At 5 feet tall it stands shorter than your home entertainment center, and it’s footprint—2 feet by 3.5 feet—is about as tiny as you can get. At 56 dBA, it’s also the quiet type. While this self-contained packaged system is busily delivering combined heating and power (CHP), it’s doing so unobtrusively—humming with less sound than an outdoor air conditioner at a distance of 100 feet. It’s so well integrated, says one admirer, that installation is almost plug-and-play. “Any ordinary electrical or plumbing contractor” can do the job in a few hours, reports Kamyar Zadeh, an engineer who has been involved in several installs. No pricey engineering study is needed; it comes with a fixed cost, making its payback easy to calculate. And because its low NOx and CO2 emissions measure less than the thresholds that most air regulators will invoke, permitting—on this score at least—will be a breeze.

Interconnection hassles with the utility grid should also be minimized with this little rectangular appliance. The power output comes to a minuscule 5.4 kW net—such a low level that standby charges probably won’t apply.

In fact, while it churns out gurgling hot water of 140†F to 150†F at 10 GPM, and kicks in its modest kilowattage with its quiet little two-stroke engine, it could almost be described as a glorified water heater.

PHOTO: ECO TECHNOLOGY SOLUTIONS LLC.

2005 Model G-60 Micro-CHP System.

The “Model T” of Home or Business Onsite Power?
Meet a new and rather unusual cogen device called the Aisin G-60. The model number signifies its rated kilowatt output of just 6.0. Subtract from this about 0.6 kW to run its pump and controls, and you net 5.4 kW. First developed a couple of years ago in Japan, the G-60 is the brainchild of Aisin Seiki Co. Ltd., a cutting-edge unit of Toyota Group Corp. and maker of about 85% of the auto parts for the parent company, “as well as parts for virtually every major automaker in the world,” notes Aisin admirer Bill Cetti, CEO of ECO Technology Solutions LLC (ECOTS, www.ecotsusa.com). Aisin also delves into technologically innovative energy systems like the G-60, the compact, clean-burning little engine that was originally developed to power some Daihatsus. Electric power generation equipment is especially prominent in the assembly lines at Aisin Seiki, Cetti adds, where “almost every type of DG [distributed generation] product you can think of is under development right now.”

This shouldn’t be surprising. Utility-generated electricity in Japan costs the equivalent of $0.30 to $0.40 per kilowatt, making the economics of onsite power extremely attractive. Buying this little heat-and-power cabinet system—fuelable by natural gas or propane, and pre-packaged with heat exchangers, tanks, pumps, and piping—costs the equivalent of just a few thousand dollars, making for a simple payback in just a couple of years. With such returns, a vast market potential for very small-scale CHP power exists—estimated 80% of the homes and businesses in Japan. Thus, Aisin began offering the G-60 about two years ago; as of early 2005 about 400 G-60 systems have been installed, “and many have been operating successfully for over two years,” reports Cetti.

It’s a nifty money-saver, but what kind of reception would it get in the US? Energy costs much less, and assorted market and regulatory barriers differ greatly. Cetti, formerly a small-utility executive for many years, saw an intriguing potential here, especially among the nation’s 900-plus electrical co-ops he knew well; and his company, ECOTS—which had actually been founded by those co-ops to explore this kind of DE technology—was uniquely well-positioned to explore market prospects (see sidebar).

Cetti next took a tour of Japanese G-60 projects, accompanied by ECOTS’ technology transfer and development vice president, Kamyar Zadeh. Visiting a hospital, restaurant, and assorted industrial and manufacturing sites, they talked with “very happy, very satisfied” G-60 customers, as Zadeh recalls. Several rapturous endorsements were particularly impressive, he adds, not for the Aisin’s economics, but because the engines reportedly ran continuously, month after month, “with no maintenance calls.” Adopters also loved the G-60’s quiet running. Zadeh himself marveled, “You can stand next to it and conduct a normal conversation. It’s like standing near a Lexus idling… It’s purring.”

Cetti and ECOTS offered to help Aisin Seiki get the G-60 ready for export to the US. To date, four installations have occurred at three sites, with the longest-running having been online for well over a year. A few other orders are pending. Here’s how some of the first few installations are doing.

Hooligan’s Sports Bar and Grill, Liverpool, NY
Summertime loads at this 498-seat restaurant peak at about 110 kW, then drop to half that, 50 to 60 kW, in the spring, fall, and much of the winter. Against these loads, a contribution of 5.4 kW from this “little shaver” doesn’t amount to much. But a restaurant does use hot water for dishwashing, albeit not nearly as many gallons as the G-60 yields.

Bottom line. Hooligan’s was probably not a particularly ripe cogen candidate for this particular product—at least not at first glance. Neither the electrical load nor the hot water utilization made it obviously viable, but, as Zadeh recounts, what did make the site appealing was the owner’s avid interest in power technology per se. Before opening his restaurant, owner Yatish Goyal had worked at the local utility, Niagara-Mohawk (N-M). This had also given him a close acquaintance with Cetti, Zadeh, and ECOTS. At the time of preparation of this article, Goyal was traveling abroad and could not be interviewed; however, details on his CHP experience were provided by Zadeh, who oversaw the Hooligan’s project at every stage, and who helpfully outlines some of the key elements.

PHOTO: ECO TECHNOLOGY SOLUTIONS LLC.

Hooligan's Restaurant, Aisin System installation.

Utility interconnection and permitting. Although the eatery wasn’t ideal for heat utilization purpose, it probably was in the sense that N-M presented some challenging regulatory and arguably obstructionist barriers. As Zadeh puts it, “We took on probably the worst interconnect possible in the US.” If a proposed new micro-mini CHP package could survive this gauntlet of connection requirements, it could probably win permitting approval and utility acceptance anywhere.

The immediate good news was that standby charges were waived because the G-60’s 5.4 kW didn’t meet the threshold of 15% of Hooligan’s base load.

However, an engineering impact study was required, and these are typically costly. Moreover, external relays were demanded; and N-M even went on to require extensive testing by an independent lab in order to affirm that the G-60’s waveforms under various conditions would meet the utility’s standards. Ultimately, the testing lab did certify the performance, Zadeh notes, and N-M gave permission to run the G-60 in grid parallel.

By contrast with this experience, though, Zadeh adds, a more recent interconnection application in Iowa required no engineering impact study; the local utility company there simply accepted Zadeh’s model recommendation “on what a utility should do to accommodate” such a small-scale onsite power source. “From what they’re now telling us,” he says, “it really doesn’t require an engineering process to implement this. And we agree. There’s nothing to it.”

Similarly, the Hooligan’s project encountered a wary reception from code-enforcing and permitting organizations. To their eyes the G-60 was new, unusual, and unlisted hardware. Naturally, they had to “kick the tires,” i.e., it had to be vetted for safety and fire hazards. In order for Zadeh to obtain an electrical permit, he had to do some considerable explaining of heat-and-power cogeneration.

On this point he notes that installation number two, done at a dairy farm in Hudson, MI, took much less effort than the first; in fact, the approval “took less than a day.” Installation site three, in Marshalltown, IA (detailed later in this article) in late 2004, also encountered almost painless permitting.

PHOTO: ECO TECHNOLOGY SOLUTIONS LLC.

System is unloaded at dairy farm in Hudson, MI.

PHOTO: ECO TECHNOLOGY SOLUTIONS LLC

Electrical work installation.

PHOTO: ECO TECHNOLOGY SOLUTIONS LLC

Open house.

Summing up this part of the experience, then: Code-enforcers obviously vary, with some requiring that the installation be done by an electrician and plumbing contractor, particularly at commercial sites, Zadeh suggests; by contrast, a residential application, he thinks, might be doable by one or the other.

Installation. Once the powers-that-be give their go-ahead, the actually delivery, positioning, connection, and commissioning tend to be easy. At Hooligan’s, the 5.4-kW output is connected to the most heavily loaded phase of a three-phase circuit, and this electricity runs as a base load. Zadeh notes, “Any qualified HVAC, electrical, or plumbing contractor can install this” using the instruction manual. “It’s very simple.”

Commissioning. Zadeh flipped the switch on the Hooligan’s G-60 on January 9, 2004, and immediately let it run flat-out for six months of endurance testing. During that time, only once did the unit stop—when N-M’s grid power ceased. This triggered an external relay to disconnect. Upon resetting, the Aisin went back to work instantly. N-M eventually gained enough confidence in the G-60 that the utility granted Zadeh’s request that the Aisin be allowed to operate in grid parallel mode without an external relay anymore. This permission was something of a coup, he says, because it demonstrated at least one utility’s increasing comfort-level with cogen—an experience which should in turn perhaps mollify other co-ops and utilities’ connection concerns in future applications.

Monitoring and controls. One temporary but regrettable quirk in the G-60, which is scheduled to be remedied, is the fact that its instrumentation displays characters in Japanese; Western letters are expected to become available in next year’s models.

As for the controls themselves, and how to run them: Everything for doing this, Zadeh says, is in the owner’s manual, but there’s still some dicey translation in the first edition. “A little bit of hand-holding” will be needed “to make sure the remote controller gets programmed correctly, and displays are read correctly,” and training in setting dip switches and control parameters is done correctly. “That’s about it,” he says. “The unit is easy to start up. You can learn operation in quick order.”

To supplement the built-in metrics, Zadeh added gauges on the electrical and gas inputs, and energy and heat outputs, to measure the overall impact.

Maintenance. No scheduled intervention is reportedly needed on the original G-60 until the 6,000-hour point, or 10,000 hours on the newest 2005 models. This equates to about four years, at which time there will be an oil change. In Japan, Aisin Seiki claims that even the original G-60s are racking up as many as 10,000 hours before the oil change or other servicing is needed. At 40,000 hours the engine needs an overhaul, but none of the units anywhere have reached this stage yet.

Operational efficiency. As of year two, the Hooligan’s unit typically runs twelve hours daily, from 10:00 a.m. to 10:00 p.m. This represents a doubling of what had been happening at first—which is a good development, Zadeh notes, because longer hours help to maximize the all-important hot water utilization. Exhaust heat (46,000 Btu per hour) from the generator is transferred to cold inflow water, this being heated in a storage tank before piping into the hot water service boiler. Initially, the storage tank was sized at 50 gallons, but this proved too small, as the water was sometimes being depleted too quickly, or at other times was filling up the tank, triggering a shutdown and thwarting further exhaust utilization. When the optimum storage-tank temperature is attained, a temperature-sensitive controller shuts the G-60 down to save fuel and give the owner the best bang for his buck. This way, “the engine never burns fuel unprofitably,” Zadeh points out. However, a really viable CHP application needs to use all the exhaust heat it possibly can, and a shutdown is in this sense undesirable. So, Zadeh replaced the smaller tank with a 100-gallon version to enable longer storage and better utilization. Now, he says, “We’re actually using almost all of the exhaust heat,” and overall fuel energy efficiency is 75%. That’s pretty impressive, he notes, but it could be even better. When an Aisin is fully optimized, it should achieve about 86% efficiency (i.e., 29% electric efficiency and 57% waste heat recovery). There’s still a way to go.

Cost and payback. As suggested earlier, the actual value of 5.4 kW of peaking power in the US comes to only a few dollars a day. In Japan, a micro-mini cogen investment might pay back in two years, but domestically will take many times that. Moreover, during this tryout period for the G-60, a purchaser will pay a much higher “early adopter” price, so to speak, of about $15,000. Aisin reportedly plans to drop this to just $6,000 or $7,000 if indications show that reasonable sales volumes will result. Making that assumption, then, a well-optimized G-60 in the US might indeed be paid off within a reasonable three- or four-year period.

A second coming? With such a heat-optimization priority in mind, then—and a bit paradoxically—Zadeh notes that Hooligan’s is now considering buying a second G-60, even though the heat output from the first is not really maximized with continuous operation. The reason why this might make good sense, though, is that by doubling the cogenerated hot water, the combined outflow can be circulated and applied at Hooligan’s not only for dishwashing, but for space heating and, in the summer, for firing chillers, even including year-round refrigeration. That’s a lot of heat load. One G-60 alone couldn’t support it all, but two might do so, very cost-effectively. Zadeh is now exploring the possibility.

He sums up, “Our first application was the most difficult. On our second, third, and fourth, the barriers have gone down, and projects are becoming easier.”

The second test site was a dairy farm in Hudson, MI, where two G-60 units are now running in tandem. Each is well-optimized and producing 5.4 net kW of electricity and about 13.5 kW of heat energy, says Zadeh. The farmer who owns them “is using all the electricity and all the hot water” efficiently, he adds, and is projecting annual savings on fuel and electricity of “a little more than $7,000,” notes Cetti.

Consumers Energy, Marshalltown, IA
The third test site is a small rural electric co-op running a single unit, commissioned on November 8, 2004.

PHOTO: ECO TECHNOLOGY SOLUTIONS LLC.

Up and running at Consumers Energy, Marshaltown, IA.

Everyone should know that an electric co-op doesn’t ordinarily need micro-mini onsite power for itself. However, as Consumers Energy (CE) account executive Paul Sams explains, the G-60 looked very interesting to the co-op management as a potential product to be sold to CE’s rural customers, especially to those, he says, who happen to need both power “and lots and lots of hot water. We believe,” he adds, “that there will be a market for them” in the Iowa outback, if and when G-60s become widely available.

In the meantime, he says, it’s appealing to be able to experiment with and demonstrate such interesting new technology, this being an opportunity for the co-op “to do something that no one else close to us is doing.” Concurrently the co-op is also testing a 10-kW solar array and some wind turbines, and likes to explore appropriate new products, he adds.

Besides this aspect the G-60 in Marshalltown has a very tangible value. Its hot water output now yields continuous space-heating within a radiant floor under an important company garage, as well as providing 24/7 hot water service supplemented, as needed, by a boiler. The 5.4-kW electrical output gets exported directly to the co-op grid.

How’s it Working?
After several months of running non-stop, Sams reports that “nothing major” has gone wrong. Once, a standby generator kicked on and this triggered the G-60 to shut down, as it’s supposed to; when normal power resumed, the unit didn’t automatically restart, though, as it should have. The glitch wasn’t mechanical and is easily correctable with a software reconfiguration.

CE’s Jacob Kvinlaug is keeping tabs on the G-60’s propane consumption and economic performance, and estimates the per-kilowatt cost of the electricity at $0.15 to $0.18— “considerably higher than we charge here,” he concedes, but a rate that would not be at all unreasonable, say, at a remote site where extending the power line is always expensive. The economics would then look very reasonable if a site could use hot water 24/7—“then,” he says, “with combined efficiency at around 80%, it makes a lot of sense.”

Cetti sums up ECOTS’ role in facilitating this unusual niche for miniaturized cogen. “We believe,” he says, “that somebody needs to be successful with DG, and somebody needs to capture the utilities’ interest so that they don’t continue to be obstacles to implementation. We think Aisin’s got a good chance of doing that. They’ve got a piece of equipment that really works—which is kind of nice.”

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

DE - May/June 2005