You might run across the acronym CHPB, which stands for cooling, heating, and power for buildings. Another group likes the letters reordered as BCHP to emphasize that it's about trigeneration for buildings. We'll use this convention, as it's the one the United States Department of Energy (DOE) has locked onto, and it, in a sense, is the parent of this new and critically important technology for the distributed-energy industry. By whatever name or initials you use, it is potentially revolutionary hardware, and in 2004, piece by piece, component by component, several versions of it are ripening and coming to market.

What all developers are striving for here is to evolve beyond the present state of one-off, custom-engineered combined cooling, heating, and power (CCHP) systems. The new generation will embrace packaging and all it entails: pre-engineering at the factory, industrywide compatibility between parts, and perhaps even pre-assembled modular systems and variations on these themes. Up to this point, building owners willing to take the plunge into CCHP have had to run a gauntlet of disjointed elements to piece together. First, engineers were hired to figure out what might work at a given site; then, each component - the genset, the heat-transfer and -distribution system, the chiller, etc. - was selected and purchased piecemeal. The chore was not efficient, easy, or confidence inspiring, and this hurdle has hindered distributed energy. In fact, one figure in the industry likens the situation to one in which a would-be car buyer might start by purchasing the engine block and then hiring mechanics to connect it to a separately sold drive-train and chassis. "That's sort of how this market works right now," says John Kelly of the Gas Technology Institute (GTI).

Ron Fiskum, technical manager for DOE's Office of Distributed Energy (ODE), uses a similar analogy from shopping: "In today's CHP system, you go down the block and buy a turbine, and then you go around the corner and buy a chiller or a hot-water system. Then you put them on-site, and now, to integrate them, you have to get pipefitters to put in all of that ducting."

Obviously one-stop shopping is easier. This is why, in recent years, a dozen makers of gensets, absorption chillers, and connective hardware have collaborated to make the experience of buying trigeneration relatively painless and even convenient. Their labors now are bearing fruit. The day rapidly approaches when all of the critical trigen components will be meshing neatly, rather like cars made at one plant and ready to drive away. Now, when your newly purchased BCHP rolls onto the site, "there'll be a minimum amount of work to be done in putting it together," says Fiskum, adding, "We hope to get all 'plug-and-play'-type systems" in the immediate future.

Standardization of parts and replicability of design will transform the distributed-energy industry and have a momentous impact on facility management worldwide. Prepackaging will mean that a building owner's cost of buying BCHP will be pared down to "something less than half" of the current outlay, predicts Kelly, director of GTI's distributed-energy group. Smoother integration of parts at the factory also will boost overall system energy efficiency to as high as 70% or better, Fiskum believes. That's more than double the current rate in most building systems.

Kelly reels off a long list of enticing advantages that owners of BCHP-equipped buildings will enjoy, beginning with "much higher quality and reliability," thanks to the more-focused and repeated testing of hardware and designs only made possible with multiple identical installations. Next is easier maintenance followed by cheaper servicing. And, as already noted, buyers will be able to shop for everything, including service and repair, from a single vendor, while still receiving the benefit of competitive bidding for subcomponents.

Tighter integration of parts will bring greater compaction to BCHP systems' overall size, allowing more powerful systems to be tucked into smaller spaces.

Modularization will yield a wider range of options for buyers to pick and choose from at the pre-assembly stage for their system (rather like selecting options when buying a car). Thus, most of the positive aspects of the current state of individualized customization won't be lost after all.

BCHP components will be tailored for buildings and won't have to serve multiple markets, as many components now must do. This means packaged systems will offer genset power perfectly optimized in size so waste heat can be used for recycling as hot water and space heating and cooling. Occupant comfort will be the prime mover. Systems will purr quietly at low decibel levels and with only faint NOx emissions. They'll be capable of running 24/7 with good reliability. BCHP controls, adds Kelly, " will integrate with building system automation. Our systems will talk to each other instantaneously." He refers to the controls (eventually) for HVAC, lighting, air-flow coordination, and so on. Whenever the building environment needs to change, "everything will work together."

Best of all, the huge total efficiency gains being envisioned will make facility operating costs tumble. Hence, regardless of past barriers to investment in cogen, such as natural-gas prices or connection tariffs, building owners will be far more ready to jump in when they see the actual performance gains of this new generation of trigeneration.

All of this should translate into a big shot in the arm of distributed energy. Currently sales of gensets tend to falter wherever natural-gas prices offset the potential electric savings. What will really tip the balance for distributed energy will be the prospect of getting some wintertime comfort heating and hot water and some significant savings on summer cooling and dehumidification - with all of it squeezed from the same recycled genset heat. This trifecta of sorts "gives you roughly another 40% of value," observes Don Erickson, president of Energy Concepts Inc. in Annapolis, MD. "When you have a scenario like we are shooting for - when you can use all of the hot water and get the chilling - then you're up to an 80% enhancement over the electric value alone. A lot of opportunities become economically viable."

Now comes the critical question: Who will be the first to sign up?

Prime candidates will include owners of buildings needing both chilling and heating and/or hot water from a fuel-fired boiler. Facilities coming to mind include hospitals, laundries, food-processing plants, hotels, and educational facilities. Fiskum and others in this market see a big potential for BCHP in office buildings, data centers, nursing homes, supermarkets, refrigerated warehouses, retail stores, and restaurants. As Erickson puts it, "We really see it applying across the board."

Who will supply the product? Well-positioned to lead the way are seven firms whose research and development have been subsidized by special DOE grants. Major recipients include Ingersoll-Rand (IR), Honeywell, GTI, Burns & McDonnell, NiSource, Capstone, and Solar Turbines. In addition, chiller manufacturers who already have fielded demonstration projects in these consortiums include United Technologies' Carrier division, along with Trane and Broad USA. Assorted smaller technology firms and engineering designers are contributing too, and more will undoubtedly jump in, adopting the standardization protocols as the BCHP momentum grows.

Shepherding these firms through the standardization and development phase has been the task of DOE's BCHP program, led by Fiskum who, with help, created it, oversees it, and runs a useful Web site (www.BCHP.org) about it. Lab testing of prototypes was and is being done at Oak Ridge National Laboratory (ORNL). Field trials have been ongoing for several years at DOE's Integration Test Center for small-scale BCHP, on the campus of the University of Maryland. All told, five pilot projects are beginning to emerge in 2004 from their developmental hothouses nationwide. (Two more will launch in 2005, Fiskum notes.) The current batch will be yielding critical performance data throughout the summer of 2004.

DISTRIBUTED ENERGY magazine also is pleased to announce that several packages are ready now for delivery and installation. As explained in the following brief survey, some packagers are gearing up for end-of-the-year sales through distribution channels. Some are easing into the marketplace more gradually, seeking partners and sites where lots of operational hours can be logged and monitored before beginning a sales push.

In any event, some exciting products are on the immediate horizon; here's a rundown on those that DOE is sponsoring. Already they're showing impressive results.

East Hartford, CT:
Four Microturbines Neatly Packaged To Dual-Effect Chiller

UTC Power, a unit of United Technologies Corporation (UTC), in partnership with Capstone Microturbines, has been demonstrating a packaged BCHP product called PureComfort 240 for a full year at UTC's Connecticut research center. In it, four 60-kW Capstone microturbines are yielding power ranging up to 240 kW, but what's most innovative here is the compact, dual-effect, exhaust-heat-fired LiBr absorption chiller. On a 95°F day, heat from the turbines will be piped into the chiller to produce 110 tons of air-conditioned cooling, or on a 32°F winter day, the same unit will crank out 900 MBh for hot water. "It'll run continuously year-round," notes Fiskum. "And we're looking at efficiencies in the neighborhood of 75 to 80%," depending on the season. Carl Nett, UTC Power's vice president of products and applications, refines the figures: "When we're in cooling mode, we achieve a total system efficiency between the electricity and chilled water of 73% - which we're very, very pleased with."

UTC Power's new PureComfort line is the first packaged BCHP system to hit the market.

Critical to achieving such high efficiency is its dual-effect absorption chiller. Typical CCHP systems sometimes produce both heat and cooling, but to do it, they must string together a single-effect chiller and separate heating components. The genius of the PureComfort system is that heating and cooling are combined into a single unit. Besides achieving greater efficiency this way, the system can be operated with well-integrated controls and monitoring. (The latter can even be done remotely, 24/7, as part of a service agreement.) The turbine's few moving parts also will ensure higher reliability. Capstone microturbines also emit low noise and low NOx; in the PureComfort 240 configuration, it's only 9 ppm. "The nice thing about this system," adds Fiskum, "is that you generate NOx from only one source and not from the chiller." In some states, lowering NOx emissions will mean a building might qualify for financial subsidies.

In December 2003, UTC rolled out this Capstone-powered version to introduce the PureComfort dual-effect line - making this system the first fully integrated turnkey BCHP trigen system out of the blocks, anywhere. Certainly it's the first with microturbines and dual-effect absorption chillers, Nett points out. The 240-kW configuration model is one of several scalable versions, with others expected to be rolling out in the near future.

Chicago, IL:
Reciporating Engine Heat for an Absorption Chiller
And a Dehumidifier

Powering DOE demo number two is a 600-kW Waukesha reciprocating engine-the only internal-combustion engine in this array of turbine-dominated gensets. Waste heat from the Waukesha will drive a desiccant dehumidifier and a small Trane chiller. Coordinating this consortium are GTI and the University of Illinois at Chicago.

One reason DOE and Fiskum like this design is that it represents a midrange system, which recycles heat from an engine type other than a turbine. The Waukesha line includes reciprocating-engine gensets ranging from 290 to 770 kW; currently all are being predesigned to mate with appropriately scaled heat-activated absorption chillers. Adds GTI's Kelly, however, "We're not locked in," meaning that Waukesha plans for its gensets to be easily connectable to any heat-fired chiller so the firm can shop for low bids from other chiller makers.

A dual-action absorption chiller

Besides Waukesha, Cummins Power Systems and Caterpillar "are all following a similar approach," Kelly says. Cummins is reportedly ready to launch a 330-kW packaged CHP this summer; Caterpillar has a CCHP packaging division too.

The likely niche for BCHP in this power range includes large department stores, warehouse clubs, superstores of 65,000-plus ft.²; large hotels and facilities with more than 150 rooms; health care facilities (e.g. nursing homes) of 50,000-150,000 ft.²; and some K-12 educational buildings needing more than 400 kW, according to in-depth research in which Kelly's group did an extensive software analysis of loads in 45 typical facilities to demonstrate potentially rapid payback.

As of early 2004, the trigen setup still was being assembled. "We hope to get all three put together," says Fiskum. "We've already done it in laboratory, and we now need to do it in the field." If this summer's demo succeeds, says Kelly, performance numbers will be assessed, and packaged products should be ready to ship soon thereafter, perhaps as early as the fall of 2004.

Sales will be handled by each manufacturer's regular distribution chain and also by energy-performance engineering firms. Waukesha distributors include Charles Equipment Company and Stewart & Stevenson Services Inc. Tech support nationally will be provided by Ballard Engineering Inc. For many sales reps, offering newly packaged hardware will be something of a novelty, as their past expertise typically has involved either power or boilers or air conditioners - but not all three in one. At this stage, Kelly observes, what's probably most appealing to all parties is the prospect of rapidly achieving "a high degree of quality control throughout the system," at levels that weren't possible with one-off designs.

Annapolis, MD:
70-kW Microturbine Drives Ammonia-Based Subfreezing Chiller

Another interesting variation of the BCHP model is occurring in the DOE-sponsored project for a supermarket in Annapolis, MD. Here, three firms - genset maker IR, Advanced Mechanical Technologies Inc., and Energy Concepts - have partnered to install an IR PowerWorks model 70-kW microturbine-based package; its exhaust will drive a grocery's refrigeration plant. Not a mere air conditioner, this system can chill the frozen-food storage cases down to -26°F, and, says Fiskum, "We can also refrigerate and heat at the same time and make hot water. This is a very good program." He adds that, technologically speaking, it is perhaps the most advanced.

What makes subfreezing temps possible is the ammonia-water (NH₃) absorption chiller, which isn't limited to the 44°F cooling floor of LiBr technologies. As Energy Concept's Erickson explains, this innovative design can be direct-fired with the heat exhaust; it is air-cooled; "and it doesn't require a bypass damper or chimney when not in use." All of this boosts the system efficiency. As for the source of input heat, this can be supplied by a turbine, a microturbine, a reciprocating engine, "or whatever, across the board," he says.

Heat from this particular IR turbine is adapted for simultaneous chilling and heating duties by means of a relatively new product called a ThermoSorber; a similar device, the ThermoCharger, performs the same tasks and also recycles some of the chilling back into the turbine's inlet air for increased efficiency.

Simultaneous chilling and air or hot-water heating are possible because the chiller is rejecting heat at an unusually high temperature of "up to 140°," he explains, due to the ThermoSorber design. "So you get twice as much benefit from the exhaust heat as with the other thermally activated technologies out there," such as a LiBr absorption chiller, which requires cooling water and yields rejection heat of 100°F.

ThermoSorber and ThermoCharger NH₃ chillers have been tested extensively with IR's PowerWorks model, but the technology isn't wedded to that line and is adaptable to virtually any generator. One project under consideration in early 2004 would draw heat from five Capstone 60 microturbines to activate a 90-ton ThermoCharger chiller.

If the Thermo-series products are so adaptable, how well-integrated can they really be? Erickson elaborates that, "if a new [ThermoCharger-equipped] BCHP system is ordered from us up-front," as opposed to a retrofit, the turbine and chiller can be supplied as an integrated package, with the ducting and mounting, etc., all preconfigured. Available chiller models are sized at 30, 60, 100, and 150 tons, with some degree of flexibility to meet more-precise chilling temperatures. Prices are slightly higher for this proprietary technology than for comparable LiBr plants, but Erickson believes that the difference will be offset by lower operating costs.

Besides the Annapolis site, a second demo has been running at a factory in Modesto, CA, since mid-2003. Erickson and his consortium would like to run more and are seeking sites actively. But aggressive marketing of the package will wait until more field hours have been racked up. "We'll certainly take an order," he says, noting that the high-efficiency system "provides attractive paybacks even at the demonstration stage."

Austin, TX:
A 4.5-MW Turbine Runs a MiniGrid and a Big, Direct-Fired Chiller

BCHP systems are for buildings, but that shouldn't be construed to imply a niche of single structures only. One large system - purchased and operated by a publicly owned utility, Austin Energy - is aimed at demonstrating how integration and packaging can work with larger components suitable for handling the cogen needs of, say, an entire industrial park.

Powering this DOE demo is a 4.5-MW Solar Turbines Centaur 50, exhaust heat from which is shunted to an advanced 2,500-ton direct-fired Broad absorption chiller. As of early 2004, it is shop-tested and in shipping for its demonstration. If all goes well, it will output an unprecedented volume of chilled water sufficient for cooling a nearby high-tech complex without the need for additional fuel. Anticipated basic cogen efficiency will range from 65 to 75%, and in the summertime trigen mode (i.e., when exhaust is being utilized for both the chiller and the hot-water output), this will soar, says Solar Turbines' Product Manager Chris Lyons, "in excess of 80% fuel utilization."

The Broad exhaust-heat-driven absorption chiller is something of a story in itself. Similar chiller technology first was established by Hitachi some 20 years ago but didn't catch on in the US due to low electric rates. Since then, China-based Broad (reportedly the world's largest manufacturer of absorption chillers) steadily has been improving the design efficiency and increasing its capacity. The Austin chiller output will be unprecedented, Lyons notes. Broad is currently the only maker of big-turbine exhaust-fired chillers (the more-popular alternative being steam- or hot-water-driven chillers), but if this model succeeds, major US firms probably will jump in too.

Besides keeping score on the big chiller's performance, DOE is also interested in the project's microgrid dynamics: The novelty of this particular grid connectivity is in its operation as a subsystem to serve a particular area. Typically, notes Lyons, all of the 4.5 MW of power will remain entirely within the neighborhood where it's much needed. The whole array is automated with advanced controls.

Commissioning is set for May 2004. After metering its performance during the summer, the package should be ready for the utility and distributed-energy markets. Meanwhile, the various components are being meshed into "a fully standardized design that can be replicated," says Lyons. "You'll have a turbine and an absorption chiller with all of the integrating ductwork packaged together," and even piping for the chilled-water system is modularized. Parts will fit each other yet retain adaptability to meet varied requirements for capacity, space, and grid connection. Due to their size and complexity, components will be shipped separately for assembly on-site.

Fort Bragg, NC:
A 5.5-MW Turbine Plus Chiller With Software Windfall

At a fourth DOE-funded project - also very large - a 5.5-MW Solar Turbine trigen system serving an Army base was scheduled for commissioning in April 2004. The military's objective here, says Fiskum, is to "provide power, heat, cooling, and hot water to the barracks and many of the offices." About 40% of the waste heat will run a 1,000-ton Broad USA LiBr water chiller, the output of which "will pretty much take care of the barracks." A heat-energy recovery steam generator will consume the remaining heat to replace some poorly performing steam boilers.

Project design, execution, and operation are occurring under an Energy Services Performance Contract. Honeywell Energy Service is the prime contractor, and DOE is an investment partner on the research portion. Subcontractors include Broad USA, Chelsea Group, and engineering firm I.C. Thomasson. Their mandate is "to develop reference designs to improve economics and simplify installation" of larger-scale, potentially packagable systems, says Fiskum.

A key goal here had been for the successful demonstration of trigen in the 2- to 5-MW range, combining natural-gas turbines with heat-recovery steam generators and LiBr chillers. Such projects would be potentially replicable, particularly at other US defense sites needing onsite generation, reliability, and security. The Fort Bragg demo accomplished several goals during testing; however, as Honeywell's Jim Peedin reports, it "ran into a lot of technical issues" in the attempt to combine both an indirect-fired absorption chiller and a heat-recovery steam generator. Thus, the original vision of integrated hardware and replicability, with this configuration, is moot.

But a highly positive result is proving to be the success of the system's automated BCHP software. Honeywell originally developed it optimizing energy-resource utilization. With it, system operators can make hour-by-hour forecasts regarding the impact of various energy options and decisions. They can tap into current utility rates, fuel commodity prices, and contract data in real time. Having this data, operators can decide how best to run the central plants, "when to do peak shaving, and when to switch fuels," Peedin explains. "We now make several decisions daily on how to dispatch the equipment or the asset. We can answer questions like 'How do you dispatch a chiller? Do you use a centrifugal chiller or an absorption chiller, and at what load do you dispatch the turbine? Do you use a boiler or a combined cycle to generate steam?' That sort of thing." The software can log fuel-consumption levels so, if the system is reaching contractual limits on natural-gas usage, "it sends out alarms to tell us when we have to do fuel switching," says Peedin, the energy asset/central plant leader for the Americas at Honeywell Automation Controls Solutions.

Other variables, such as spot market pricing and even weather patterns, can be factored in to help the operator make the smartest use of resources.

Peedin thinks that the Optimizer improves the operator's ability to boost efficiency perhaps 10 to 15% better than a seat-of-the-pants judgment. Alan Houghton, a Center of Excellence leader at Honeywell Integrated Energy Services, concludes that "in final analysis, we're producing something just under a $10 million annual savings" for the Army base, "not only by creating efficiencies in the operations but also by optimizing the physical plant, based on essentially real-time energy pricing." More precise figures will be analyzed after the 2004 peak-cooling season.

Because the Optimizer software can be used for any BCHP or CHP application, Honeywell probably will make it commercially beginning later in 2004. Says Peedin, "I think it is going to have a pretty significant impact" on the cogen industry. "I'm as excited about this part of the project as I am about the hardware."

College Park, MD:
Two Small BCHP Systems Run Head-to-Head

A final DOE project can be seen at the agency's Integration Test Center for small-scale BCHP. It's also the longest-running experiment of this sort, and in fact, says Fiskum, "it's the first true BCHP project in the world."

The compact design applies BCHP "on a kilowatt scale instead of a megawatt scale," explains Professor Reinhard Radermacher, director of the college's Center for Environmental Energy Engineering. This scale will yield a practical package for affordable, single-building retrofits. In this demonstration, two alternative systems are running in the same building side by side for comparison. In zone one, a pair of Goettl engine-driven air-conditioning units are running; their waste heat is being used for dehumidification in a Kathabar liquid desiccant system, also supplying 3,000 cfm of dry air to a rooftop unit. Unfortunately this configuration "didn't run that well" during its first summer and is being upgraded to a single 75-kW DTE engine generator for new trials in 2004.

In zone two, exhaust heat from a 60-kW Capstone microturbine is utilized in a Broad absorption chiller. This generates 20 tons of chilling. Waste heat from that goes, in turn, into an ATS solid desiccant system, which provides 3,000 cfm of dry air to the building to assist the rooftop unit.

Radermacher describes the center's goal with a statement that also sums up the worthy aim of this entire new generation of BCHP: "The future of these systems is that they're going to be dropped into place and hooked up, and they will run well - and you can forget about them."

DOE's vision is likewise for a robust BCHP industry delivering a full spectrum of turnkey solutions for facilities of all sizes and kinds. Perhaps by 2020, trigeneration sets "will be the preferred method of energy utilization in commercial and institutional buildings," the ODE Web site states.

"Its going to take a little time for this to evolve," GTI's Kelly remarks, "but I think we're really starting to move."

La Mesa, CA—based writer DAVID ENGLE specializes in construction-related topics.

DE - May/June 2004