<>31 Jan 2005  UFTO Note - Waste Heat to Power
<>12 Jan 2005   UFTO Note - Modeling the Grid -- Breakthrough



Subject: UFTO Note - Waste Heat to Power
Date: Mon, 31 Jan 2005

There is a lot of interest in recovering waste heat.  Combined Heat and Power (CHP) is at the heart of a large part of the distributed generation business.  The heat can be used to heat water, provide process heat, and even cooling.  Converting waste heat to electric power is getting attention as well.

On the bleeding edge, there are a number of efforts underway to do it without moving parts--solid state conversion (of course not limited to waste heat).  There are programs, for example to put thermoelectric converters on the exhaust manifold of diesel trucks, with the goal of replacing the alternator.  Thermoelectrics, thermionics, thermophotovoltaics -- all are being pursued with renewed vigor, in the hope that new physics can overcome the longstanding problem of high cost and very low efficiency…a subject for another day.

Waste heat gets wasted only because it tends to be hard to use.  A diesel engine converts about 1/3 of the fuel energy to useful work (electric power, in the case of a genset) -- the rest goes off as waste heat in cooling water and exhaust -- unless a cost-effective means can be found to use it, as in CHP.

Making more electric power with the waste heat is another matter. The age-old Rankine cycle, the basis of all steam power plants, can be made to work at lower temperatures by using something other than water as the working fluid ("refrigerant"), typically an organic compound, thus the term "organic rankine cycle" (ORC).  In effect, this is a heat pump or refrigerator running backwards.  Instead of using mechanical energy to create a temperature difference, mechanical energy is produced by a temperature difference.

The main challenge isn't the theory, it's the practical difficulty of doing it.  Factors such as temperatures (inlet and outlet), flow rates, size and type of heat exchangers, type of expander, materials, controls, etc. must be considered in the trade-offs of cost, performance, reliability and longevity.

It's a lot harder than it looks.  Despite many attempts, and the obviousness of the basic idea, there are actually not very many commercial providers of such systems, particularly in smaller sizes which can operate effectively at lower waste heat temperatures.

UTC, for example, announced it's new "PureCycle" 200 kW unit only last Fall.  It requires inlet temperatures above 500 deg F.

Ormat, (ORA-NYSE) long established ORC maker for geothermal plants, is moving into the industrial waste heat market.  They too need relatively high temperature, for units in the 250kw - MW range.  They also sell small standalone ORC-based generators which burn a fuel as the external heat source.

In Europe, one can find Turboden (Italy), Triogen (Netherlands) and FreePower (UK).  All require high temperature, with the possible exception of FreePower, who say they can operate as low as 230  deg F.

High temperature means industrial processes that put out high temperature waste heat.  Ormat, for example, has a 1.5 MW showcase unit that takes air at 520 deg F from a cement plant in Germany. 

The water jacket of the lowly diesel engine, however, can only be allowed to go to around 230 deg F (and the water must be returned no cooler than around 215 deg F).  While such temperatures can be readily adapted to CHP uses, power conversion is more difficult.

Cooler Power, Inc, a startup in California, has successfully built units that work in this range.  The engine's cooling water is taken (before it goes to the engine's own radiator), and is fed to a heat exchanger where it is heated further by the engine exhaust.  In another heat exchanger, the hot water heats and vaporizes the organic working fluid, which then drives the expander which turns the generator. The expander is key. In principle, any compressor technology can work backwards to act as an expander: scroll, screw, turbine, or piston. All have been used at one time or another.  Cooler Power initially used a scroll, but then developed its own proprietary modification to a commercially available screw compressor, as the heart of the system. They have a patent in final review stages covering the modification and use of the screw expander, as well as the control system and choice of working fluid.

Cooler Power has proprietary software to develop process flow diagrams to size and specify components  or installations.  The proprietary Program Logic Control (PLC) circuits are designed for optimal failsafe performance and contain algorithms that are protected from reverse engineering.  Each of the key components (heat exchangers, expanders, condensers,  generators) are designed to last 20+ years and come from one or more sub-sectors of  the existing industrial equipment industry.

The system can be scaled to fit applications ranging from 50 kW - 1 MW.  Installed costs are in the range of $1500-1800/kW.  Depending on the sales price for power, payback can happen in 2 years or less.  It's important to emphasize that this is green power, which usually enjoys premium pricing.  There is no fuel cost; operating costs are very low; and there are also (monetizable) environmental benefits.

A showcase  50 KW beta unit was installed in 1992 at the Newby Island landfill site in Milpitas, CA, on a 1 MW engine.  A new 150 kW system will come on line in March. The company anticipates installing 10 units in 2005, with rapid growth thereafter based on already-established customer and marketing relationships, selling both systems and power.  They raising an equity investment round currently, and welcome both investor and customer interest.

Ray Smith, COO
Cooler Power Inc,
Redwood City, CA
650-482-4905,  rsmith@coolerpower.com



Subject:  UFTO Note - Modeling the Grid -- Breakthrough
Date: 12 Jan 2005

To start the new year off with a bang, I may be going out on a limb here, but I don't think so.  I hope you'll take a close look at this….

DOE, EPRI and the entire power industry is abuzz with talk about how the grid can be operated better. The grand vision comes up hard against the incredibly difficult problem of modeling.  For many decades, the best mathematicians, operations researchers, utility engineers and others have struggled to come up with (computerized) representations of the grid that can guide planners and operators.

Since the beginning, despite ever faster-cheaper computers, and tremendous innovations in algorithms and computational methods, the state of the art has been forced to make many bad compromises among such factors as speed, accuracy, detail, breadth, time domain, treatment of boundary effects, and applications.  Unless corners are cut, a solution might not be found at all (i.e. converge).  Areas of study and tools are stove-piped into many separate categories of time-scale and function:

- Real time (sec. to minutes)
  optimal power flow, voltage and frequency control, contingency analysis

- Short term  (hours to a week)
  unit commitment,  thermal-hydro coordination

- Annual  ( 1-3 years)
  maintenance scheduling, rate-design, production costing, hydro scheduling…

- Long term (3-40 years)
  generations expansion, transmission planning, etc.

  (see "A Primer on Electric Power Flow for Economists and Utility Planners"  EPRI TR-104604, Feb 1995.)

To make things worse, the industry is highly fragmented and way behind the curve.  Utilities don't have the same cadre of experts in-house that they used to.  Vendors sell "black-box" solutions that don't live up to promises.  Obsolete tools continue to be used because "everybody else uses them" and "regulators accept them". (Never mind the results may be worthless.) A guru of power flow analysis, now retired, told me that much of the industry isn't even using more powerful real time analysis tools that are over 25 years old.

So there are major institutional problems and technical ones, and the two are intertwined.  Not only is the problem fiendishly hard, but lot of people also have vested interests in the status quo (e.g., experts have devoted entire careers, and don't look kindly at upstart claims of a breakthrough--just as in every field of human endeavor).


This is a long prologue to a story of just such a claimed breakthrough.  Optimal Technologies appeared on the scene late in 2001, announcing they had analyzed the June 14, 2000 California blackout, and stating they could have prevented it by fine-tuning the grid according to results from their analysis tool, AEMPFAST.

 Needless to say, the world was not especially open to the idea that a newcomer had succeeded in coming up with a methodology that did what so many had sought for so long:

"AEMPFAST is based on a new near-real-time (solves a several thousand bus system in milliseconds) mathematical approach to network analysis, optimization, ranking, and prediction called QuixFlow … a proprietary N-Dimensional (non-linear) analysis, optimization, and ranking engine that also has defendable predictive capabilities and is applicable to any problem that can be modeled as a network. … QuixFlow uses no approximations; it handles multiple objectives; and is able to enforce multi-objective inequality constraints."  [from factsheet - see link below]

I have been closely following the company's progress since then.  Their revolutionary claims are finally beginning to overcome the natural skepticism and resistance.  At least one major ISO/RTO is signing up, and DOE and a number of large utilities are taking it very seriously. The implications are, as Donald Trump would say, "huge".

Here is an introduction in the company's own words:

Optimal Technologies is a private company focused on making power-grid systems more efficient, more reliable, and more cost effective to plan and operate. In other words, "smarter". Think of Optimal as the Internet for power grids [or Sonet for telecommunications] self-healing, self-enabling, lowest cost operation with highest reliability.

Problem: Power system infrastructures and the grid networks that support them are breaking down faster than solutions can be developed to address the underlying problems.

Because of inadequate core technologies and especially slow and limited mathematical tools, the utility industry is plagued with many tools based on algorithms that no longer work well for their intended tasks and that do not work well together. Last year's blackout that effected more than 50 million people should help provide some context. Despite new advances in materials and hardware, blackouts and brownouts are becoming larger and more common because utility system planning and control methods are still in the horse and buggy era -- done much as they were 50 years ago -- fragmented and piecemealed. In other words, even though system peripherals (such as wind energy, distributed gas generation, fuel cell generators, meters, and demand-side management) are improving, the core grid Operating System that makes them all work well together doesn't exist.

New Technology: Our software and hardware solutions are based on a revolutionary new mathematical approach to network analysis, optimization, and management. Our technology is far better than current approaches to understanding and managing networks, and allows for both local and integrated, end-to-end views of Generation, Transmission, Distribution and Load. Unlike competing products, our technology can view the complete energy delivery supply chain as an integrated asset, which allows for entirely new levels of risk review and risk management -- previously not possible. Optimal's new technology should be viewed as "Foundational" in that it has pervasive application within the power industry and provides a common framework for many new tools.

Optimal's Solution: Think of us as the much needed underlying "operating system engine" that integrates, defragments, and prioritizes utility planning, operations, and business processes in the best controllable and defendable way. Our technologies have the ability to simultaneously analyze, optimize, and manage generation, transmission, distribution and customer load Ð down to the individual power line and building. Instead of viewing customer load as a problem, our technology has the ability to make all aspects of the system, including customer load, potential risk-reducing resources [i.e. reliability enhancers] not otherwise possible.

Products: Applications include: Congestion Management, Locational Marginal Pricing, Simultaneous Transfer Limits, Multi-Dimensional Reliability, Automated Network Planning, Emergency Control, System Restoration, and Smart Asset Management.

Beyond the scope of this note, Optimal also has a suite of software and hardware for the demand side, which enables measurement and control -- and optimization -- down to individual loads. 

There is a great deal of information on the company's website:

Roland Schoettle, CEO
Optimal Technologies International Inc.
rolands@otii.com       707 557-1788

AEMPFAST FACTSHEET (good starting point)