Lighting for Zero Energy Homes

In the 2016 ALA Action Agenda under Public Affairs, there is a list of agencies and organizations that the ALA Engineering Committee and I interface with on a regular basis for the purpose of exchanging technical information and to keep up-to-date on their residential lighting involvement. Several of the organizations in the Action Agenda now list projects that involve zero-energy homes. According to the Department of Energy (DOE), only one percent of U.S. home builders are currently building zero-energy homes, but the segment is growing rapidly. Standards are being developed, building codes are being written and financial and legal structures are being put into place. It is a good time to investigate the lighting technology that these homes might use, as well as the product and marketing opportunities they represent.

The ALA recently signed on as an Innovation Partner in the DOE Zero Energy Ready Home™ program, which has the objective of educating consumers about the benefits of such homes. You will hear more about this program in the next few weeks via an article in  Lightrays and an ALA webinar. For immediate information, you can visit the DOE's Office of Energy Efficiency & Renewable Energy website .

There are several definitions being used, but overall, a zero-energy home is built or modified so the total amount of energy used by the home is equal to the energy produced on site from renewable sources, such as solar panels. If the home is all electric, then at times, the home will generate more electrical power than it uses (the electric meter runs in reverse) and send power out to the electrical grid, while at other times the home will draw power from the grid. Over a given period of time, such as a year, the energy sent equals the energy received. That is a net zero condition. 

The DOE program, however, is organized around the idea of zero-energy ready homes, which means that the building is equipped with the infrastructure to become a zero-energy home, but it might not initially include all the necessary systems and equipment to allow it to operate at the net zero point.

Lighting Opportunities in a Zero-energy Home

Just because a home is designed to operate at zero net energy does not mean that consumer choices and the rules of good lighting have to be suspended, but rather, that well-designed, good looking and energy-efficient lighting products will have to be carefully chosen along with a plan to integrate them into the overall energy use of the home. According to the DOE, such plans usually call for a total energy reduction of 40 to 50 percent compared to conventional homes being built in the same area.

With lighting being a significant part of residential energy consumption, this creates a new opportunity for showrooms and manufacturers' representatives who work with architects and builders, and also for manufacturers who are building efficiency, as well as connectivity into their products. Products such as fixtures that include energy storage or a portable that includes a USB low-voltage interface that can efficiently tap into a home's local smart grid will become increasingly important. Design flexibility is important too, and those manufacturers who have pursued custom driver and light engine designs for their LED fixture products will, I believe, be particularly well positioned to take advantage of these new opportunities.

Zero-energy homes can only be built if it makes technical and economic sense to generate and manage sufficient energy on site to meet the needs of the home. Fortunately, residential lighting systems are in a good position to contribute substantially to that energy-management effort because they are rapidly becoming more efficient and lighting's portion of total home energy use is going down. That is due, of course, to the fast-growing use of solid-state lighting. LED bulbs providing 1600 lumens (the light output of a standard 100 watt incandescent bulb or a 72 watt halogen-incandescent bulb) can now provide that same light with excellent color quality (90+ CRI and 2700-3000K), while drawing about 12 watts - more than an 8X improvement in efficacy (lumens/watt) over standard incandescent and a 6X improvement over halogen-incandescent sources. Remember too that Energy = Power x Time, so dimming and switching controls can also add substantially to home lighting energy savings without compromising the quality of light. Today, well designed high-quality residential lighting can provide more light for less energy than ever before in electric lighting history.

Regulatory Requirements

One of the reasons that ALA wants to be active in the development of zero-energy home programs is so there is strong industry participation in the regulatory activities. Right now, the DOE lighting requirements are relatively straightforward: 80 percent of the fixtures in the home or the bulbs in 80 percent of the sockets must be Energy Star qualified. The new Energy Star lighting requirements, including Luminaires V2.0, which becomes effective June 1, 2016, and Energy Star Lamps V2.0, which becomes effective Jan. 2, 2017, will make qualifying both bulbs and fixtures faster, easier and less expensive because of new provisions to qualify fixtures with standard screw-base (and other standard) socket types.

California has an aggressive plan that requires all new homes to meet zero net energy requirements starting in 2020. You can download and review the action plan (June 2015) that's been set up to meet those requirements here . More than 140,000 single-family and multi-family homes are built in California each year, and the plan is structured such that 5 percent of that total will be zero-energy homes in 2017. That proportion doubles to 10 percent in 2018 and then increases dramatically to 100 percent by 2020. Lighting requirements for homes are regulated by California Title 24 (permanently-wired fixtures) and Title 20 (bulbs and portable fixtures). The recently completed 2016 Title 24, which goes into effect Jan. 1, 2017, requires all residential fixtures to be high efficacy, which means that while they may utilize screw-base bulbs, those bulbs will have to meet minimum efficacy requirements of 68 lumens per watt by Jan. 1, 2018, and 80 lumens per watt by July 1, 2019. There are also color quality and other performance requirements that will have to be met. Since California is on a three-year revision cycle for their lighting codes, the ALA is already planning how to be involved as they cycle begins this year for the 2019 code. From a lighting standpoint, that is the code that will be taking the challenge of zero-energy homes head on.

I'm expecting to learn plenty about zero-energy homes in 2016 and will be especially looking for information that helps define the lighting technology and systems, such as control platforms that are being considered and can provide their usefulness and value. Your help is important in such work. I count on your questions and comments, which are always appreciated.

Sincerely, 

Terry McGowan, FIES, LC

Director of Engineering & Technology

[email protected]