Letters: March/April 2013
Do Demand-Controlled Pumps Save Energy Too?
As I read the article about demand-controlled recirculating pumps (“Demand- Controlled Pumps: Sticker Shock Versus Value,” HE Sept/Oct ’12, p. 12), I was curious about where the energy savings come from. It seems, though water is clearly saved, that the saved water wasn’t necessarily hot. Can you explain?
Author Dave Grieshop replies:
The model savings depend on water that is warmer than the ground source being returned to the water heater with each cycle, which occurs with a dedicated, insulated return. In reviewing the retrofit model in my article, I now appreciate that without a dedicated return, heating energy is lost if any cold water gets used between pump cycles. How many such cycles occur depends on occupant behavior. For retrofit, using the cold line for return water, I have therefore revised my annual energy savings down from $105 to $53 for electric, and from $92 to $44 for gas; and I’ve changed my model accordingly. Continuous improvement is a good thing!
Yet when all is said and done, we should not forget that what consumers want is hot water now, and a continuous flow of hot water at that. The demand-controlled pump can provide the “hot water now,” and the water heater has to take care of the rest.
Lighting Your Workshop with LEDs
Can someone indulge me and provide a suggestion for T-8 LED tubes to use in a workshop? Or can someone provide me with a reliable source of info regarding LED tubes? I live in Alaska and am having trouble finding an outlet store where I can see the bulbs to find out how much light is produced, so I can determine what wattage to get.
Thank you for your time.
Author, energy efficiency specialist, and fellow Alaskan Todd Hoener replies:
I work for Golden Valley Electric Association, up here in Fairbanks, as the utility’s end-use and renewable-energy specialist. I have often encountered your problem myself, and with many customers, both residential and commercial.
There are good LED T-8 lamps on the market. There are also some fly-by-night products. Several years ago I was shown some 4-foot LED T-8 lamps that I thought were great. They were manufactured by Light Squared Labs out of Vancouver, Washington; cost around $50 each; and were being retrofitted in one of the University of Alaska Fairbanks buildings up here. They performed great. I obtained two pairs, with two different color temperatures, and put them in our utility lobby so consumers could see them and compare them to the fluorescent lamps in similar ceiling-mounted fixtures. They are still there, and I think they still are great. Trouble is, the company no longer exists, and who knows who will honor that five-year warranty should anything go wrong with this expensive investment?
Part of the problem these days is that energy efficiency is in on a global scale, and LEDs in particular are really in vogue. That’s good and bad. There is a market demand for LEDs, so—according to the economic theory—there are suppliers accommodating the growing demand. Many producer/suppliers are from countries outside the Unites States that are not accountable for any claims they may make regarding reliability or warranty. A lot of those LED lamps are obviously available on the web. LEDs are an emerging technology and a competing technology.
Purchasing LEDs from brand-name manufacturers (such as GE, Philips, and Panasonic) buys a little accountability. At least you have a name you can tie a warranty to, if the quality fails. Such accountability should also hold true if you purchase from brand big-box stores (Lowe’s, Home Depot, and others). But brand-name lamps often cost more, and LEDs are expensive. I find that the house brands of the big-box stores have accountability (tied to the box store), are less expensive, and are pretty reliable. CREE is getting a good name, but its LEDs can be pricey, even though CREE has received many federal research grants. The research grants have honed the company’s products.
It sounds from your query as if you understand efficacy, but I will touch on it just in case. The efficacy of a lamp is determined by its lumens per watt (Lm/W). Efficacy tells you how much energy it takes to produce the light from its origin or source; the higher the Lm/W the better. You need to know the Lm/W to decide if the lamp you are buying is going to give you the light you desire. Just because you are replacing a fluorescent tube lamp with an LED does not guarantee that you’ll get an equal amount of light. My research has shown that some CFLs, for example, have a better efficacy than LEDs, but LEDs are gaining in this important area.
But let’s get back to your question. There is no single LED or single outlet I can recommend. I read a lot about products, but I’m more influenced by what suppliers show me in application. I’m lucky that many vendors often want to show me their products. Those vendors and I, however, have no idea if the products they are pitching will be around in the near future.
Here are some resources you can try that are trusted sources of good information—and these folks communicate daily with the lighting world:
- Lighting Design Lab in Seattle.
A nonprofit with no conflict of interest.
- Lighting Research Center out of Troy,
New York, affiliated with Rensselaer Polytechnic Institute.
- DOE's EERE CALiPER program.
- LED Light Review.
Hopefully this will get you started and result in a satisfactory solution. I know it’s work and it’s a lot of runaround. Bear with me; we’re all learning how to cope with LED evaluations. Please let me know if this helps and what your results are; I’m interested in what everyone finds out.
More On Energy Upgrade California
I would like to take a few minutes to respond to the Energy Upgrade California article written by Steve Mann (Sept/Oct ’12, p. 6) and the related letter from Kevin Hanlon (Nov/Dec ’12, p. 4).
I am a senior program manager at Pacific Gas and Electric Company (PG&E) and have been working on the Energy Upgrade California (EUC) program for PG&E since its inception in 2010. I want to start by thanking Steve and Kevin for sharing their perspective on EUC, and Home Energy magazine for sharing this information with its readers. I am encouraged to hear that others are interested in discussing and sharing the best practices and lessons learned from our experience in California. And I hope that these discussions help drive improved home performance programs here and across the nation.
I would like to clarify a few items discussed in the articles and help provide context for some of the questions that it raised.
Energy Upgrade California is a statewide brand that was created by, and is being used by, investor owned utilities (IOUs) such as PG&E, the California Energy Commission, the California Public Utilities Commission (CPUC), and local and regional entities across California to promote whole-building upgrades and related training and financing initiatives. This level of coordination between customer, American Recovery and Reinvestment Act (ARRA), local government, and private-investment funds required unprecedented cooperation. This also challenged us all to move quickly while making implementation decisions that could encompass all of these organizations and interests into one customer program offering.
In his letter, Kevin asks why we chose to create the EUC brand instead of leveraging the existing Home Performance with Energy Star (HPwES) template. To understand this choice, it is important to know that the impetus for creating a residential home performance program derived from different sources. First, the CPUC, based on the goals set forth in California’s Long Term Energy Efficiency Strategic Plan and with knowledge of the impending influx of ARRA funding, guided the IOUs to greatly expand the proposed residential whole-house program for the 2010–12 Energy Efficiency program cycle. Shortly afterward, and in parallel to the IOU program’s development, came the influx of ARRA funds to promote residential, multifamily, and commercial energy efficiency programs, most of which went to fund the development, implementation, and outreach for Energy Upgrade California.
The PG&E home performance program, or Whole House program, was launched in August of 2010 and was followed by the creation of the EUC brand in April of 2011. EUC was created to include the IOU rebate programs in addition to workforce education and training, local government incentives, financing, and customer lead generation activities through the statewide web portal (www.EnergyUpgradeCalifornia.org). The designers of both the IOU and the ARRA-funded programs were familiar with HPwES and chose to leverage several best practices. However, since the California program offers both calculated and deemed incentive structures, Workforce Education and Training (WE&T) and financing, it was deemed necessary to create a brand that encompasses all of these activities and provides one location for consumers to access the resources they need to complete an upgrade.
The article also suggests—rightfully so—that a lack of consistency statewide on various program design facets, such as incentive levels, measures, submission requirements, and quality assurance, can make it challenging for program participants who bridge program boundaries. PG&E has heard and internalized this feedback and is working with the other IOUs and regional government entities to improve statewide consistency. In fact, starting January 1, the incentive levels became consistent statewide in an effort to decrease confusion and expand the incentive range to drive additional and deeper retrofits.
PG&E plans to continue to evolve the program in the coming years to drive market transformation and customer value for home performance in California. I welcome additional feedback, questions, and dialogue on how this can be best accomplished. For those who are interested in learning more about the evolution of EUC, I invite you to join my session at the upcoming ACI National Home Performance Conference in Denver, Colorado.
Senior Program Manager
Pacific Gas and Electric Company
San Francisco, California