Maura,

  Good article, and I appreciate how it addressed the need for some developing societies to use more energy, not less. Reduction in energy usage in developed economies can help offset some of that. Immediate adoption of the most efficient technologies the developing economy can afford is another helpful method for ensuring the lowest possible energy consumption. 

  The article mentions that in order to completely mitigate the carbon emissions problem, that we need to adopt different energy sources, but it does not suggest any. Having been involved in own way or another in energy production or production of associated technologies I think it is obvious that the primary "alternative" energy source, solar and wind, leave much to be desired in the way of providing baseload power. Nuclear power plants on the other hand, have proven clean, reliable, and very effective for producing baseload power. I am a strong advocate for the increased use of nuclear geenration and encourage everyone to look into SMR's: Small Modular Reactors which can be installed in multiples to match the load requirement, and are relatively easy to expand in capacity by design. 

Nuclear reactors at least in the United States have been regulated into a corner where the cost to construct a new one is so high that it is impractical to do so. Hence gas plants are springing up like weeds.. Plus there is a simple economic reason for this. Even before fracking came along, the United States has always been essentially the "Middle East" of natural gas. We have so much that unless it is very high quality, we just flare off the excess.

There are of course a lot of niche situations. Cogen plants, waste wood plants, manure plants, landfill gas plants, to name a few. These all meet the ideal "green energy" concept and the economics is quite good in some cases, tenuous in others.

Frankly though LED lighting doesn't exactly have the best economics. Relamping to LED is flat out stupid. Modern reasonably good efficiency MH and fluorescent fixtures are very close to LED efficiency in the first place and relamping with tubular or "corn cob" lamps is less efficient at best, plus all the shadows and goofy lighting it tends to throw off. This means replacement of the whole fixture is the best alternative. The energy efficiency economics dictates that when a system falls into disrepair to the point where a lot of fixtures need replacement and relamping as well, then it makes sense economically but mostly from a cost point of view (LED fixtures are on par with MH and fluoresecents with lighting efficacy considered). The second and more productive case is where for whatever reason relamping is prohibitively expensive (requires a crane) or where relamping is a constant chore because for whatever reason the existing fixtures don't hold up well to the environment.

This is the problem with this "green" technology...the cost picture is usually tenuous at best. Very few technologies, especially wind and solar, ever make economic sense except in niche situations. It only really makes sense most of the time when there is something else other than energy costs driving it. This is entirely different from VFD's and other types of process or manufacturing equipment technologies where generally the improvements are immediate and substantial.

And contrary to popular belief if you check EIS numbers, at least in the United States electricity usage has been on a steady decline. The increased use of server farms and decreasing PC's from the monster 400 W power supplies of the 1990's down to 35-100 Watt laptops of today is having an impact along with lighting, HVAC, variable frequency drives, and many more technologies driving energy usage overall down, even as solar panels and wind take off.