Musing about resilient power systems – natural gas, NGL (propane) and nuclear
Widespread power outages stimulate me to intense bouts of thinking about building resilient power systems, both when they happen to me and when they happen to someone else. During the summer of 2012, during one of the hottest weeks of the year, we lost power for a little more than a week as a result of the derecho that knocked out power for millions of people from Ohio to the coast of Virginia.
That experience made me think deeply about ways to increase our personal ability to withstand external events. However, like many other long-term or expensive propositions, power outage preparations moved to the back burner until a couple of weeks ago, when we started to hear about Hurricane Sandy and its potential impact on the US east coast.
For a number of years, my wife and I have bandied about the idea of purchasing an emergency generator. I have resisted the subtle pressure for a number of reasons; I’m a cheapskate who hates the idea of investing a large amount of money into an asset that will almost never be used; I don’t like the effort associated with maintaining the system; I’m worried about the potential hazard of storing a substantial quantity of fuel; I do not like the noise and smells from the lower cost models; and I fully understand that running a generator for any length of time requires a continuing fuel supply effort.
I’ve had friends that smugly spoke about having a generator if the power goes out; I pointed them to the gas station line stories that often accompany hurricane sized power outages. Then there is the operational cost issue; with gasoline at $4.00 per gallon, each kilowatt hour produced will cost about $0.40-$0.50; running my home with a generator will cost close to $2.00 per hour in fuel alone.
I’ve considered the diesel fuel option; it has some advantages over gasoline due to improved fuel efficiency and better storage characteristics, but home-sized diesel generators have cost, noise, pollution and smell issues that are worse than the ones associated with similar capacity gasoline generators. As a long time diesel car owner, I am also well aware that the current price per gallon differential between diesel and gasoline wipes out the fuel efficiency advantage.
In my investigations for alternatives, I’ve read about natural gas generators that avoid many of the issues associated with gasoline or diesel generators. The engines can be quieter than liquid fuel alternatives, they produce few pollutants other than CO2 and water vapor, the catalog listed sustained run times for natural gas generators are often 2-3 times as long as for the same engine burning gasoline and the fuel is cheap these days when compared to gasoline on a per unit heat basis. Perhaps best of all, natural gas generators can be connected directly to a pipe that takes care of most of the fuel supply problems.
There are a few issues, one of which is a deal killer for me – my neighborhood does not have any natural gas distribution lines. (As a matter of fact, in the dozen or so homes that I have occupied in the past 50 years only two or three were in a neighborhoods with a gas distribution system.) Another related issue is the fact that neighborhood distribution lines are limited in size; they are not designed to supply all of the homes with enough fuel to power generators. If a moderate portion of the homes on a system fired up generators, there would be fuel constraints caused by low pressure in the pipes.
A final issue associated with natural gas generators was highlighted by recent news stories about distribution systems that were broken by uprooted trees and damage to customer connections. In at least one case, the gas company shut off the gas supply because they were finding a large number of flares at the end of broken pipes. An expensive generator would be rendered instantly useless if the fuel lines are isolated.
Then there is the nuclear option. I’ve always been intrigued by the fact that a tiny amount of relatively cheap fuel can provide emission free, reliable power for a long period of time. However, I know I am just dreaming when I even consider home sized atomic engines.
While it is technically possible to build fission power plants that are physically small enough to power a home (space agencies in both the US and in Russia have done it) it is highly unlikely that such a power system could ever be economical. There are way too many overhead items, there would be way too much resistance from people who fear anything nuclear and there would be legitimate safety and security questions due to the need to make a home sized-system operator independent.
My Hurricane Sandy focus on resiliency made me realize that I have an underused asset at home. Last year, my wife and I invested in a large underground propane tank to supply the nice-looking gas fireplace that the builder of our home thought was a good selling feature, even though the neighborhood does not have a gas distribution system or any plans to build one. Propane can be stored indefinitely without spoiling and it burns as cleanly as natural gas.
With that propane tank already planted in our yard for other esthetic reasons, I have the opportunity to increase our home storm resiliency with a generator that has characteristics that are similar to natural gas. The system will have the added advantage of having on site storage that allows a substantial run time without any need for a pipeline connection. From the cheapskate point of view, I like the idea that my existing investment in a propane tank will reduce the overall cost of a backup power system. The tank will not be just an idle bit of capital. Unfortunately, delivered propane costs about as much as gasoline at the pump, but we are just talking about an emergency generator here.
I have figured out what many rural people and RV owners have known for a long time; propane (also called LP gas) makes it possible, though not cheap, to have temporary power independence that can operate cleanly and automatically.
I think my next installment in this series will include a discussion about the way that the resilient power options discussed above change when the problem is expanded from a single family home to a community, campus, or industrial park. As you might imagine, I believe that the nuclear option will move up the list for somewhat larger power output machines. In the meantime, I need to get ready to cast a vote and I need to do some more research on propane generator options.
Additional reading
How N.Y.U. Stayed (Partly) Warm and Lighted
How Natural Gas Kept Some Spots Bright and Warm as Sandy Blasted New York City
There is always the possibility of non-electric fallbacks for the rare occasions when the electrical system fails also. Admittedly that means that you have to have alternative devices to get you through until the grid restarts, but those can also double up as recreational camping equipment, for example. And most people do also have a generator already, in their garage, if they can find a way to use it economically.
Good to hear that you’re getting ready to vote, Rod. I hope everyone else (in the US) is doing the same, if they haven’t already voted early.
How about a plugin hybid like the Chevy Volt.
It has a very efficient generator onboard 30%? conversion gas kwh to electric
It can run off its batterys shutting off the engine for a while – very efficient.
You could use solar panels as well to keep her charged up.
We do have the shining example of the Toyota Prius which has had good publicity. A New York Times story covered how a Prius owner had prepared his home for a possible repeat of a blackout in 2003 and in doing so was prepared for the next blackout in 2006. He had placed a UPS (universal power supply) in his home to keep the basic electrical needs running including his furnace. The Prius was the energy source to keep the UPS charged which without a charge would have lasted only a few hours or possibly less. The recommended technology is an inverter to regulate the voltage and something like solar panels or batteries to supply a charge. In this case the Prius was the energy source whereas an equivalent in the past might have been a noisy diesel generator in the backyard.
A bit ago I jumped the gun worrying about too much gas capacity being installed; I think. I should have been worrying about supply.
In a home emergency situation, unless you absolutely need a higher energy solution (ac/heat for example) id go with low voltage and switch to outdoor cooking. You can buy very cheap solar battery backups to supply light/computers/phones for a short time that will work well in most areas or use hybrid transportation in some kind of combined solution as was stated.
Fuel supply for generators will always be a problem and like you say the emergency situation is very unpredictable and temporary. Convenience is basically out the window.
But as for cheap gas specifically – Gas supplies was not able to fill reserve completely even recently with the drilling boom, and there is reason to believe now that there will be reduced supplies or a significant supply problem in the near future.
One thing that we know about shale gas and shale oil production is that the wells come on very strong and then the rate of production declines very quickly..After one year, the level of production drops by 65% to 80%. After two years, it drops another 35%.
( http://seekingalpha.com/article/957771-haynesville-shale-production-2013-will-be-the-year-it-finally-starts-dropping )
BTW – Carbon Monoxide is the most common cause of poisoning death in the United States.
Unintentional CO exposure accounts for an estimated 15,000 emergency department visits and 500 unintentional deaths in the United States each year ( http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5650a1.htm )
Generators and Other Engine-Driven Tools2
• Of the estimated 69 CO fatalities in 2007 that were associated with Engine-Driven Tools, 93 percent (64 deaths) involved generators. Additionally, generator usage was associated with seven of the estimated 24 multiple appliance CO poisoning fatalities for a total of 71 deaths in which a generator was involved in the CO poisoning.( http://www.cpsc.gov/library/foia/foia11/os/co10.pdf )
Can you imagine the outcry if nuclear power was even close to that number?
I’ve always been a strong advocate of using methanol for home back up fuel cell generators. Methanol can be made from natural gas, coal, urban and rural biowaste, and from electricity, air, and water or from electricity and sea water (with air being derived from CO2 absorbed by seawater).
Methanol is also safer to store than gasoline since methanol doesn’t evaporate and form vapor as readily as gasoline does.
Methanol vapors must also be about four times more concentrated in air than gasoline vapors in order to ignite.
Methanol vapors also disperse more rapidly in the air than gasoline
Methanol burns 25 percent as fast as gasoline and methanol fires release heat at only one-
eighth the rate of gasoline fires.
These properties together make methanol inherently more difficult to ignite than gasoline and less likely to cause deadly or damaging fires if it does ignite.
I think most of you are missing my point here – I am seeking a solution that provides a rough equivalent to the electricity that I get from my power company.
It is the wonderful convenience and enabling power of electricity available at the flick of a switch that I am after. I do not want to have to take the contents of two refrigerators to the dump again; I do not want to have to live somewhere else for a week again because it is too darned hot in my house to sleep; I want to be able to work on my comfortable, big screen desktop computer; I want to be a hero to my wife, who likes having power; and I want to offer a sanctuary for neighbors who want to have a cold drink, watch some television, store some food or charge some batteries.
I am not interested in patching together a makeshift system; I want something that will work in automatic and does not require babysitting. I am not thinking about a portable generator and extension cords; I am thinking about automatic transfer switches, a quiet machine housed in a weather protected enclosure, and remote monitoring so I do not have to go out into the weather.
Cost is a consideration, but I do not need to pinch pennies and I do not expect to have to actually operate the system for more than a few hundred hours per year – and may go for several years without having to operate it at all.
The idea of using a hybrid car as a back up power system is intriguing on the surface, but is WAY more expensive and less automatic than a generator. It also would mean that the house would have to shut down if you wanted to use the car for its designed purpose of transportation for more than a few minutes. (If someone suggests a larger battery, please include the cost of that in your mental computation of the system cost and remember that my goal includes keeping at least one heat pump and one refrigerator running.)
That’s all you had to say Rod. SSS requirements (Spouse Says So) always take precedence.
I have looked into a NG powered auxiliary generator for backup. The only way that this is even marginally economic in my case is because I currenty have a dual power (gas/electric) heating plant in the house, and use NG for my stove, hot-water and clothes dryer. Consequently the total amount of electric power I need is relatively small. Nevertheless, the cost for these units, even lower wattage ones, which are low noise machines housed in a weather protected enclosures with automatic transfer switches, is prohibitive if everything is taken into account.
Now power failures in this area are almost always due to Winter storms and thus heating is my primary concern, food can go in coolers placed on the back porch, and the gas furnace and the boiler have battery backup charged by a thermocouple (they were bought this way) as they only need control voltage to run. Thus I cannot justify the cost for lighting and such which is all it would be used for.
Rod,
I live in a rural area of West Virginia that can sometimes have a storm caused power outage lasting several days. Because of the low population in the area we are the last to get power back. I bought a nice back up generator that runs off natural gas. Since I’m on the road quite a bit I wanted a generator that required little maintenance and would auto start and shutdown when the power came back on. To get these features I had to go with a more expensive model but I’m happy with the convenience and peace of mind that its brought. OBTW – I have about 28 acres, half wooded, half fields and my own water supply and natural gas well. I pipe it straight to the house and the gas company sends me a check once a month which covers the electric bill. All that and a nice view of the hills. Almost heaven…
JimB
@JimB
Sounds delightful, especially that part about having your own natural gas well. Since I do not have that luxury, the LP gas (propane) tank with a generator and a more reliable utility connection than what you have seems like the best option for me.
Of course, I’d really love to have my own backyard nuclear plant, but until we pass through the analog to the “mini-computer” stage (I’m working on the equivalent to the Digital Equipment VAX, for example) in the nuclear world, we will not be able to approach the ‘PR’ (personal reactor) stage.
So do you expect to replace this “backyard” nuclear plant every three years with a new model? I think that the average life-span of today’s “VAX-equivalent” PC (personal computer) is about three years.
@Brian
I think you are a little confused. The “VAX-equivalent” in my example is the large room sized mini computers that DEC, Sperry, Univac and Honeywell – among others – were building in the time before the personal computer revolution. They were reasonably reliable examples of relatively “small” hardware that enabled the computerization of modest sized entities – companies that were not in the Fortune 100 and could afford IBM style mainframes and associated infrastructure. (Relatively small, in this case, means in comparison with the building sized mainframes.)
They could be supported by colleges, reasonable sized auto dealers, grocery chains and other organizations that could benefit greatly from computers but that were not major research universities with DOD funding, automobile manufacturers, or huge agribusiness conglomerates.
Though many PC’s are replaced on a relatively short cycle (I’m not sure where you got your three years from, but I’ll accept it as a point of departure), many of the replacements are a result of something better coming along, not a result of a machinery failure. Of course, people who think of their computers as disposable are a little like people who never figure out how to change the oil in their car; they may not keep up with regular maintenance and get frustrated when the machine performance begins to drop off. Though there are many people who still replace their cars every few years, there are also a substantial number of cars still on the road that are as old as you or I.
I happen to own a few rather ancient computers that are still capable – from a hardware point of view – of starting up and running, but I retired them years ago because of software incompatibilities or because they had restrictions within which I was no longer willing to live.
In other words, I’m challenging your implication that smaller, personal sized devices are inherently short-lived.
Rod – I think that you missed my point.
By the way, I used “three years,” because that’s a typical length for the corporate cycle for replacing computers. Your company probably has a policy of keeping their employees computers around for about that long before they are replaced. This usually has to do with the duration of the maintenance agreement with the manufacturer.
For what it’s worth, I kept my previous laptop from work for a little over seven years, returning it only when my employer forced me to replace it with a new model. By that time, almost all of the major components had been replaced — including the mother board, the screen, the hard-drive, and the keyboard — so it is debatable whether it was the same computer as the one I was originally issued. Nevertheless, the plastic outer shell (complete with the service tag sticker added by my company) was still the same, so to the company, it was the same computer.
By the time the keyboard had failed the computer was no longer covered by the maintenance agreement, so my company could not have it replaced. Fortunately, the IT guy was nice enough to swap my broken keyboard with one from a similar model that was being retired because it was over three years old. That allowed me to keep using the laptop for another two and a half years.
I’ve found that old PC’s that have lasted a long time are typically computers that have been rather lightly used and certainly are no longer used every day. The same can be said for antique automobiles.
Getting back to the topic, however, you are spot on with some of the reasons for why people replace computers after a relatively short amount of time, but that just reinforces my original point. My point is that computer technology, and electronics in general, are a bad, bad analogy for the technology used for electricity generation. It’s apples and oranges.
@Brian
Speaking of Apples and oranges, I have never replaced a motherboard, keyboard or a screen on any of the computers I have owned since 1987. My computers are not necessarily treated gently and certainly are not lightly used.
Perhaps there is a reason why the initial capital cost of the computers that I purchase tends to be a little higher than the capital cost of the computers selected by most corporate IT departments.
If you do not like the analogy of computers moving down from huge mainframes accessible only to the privileged few, perhaps we can talk about how the automobile liberated individuals from having to depend on corporate railroads. Once again, there are examples of short lived machines, or machines that only last because they are lightly used, but there are also examples of machines like my 2001 Jetta TDI that served me reliably for 222,222 miles and was still a relatively valuable trade in after ten years of operation with a relatively high duty cycle.
Rod – Small Reactors (for energy backup) –
There are both minimum and maximum size limits for nuclear reactors. A nuclear reactor has to achieve criticality to reliably sustain controlled nuclear fission. There are additional practical constraints for fluid fuel reactors that need to keep their nuclear fuels dissolved in the molten salts. A true Thorium LFTR, powered by U-233 fuel and using a graphite moderator has a low end power limit of about 1 MW (thermal). Below this size, you have problems maintaining criticality.
A near relative of LFTR fluid fuel reactors, the Aqueous Homogeneous Reactor has the characteristic of being buildable in significantly smaller size, down to about 10 KW (thermal), or a hundred times smaller than a true LFTR. There is a medical isotope producing homogeneous reactor in Russia called ARGUS that is 20 KWt and burns HEU U-235. If you are willing to use somewhat exotic nuclear fuels, Israeli nuclear designers have designed small homogeneous reactors based on an Americium isotope that requires only 0.7 kg of Americium fuel (this reactor is estimated to weigh 4.95 kg and the radius of the reactor case is 9.6 cm). [1]
Even smaller reactors that would operate in pulsed mode are possible. The density of fissile fuel has a profound impact on the amount of fissile required to form a critical mass. If the fissile fuel is cooled and held under extreme pressure, ultra-high density configurations of fissile are possible which open the possibility of extremely small pulse mode nuclear reactors. Molten salts with good thermal storage characteristics can be used to absorb the heat produced by a small pulse mode nuclear reactor. A pulse mode reactor combined with molten salt heat storage can release the pulsed heat produced smoothly and gradually over an extended period of time to permit easier use of the energy.
LLNL’s NIF fusion experiment is a pulse mode fusion experiment. The expected fusion energy produced by fusion of a single hohlraum is only ~1.8 Mjoules – this is the amount of energy produced by efficiently burning about 0.014 gallons of gasoline.
[1] – Y. RONEN, E. FRIDMAN, and E. SHWAGEROUS, “The
Smallest Thermal Nuclear Reactor,” Nucl. Sci. Eng., 153, 90
(2006).