Resources for Green Living in the Chesapeake Bay Area

One of the easiest and least expensive, and therefore most effective,

ways for a person to make a positive impact on reducing their overall energy consumption is through the use of more energy efficient lighting fixtures and bulbs such as those that have earned the ENERGY STAR. Energy consumption can be further reduced by the adoption of more energy efficient habits such as opening the blinds during the day and turning off lights when leaving a room.

The best source of light we know is, no shock here, the sun. The sun provides the “greenest”, highest quality and least expensive (it’s free!) way to light a room (or a landscape) during the day. However, when the sun goes down, a number of different technologies make effective, artificial lighting possible. Light sources, lighting fixtures (known as luminaires), and lighting controls are the three basic elements necessary to provide a space with sufficient illumination needed to perform various tasks.

Light sources include, of course, the sun, traditional incandescent and fluorescent lamps, high-intensity-discharge lamps, and now solid-state devices, aka LEDs, that promise to change the way we light our world. Ballasts regulate the power to some of these light sources. Advances in lighting controls offer further energy savings by reducing the amount of time lights are on but not being used. Lighting controls include switches, dimmers, occupancy sensors, photosensors, and even automatic systems that can reduce electric load demand when needed.

Making improvements to your lighting is one of the fastest ways to cut your energy bills. An average household dedicates 11% of its energy budget to lighting. First and foremost, homeowners should make the most use of the daylight available to them by opening the blinds and cleaning the windows. Using new lighting technologies can further reduce lighting energy use in your home by 50% to 75%.

Daylighting reduces the need for electric lighting by introducing daylight into a building. Effective daylighting is achieved through the strategic placement of skylights and windows, as well as lighting controls that monitor available daylight and respond as needed to decrease or increase electric lighting.

Throughout the 1900s, use of the sun as a source of energy has evolved considerably. Early in the century, the sun was the primary source of interior light for buildings during the day. Eventually, however, the cost, convenience, and performance of electric lamps improved and the sun was displaced as our primary method of lighting building interiors.

Attempts to use sunlight directly for interior lighting via lens collectors, reflective light-pipes, and fiber-optic bundles were the next step.

The most recent technology, Hybrid solar lighting, collects sunlight and routs it through optical fibers into buildings where it is combined with electric light in "hybrid" light fixtures. Sensors keep the room at a steady lighting level by adjusting the electric lights based on the sunlight available. This new generation of solar lighting combines both electric and solar power. Hybrid solar lighting pipes sunlight directly to the light fixture and no energy conversions are necessary, therefore the process is much more efficient. It is currently being developed and tested by Oak Ridge National Laboratory in collaboration with the Department of Energy and several industry partners.

http://www1.eere.energy.gov/solar/solar_lighting.html

A filament, usually of coiled tungsten wire, is heated to incandescence by the flow of current. (Nearly 90% of the energy we put into an incandescent lamp comes out as heat. The light we use is really nothing more than the byproduct of heating the filament. Furthermore, the heat that is given off can significantly increase a building’s cooling requirements using even more energy.)

Low pressure mercury is ionized inside the lamp, producing primarily ultraviolet radiant energy which causes phosphors to fluoresce.

Pressurized gases inside an arc tube are ionized by current flow between electrodes, emitting light. There are three different types of HID lamps each containing different gases, they are: mercury vapor, metal halide, and high pressure sodium

are semi-conductors that convert electricity into light. Once used just as indicator lights for electronics, LEDs have evolved into a major lighting technology that may change the future of general illumination. LEDs are highly regarded for their long life, energy efficiency, non-toxicity, durability, and flexibility.

Information above adapted and taken from http://www.lrc.rpi.edu/ and http://www1.eere.energy.gov/consumer/tips/lighting.html

To save the most energy and money, replace your highest used fixtures or the light bulbs in them with energy-efficient models. The five highest use fixtures in a home are typically the kitchen ceiling lights, the living or family room table and floor lamps, and outdoor porch or post lamp.

The smallest things can add up to a real difference. If every American home replaced their 5 most frequently used light fixtures or the bulbs in them with energy efficient models, such as ones that have earned the ENERGY STAR, we would save close to $8 billion each year in energy costs, and together we would prevent the greenhouse gases equivalent to the emissions from nearly 10 million cars.

FACT: The energy used in the average home can be responsible for more than twice the greenhouse gas emissions of the average car. When you use less energy at home, you reduce greenhouse gas emissions from power plants and help protect our environment from the risks of global climate change.
Information above adapted from, http://www.energystar.gov/index.cfm?c=lighting.pr_lighting
Additional sources for further research