New biomass power plant defines sustainability, efficiency

Harley Sietsema points out part of the new turkey waste-to-energy system near Howard City. HTI's patented high-temperature heat exchanger will transfer a "high-temperature" heat to the biomass/hot air turbine.

The words have been used promiscuously, so it's tough to know what they mean anymore.

Harley Sietsema knows. But as he prepares to fire up an engine of energy production previously unknown, he doesn't use the words. Sustainability and efficiency are implied as he ensures that his animals get nothing but the best. His farms' efficiency sustains turkeys and pigs from birth to death, which in turn sustains the efficient family business as it has for two - and potentially three -generations.

Soon, Sietsema Farms will jump into efficient environmental sustainability with what can only accurately be called a Starved Air Low-Temperature Biomass Gasification System, also known as SALT, and the result will be an environmentally benign system to power Sietsema's feed production mill at Howard City.

"This will have zero carbon footprint," he said as he checked construction progress on the turkey litter-powered alternative energy plant.

Not only will the energy system generate no air emissions or require any water to operate, it will generate 462 kilowatts per hour, enough to provide electricity for "350 to 400 average American homes," according to Pat Dickinson, with the business development unit of Heat Transfer International (HTI), the Kentwood company that designed and built the energy center.

"Turkey litter is a pretty good fuel," he said as the SALT system prepared for its first test run. "It produces 4600 to 4700 BTUs per pound at 35 percent moisture."

Among the many unique characteristics of the system is that turkey litter isn't burned. It's roasted in a self-sustaining system that creates a combustible gas known as syngas, short for synthesis gas.

Initially, the litter begins roasting with help from natural gas, but once it begins roasting, the gas can - and will be - turned off.

"It's like a campfire," said Norma McDonald, owner of Phase 3 Renewables based in Cincinnati, a key consultant on the project. "Once started, as long as fuel is added, it won't go out."

The syngas created from the roasting litter is pulled with an induction fan through the entire system, including its first step, a chamber where oxygen is introduced from ambient air in three stages. Each stage creates more heat as it reacts with oxygen. McDonald said it acts like combustion, but is really a chemical reaction.

No matter the process, when the heated air reaches its hottest temperature, 2100 degrees, it expands, and its expansion is a force to be reckoned with.

"It's like when you come into a nice warm room from a cold winter's day outside," she said. "The warm air kind of hits you. As warm air expands, it has a tremendous force." That expanding air goes into a patented ceramic heat exchanger, which produces dynamic air flow, which turns a turbine. The turbine is connected to a generator, which creates electricity.

The only byproduct of the process is spent litter, which has been roasted into ash. It retains all the fertilizer properties and micronutrients the litter had, except nitrogen. The ash is collected, and looks like sand, Sietsema said. He's still investigating ways to market that fertilizer most efficiently.

Powering the feed mill

The beauty of Sietsema Farms' estimated 70,000 pounds of turkey litter every day, of course, is that it's a sustainable energy source that will not run out as long as turkeys are growing.

And grow they do, in one of the most efficient operations in the state, due at least in part to the mills that produce their feed.

As impressive as the new energy system is, the feed production facility at Howard City matches it. Thoroughly computerized, the mill operators can at a glance know exactly what's being blended where and for which farm and which birds. That's important, Sietsema said, when adjusting feed rations based on a turkey's growth stage.

"We have 40 different nutrition formulas for a turkey's 20-week life," he said.

Not only do those formulas produce the best possible nutrition for the birds, it keeps them healthy and helps them gain weight more efficiently, and thus produces the best-quality turkey for consumers. But to make feed that's efficient to digest and produces sustainable gain, steam must be added to the rations in order to pelletize it. That's when Sietsema can further utilize the zero-carbon footprint energy plant.

Heat that otherwise might be wasted in the system will be captured and used to heat water in a boiler that formerly used natural gas. Steam created by the boiler is injected into the pelletizer.

Even though located in a Renaissance Zone and financed in part by USDA and MDA grants, the entire system, of course, has been injected with pellets of criticism from concerned local citizens.

"There were a few concerned citizens who worried about turkey litter being hauled into this site," Sietsema said. "We had to sort through that by getting special use permits. And then, Pierson Township had no ordinances that spoke to an alternative energy system. So they had to create an ordinance and we had to get a special use permit within the ordinance."

The same concerned citizens forced Sietsema to work with the Michigan Department of Environmental Quality (DEQ) for an air emissions permit, even though McDonald said the system's emissions are "far below the threshold required by the DEQ."

Sietsema said the plant would not have needed air permits, except for "several ladies who raised a ruckus." Their ruckus prompted the DEQ to go through an air emissions public hearing in addition to the hearings about the energy plant's building plans.

Those hearings delayed the project, which Sietsema said should have been done last October.

"All the air quality permit does is require me to have another employee to monitor things to be sure we don't stub our toe on the parameters of the permit," he said. "It's getting to the point where you need to have an attorney on staff."

The last hurdle to be cleared before a planned Oct. 23 open house, to which Governor Granholm has been invited, is an agreement with local utilities.

Great Lakes Energy and Wolverine Power, however, were reluctant to talk about the system that will add to its power generation grid, and after repeated calls for information, would only issue a statement:

"Great Lakes Energy and its power supplier, Wolverine Power Cooperative, are in discussions with the member. We believe that we are making progress towards a solution that will work in all parties' interests. It would be premature to air the alternatives the parties are discussing until we reach agreement. We very much appreciate the involvement of the Michigan Public Service Commission staff in these discussions."

During those discussions, said Judy Palnau, media specialist with the Public Service Commission, three methods of getting an agreement to put power on the grid were floated. They all involved the way costs are handled, she said.

Sietsema said it appears that a purchase power agreement would be preferable to the utilities, which means he would continue to buy electricity for the plant from the existing grid, and would simply sell his kilowatts back to the utility. The agreement to that kind of system, however, depends on what price the utility will pay.

"We're just trying to get a fair value for our power," Sietsema said. "In negotiations so far, we wanted retail value, and they wanted wholesale. But I think we can work out an understanding."

Perhaps understanding is the key to this whole pioneering energy project. It started with Harley Sietsema understanding efficiency in his business, and maybe it ends with the understanding of sustainability only a zero-impact power plant can produce.

Either way, by sometime this fall, there will be a zero-carbon footprint, self-sustaining, efficient new way to produce power near Howard City. And it all starts with knowing what sustainability and efficiency mean.