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Biomass thermal: Technology is changing the game |
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"I'm surprised at how much of energy policy and media are focused on biomass for cellulosic ethanol and electricity generation," says biomass thermal expert Scott Nichols. "I'm not sure that's the smartest policy long term."
Nichols, president of New Hampshire-based BioHeatUSA and board of
directors secretary for the Biomass Thermal Energy Council, is a
biomass thermal advocate. "It's the common man's energy source -
affordable and very powerful," he says.
In an audio conference presented by Biowood Energy in December, 2009,
Nichols outlined the potential of biomass thermal as a local and
regional renewable energy solution. He detailed how this is being
realized through the use advanced and proven technology.
Thermal energy accounts for about one-third of America’s energy use -
transportation takes up 29 percent and electric power generation 40
percent. But electric generation using biomass falls far short of the
energy conversion efficiency biomass thermal provides.
Nichols cited the example of the Schiller power station in Portsmouth,
NH, a coal plant conversion project. He thinks it will do great things
for air quality and the forest industry - it will use 400,000 tons of
wood chips per year or about 20 percent of New Hampshire's forest
economy - but biomass electricity is only 25 to 30 percent efficient in
terms of energy conversion. In contrast, co-generation or heat
production alone is 70 percent efficient or more.
In the case of cellulosic ethanol, production rates are about 75
gallons per BDT, resulting in an output of 6.5 million BTUs per ton of
biomass - half the available energy in a ton of wood pellets.
Coming in from the cold
In cold climates such as the northeastern U.S., 75 percent of
residential energy is used for heating, 25 percent for electricity.
Biomass energy is important because it's available locally and
regionally. Using biomass solves a lot of local and regional forestry
and economic issues.
"Using biomass more, and properly, enhances the value of timberlands
and decreases development," says Nichols. He adds that resource
sustainability is essential. "We must make sure the limited supply of
biomass is used appropriately - if used faster than it grows, it's not
only not sustainable, it's also not carbon neutral."
The USDA “Billion Ton Report” estimates that a billion tons of biomass
replaces 30 percent or more of the country’s petroleum consumption and
there are 368 million dry tons of sustainable woody biomass in forest
lands alone available for energy uses. Forest Energy Associates
estimates that current use at 50 million bd. (bone dry tons) annually
is one-seventh of what's available. But as more biomass energy goes
mainstream, more pressure will be put on the resource.
Biomass vs solar
The choice for alternative energy at the residential or small commercial level is often between biomass and solar energy. If you do the math, says Nichols, biomass wins out.
Compared to a solar photovoltaic system, a biomass boiler can make 8
times more energy per year for the same installed cost. There's about a
40-year payback for a solar photovoltaic system (without rebates and
tax credit). An equivalent biomass thermal system offers a 5 to 10-year
payback.
In northern climates, a biomass boiler installed for $12,000 and
burning five cords of wood or five tons of pellets will create the same
amount of energy in one year as a 12.5 KW solar photovoltaic system
costing eight times as much.
Nichols says it's "frustrating" that in the U.S., residential wind and
solar energy installations are eligible for a 30 percent tax credit
with no cap while there's a $1,500 cap for biomass energy.
The nitty-gritty
Once the "ugly stepchild" of renewable energy, says Nichols, "biomass
is entering the mainstream by making whole system installation and
appliances seamless, convenient and comfortable."
Issues like ash residue, fuel supply and storage, safety, emissions and
availability have not just been overcome. Currently, most of the
technology comes from Europe but Nichols sees no reason why it couldn't
be made in North America.
Here are some of the options.
Fully automatic pellet boilers (shown above)
This game-changing technology brings biomass to an operational level
similar to oil and gas boilers, says Nichols. It's reliable and
self-maintaining enough to replace existing oil, gas or coal
residential or small commercial heating appliances without a backup
system.
Available systems can include automatic feeding from bulk storage - a
vacuum draws pellets through a hose from a larger bin into the boiler
as needed. The system is self-lighting, self-cleaning (chamber and heat
exchanger tubes) and can have multiple safety features (airlocks,
sprinklers, air intake sensors, etc.). Minimum owner interaction is
required to run it.
The boiler works best with premium and super premium pellet fuel which
reduce ash removal. It can be ganged with other boilers and the whole
system run automatically.
Multi-granulate boilers
Nichols notes that "as the biomass resource will be challenged more and
more, people will need appliances that will burn what's available at a fair
price." This type of boiler uses a broad variety of biomass.
The boiler handles ash very well - ash content and the fusion
temperature of ash in fuels varies a lot. For example, the trunk of a
tree without bark produces 25 percent ash. The full tree ground up
produces 3 percent ash. The system can also convey different shapes of
fuel.
It's currently not available in the U.S. but is coming.
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