Global CFL sales
In 1989 and the early 90s, when CFLs were still a novelty, the global CFL market increased by more than 30% annually. Since then, growth of the global CFL market has slowed down, but there are no signs of a leveling out in sales. Global CFL sales
Industry estimates from early 1994 predict a stable average global growth rate of ~15%/year from 1995 to 1998 for both modular (lamp only) and integral units (lamp + ballast). However, more recent estimates by industry analysts show that the growth rate of integral CFLs may have taken up speed again, especially in the southeast Pacific and eastern Europe regions. This regional increase is so strong that it is likely to have an impact on the global growth rate for 1995-98, which may be as high as 20% on an annual average basis.
In 1994, global CFL sales reached ~200 million units, according to preliminary industry estimates. The industry surely would like to see higher growth rates, but "it would be unrealistic to expect the very high initial growth rates of 30-50% to persist over many years" one industry analyst says. But the industry is optimistic for the future and believes that new CFLs and a growing environmental awareness followed by large-scale DSM programs in developing countries will boost CFL sales.
CFLs vs. incandescents
CFLs are often used to replace incandescent lamps, but a look behind the numbers reveals a complex issue. If the bulbs are so good, why isn't the CFL market growing faster? asked Paul Wallich in the October 1994 issue of Scientific American (Is a Bright Idea Flickering?).
Part of the conclusion he reached, after interviewing several people (including IAEEL Newsletter's Evan MiIlls), is a paradox: If counted in units, the CFL market will always appear small compared with sales of incandescent bulbs. This is because they last about 10-times as long as incandescents. "If half the light sockets in the world held CFLs, the lights would still account for only about 5 percent of bulbs sold" he concludes.
Assuming that each CFL has a life of 10 000 hours and that each CFL replaces an incandescent lamp, the 200 million CFLs estimated to be sold in 1994 are equivalent to 2 billion incandescent lamps, with an average life of ~1 000 hours. By comparison, global sales of incandescents are estimated at ~9.5 billion units in 1994.
However, comparing total CFL sales with the sales of incandescents may not always be fair. Of the 200 million CFLs sold, less than half (~90 million) are integral CFLs, according to the estimates. It is safe to say that virtually every one of these lamps is bought instead of an incandescent lamp. Thus, converted into "incandescent equivalents", the global sales of integral CFLs are equivalent to at least 900 million incandescent lamps, or almost 10% of the sales of incandescents. But what about the remaining 100 or so million modular lamps sold in 1994?
It is very hard to estimate the proportion of these modular lamps being used to replace incandescents. Modular lamps require either an adapter or a dedicated luminaire with a built-in ballast. In the industry, analysts seem to believe that screw-in adapters will be used less and less (although there is no unanimous agreement on this), and the overwhelming majority of modular CFLs will be used in dedicated luminaires. Most of these are used instead of luminaires for incandescent and other filament lamps.
But in some regions, new CFL luminaires for the commercial market may actually be replacing old luminaires for linear fluorescent lamps. Even though the efficacy of the CFL (including ballast) generally is lower than that of a linear fluorescent lamp with ballast, the application could still be more efficient. This is because a CFL luminaire generally offers more possibilities for directing the light towards the area where it is actually needed, for instance, when combinations of task lighting and ambient indirect lighting replace old lighting systems that provide uniform light levels over a large office space.
Estimated savings
To more accurately predict the CFL-related energy savings on a global scale, we need more detailed knowledge about the features of different markets such as usage patterns, where and how dedicated luminaires are used, what ballasts are in use, and so forth. An attempt at estimating the minimum energy savings achieved by CFLs sold in 1994 may look like this:
According to an estimate based on the very modest assumption that only 100 million CFLs will replace incandescent lamps (all 90 million integral CFLs and a modest 10 million of the modular units), global CFLs sales in 1994 should yield a 50 billion kWh savings over their lifetime. (100 million * 50 W average savings/CFL * 10 000 hours.) This is equivalent to about $ 5 billion worth of electrical energy.
The annual savings over 5 years can be estimated at ~10 billion kWh or 2 000 megawatts of electric generating capacity (assuming that all lamps-commercial, outdoor, and residential-are used an average of 6 hours/day). However, the savings are bound to be bigger since the number of modular CFLs assumed to be replacing all types of filament lamps is likely to be underestimated.
Nils Borg