Thursday, March 18, 2010

Biomass Follow-Up

"The future is already here - it is just unevenly distributed" -William Gibson

[this is a follow-up to my first TCLP biomass post]

I am one of those people who six months ago thought a biomass power plant was a great idea and a way to generate sustainable energy. But after studying the situation I have come to believe that the best solution is a natural gas power plant for the base load, using behavioral economics to encourage conservation, and pursue more wind power.

And that is the point of my opening quote. There was a lot that I thought I knew as a science and tech geek (I studied biogeochemistry in grad school and in my job now make the Internet work) but as I read about biomass I discovered new information that just has not been distributed yet. How are the board members of TCLP expected to know these things? They're volunteers with busy lives. So I hope the information I distribute here is helpful.

Here's what I now believe would be the best approach for Traverse City Light and Power.

1. Build a natural gas power plant as a transition to the 30 by 20 plan.

Because natural gas is clean, efficient, available, can be replaced by biogas, and has half the carbon dioxide emission of coal.

WaPo editorial: A natural choice
But existing gas-fired plants are running at only about 25 percent capacity, in part because many are switched on only when demand spikes. The Congressional Research Service reports that doubling the use of existing plants could replace about a third of coal-fired power, getting America a third of the way to its goal for 2020. For reasons of infrastructure, that might be too optimistic a scenario. But BP -- which has a stake in natural gas -- estimates that retiring the 80 dirtiest coal plants and replacing them with gas-fired power would get America 10 percent of the way to its 2020 emissions target and increase domestic gas consumption by only 5 percent.

Voices: Natural gas can lead the way
Burning coal for electricity accounts for more than 40 percent of all carbon dioxide emissions in the United States. Natural gas emits only about half as much carbon dioxide as coal for a given amount of electricity generation. Thus, for the electrical power sector, offsetting 40 percent of coal-fired electrical generation with the existing excess capacity for electrical generation from natural gas-fired plants would meet the stated goal of the Obama administration (and Congress) of at least a 17 percent reduction in carbon dioxide emissions by 2020...

...Using gas to generate electricity would also reduce other types of pollution: It produces only a tiny fraction of the sulfur oxides, particulates and formaldehyde, and none of the mercury that comes from burning coal. Substituting natural gas for coal also eliminates the many environmental problems associated with the disposal of both coal mine wastes and the 130 million tons of fly ash produced each year in the United States alone, as well as the health impacts and healthcare costs related to mining and burning coal.

2. Plant biomass feedstocks (poplar, switchgrass, etc.) now as carbon offsets to the natural gas plant. Then as technology improves this purpose-planted biomass can be harvested and used without impacting the forests over the next 30+ years.

3. When putting out the RFP for the natural gas power plant, include engineering work for biomass pyrolysis and/or anaerobic digestion to produce biogas (methane) on-site.

The advantages of pyrolysis are that the byproducts are biochar which can be sold to farmers as a soil amendment, bio-oil which can be further refined, and bio-gas which can be burned for energy in the gas fired power plant. And this bio-gas burns without the ash and other byproducts that green biomass does.

See: Scientists see biochar as promising fuel source

4. Continue to develop and pursue wind power capacity as reported in the Northern Express: The rush to Biomass

Also consider novel hydropower options as I detailed in my first post about biomass.

5. Offer credits to rate payers for conservation, efficiency, and distributed power generation.

TCLP could cut demand by 5% by changing the billing statement. TED 2010: David Cameron Shows How All Electric Bills Should Be
Utilities Finding Peer Pressure a Powerful Motivator
Using Peer Pressure as a Tool to Promote Greener Choices
in one study, researchers asked each of four groups of utility customers to cut energy consumption for a different reason — the good of the planet, the well-being of future generations, the financial savings, or because their neighbors were doing it. By comparing electric meter readings, the researchers determined that only the last message had any effect, eliciting a 10 percent drop in consumption. A subsequent study found that when electric bills compared a customer’s energy consumption against the neighborhood average, profligate customers scaled back. In fact, the social norm was so powerful that thrifty customers also responded, by splurging. The weirdly effective fix was to add a smiley face to the thrifty bills — like a gold star from teacher.

Another 5-10% of demand could be eliminating per household by killing "vampire" power with devices that completely turn off electricity.

There are 11,000 households. A Smart Strip cost $30. Meaning TCLP could buy two Smart Strips for every house for about $600,000 and achieve up to 10% reduction in electricity consumption.

What I like about this plan of mine is that if natural gas becomes too expensive TCLP could pyrolisize more biomass. If biomass becomes too scarce TCLP could purchase more natural gas.

Arguments that have been made against natural gas is the expense and the fact that it is a fossil fuel. However, if and when the cost of carbon pollution is accounted for, as seems likely, coal will become cost prohibitive versus natural gas. And in terms of being a fossil fuel and therefore a carbon source, carbon offsets can be planted to account for the carbon emissions of a natural gas plant and the power plant can be transition to a carbon neutral biogas plant.

A good argument against biomass is the engineering studies apparently only consider the client's power plant. Not five others too. Or competing with biomass to make diesel fuel (Engineered E. Coli Bacteria Produces Road-Ready Diesel)

The Record-Eagle had an editorial about questions that need to be answered before the biomass plant is constructed: Questions on biomass

These are good points.

And I read the Integrated Resource Plan (IRP) done by R.W. Beck. I know this report tells TCLP that biomass is affordable and available. However, I read the full IRP. The price of natural gas forecast does not include the recent discovery in Appalachia. Regardless, the forecast shows the price only eclipsing the current price for natural gas in 2020. And the biomass price forecast only includes the currently operating biomass plants and what DTE and Consumers Energy are expected to use.

But other things were left out and a consultant needs to be asked these questions:

- What will be the price of biomass if there are more than five biomass plants in northern Michigan and two or more cellulosic alcohol factories?

- Is there enough biomass to support multiple energy and alcohol fuel users?

- The first time Michigan's forests were cleared it was with horse and sledge and done in the winter. What impact will road building, trucking, and heavy machinery have to the forest soil structure? What will be the impact to nutrient cycling in the forests if the litter is removed? Will the forests regrow or will they be like ski resorts that have found their slopes cannot support the former flora? (See: Ski resorts rethink bulldozing for trails)

Once these questions are answered, the benefits of natural gas are examined, and the possibilities of biogas from the pyrolysis of biomass is considered, I believe the answer as to what to do next will be clear.

Other links that may be of interest:

IPR: TC Mayor Weighs In On Biomass

Converting Coal Plants to Biomass