The more research that one conducts on this topic, the more the answer becomes very clear. Glass takes more energy to recycle than plastic. This is true for a number of different reasons.
To understand those reasons, it is first necessary to understand that glass takes more energy to initially produce. The exact amount of energy required, of course, depends on the type of glass product being produced. A number of different factors go into this including the size of the unit, its thickness, shape and any number of other possible factors. However, once produced, glass can last considerably longer than some plastics.
Glass is also not as efficiently recycled as plastic. The Glass Packaging Institute notes that recycling glass uses 66 percent of the energy it would take to manufacture new glass, on average. Plastic shows a much greater efficiency in using energy to recycle, only requiring 10 percent of the energy it takes to produce new plastic.
Given that plastic, generally, uses less energy to produce than glass, and given that plastic also uses less energy when being recyeled, on average, than glass, the answer to this question seems clear. However, there are other factors to consider when choosing a packaging product.
In some cases, even though glass may take more energy to recycle, it could be the best option. Glass can be more protective, in some cases, than plastic. Glass also may preserve the taste and character of some foods and beverages better than plastic.
It is also important to remember that no matter what product is chosen, it will take a substantial amount of energy to recycle it. There are energy costs associated with pickup and transportation to a sorting facility. From there, the products may be forwarded to a recycling center where it will be actually be processed.
Given the fact that any product can take a significant amount of energy to recycle, there are other options that can be considered. Some of these may be just as good as recycling, if not better. The United States Environmental Protection Agency uses the phrase "reduce, reuse and recycle" to promote good conservation practices. The phrase is simple to remember, but represents so much more than a memorable jingle.
Many do not realize this is not just a simple saying but rather a way to prioritize the use of products. Reducing the use of certain products, whether they be glass, plastic or something else, is the best option because if the product does not have an initial use, there is no reason to manufacture it. Reusing a product comes next. This is an attractive option because it takes no energy to recycle. The consumer is simply finding a secondary use for the product or repeating the primary use. Recycling is the third option in the hierarchy.
In addition to reducing the amount of energy needed to recycle, there are other reasons why recycling is important. First, recycling uses fewer natural resources because natural resources already harvested are being reused. Second, recycling keeps the landfills from receiving as much trash as they would otherwise.