Comments on: Forced Coal-Plant Conversions to Natural Gas: False Hope for "Cheap" Climate Action

By: Ric Smith

Ric Smith — Sat, 20 Mar 2010 06:36:22 +0000

Could Mr. Peltier give references on the difficulty of converting coal boilers to gas. Is Mr. Peltier associated with Power Magazine?

By: JamesG

JamesG — Tue, 13 Oct 2009 14:02:27 +0000

Did you actually talk to any power engineers or are you just being a natural conservative and opposing any proposed change on principal? Haven’t you even noticed that the big players in the energy business are all seriously considering changing to gas too? Your argument boils down to saying they didn’t do this before because it wasn’t efficient. Well no it wasn’t – because the gas reserves weren’t exploited. Perhaps because folk like you keep blocking progress by banging on about how much coal is in the ground.

On conversion costs: A gas burner doesn’t actually need much you know. Haven’t you seen them? Have a look at that little box on your wall: Gas is piped in, it is burnt and …er that’s it! There’s no pulveriser, grinder, separator, hopper, conveyor, slag+ash handler, scrubbers etc, etc that coal needs. Conversion largely involves making all that extra stuff redundant. It is quite simply better tech. The thermal efficiency calc of coal doesn’t even include the running cost of all that extra equipment. Nor does it include transport costs. The combined cycle designs are indeed incredibly efficient and the gains over coal are astounding. Yes it costs money, but if the people with money are prepared to get on board then why not actually look again but with less knee-jerk cynicism this time.

By: Tom Tanton

Tom Tanton — Sun, 11 Oct 2009 13:43:15 +0000

T. Caine–most of the coversions of coal plant to biomass are for “co-firing” not complete switch over; and yes they tend to be in the smaller older units, partly because of the amount of biomass avaiable within a radius of the plant. It doesn’t make much sense to add the fuel processing (grinders etc.) to co-fire if the heat input from biomass is only a VERY small percentage. As it is most units are co-firing maybe 7-8% of heat input from wood/woody biomass.
Biomass co-firing has advantages (of course some disadvantages) over conversion to N.G. sinmply beacuse of fire box size and radiant/convective heat transfer.

By: T. Caine

T. Caine — Sun, 11 Oct 2009 02:19:07 +0000

Robert-

Great article. How does this relate to converting coal plants to biomass? There seem to be a growing number of these on the books though they seem to be in smaller plants (under 500 MW). Assuming that you have a consistent feedstock of material, does this conversion face more or less inefficiencies and cost implications than one to Natural Gas?

By: Ed Reid

Ed Reid — Sat, 10 Oct 2009 12:54:26 +0000

By the time the gas resources were developed, the plants were converted and both were connected to the far more robust transmission system, the emissions reductions required by W-M would begin to require them to be shut down. Once the potential investors and utility regulators realize that, the likelihood of raising the required capital should approach zero asymptotically.