This article was originally published in the July/August 1994 issue of Home Energy Magazine. Some formatting inconsistencies may be evident in older archive content.



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Home Energy Magazine Online July/August 1994



A Journey through the Gray Literature


by Alan Meier and Steve Greenberg

Alan Meier is executive editor and Steve Greenberg is technical editor of Home Energy.


If you're looking for measurements of energy savings available from the latest efficiency gadget, chances are that some utility company has them. But can you see the data? As a study conducted at Lawrence Berkeley Laboratory showed, you can't count on it.

The energy efficiency business suffers from a critical shortage of reliable, unbiased technical data on new products and techniques. To be sure, many manufacturers claim to have documentation proving that their products vastly cut energy use, but closer inspection often reveals that most of the proof is suspect. Yet, independent tests have often been done--sometimes by your own utility. Utilities carry out a tremendous amount of informal investigation, measurement, and testing, but it never reaches the public, or even the appropriate professionals as a formal report for conference publication. Why does this happen? Welcome to the mysterious world of gray literature.

The Netherworld of Gray Literature

Black literature is the stuff that gets into the journals and magazines like ASHRAE Journal, Science, or Home Energy. There are indexes and databases which help one identify articles on a specific topic, and libraries where one can actually get access to the journal (even if it was published years ago). White literature is the stuff that never even gets written. Somewhere in the middle of the spectrum is gray literature. It consists of memos, reports, or even just a few measurements written on a piece of paper. There's no index or database of these documents. The gray literature resides in the filing cabinets and dusty closets of the utilities. There are rarely more than a few copies. For perfectly good reasons, only a few people really know what's there or who has it.

The California Institute for Energy Efficiency (CIEE) sponsored an investigation into the state of gray literature in California utilities pertaining to energy conservation, which was conducted by Lawrence Berkeley Laboratory researchers. CIEE wanted to know if the gray literature was as valuable as some people claimed, and if it would be worthwhile to organize the gray literature to make it more accessible. The utilities gave us carte blanche to paw through their files, stumble around their dusty closets, and talk to the staff who make and use gray literature.

There's Gold in Those Files!

We found lots of useful information as a result of the study. Utilities are naturally most concerned about energy use, so it was not surprising that a lot of the gray literature we found involved measurements of energy use. Some of our favorite measurements were of energy use for: fish aquariums, gas lamps, spas, compact fluorescent lights, a photovoltaic-powered home, and horizontal-axis washing machines. There were studies measuring the energy use of vending machines, thermal storage systems, lighting, restaurant equipment, and chillers. But the investigations often went much further, measuring energy savings to be gained from various retrofits or improvements. For example, one utility measured the savings for a variety of insulated covers for spas.

We quickly learned that gray literature mostly tries to answer small questions. You won't find an evaluation of energy savings in 10,000 homes that accrue from a utility insulation program. These matters are too important and probably have an impact on rate cases. More than likely, there's a copy of that type of study (or at least its title) filed with a public utilities commission.

Laboratory studies of compact fluorescent lamps (CFLs), however, do fit the small question requirement. For example, at one utility engineers estimated CFL lifetime by operating the lights in an oven to accelerate deterioration. There were also numerous studies of CFL light output and quality. Only a few models would be tested in any study, so the results could not be considered representative. The utilities were also reluctant to release the results because a manufacturer might capitalize on them, or worse, might sue the utility because its product was not tested (this has happened). Utility engineers often served as guinea pigs for the tests, by taking the new gadgets home and testing them on their own refrigerators, washing machines, or light sockets.

But small answers can still be important answers. And there were many small, important answers that could save consumers a lot of money.

Sometimes we found formal reports, especially if the work was performed for the utility by an outside consultant or university. But more often, the gray literature consisted of a few pages of summary calculations or measurements. These documents rarely found their way into any central library or database. The only way to find the gray literature was to ask the staff. If their minds were elsewhere (such as the next rate case), we were out of luck. It also helped when we had information to swap--that is, when they learned something from us.

Often, when we described some work done by another utility, staff members would reply, That reminds me of a study we did. Now where did I put it? And they would go searching through a drawer that they initially said contained nothing useful. It also helped when there were two or three people from the group present, because they would remind each other of projects they had managed. We also found many valuable gray literature leads outside the office, in cafes, and at conferences. Often we learned not only about a study, but about why it had taken place or why it had been halted.

The CIEE study uncovered dozens of little stories that the utilities would have been happier to keep from becoming public. For example, the report on spa covers got one utility into hot water. The manufacturer of the spa cover somehow obtained a copy and used it to promote its product. For years, the utility had to badger the unscrupulous firm to stop using its name in advertisements.

We also learned that there was no predicting where the useful gray literature would be found. Every utility department had reasons for doing its own studies, from research and development, to customer services, to planning and marketing. In at least one case, it appeared that different departments of a utility were investigating the Green Plug (a plug-in device that can lower a refrigerator or other appliance's energy use) without the other department knowing. One report was prompted by a high bill complaint. A senior citizens community was equipped with a district cooling system which worked poorly (leading to the complaint) so the utility hired a consultant to make an in--depth study of the system. In the course of a conversation with one utility staffer, we realized that she would benefit from this earlier report. Ironically, we had to draw a map so that she could find the right closet where the last copy of the report appeared to reside.

Even Spies Should Be Curious

Utility gray literature sounds dull, but it can be surprisingly useful for a variety of purposes. One California utility asked a consulting firm to find out if the energy use of the missile industry would grow over the next decade. The consultants diligently listed every firm in that utility's service area which made missiles or missile parts, and the energy use of each facility (there were many). A clever spy could potentially infer many technical specifics about the activities at each facility from this information. Fortunately only a few copies of this report were prepared and the utility tightly controlled access.

A similar report was written about the cement industry. Most cement companies jealously protect energy consumption data because it is a key indicator of their costs. Again, the consultant drew upon the utility files and compiled a list of energy use and output for each site. Here, too, the utility staff zealously guarded the report; we were not even allowed to photocopy the executive summary. We were constantly impressed with all of the utilities' desire to protect customer confidentiality. Utilities take their relationship with their customers extremely seriously, and will go to great lengths to avoid undermining it. Wider dissemination of some gray literature could threaten this relationship.

So Much Information, So Few People Know

The gray literature stuffed into utility files contains useful information for utilities, consumers, and energy professionals and maybe even spies. Some of the new electronic energy-saving devices would probably never have reached the Home Depots and Wal-Marts if the results from all the utility studies had been publicized. Could this information be shared so that more people benefit? Probably not. Too many companies would object or, worse, litigate. The utilities get sued all the time because they have deep pockets. As one utility employee said, We breathed a sigh of relief when Consumer Reports published its article on the Green Plug, because then we could refer consumers to that article rather than trying to stay neutral.

But even if the utilities were protected, could the gray literature be identified, collected, and disseminated? Again, probably not. Many of the authors of gray literature don't expect their memos, reports, or investigations to be widely distributed. They are typically writing for a very narrow audience (themselves, the person who commissioned the project, and perhaps a few others). So, the gray literature often skips the familiar trappings of a report, such as an introduction, discussion of results, conclusions, references, and so on. It is surprising how many documents lack even a date and author! Gray literature is very short and to the point, but without this context and the reader's knowledge, it is easy to misinterpret a comment. If the authors expected their documents to be widely disseminated, they would probably revert to a duller, more verbose style. Or worse, they would avoid writing anything down or would throw away all gray literature at the end of a project. Either way, formal dissemination would probably be the death of gray literature.

Gray Literature Into Black

Gray literature doesn't always stay gray. Maybe 5% is eventually converted into black literature as official reports, papers in conference proceedings, or journal articles. The utility staff responsible for gray literature are often among the utility's brightest, most self-motivated, and most active. They are also in constant demand, so they don't have time to write journal articles and formal reports.

Home Energy is a major converter of gray literature. Our staff hear of an interesting report through the grapevine and obtain an unreleased copy. That report might get translated into an article, or serve as background that permits the staff to write more confidently about a technical matter than would be possible using only publicly available literature.

Gray literature also goes white, that is, disappears without a trace. Gray literature is nearly always linked to people, rather than to an office. If a person is transferred or fired, her gray literature goes to the dump.

Gray literature contains valuable information for those involved in energy efficiency, but for a variety of legal and practical reasons, it is unlikely that much of it will surface. Most utility authors know that their gray literature is incomplete research that does not fully consider all aspects of a product or range of products. They realize that the results could be misleading and abused. To satisfy their professional integrity, they prefer not to circulate the documents. At the same time, the threat of lawsuits by companies that feel their products' capabilities have been falsely degraded, neglected, or incompletely considered in the informal documents is a real possibility. This is a battle the utility staff do not want to fight because, even if the utility is right, the costs are too high.

However, that does not mean that a specific report or investigation is unobtainable. We found most utility staff were eager to share the results with anybody demonstrating a sincere interest in a topic and a willingness to respect the utility's need for confidentiality. This was especially true when the utility learned something in return. n


Portrait of a Gray-Literature Source

Gray literature is not only generated in California. Large and small utilities across the country produce these documents. Northeast Utilities, Consumers Power (of Michigan), and Bonneville Power Administration for example, all create useful gray literature. Smaller utilities, such as the Sacramento Municipal District, and many little ones in the Midwest, have generated some of the most valuable gray information.

Our experience in California suggests that gray literature is linked to the person and personality. The kind of people closely associated with the gray literature have technical training, but are not limited to a narrow engineering slot, and have been with the utility for at least a decade. These people--still mostly guys, but that's changing fast--are bright and easily spotted by their initiative and willingness to try things. They are a key part of an effective utility, by providing customer service, technical information, and institutional memory.

Mark Martinez of Southern California Edison Company (SCE) is a perfect example of a gray literature source and repository. Indeed, he is one of the most prodigious generators of the stuff. Mark has worked at various positions inside SCE, but he is now a supervisor of field measurement for the demand-side management measurement and evaluation groups. Scattered around his office are samples of the latest energy-saving gadgets and meters. Mark enjoys measuring things, and he has the resources to do it himself or assign it to somebody else (as part of Edison's DSM load-research activities). At any given time, he is involved in several different monitoring projects, from an elevator in a department store (to check if variable speed motors save energy) to a microwave clothes dryer. Even his house is the guinea pig for some devices (see The Refrigerator Widow, HE Mar/Apr '93 p.46 for a fond, if exasperated, description by Mark's wife of his domestic investigations).

Mark plays two other key roles as a repository and clearinghouse. He somehow keeps reports (and remembers that he has them) that everybody else has lost or discarded. Just as importantly, however, he distributes the information by advising other departments of monitoring and research projects. He also prepares reports for many of the formal measurement activities that are filed with the California Public Utilities Commission and he enjoys talking to his counterparts in other utilities--it's a small community--so that he knows what projects other utilities have done.


Energy Consumption of Aquariums


Is it possible that a tankful of tiny goldfish could be responsible for a customer's high bill complaints? This may be the reason--the gray literature document doesn't explain--why Pacific Gas and Electric Company researchers investigated the energy use of aquariums. They tested two tank sizes: 20 gallons and 55 gallons. Most aquariums have three energy-using components: a pump, a lamp, and a heater (although coolers are available).

The most important factor affecting an aquarium's energy use is the ambient temperature of the air around the tank. Results of the study are shown in Figure 1. For the 55-gallon tank, energy use climbed from about 475 kWh per year at 80deg.F air to 2,600 kWh per year at 65deg.F air. The electricity costs for a medium-sized aquarium are probably equal to the cost of fish food, and sometimes even the fish themselves.

The report did not include any conclusions, but it doesn't take too much intelligence to deduce that a large aquarium can easily consume as much electricity as two refrigerators. Also, electricity consumption in an aquarium will climb when people leave the house and lower the home's thermostat. These conclusions are not earthshaking, but they are certainly useful for the customer services department trying to explain high electric bills to irate customers.


Figure 1. As the room temperature rises, energy use for heating water decreases. However, even when the room is 80deg.F, some electricity is needed to run the light and pumps.


Spa Covers


Most of the heat lost from a spa is in the upwards direction, so it is important that the spa be covered when not in use. Better yet, that cover should be well-insulated. In a gray literature study, Pacific Gas and Electric Company researchers compared the energy use of a spa fitted with a new cover made of ABS Rovel to one fitted with a soft cover made of insulation covered with Naugahyde. The project was reported in a three-page document. The simulated weather conditions were that of a coastal California climate, that is, 60deg.F for 16 hours and 70deg.F for eight hours. This corresponds to a 0.7 kWh per day savings. The researchers found that the Rovel cover cut energy use 32% compared to the conventional cover.

Surprisingly, the savings were greater than those claimed by Rovel's manufacturer. The Rovel cover costs twice as much as a standard cover, but the Rovel has additional features that make it easier to use. The researchers did not calculate cost-effectiveness, however, and the tests are hardly representative of all the conditions in which a spa is used. There are also many other brands and types of spa covers available. PG&E selected those products because they were typical of what was available, and the conditions because they were convenient to establish. That is why the utility was annoyed when the manufacturer of the more efficient unit claimed that PG&E had endorsed its product.


Figure 1. Pacific Gas and Electric performed three twenty-four hour tests on each spa cover. Under these operating conditions, the Rovel cover used less energy than a standard soft cover.


Gray Payback


The gray literature survey conducted by Lawrence Berkeley Laboratory for the California Institute for Energy Efficiency cost about $50,000. In the end, we concluded that it would be very difficult, if not impossible, to compile and disseminate all of the information we found. But clearly, the literature that lurks in the file cabinets of utilities can benefit consumers.

One of the gray documents discovered early in this project demonstrates the roundabout way in which benefits may reach consumers. Pacific Gas and Electric Company sponsored a detailed study of the energy balance in a photovoltaic home. The informal report was produced for the the company's Research and Development Division, but it later became black literature through Home Energy (see Home Alone--Living Off the Grid, HE May/June '93, p.13). Surprisingly, the study found that the gas oven was a significant consumer of electricity. It turned out that the 300 W electric igniter stayed on while the oven burner was on, a design used in almost all new gas ovens. This results in the amazing situation of a gas oven using more electricity to cook a potato than a microwave oven! (See Hot Potato, HE Nov/Dec '93, p.14.)

We alerted the folks responsible for researching the federal government's energy-efficiency standards for appliances. To our surprise, they had not considered the igniters' electricity use in their analyses. They have included it now, however, and future standards will also include the igniters' electricity use. Only a modest additional cost is needed to replace the present igniter with an intermittent ignition device, so we are confident that future standards will require it. Consumers across the country will save far more than $50,000 per year total when the new igniters appear.

Other results from gray literature research could save consumers a lot of money, both in energy bills and from misdirected investments. Two examples are spa covers and electronic energy-saving devices that plug into appliances. One report identified a spa-cover technology that could cut heat losses to a significantly greater degree than others. If the utility had communicated this information to consumers, a $50,000 reduction in spa-heating bills would be entirely possible. The power-saving devices are a different case: here consumers are buying devices that may not save much electricity. This money could be more profitably invested elsewhere. Unfortunately, it would be very difficult for utilities to avoid lawsuits while making these simple kinds of recommendations and we don't know how to solve this dilemma.

There is some duplication in the gray literature; several utilities will undertake a similar investigation. In the course of this project, we alerted utility staff to studies already undertaken at other utilities, thus helping to reduce some duplication. This study also alerted utilities to the value of the gray literature; perhaps they will make more use of it.



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