Frequent commenter and alternative fuels expert Ben Thorp responds to my piece on electric transportation the other day, noting:
Energy efficiency … may be the largest issue if saving fossil fuel or the global environment is a major concern. The US utility energy efficiency has been ~34% for decades as reported by the Department of Energy. When you add line losses and battery efficiency and driving losses there are huge efficiency challenges. Let’s focus on the major issues to see if anyone has solutions.
Ben: I think you’re right on here. It’s true that the efficiency of energy generation, transmission, and distribution is a big deal. If we start with a certain amount of chemical energy from coal or natural gas, for instance, obviously we want as much of that as possible to be delivered to the end customer. And even where efficiency appears to be inconsequential, that’s really not the case.
For example, let’s take solar PV. Efficiencies range from the high single digits into perhaps the low 30s. Of course, we’d all like this to be better, as improvements will decrease the cost per Watt. But is efficiency really the main issue? The fuel’s free; regardless of how much you use, the cost is still zero.
But let’s talk about the other components of the cost equation: the footprint of building the PV, shipping it, installing it, connecting it, maintaining it and disposing it at the end of its useful life. And what about the land use? We love PV on our rooftops, but we get concerned when solar projects contemplate covering big chunks of the desert.
And what happens when the land we’re talking about is extremely valuable because of supply and demand, e.g., Bermuda? Last time I was there, one of the purposes of my trip was to advise the island national on the use of renewable energy and electric vehicles. They have 160 MW of diesel plants, and they hate them with a passion, but replacing them with solar really isn’t an option.
So yes, let’s drive those efficiencies. Thanks for the note.