The Ultimate Distributive Generator

Rocky Mountain Institute founder Amory Lovins has long advocated distributive electrical generation. There is an extensive discussion of the distributive generation concept in the book "Small is Profitable" parts of which are available in electronic form at the smallisprofitable.org web site. Among the materials found on the "smallisprofitable.org" is a list of 207 Benefits of Distributed Resources. One could go down the list of benefits, and with the exception of benefits that name or apply to renewable generating sources, much of the list would apply to small factory manufactured Liquid Fluoride Thorium Reactors.

The first ten items on the list will be sufficient to demonstrate how well the benefits of LFTR tracks with the benefits of distributive generation:

1 Distributed resources' generally shorter construction period leaves less time for reality to diverge from expectations, thus reducing the probability and hence the financial risk of under- or overbuilding.

2 Distributed resources' smaller unit size also reduces the consequences of such divergence and hence reduces its financial risk.

3 The frequent correlation between distributed resources' shorter lead time and smaller unit size can create a multiplicative, not merely an additive, risk reduction.

4 Shorter lead time further reduces forecasting errors and associated financial risks by reducing errors' amplification with the passage of time.

5 Even if short-lead-time units have lower thermal efficiency, their lower capital and interest costs can often offset the excess carrying charges on idle centralized capacity whose better thermal efficiency is more than offset by high capital cost.

6 Smaller, faster modules can be built on a "pay-as-you-go" basis with less financial strain, reducing the builder's financial risk and hence cost of capital.

7 Centralized capacity additions overshoot demand (absent gross underforecasting or exactly predictable step-function increments of demand) because their inherent "lumpiness" leaves substantial increments of capacity idle until demand can "grow into it." In contrast, smaller units can more exactly match gradual changes in demand without building unnecessary slack capacity ("build-as-you-need"), so their capacity additions are employed incrementally and immediately.

8 Smaller, more modular capacity not only ties up less idle capital (#7), but also does so for a shorter time (because the demand can "grow into" the added capacity sooner), thus reducing the cost of capital per unit of revenue.

9 If distributed resources are becoming cheaper with time, as most are, their small units and short lead times permit those cost reductions to be almost fully captured. This is the inverse of #8: revenue increases there, and cost reductions here, are captured incrementally and immediately by following the demand or cost curves nearly exactly.

10 Using short-lead-time plants reduces the risk of a "death spiral" of rising tariffs and stagnating demand.

Every item on this shortened list would apply to small factory manufactured LFTRs. Thus such LFTR would seem to fit welll into a broad definition of distributive generation. Indeed a strong case can be made, that the small LFTR is an ideal candidate for distributive generator, and that candidates propsed by the RMI carry significant liabilities and limitations. This view directly contradicts the view of the RMI which holds. The RMI favors "Micropower", that is the use of very small decentralized units, but David Bradish has pointed out several problems with this construct in RMI literature. Bradish found that "the largest non-nuclear source of electricity . . . is decentralized generation . . ." Which RMI literature describes as “Non-Biomass Decentralized Co-Generation.” Here my focus diverges from Bradish, who argued that for diverging and conflicting RMI definitions of "Micropower".

My purpose is served by noting that the RMI institute appears by referring to Non-Biomass Co-Generation to be endorsing fossil fuel energy generation, how-be-it in more efficient, decentralized forms. Elsewhere the RMI refers to "Micropower" co-generation as including "turbines and generators in factories or buildings (usually cogenerating useful heat)". As the RMI admits, "Combined-cycle industrial cogeneration and building-scale cogeneration typically burn natural gas, which does emit carbon (though half as much as coal). so they displace somewhat less net carbon than nuclear power could: around 0.7 kilograms of CO2 per kilowatt-hour.(7)"

This is a truly astonishing claim and we ought to expect hard data to back it up. Instead we read in footnote 7 the following words: "7. Since its recovered heat displaces boiler fuel, cogeneration displaces more carbon emissions per kilowatt-hour than a large gas-ï¬ï¿½ red power plant does". That is it, no data at all for what must be seen as an astonishing and highly questionable assertion. But RMI does offer a further argument,

Even though cogeneration displaces less carbon than nuclear does per kilowatt-hour, it displaces more carbon than nuclear does per dollar spent on delivered electricity, because it costs far less. With a net delivered cost per kilowatthour approximately half of nuclear’s, cogeneration delivers twice as many kilowatt-hours per dollar, and therefore displaces around 1.4 kilograms of CO2 for the same cost as displacing 0.9 kilograms of CO2 with nuclear power.

This analysis would and should not go unchallenged, but I will leave the question for others to address. It is clear that the RMI analysis ignores the role that lower cost, factory built small nuclear generating plants can play in distributive generation.

The RMI wavers between viewing renewable micro-generators as supplements to fossil fuel powered central grid generating stations, or as replacements for them. Thus:

68 Distributed resources such as photovoltaics that are well matched to substation peak load can precool the transfomer—even if peak load lasts longer than peak PV output—thus boosting substation capacity, reducing losses, and extending equipment life.

69 In general, interruptions of renewable energy flows due to weather can be predicted earlier and with higher confidence than interruptions of fossil-fueled or nuclear energy flows due to malfunction or other mishap.

Would tend to suggest that some local electricity would be supplied from the grid. Given the RMI's often stated to nuclear power, that electricity could well come from fossil fuel powered generating facilities. The RMI leaves this ambiguous.

It is not without significance that on the "smallisprofitable.org" site we find these words, "Grants from the Shell Foundation, The Energy Foundation, and The Pew Charitable Trusts partially supported the research, editing, production, and marketing of this publication, and are gratefully acknowledged". Shell Oil which is the source of funding for for the Shell foundation, andShell is very much involved in the natural gas business. Shell, while decrying dirty coal is very much involved in coal gasification technology as an adjunct to power production.

If we accept the RMI's view we are forced to acknowledge that electrical generation will continue to produce CO2 for a long time to come, because the RMI does not have a practical plan to rid the Grid of CO2 emitters, and would only somewhat cut back CO2 emissions. Not only does the RMI fall short of demanding the total replacement of CO2 emitting generation facilities, they actually advocate the continued building of new micro-power, natural gas burning co-generation facilities. This would be a problem to those who think that to the extent possible electricity should be generated with no CO2 emissions.

I have a few other observations about the RMI concept of distributive generation. The RMI counts all renewables as distributive generators, but conditions are emerging in Texas and other states in which most of the features of distributive generation appear to be lacking in renewables projects. For example, a recent report from the Electrical Reliability Council of Texas, looked at new grid requirement imposed by the growing West Texas wind industry. The grid expansion turns out to be quite expensive. The report stated:

The estimated costs, excluding collection costs, of the transmission proposal that best meets the criteria for each are:
Scenario 1, Plan A, 12,053 MW, $2.95 billion
Scenario 1, Plan B, 12,053 MW, $3.78 billion
Scenario 2, 18,456 MW, $4.93 billion
Scenario 3, 24,859 MW, $6.38 billion
Scenario 4, 24,419 MW, $5.75 billion.

ERCOT adds:

The cost of transmission is “uplifted to load;” it is rolled into costs that all ratepayers pay (also known as a “postage-stamp” transmission rate because – like stamps – it’s the same access fee no matter where the location is).

The RMI states:

82 Distributed resources have an exceptionally high grid reliability value if they can be sited at or near the customer's premises, thus risking less "electron haul length" where supply could be interrupted.

83 Distributed resources tend to avoid the high voltages and currents and the complex delivery systems that are conducive to grid failures.

101 Distributed resources (always on the demand side and often on the supply side) can largely or wholly avoid every category of grid costs on the margin by being already at or near the customer and hence requiring no further delivery.

Perhaps you have noticed a contradiction between the attributes of distributive generation as suggested by the RMI and the RMI claim that all renewables belong in the category of distributive generation.  I would argue that large renewable projects, located for maximim access to renewable energy rather than proximity to customers, costing billions of dollars to construct, requiring large scale fossil fuel burning backup, and requiring billions of dollars in grid expansion are not distributive generating facilities.  

I will now turn to the question of how the LFTR can be the Ultimate distributive generator.  First, unlike gas co-generators, LFTRs do not burn fossil fuels.  They can be located close to customers.  LFTRs can perform as co-generators.  They can produce both electricity and heat.  There are distinct environmental advantages to nuclear co-generation.   Air pollution becomes a significant issue when fossil fuels or biomass are burned in co-generation facilities.. In addition to CO2. cogeneration produces NOx.    Diesel powered co-generators may also produce SO2.

In contrast, the LFTR produces no air pollutants and no CO2. Heat from the LFTR can be used both for topping and bottoming cycles. Given the use of exotic materials, LFTT could produce heats of 1000 C, and possibly higher. LFTR technology probably should never be pressed beyond 1200 C but PBR technology might provide higher heat, perhaps up to 1600 C. Waste heat from industrial processes, could be run through boilers, for steam generated electrical production.

Topping cycles could use "waste" heat for water or space heating, for lower temperature industrial processes, or for desalinization. The desalinization option would be especially attractive for aired
areas adjacent to sea coasts.

Canadian Reactor Scientist David LeBlanc has proposed a novel LFTR design using an elongated cylinder core. This design would allow a single reactor design to be built with various heat outputs. The only only change would be to the length of the reactor core. Thus factor assembled trasctors can be built to customer output requirements.

Because their higher operating temperature small LFTRs produce electricity with greater thermal efficiency than LWRs. Their high level of inherent safety, and smaller size open unusual siting options, and their high operating temperature will allow them to produce[ost carbon process heat for many heavy industrial processes. Thus small LFTRs posses considerable promise as co-generators. Single LFTR units can be used to produce power for isolated communities, or be placed in compact urban centers to provide space heat and/or hot water for commercial and residential customers. In addition, small LFTRs in the 100 MWe to 300 MWe range, can be clustered into larger power producing units that can generate the equivalent amount of electricity to a very large nuclear plant. Such a facility would have many of the advantages of distributive generation. Units can be built one at a time, lessening the financial risk imposed by the single huge investment approach imposed by the choice of a single huge reactor. The choice several small reactors decreases the effect of reactor down time on grid operations. The choice of LFTRs would of course eliminate down times for reactor refueling. LFTRs could be sited at the location of old coal and natural gas powered generating plants. The LFTR power output cab be matched to the old plant's, thus allowing for simple reuse of the old plants grid hookuo, without modification.

Thus the RMI should recognize that the LFTR fulfills all distributive generation criteria. They don't because it is a nuclear reactor. Not only does the LFTR fulfill the criteria, but it fulfills them better than any of the generating systems proposed by the RMI. It does not burn fossil fuels or require fossil fuel fired backup. It can produce electricity 24 hours a day, 7 days a week, without shutdown for refueling, the onset of night, or changes in the weather. it will be easy to site, will not require dozen of square miles of land to produce electricity, can be cooled with air rather than water. if sea water is chosen for cooling, it can in turn be desalinated. No convention or renewable electrical source can fulfill the distributive generation role better than the LFTR can. The LFTR is thus the ultimate distributive generator.