How We Rate Light Bulbs
Environmental Impact
Our Environmental Impact Rating for Light Bulbs is based on a product's Consumption and Toxicity Ratings (see below), manufacturing location and manufacturer's commitment(s) to environmental stewardship (visit the How We Rate page for details).
The higher the Environmental Impact Rating, the lesser the environmental impact of the CFL relative to others within the category.
Consumption
Our Consumption Rating for Light Bulbs is based on a product's lumens per watt (light output) rating relative to others within the category. The higher number of lumens per watt a light bulb can produce, the more efficient it is (it uses less energy to produce more light).
The higher the Consumption Rating, the more energy-efficient the light bulb.
Toxicity
Our Consumption Rating for Light Bulbs is based on a product's lumens per watt (light output) rating relative to others within the category. The higher number of lumens per watt a light bulb can produce, the more efficient it is (it uses less energy to produce more light).
The higher the Consumption Rating, the more energy-efficient the light bulb.
Lifecycle Cost
Our Lifecycle Cost Rating for Light Bulbs is based on a product’s cost of ownership, including its purchase price and cost of operation (energy costs), relative to others within the category. A product’s return on investment potential is revealed in its Lifecycle Cost Rating since this rating uses the product's lifetime energy cost in relation to its purchase price. In many instances, products that have higher purchase prices but also have higher efficiency ratings bring a quick return on investment through reduced utility expenses.
The higher the rating, the more cost-effective the CFL.
Price
Our Price Rating for Light Bulbs is based on a product’s purchase price relative to others within the category. The higher the Price Rating, the better (lower) the price of the product.
