LED Strips are a Hammer and Every Lighting Problem is a Nail
As mentioned in our last article, lighting is one of two common uses of household power that is relatively easy and inexpensive to make resilient. However, lighting is still a complex discipline, and “keeping the lights on” during a power outage is a problem with a long history.
At one extreme, we have the “solution” of keeping candles and flashlights around the house as backup sources of light. At the other extreme, we have the option of including every light in circuits to be powered by an emergency generator or battery system in case of an outage. Between these two extremes are many promising and cost-effective solutions, some of which require additional equipment or the use of “smart” logic to keep the appropriate lights on.
In this article, we look at the alternatives for the design of a modern “resilient” lighting system under the various options and technologies available today.
Energy Efficient Lighting
Regardless of which option is selected, the first step in attaining cost-effective resilience is to convert all lighting to LED lights. LED lights are much more efficient than almost any other lighting technology. Virtually all conventional lights, from the ubiquitous light bulb to fluorescent tube, can be exchanged for LED versions. These are generally simple to install and economical, but they are not easy to make resilient.
LED lights are inherently low-voltage lights (DC or AC). They require internal circuitry that allows them to be supplied by standard AC voltage (110V in the US and 230V in Europe). An example of such lights is pictured on the right.
Backup Lighting Systems for Homes
All multi-family residential and similar buildings have grid-independent emergency lighting required by most fire safety codes and related regulations. This is an option for single-family homes as well. In fact, there are a few options that can be implemented to improve lighting resilience:
- A separate emergency-only lighting system that only comes into operation during power outages. These systems can be designed to light stairs and other important areas of the house (like you see in the images below).
- Lighting systems that are connected to the grid power, but “buffered” by their own batteries to allow for operation during power outages. This option requires the use of localized batteries, which means these components of the lighting system would be best designed to operate in DC mode, not AC as is commonly done with most LEDs.
- More conventional AC-powered LED lights that are connected to circuits that are part of the overall emergency power supply for the home.
If the objective is to attain resilience against the occasional, yet inevitable utility power outage, option 2 (e.g., low voltage lighting that can be backed up by local and distributed batteries) is a logical choice.
Of note, homeowners also should consider dimmable lighting in the design of a resilient lighting system. Lights that can deliver reduced lighting and use less power during outages and emergencies is ideal.
Easy Emergency Lighting Solutions
LED strips can be a good source of emergency lighting during power outages. They use power at 12V or 24V and are very tolerant of the voltage variation common to most backup batteries. They are available in dimmable, waterproof and white or multi-colour versions with adhesive tape backing, and in some cases they are prewired. They’re also easily cut to length.
In addition, the DC power supply plugs in using standard DC5521 round plugs. Thus, it is easy to use low-voltage DC batteries (which we discussed in our previous blog) for backup power.
Thanks to their ease of installation, LED strips with a local battery backup can be the perfect solution for most homeowners. Here are a few examples where this makes a lot of sense:
Cupboard and Closet Lights
Adding a door-activated switch makes automatic illumination of the inside of a closet a snap. The LED strips can be mounted horizontally or vertically, though vertical installation allows for better illumination of the entire closet during outages.
Stairwell and Hallway Lights
Stairs are one of the most dangerous features in buildings, especially during power outages. Proper lighting under all conditions is key for ameliorating the danger.
Below are some pictures of a simple RGBW (Red, Green, Blue, White) LED strip installed under a stair rail to illuminate stairs that would otherwise be in a dark area. Dimmed red gives satisfactory illumination at night without disturbing sleep in the way that a bright white light would.
If we add a battery to backup the stairwell light, this type of design can easily keep the lights on for 12 hours or more, depending on the dim setting, during a utility outage.
Additional Light Placements and Functions
The cost, power and versatility of LED light strips make it quite easy to incorporate them into other spaces, like bathrooms and dining rooms. A local battery (like the one pictured) can also be used to serve multiple lights that can provide backup illumination for larger areas, such as basements or workshops.
Homeowners can further customize and control backup lighting by using an LED control panel, like the 4-switch panel pictured. For instance, the panel can be used to dim the lights, change the color or even dim specific colors on the LED strip, in addition to providing power to the area. And because there is a battery buffer behind this system, these lights can be expected to remain operational for some time during a power outage.
Standalone LED fixtures can also be used without being “integrated” into an existing lighting system The figure on the right illustrates the use of a white LED strip shining downward and an RGBW LED strip shining upward. The W in the RGBW strip above is simply in parallel with the strip shining downward. And once again, it is a trivial matter to put a lithium ion battery backup into the supply circuitry.
Conclusion
There are several ways to attain lighting resilience in a home, including making it part of the overall emergency power plan, complete with sophisticated house controls. Thanks to the advent of LED technology, however, we are now in a position where we can separate resilient lighting from the general problem of keeping a house powered during outages and emergencies.
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