It’s bigger than a breadbox, but, standing at only 5 feet tall, it’s probably smaller than your home entertainment center, and its footprint—at 2 by 31⁄2 feet—is about as small you can get. At 56 dBA, it’s also the quiet type: while this self-contained packaged system busily delivers 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. 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—which are often daunting for onsite power jobs of all kinds—should also be minimized with this little rectangular appliance, because the power output comes to a minuscule 5.4 kilowatts, net. At that low level of productivity, standby charges probably won’t apply either.
In fact, while it churns out gurgling hot water of 140°–150°F at 10 gallons per minute, kicking in its modest kilowattage with its quiet little two-stroke engine, it could almost be described as little more than a glorified water heater.
The “Model T” of Onsite Power?
Meet a new and rather unusual cogen device called the Aisin G60; the numbers signify its rating of just 6.0 kilowatts of electric output. Subtract from this about 0.6 kilowatts to run its pump and controls, and you net 5.4. First developed a couple of years ago in Japan, the G60 is the brainchild of Aisin Seiki Co. Ltd., a cutting-edge subsidiary of Toyota Motor 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, chief executive officer of the Leesburg, VA-based Eco Technology Solutions LLC (or ECOTS; www.Ecotsusa.com). Aisin also delves into technologically innovative energy systems like the G60, which was originally developed for Daihatsu. Power generation is especially prominent at Aisin Seiki, he adds, “with almost every type of DG product you can think of under development there right now.”
This shouldn’t be surprising for an engine manufacturer based in Japan, where electricity costs the equivalent of 30 to 40 cents a kilowatt. Buying an Aisin G60 there costs the equivalent of a few thousand dollars; hence, simple payback comes in just a couple of years. With such appealing economics, a vast potential for very-small-scale CHP exists in Japan (at least for peak times), estimated at perhaps 80% of Japanese homes and businesses, according to Aisin’s published expectations. Thus Aisin began offering the little heat-and-power cabinet, fuelable by natural gas or propane, and prepackaged with heat exchangers, tanks, pumps and piping. As of early 2005, reports Cetti, about 200 of the G60 systems have been online “and operating successfully for over two years.”
It’s a nifty little package indeed. But would it sell like that in the US? Energy costs less here, and barriers differ greatly. Cetti thought it might. As a former utility executive himself, he saw an intriguing potential, especially for the nation’s 900-plus electrical co-ops. And ECOTS seemed uniquely well positioned to explore market prospects, having actually been founded by those co-ops, for purpose such as this.
Cetti took a tour of Japanese G60 projects, accompanied by Kamyar Zadeh, ECOTS’ technology vice president. The two met “very happy, very satisfied” G60 customers, Zadeh recalls, at a hospital, restaurant, and industrial sites. Their rapturous endorsements were amazing to him, not so much for the reported economics, but because the engines ran continuously, month after month, “with no maintenance calls.” Owners also raved about the low noise output, this being a make-or-break aspect in many projects. 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 Zadeh offered to assist Aisin with the development of a US market. To date, four have been put in at three sites; other orders are pending. Here’s how some of the installed ones are doing.
Hooligan’s Sports Bar and Grill
Summertime loads at this 498-seat restaurant in Liverpool, NY, peak at about 110 kW, dropping by half in the spring, fall, and much of the winter. Against these loads, a contribution of 5.4 kW from this “little shaver,” the G60, doesn’t amount to much. But a restaurant does use hot water for dishwashing, albeit not nearly as many gallons as the G60 yields.
Bottom line: Hooligans was not a particularly ripe cogen candidate, at least not at first glance. Neither the electrical load nor the hot water utilization made it what you would call an ideal application for a first outing. But what did make the G60 appealing was the owner’s avid interest in power technology itself: Before opening his restaurant, owner Yatish Goyal had worked at the local utility, Niagara-Mohawk (N-H). This had also given him acquaintance with Cetti, Zadeh, and ECOT. At the time of preparation of this report, Goyal was traveling abroad and could not be interviewed; however, details on his CHP project were provided by Zadeh, who oversaw the Hooligan’s project at every stage, and who helpfully outlines some key elements.
Utility Permitting
Although the eatery wasn’t ideal for heat utilization purpose, it probably was in the sense that N-M presented some challenging barriers. Zadeh observes: “We took on probably the worst interconnect possible in US.” If micro-mini CHP could survive this gauntlet, it could probably win permitting approval and utility acceptance anywhere.
The good news was that standby charges were waived because the G60’s 5.4 kilowatts didn’t meet the threshold of 15% of Hooligan’s base load.
However, an engineering impact study was required; external relays were demanded; and N-M even went on to require extensive testing by an independent lab to affirm that the G60’s waveforms under various conditions would meet the utility’s standards. Ultimately, the testing lab did certify the performance, and N-M gave permission to run the G60 in grid parallel.
By contrast with this experience, Zadeh points out, a more recent interconnection application in Oklahoma 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, he says. “From what they’re now telling us, it really doesn’t require an engineering process to implement this,” he says. “And we agree: There’s nothing to it.”
Similarly, the Hooligan’s project encountered a wary reception from code-enforcing and permitting organizations. The G60 was new, unusual, and unlisted hardware; naturally, it had to be vetted for safety and fire hazards. And in order to obtain an electrical permit, Zadeh had to do some considerable explaining of heat-and-power cogeneration.
On this point, he comments that installation number two, done at a dairy farm in Hudson, MI, took much less effort that the first; in fact, the approval took less than a day. (Installation number four, described below, also encountered almost painless permitting.)
Code enforcers vary, obviously. Some may require the installation be done by an electrician and plumbing contractor, Zadeh suggests, particularly at commercial sites. A residential application, he speculates, might be doable by merely one or the other.
Installation
Once the powers-that-be gave their blessings in every case, the rest was easy. At Hooligan’s the 5.4-kW output was 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 contract can install this” using the instruction manual. “It’s very simple.”
Commissioning
Zadeh flipped the switch on the Hooligan’s G60 on Jan. 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 quit. This triggered an external relay to disconnect. Upon resetting, the Aisin went back to work instantly. N-M eventually gained enough confidence in the G60 that the utility granted Zadeh’s request that the Aisin be allowed to operate in grid parallel mode without an external relay. 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 the concerns of other co-ops and utilities in future apps.
Monitoring and Controls
One temporary but regrettable quirk in the current G60 model—which is scheduled to be remedied next year—is the fact that it displays instrumentation characters in Japanese; Western letters are expected to become available in the future models.
As for the controls themselves and how to run them, everything for doing this is in the owner’s manual, Zadeh says, although there’s still some dicey translation in the first edition to be deciphered. “A little bit of hand-holding” will be needed, he says, “to make sure the remote controller gets programmed correctly, and displays are read correctly,” along with training in setting dip switches and control parameters correctly. “That’s about it,” he concludes. “The unit is easy to start up. You can learn operation in quick order.”
Lastly, to augment the unit’s built-in metrics, Zadeh added gauges on the electrical and gas inputs, as well as the energy and heat outputs, to measure the overall impact.
Maintenance
No scheduled intervention is needed on a G60 until the 6,000-hour point (projected to arrive in year three or four). At that time there’ll simply be an oil change. In Japan, Aisin Seiki claims that G60s are racking up as many as 10,000 hours before the oil change or other servicing would be needed. At 40,000 hours the engine gets 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 12 hours daily, from 10 a.m. to 10 p.m. This represents a doubling of what had been happening at first—which is a good development, 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, says Zadeh, the storage tank was sized at 50 gallons. Unfortunately, this proved too small, as the water was sometimes being depleted too quickly, and at other times was filling up the tank, triggering a shutdown, and thwarting any further exhaust heat utilization. When the optimum storage tank temperature is attained, a temperature-sensitive controller shuts the G60 down, thereby saving fuel and giving the owner the best bang for his buck. “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. So, Zadeh replaced the smaller tank with a 100-gallon version, allowing 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 great, he notes, but it could be better: When fully optimized, an Aisin G60 should really achieve about 86% efficiency (i.e., 29% electric efficiency and 57% waste heat recovery). There’s still a ways to go.
Cost and Payback
As noted above, the actual value of 5.4 kilowatts of peaking power in most US markets comes to only a few dollars a day. In Japan, a micro-mini cogen investment might pay back in two years, but it will take many times that here. Moreover, during this trial-balloon period for the G60, a purchaser will pay a much higher “early adopter” price of about $15,000. Aisin reportedly plans to drop this to just $6,000 or $7,000 if it sees indications that reasonable sales volumes will result. Making that assumption, then, a well-optimized G60 in the US might indeed be paid off within a reasonable three- or four-year period.
More to Follow?
With such a heat-optimization priority in mind, then—and a bit paradoxically—Zadeh says that Hooligan’s is now considering buying a second G60, even though the heat output from the first is not really maximized with continuous operation. The reason this does make 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, including even year-round refrigeration. One G60 alone couldn’t support all this, but two might, 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.”
Test site number two was a dairy farm in Hudson, MI, where two G60 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 of electricity and all the hot water” efficiently, he adds, and is projecting annual savings on fuel and electricity of $7,000.
Consumers Energy
Consumers Energy, G60 test site number three, is a small rural electrical co-op in Marshalltown, IA. Its single unit was commissioned on Nov. 8, 2004.
Everyone knows that an electric co-op obviously doesn’t need micro-mini onsite power for itself. However, as CE account executive Paul Sams explained, the G60 looked very interesting to the co-op as a potential product to be sold to CE’s rural customers, especially to those who happen to need both power “and lots and lots of hot water,” he says. “We believe that there will be a market for them” in the Iowan outback, if and when G60s becomes widely available domestically, he adds.
In the meantime, the co-op finds it appealing to be able to experiment with and demonstrate new technology, he says, this also being “an opportunity to do something that no one else close to us is doing.” CE is also testing a 10-KW solar array and some wind turbines, and likes to find appropriate new products, he adds.
Besides this, the specific G60 application at CE has tangible value: Its hot water output now yields continuous space-heating in a radiant floor inside a company garage, as well as uninterrupted hot water service. This is 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 G60 to shut down, as it’s supposed to. When normal power resumed, the unit didn’t automatically restart, though, as it should have. Sams was told by Zadeh that the glitch wasn’t mechanical and is easily correctable with a software reconfiguration.
CE’s Jacob Kvinlaug is keeping tabs on the G60’s propane consumption and economic performance, for future reference. He estimates the per-kilowatt cost of the electricity at 15 to 18 cents—“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.
Cetti sums up ECOTS role in facilitating this unusual potential 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 Ainsin’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 - September/October 2006
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