A community biomass gasification CHP project in Alaska aims to break new ground.

Among the potential forms of renewable energy from biomass, CHP (Combined Heat and Power) is emerging as one of the most viable options. With its one-two punch of thermal and electric energy, CHP is generating a lot of interest.

Many North American pulp, paper and lumber mills have been using biomass CHP systems since the 1980s, burning residues to produce process steam as well as electricity to run their own operations or sell to the grid. New technologies such as biomass gasification are propelling CHP into the renewable energy mainstream.

Opinions vary on the specifics — size, location, feedstock, etc. — but experts generally agree that CHP projects offer better efficiency than stand-alone biomass power generation. 

Thomas Deerfield, founder and CEO of Alaska-based Dalson Energy, is convinced that biomass CHP could be a key component of Alaska’s energy supply. In his presentation at the recent Pacific West Biomass Conference in Sacramento, California, Deerfield laid out the fundamentals of a project he is working on to bring a biomass gasification CHP plant to Tok, Alaska and its surrounding communities.

North to Alaska
The first U.S. demonstration of biomass gasification to internal combustion engine, the project is a collaboration among various partners. Dalson Energy is working with Alaska Power & Telephone (AP&T), Nexterra Systems, GE Energy, the community of Tok, the State of Alaska, and the U.S. Department of Energy (DOE) on the project.

The proposed project combines Nexterra’s proprietary gasification technology and syngas conditioning system with GE Energy’s expertise in high-efficiency IC (internal combustion) engines. Nexterra uses a fixed-bed updraft gasification system which has been commercially proven for converting biomass into synthesis gas or syngas, a clean-burning combustible gas that can be used like natural gas to generate electrical power and heat.

The proposed system in Tok will combine Nexterra’s technology and a GE Jenbacher gas engine. The combination will create a modular biomass combined heat and power (CHP) plant, enabling the community of Tok to economically self-generate renewable heat and power.

The installation will be an "island grid", not connected to the greater grid, which will provide electricity to Tok and four surrounding communities. It’s a concept that has wide application potential - rural communities, light industry, campus sites and more.

The proposed system at Tok will produce 2 MW of electricity and have relatively low feedstock requirements.  Deerfield sees it as a “stackable system” that can be scaled up by adding 2MW units to a total of ten.

Feedstock will be woody biomass from the State of Alaska forest land leased to AP&T through a 25-year, 27,000-acre sustained yield harvest plan. The system will convert approximately 12,500 tons of biomass per year to heat and power that will use approximately 625 acres/year at 20 tons/acre, or a total of 12,500 acres over 20 years. This amounts to less than half the biomass available from the leased parcel of state forest land.

The project is currently waiting for $10 million in DOE funding and potential funding from the government of Alaska.

Work in progress
In his conference presentation, Deerfield noted that some of the familiar CHP issues still need work – tars, scalability, commercial availability, capital costs and diverse feedstocks.

“Tars are the most difficult CHP issue in many cases,” he said. “Building a gasifier is relatively easy but making clean gas is tougher.” Scalability is also a big issue because large systems are old technology. “There’s a huge need for technology that breaks down to the community or village scale, 2 MW down to 1,000, even 100, KW. Commercial availability is another issue – there are few if any order forms or price sheets for community or village scale CHP systems.”

He also referred to “overblown issues” which may be keeping viable CHP projects from going forward more quickly.  To the prevailing question of how to make renewable biomass energy cheaper than conventional fuel so it can compete, Deerfield’s answer is “forget it – it won’t happen in the lower 48 states, at least not until oil prices escalate.”

But, says Deerfield, in Alaska it’s a different story. “Eight, nine, ten dollars a gallon for diesel fuel to run generators results in up to a dollar per kwh retail price for delivered electricity to villages in Alaska - now that's a viable market” for CHP.

With this in mind, Deerfield says he searched for the last 10 years to find a medium scale biomass CHP gasification system ready for prime time. Several companies came close.  He finally chose Vancouver, B.C.-based Nexterra Energy. He feels their technology is closest to commercial viability – “version 1.0” is in operation in Victoria, B.C. at the Dockside Green development.

“The price is still high because it’s an early stage system,” says Deerfield, “but because energy costs are so high in Alaska, there’s less than 10-year payback on a $20 million, 2 MW system.”  Deerfield adds, “The ‘secret sauce’ to the Nexterra system is tar cracking” which mitigates that sticky issue. 

Since the CHP installation will use high efficiency GE Energy IC engines, Deerfield notes that GE Jenbacher commissioned a study to look worldwide for a gasifier developer and manufacturer that can produce gas to run in Jenbacher technology. They also chose Nexterra.

Local action
Community scale CHP systems such as this may not be THE answer, says Deerfield, but they are an answer, especially for Alaska. “Localization of systems provides local economic benefits, local control, greater redundancy, less targets for vandals and terrorists,” notes Deerfield. “The renewable energy industry has been focused on large-scale solutions. We need more small and community-scale systems, even more than the big ones. I'd rather see a thousand 2 MW systems go in the next couple of years than one 2000 MW system. It would be better to have hundreds of 300 kWh systems replacing diesel generators than importing the diesel to run those generators.”

There are many more reasons to deploy at a community scale, he adds. “The systems are more likely to be locally serviced and maintained and they increase local awareness and buy-in, which is really important to convince communities to allow systems.”

But what about the efficiency of new technologies and systems like the one he’s proposing? “We talk more about efficiency than we need to,” says Deerfield. “Efficiency is important but why are we so worried at this point? Let's start with getting some systems on the ground and then start tweaking toward efficiency.”

As far as operations and maintenance costs are concerned, “renewable energy O&M costs can be a net gain for local economies in taking wages for local workers.”

In short, Deerfield’s message is that the time has come to get past the issues and act. “Forces are conspiring,” he says, citing realities like escalating fossil fuel costs, aging infrastructure and growing energy demand.

“Let’s make some new mistakes,” he suggests, “not the old ones over and over.”

www.dalsonenergy.com
www.nexterra.ca

< Prev		Next >