Biomass Incineration, Renewable Energy, and the San Joaquin Valley

Kern County, March 4, 2012 – San Joaquin Valley agriculture  provides around 800,000 tons of biomass as a fuel for power plants annually.  The overwhelming majority of this biomass consists of wood chips from orchard removals which is done every thirty years or so with almonds.  There are currently fifteen valley based power plants ready to take this fuel.  These fifteen plants, operating 90% of the time would need around 3 million tons of annual fuel supply.  They are not getting even a third of their fuel from agricultural sources so the rest is woody biomass being diverted from landfills and mostly from large urban areas outside the San Joaquin Valley.

Some of these power plants (5) can also burn coal, tires, and pet coke as fuel.  But, they need to burn as much biomass as possible to receive renewable energy credits under California law AB 32 and to comply with green house gas reduction rules such as the California emission performance standard.

The San Joaquin Valley Air Board gives several of these plants offsets for their pollution if a certain percentage of their fuel comes from agricultural sources.  This offset is rationalized with the claim that the agricultural biomass would otherwise be burned openly in the fields resulting in far more pollution when compared to the controlled burning at a power plant.  It should be noted though that open agricultural burning is now banned by law.

Here is the interesting part:

Burning biomass for renewable energy is probably a bad idea.  In terms of producing energy, biomass incineration puts way more CO2 into the air than natural gas a fuel.  If the goal is to decrease levels of CO2 in the atmosphere before catastrophic climate change takes place, it is not very wise to put even more CO2 into the air in the short term (next 20-50 years) with the future hope that new trees growing in the forest and in orchards will eventually absorb this same quantity of CO2 and make the balance carbon neutral over the long run.

In any case, there are often better uses for this woody biomass than burning it up for inefficient energy production.  It can be recycled and reused more than once in most situations.  Clean wood chips are in great demand with low water use landscaping.  Much of the biomass can be composted and the carbon sequestered for many years in the top soil instead of being released immediately to the atmosphere.  Much of the demolition timber from urban landfills can also be reprocessed into useful building material leaving more trees in the forests.

Any reuse of biomass that minimizes trucking would produce a big gain in terms of decreasing CO2 and criteria air pollutants.  Currently, if all the biomass fueled power plants in the San Joaquin Valley are operating at their full potential, over 2 million tons of biomass needs to be trucked annually to the San Joaquin Valley from collection points in the state’s major urban areas.   These collection points are 120-170 miles away from these power plants.  The trucks carrying this biomass are currently clogging our highways, emitting tons of CO2, and polluting valley air as a major source.

Besides the pollution added to San Joaquin Valley air from the trucking of biomass fuel over great distances, there are also the emissions from the biomass facility itself.  The excessive CO2 emissions do not pollute the air and they supposedly qualify as biogenic or carbon neutral (no lifecycle study of various sources and related energy consumption  or CO2 emissions has been done).  On the other hand, no one is claiming that the criteria air pollutants such as NOx and particulates from these plants are neutral and harmless.  Biomass incinerators, by their nature, produce 20-30 times the NOx emissions when compared to a modern natural gas power plant producing the same amount of power.  Ironically, these highly polluting facilities are given offsets for this pollution and more lenient rules by the local air board with the excuse that open burning would be necessary without them.  Besides allowing higher NOx rates, the air board also says the biomass fuel can be contaminated up to 2% with other substances such as rubber or plastic.  That contamination is quite common with the biomass from urban landfills but not from agricultural sources.   This means these biomass incinerators are permitted to emit toxic fumes from up to 60,000 tons annually from the incineration of plastic like material into our fragile air supply.

In the end, the attempt to satisfy the Renewable Portfolio Standard and meet AB 32 goals here in the San Joaquin Valley with expanding biomass fueled power plants has questionable legitimacy.  These facilities have a negative effect on CO2 levels in the atmosphere over the short term and they are directly making the already horrible air quality in the valley worse which affects the health and economy of several million residents.

I demand that Mary Nichols, head of CARB, respond to these comments because she has often been heard to say that the last thing she ever wanted to see was that the implementation of AB 32 would have a negative effect on air quality.