 2008 at 4:07 pm
The energy needed for heating can be greatly reduced by insulating very well, making the house essentially airtight & installing a heat exchanger for ventilation so outgoing stale air warms incoming fresh air. (See R2000 http://r2000.chba.ca/ )
My parents were living in such an electrically heated house in eastern Ontario when the big ice storm cut off the electricity for several weeks in the late 1990s. I called them a few days after the storm & the house was just getting cold enough then that they were draining the plumbing before going elsewhere until the power lines were restored.
Putting the insulation on the *outside* of thermal mass, such as concrete block walls, will also help since to some extent that stores heat from the summer for use in the winter & stores ‘coolth’ from the winter for the summer.
If such techniques are used to reduce the energy required for heating & cooling, then using nuclear generated electricity for heating becomes reasonable.
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April 24th, 2008 at 5:17 pm
Interesting. But doesn’t that need to be new construction? Also, it seems like it still might not be that reasonable for big buildings. I’m not sure you could hope to retro-fit the empire state building or something like that with extreme amounts of insulation.
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April 24th, 2008 at 6:07 pm
I very large district heating systems, substations are used to distribute heat to the end users. The substations are supplied on a closed loop with high pressure superheated water, usually at temperatures around 400-500C. This then powers local steam generators which are used to produce steam for the delivery network.
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April 24th, 2008 at 6:19 pm
DV82XL said:
That sounds like it would be the way to do it if you set it up in steps like buzz0 proposes then you could have the “substation” take the place of the local plant in colleges and complexes and then you would connect those up to the main loop and then local substations to eventually even heat neighborhoods.
It sounds like that might be a good way to do it: Do the district heat thing for where you have complexes or big buildings that benefit from it. Then where you have avaliable district heat you can connect other smaller places to it. For places away from it you can use heat pumps and electric heat if it’s not too severe a winter but if it is you can use gas or something and try to slowly phase out fossil fuels as you can expand heating and that kind of thing. Maybe also use electric to augment fossil fuels some places.
Of course, first thing would be getting a nuclear-powered system for electricity because that’s the big thing.
Also at this point I think a lot of people would freak out at the idea of nuclear-heated water in their homes and offices even if it had several degrees of separation.
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April 24th, 2008 at 7:13 pm
Q said:
Maintenance requirements would be very small. Maybe an oil change once every 12-24 months (synthetic oil). The engine is by far not as stressed as in a car. The worst thing for an engine are constant load changes and cold starts. Cold starts, because of oil washing on the cylinder walls, and the formation of acids in the oil from partially burned fuel, can be equivalent to 500 miles of driving. This engine would run during the winter basically always warm, as the cooling water is used for heating at sufficient temperatures. The other nice thing is that the remainder of the system did need little additional electricity. Water was circulated via the water pump of the engine, only bypassed by an electrical pump when the engine was off. No air blower for the burner was needed of course. I don’t think expanding it to a hybrid would be any problem. Just means a few electromagnetically (or hydraulic) operated clutches.
I think nuclear district heating would be a non-starter with todays anti-nuclear hysteria. Even most (but not all!) rabid anti-nukes can’t see radioactivity move through electrical wiring. You won’t be able to convince them in case of an actual material movement between a nuclear plant and their home, even if the hysteria abates a little.
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April 24th, 2008 at 7:41 pm
Yeah well direct heat from a nearby reactor would be the best way to heat an arena or a big factory or a huge complex of buildings and would be the natural choice for universities or any other existing heat system like that. It’d be nice in that it would largely use what would otherwise be thermal discharge.
At this point the hysterical crowed would hardly care that it’s local steam heated by district steam heated by closed-loop hot water heated by the heat exchanger that heats the working fluid which is heated by the reactor loop fluid. Silly, yes. There are so many degrees of separation and even if it was reactor water it’s not like it’s radioactive beyond perhaps a small amount of tritium. Does that matter? Not really. People would still flip out.
I’d say heat pumps where you can use them. Electric heat may have a place too. For the big jobs we’d be stuck with gas or oil. Direct nuclear heat would be nice but people wouldn’t buy it at the moment.
But that could all change if there were a healthier mindset and more education so who knows.
Also the prospect of having extra heat left over to heat your pool and melt the icy walkways without worry would be a great luxury.
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April 24th, 2008 at 7:49 pm
KLA said:
Unfortunately this will be one of the issues it will have to face. AECL built and run the WS-1 reactor at Whiteshell Nuclear Research Establishment in Manitoba, for several years. The reactor was a high temperature version of their SLOWPOKE reactor scaled-up to 10 MWth, called SLOWPOKE-3. The economics of a district-heating system based on SLOWPOKE-3 technology were estimated to be competitive with that of conventional fossil fuels. However, the market for this technology did not materialize.
The SLOWPOKE designs were unique in that it is the only nuclear reactor design to date that has recieved international licensing for unattended operation. Another project by a Canada-France consortium, International Submarine Transportation Systems (ISTS) would have powered the world’s first commercial nuclear submarine with a 1.5Mw SLOWPOKE-2 reactor. This unit would provide the heat to power a Stirling engine designed by Energy Conversion Systems Inc. They got as far as building the craft, known as the SAGA-N, before the project collapsed in a tax dispute between Canada and France over funding.
A Chinese version of the Slowpoke exists, designated the Miniature Neutron Source Reactor (MNSR). This version is nominally rated at 27 kW with similar characteristics and performance. A clear case of reverse design from the one we sold them, it has dominated the foreign market for these designs, leading to the termination of AECL production. Six SLOWPOKE-1 reactors are still in use at several Canadian Universities.
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April 24th, 2008 at 8:56 pm
Wow. Some great ideas, but why wait until there is a nuclear society? I have an idea for how you could save a ton of pollution and energy now! (I live in NYC BTW)
You have Indian Point which is less than 40 miles from NYC. That’s not too long for a heat pipeline. They do it in Iceland and other places for 60 or 70 miles and the fluid is moved reasonably fast and with some insulation it doesn’t loose more than a few degrees. So what about this? you take the condenser water from Indian Point and that’s close to boiling before they blend it with more water to dilute the heat. Then you take the water at about 90 C and you send it back to the reactor to heat it up more to maybe 200 or more C, but you still get almost half the heat as what would be waste. Then you have the pressurized water go down a pipeline to New York.
It shouldn’t be hard to build a pipeline to New York because there are plenty of good routes to take that already are existing, like the railroad or the aqueduct or the power lines and also there are already pipelines that carry gas up and down the Hudson. So then you follow those and you take the pipe into the uptown Con Edison steam plant and you use it to make the steam. You might need the gas burners too to heat it up all the way but you still get *most* of the energy from the nuclear plant and you can run the ***EXISTING*** city steam system on it. Plus a lot of it would be waste anyway and you do something useful and help with cooling!
Gas is getting more expensive so they have raised the city steam prices – I paid way more this past winter than before for the apartment heat which is on the steam system. They use a lot of gas too to make the steam so it would make a big difference. Plus, some of the plants are heat and electric and when the heat demand is high they have to divert from the electric side. But if they had more energy from the reactor then they would not need to and therefore it helps with electricity!
Why should anyone be upset about that? I mean the water from Indian Point goes to New York anyway but it goes in the Hudson and it’s not useful because it’s obviously cold because it’s mixed with the river water. So why complain? Besides the water is not radioactive anyway
Does that sound like a good idea? I think it’d be a great use of nuclear energy!
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April 24th, 2008 at 9:06 pm
Gotham Geek said:
Ya, it’s a good idea IF they have the heat capacity at the reactor to supply this system. Normally this type of heat transmission needs temperatures >400C to be effective.
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April 24th, 2008 at 9:12 pm
DV82XL said:
Hmmm. They might not or at least not without diverting heat from electricity generation. They could add another reactor I guess and then use that for also electric when not as much energy is needed for heat. You know they have three reactors but one is decommissioned because it’s really old and doesn’t meet their standards.
A lot of people want it shut down but I’d just as soon see it expanded because righ now they’re increasing how much coal a lot of coal power plants can use in Pennsylvania and it’s been shown to effect our air. They are doubling some of the plants because it’s an easy way to get around the emission laws if it was built already and it’s added to it then it’s not the same standards like new.
Also, the cost of power is going up too in NYC so I think it’d be preferable to add to nuclear plants versus adding to coal and they could add the heat pipe in the process. BTW: I’ve been to Indian Point and they have plenty of space to expand.
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April 24th, 2008 at 10:01 pm
Well, Gotham Geek, your I think it’s a great idea for utilization of nuclear energy for a high energy need that currently uses fossil fuel. However, I doubt that Indian Point would have the output to provide much heat for NYC and I doubt it could do 400C for the heat pipeline without diverting quite a bit of energy from electricity generation.
Could it be done if it were upgraded? Sure and I advocate upgrading all existing nuclear plants whenever possible because it’s often faster and easier license-wise than building a new one. Adding reactors to what we have is imperfect but it’s so goddamned hard to get a new license that it can be a better interim solution to extend existing ones to more capacity.
I’d be all for adding capacity to Indian Point and also possibly using it for heating needs. But I really don’t see that happening because that plant has been such a lightning rod and the idea of pumping fluid from it would be very difficult to get to fly.
In general, the waste heat along from nuclear plants is not going to be enough to do much heating. It may be economical if it is very close to some suitable areas to heat and it may also be useful for some degree of preheating water, but really to do it right you need dedicated capacity for heating and right now most plants don’t have any excess thermal capacity that isn’t already used for electricity.
Your idea is good though and we could use more people with that mindset.
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April 24th, 2008 at 10:11 pm
In the Swiss village of Beznau, heat losses from a nearby nuclear power plant are being used in a district heating system.
In the Beznau reactors , water is heated to a temperature of 312C. Through the first heat exchanger, the water of the second cycle is vaporised at a temperature of 260C and a pressure of 55 bar. The water then powers the high pressure turbines and then the low pressure turbines. After this, there is enough energy available to heat the water of the district heating network to a temperature of 85C and if this is not enough to meet the demand, the temperature can be further raised to 125C through a heat exchanger between the high and the low pressure turbine. This system supplies heat to over 2300 clients, ranging from small individual houses to large industrial buildings and hospitals in the local area.
The amount of heat that is sold to consumers converted into heating oil and then into CO2 emissions amounts to around 12 600 t of heating oil. Burning this much amount of oil would emit 44 000 t of CO2.
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April 24th, 2008 at 11:11 pm
Seems like a really good use of the reactors to displace some fossil fuel. I can see how it would have a big return for hospitals or big industrial clients. 125C seems like the minimum you could do it at locally but to do a big system over long distances I think you’d need more. Lower temperatures would mean you have to push more fluid to do the job. Higher would be better for transmission.
Good idea though! Nuclear can do more than make electricity! Also, I liked the heat pump stuff!
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April 25th, 2008 at 12:46 am
Remember too that nuclear energy is an excellent source of process heat for various industrial applications including desalination, synthetic and unconventional oil production, and the potential applications of the High Temperature Gas Reactor (HTGR) nuclear steel making.
The potential application of nuclear heat depends mainly on the temperature required. With reactor output temperatures (ROT) of up to 700°C there is a wide range of possibilities, at 900°C there are further possibilities, and at 950°C an important future applications open up.
The Fischer-Tropsch process was originally developed in Germany in the 1920s, and provided much of the fuel for Germany during the Second World War. It then became the basis for much oil production in South Africa by Sasol, which now supplies about 30% of that country’s gasoline and diesel fuel. However, it is a significant user of hydrogen which is now produced by coal gasification with the water shift reaction. A nuclear source of hydrogen coupled with nuclear process heat would double the amount of liquid hydrocarbons from the coal and eliminate most CO2 emissions from the process.
the great majority of the more than 7,500 desalination plants in operation worldwide today use
fossil fuels with the attendant emission of carbon dioxide and other greenhouse gases. Increasing the use
of fossil fuels for energy-intensive processes such as large-scale desalination plants is not a sustainable
long-term option in view of the associated environmental impacts. Thus, the main energy sources for
future desalination are nuclear power reactors and renewable energy sources such as solar, hydro, or
wind, but only nuclear reactors are capable of delivering the copious quantities of energy required for
large-scale desalination projects
Paper manufacturing, a huge user of process heat, is being considered as a market by South Africa’s Pebble Bed Modular Reactor (Pty) Limited. In fact any thermochemical process that requires large heat inputs can use this technology.
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April 25th, 2008 at 12:59 am
Indeed. For such processes it is generally more economical to use a direct heat source even if it’s piped in than electric just because of things like the fact that you save the loss of the thermal conversion.
Yeah there are a lot of applications which use fossil fuel because they need lots of heat on site. Papermills are a good example. They often burn a lot of natural gas but some burn oil or coal. If you could pipe in heat from a reactor or even have a small one on site that would be a great way to reduce it.
Also refining of oil, chemical production, potentially waste water treatment, heating of structures of course, various mineral refining, desalination, water processing, treatment of hazardous waste (for example, decomposition of dioxins or PCB’s or treatment of contaminated soils.), recycling of materials like glass and plastics
there are numerous processes and applications that simply need lots and lots of raw heat. If heat is avaliable there are also processes which may otherwise not be feasible.
Now as far as synthetic fuels: they are actually not that hard to do at all. The Fischer-Tropsch process is well established. There other methods like thermal decomposition and hydrogenation cracking. In some methods it’s as simple and putting coal and low quality oil in a big pressure cooker and then heating it while injecting hydrogen until it resequenced into tars and then taking the tars and putting them in a big cracker-stack.
The biggest problem with synthetic fuels and non-conventional oil is the massive energy (generally in the form of heat) which is needed. “Light Sweet Crude” is worth the most of crude compared to heavy crude because it requires less energy to make into the end product. Heavy oils and tars can be done too but that needs a lot of cracking and steam reformatting. This takes tremendous thermal energy.
Coal is mostly carbon so to turn it into short-chain hydrocarbons you need to provide hydrogen to the reaction and this is generally done with steam reformatting at high temperatures – it can be derived from coal or methane but coal produces a lot of carbon dioxide and carbon monoxide.
I’ve heard that some synthetic plants in South Africa and which were in Germany took in three times more coal than was used for the actual product. Two thirds of the coal was burned to provide the heating and only a third for the synthesis of the product. That’s the only reason why making hydrocarbons is a problem is how much you need to burn to do it.
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April 25th, 2008 at 1:50 am
One thing I really like about this page is how common sensical it is, because I didn’t see one time anyone “require” the use of nuclear energy for heating or industry. Let me guess: If you provide such energy at a good rate and with high reliability and QOS then people and companies will gladly switch to it without being forced? And you can do this by just encouraging its use through good regulations that make clean energy less difficult and dirty stuff pays for what it does?
God what a non-revolutionary concept that nobody ever seems to get behind???
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April 25th, 2008 at 1:58 am
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April 25th, 2008 at 2:01 am
DV82XL said:
27 kilowatts??? Are you sure you didn’t drop a zero or three? If so, just how “miniature” is the system?
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April 25th, 2008 at 2:13 am
inky i now know Y said:
as in one of those little DC motors where the the stator is in a field provided by perminant magnets? I don’t think those are used much for anything besides toys and stuff in general.
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April 25th, 2008 at 4:25 am
Burya Rubenstein said:
The maximum power of the MNSR is ~ 30 kWth, the heat being removed by natural convection. For comparison the SLOWPOKE-2 reactor at the University of Toronto is run at 20 kilowatts nominal power (thermal). SLOWPOKE after all is an acronym standing for Safe Low Power Critical Experiment.
These are used predominantly for neutron activation analysis, although there is continued interest in the development of Boron Neutron Capture Therapy (BNCT) as a potential treatment for cancer and especially certain brain tumors which would also use flux from these reactors.
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April 25th, 2008 at 1:19 pm
Yeah the slowpoke is basically a research reactor as opposed to a power generation one, at least in general. It might make enough thermal energy to run a sterling engine or something. It’s very safe because it’s low power and if the water should start to boil around the fuel elements this will reduce moderation and slow the reaction thereby causing the reactor to basically stay in equilibrium.
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April 28th, 2008 at 9:22 pm
DV82XL said:
I hate to contradict your usual impeccable posts, but the WR-1 reactor at Whiteshell was not a Slowpoke-3. The WR-1 was an experimental Candu design with a vertically oriented Calandria (a la Gentilly-1) utilizing an organic coolant (oil). The Slowpoke-3 was to be commissioned at Whiteshell, but the project was cancelled due to the deterioration of market conditions (gas was cheap). I assumed you mis-typed WS-1 for WR-1, but if the Slowpoke was to be designated WS-1 (I could not find a reference) it did not operate.
In any case, I wonder if AECL has anyone left with enough Slowpoke knowledge to resurrect the Slowpoke-3? After a few more years of high fuel prices, the business case should look pretty good for institutional sites.
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April 28th, 2008 at 10:05 pm
You’re quite right I got them mixed up because the waste heat from the WR-1 was used to heat the Whiteshell Laboratories complex during its time. Usually I check these things before posting – thanks for catching it.
However AECL’s Slowpoke Energy Systems did build – and partly commission a SLOWPOKE-3 demonstration reactor (SDR) at Whiteshell Laboratories, but terminated the project after market interest in the SLOWPOKE heating system dwindled. AECL shopped its SES technology around during the Eighties, before deciding that the competition with fossil fuels wasn’t worth the fight. With nuclear power you can’t just be comparable in cost, you must be persuasively superior. The fact is that it was just ahead of its time, it would probably garner more interest in the present high fuel price market of the present. This idea like the CANDESAL bulk water desalination system based on a small CANDU, and a few other projects suffered from the fact that AECL as a Crown corporation has to dance to a very different tune than a private company and mistakes are best left forgotten, similar to the way NASA seemed to want to forget Skylab ever existed. (In fact there are more similarities between those two than there are differences at least in corporate culture)
There are still a few SLOWPOKE-2 reactors in operation in Canada at several universities as neutron sources, and as I understand it there is (or has been) some developmental work done by the cadets at the Royal Military College in Kingston, Ontario with the reactor there, but I haven’t checked recently.
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April 28th, 2008 at 10:38 pm
Doc,
Overall a great post. Lots of information here. I’m a big fan of ground source heat pumps (I refuse to call them geothermal due to the geyser confusion) and have been for almost 20 years. Still don’t have one, though…
I moved into a brand new house last fall. My last house used an oil-fired hydronic baseboard system for heat, quite common where I live. For the new one I insisted on in-floor radiant heat, initially supplied by an 18kW electric boiler. Due to specific time and budget constraints, I just could not get that ground source heat pump into my mortgage (and marriage). But the radiant heat setup does put me in a position to upgrade to a heat pump (air or ground source), or even to use solar thermal collectors to offset the electricity costs since radiant heat uses 120F temperatures rather than 180F temps.
I thought you were overly critical of ground source heat pumps for heating in cold climates. While it is true the most cost-effective installations are those that requires both heating and air conditioning, a heating-only installation should have no problem, if the ground loop is designed properly. However, proper design sometimes means making the ground loop bigger so that the ground temperature is not lowered below that which it can recover during the summer. Bigger = more capital cost. The alternative is to fall back on electric resistance backup late in the heating season. There’s a balance, but it works.
There is a cold-climate air source heat pump on the market now, built in Bangor, ME by Hallowell. They claim a Coefficient of Performance of 3 down to -20C. Sounds great, although it still has to prove itself in terms of longevity.
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April 28th, 2008 at 10:45 pm
DV82XL said:
I’m sitting about 5.5 miles from one right now…
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April 28th, 2008 at 10:50 pm
Brad F said:
And that would be..? I’m near the Slowpoke reactor at l’Ecole Polytechnique de Montreal.
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May 2nd, 2008 at 10:38 am
DV82XL said:
Dalhousie University in Halifax.
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May 8th, 2008 at 5:32 am
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July 30th, 2008 at 1:01 am
What would be the best solution for people who live in rural, spread out areas that would also require a lot of heating, such as in the upper midwestern US? Would it still be economical to set up a district heating system up there for a rather scattered and spread out population?
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July 30th, 2008 at 1:13 am
Neurovore said:
No, these systems only are practical in urban areas.
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July 30th, 2008 at 2:57 am
Neurovore said:
The short answer: No. If you had some big facilities like college campuses or large clusters of major heat needs then it might be economical to pipe heat out to such areas. But really it’s not economical except for where there’s a great need for heat in small areas or clustered heating needs.
For such circumstances the other methods like heat pumps, electric heat, synthetic gas etc are a better bet.
Electric heat would certainly be the simplest, but if you have an area where there are a lot of people spread out in and it gets very very cold it might be a big load on the power grid. Like anything, it’d need to be transitional anyway and nothing happens overnight.
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