1) His were written two years ago, and the process has had that much time to be refined and tweaked and tested.

2) When touting a new energy production method, its promoters will use the numbers that show it at its best, in this case, comparing the total amount of oil that could be produced if all agricultural waste in the US were used. Of course that's not going to happen, and of course every plant will not run at top efficiency all the time. TDP will not totally supplant imported oil and mined coal, but it can significantly supplement those sources without revamping our entire energy infrastructure, as some of the alternative energy methods require. With TDP, you don't have to retrofit your automobile or the boiler in your basement.

3) Greg says the process still doesn't produce the same bang for the buck as coal, oil, and gas taken out of the ground. Again, it's now spring 2005. If oil demand continues to rise while capacity is stretched (as seems likely in the short term at least), or there are significant attempts at disruption of Middle East sources, that could change. Also, when you factor in all the costs of getting oil, gas, and coal out of the ground and transporting it to its destinations, and all the costs of disposing of industrial and municipal waste, and all the wilderness areas that won't need to be drilled or dammed, the numbers might look different. We typically don't calculate total energy costs, which skews comparisons.

4) TDP might be commercially feasible now in countries where oil is much more expensive, concerns about livestock waste are more pressing, and economic vulnerability to fluctuating oil prices is greater. Also, in many developing areas with poor infrastructure or transportation, local energy production makes more sense than importing oil or gas or coal. We are in a global economy, and any reduction in reliance on Middle East oil, anywhere, helps everybody.

UPDATE: Stephen den Beste was also skeptical back then. He doesn't actually refute any of the claims, just warns people to "be skeptical." Well, it's two years later, much more data about the process has accumulated, and Den Beste'a article doesn't refute any of the points I make above, so I await a point-by-point debunking.