Iowa Public Television

 

Wisconsin Renewables

posted on August 31, 2007


Like farmers, America's power utilities have the unenviable task of supplying growing demand for their product while meeting tougher environmental standards. Increasingly, utilities are relying on alternative forms of energy production in hopes of meeting their goals.

Developing these renewable power projects, however, requires significant investment to deploy new and evolving technology.

But some operations are capitalizing on resources that, until recently, were unused. A case in point can be found in Wisconsin where as Peter Tubbs discovered last winter, an innovative partnership is generating less pollution and more power, by converting "waste into watts."

Methane gas is both a problem and a solution for three diverse Wisconsin businesses. Dairyland Power Cooperative of La Crosse is mandated to increase the amount of renewable energy it provides to its customers. Timberline Trail Landfill near Bruce, Wisconsin operated by Waste Management, has methane gas that needs to be removed from its cells of compacted trash. Norswiss Dairy of Rice Lake needs bedding for its herd of dairy cows that would entice the cows to lie down.

In 2003, the 1200 cow dairy had a bedding problem. Despite bedding its recently expanded herd with a semi load of wood shaving each week, the cows stood around. Spending most of their day standing on concrete, rather than lying down was stressing the herd and reducing milk production.

Andreas Herr, Norswiss Farms: "A cow that lays down makes more milk, is more comfortable, lives longer and makes you more money and that's what we're here for is to make a profit on our cows, out of happy cows."

Anaerobic digesters typically are used to extract methane from organic waste for electrical generation, but one of the byproducts is the solids that can be extracted and dried. Despite their 60 percent moisture content, the solids make excellent animal bedding. With a texture like peat moss, and little odor, Norswiss beds its stalls at three times the depth of wood shavings, and receives a dramatic financial return.

The cows prefer the bedding so much, they now lie down over 12 hours per day. This reduces their stress, drops their infection rate, and increases their milk production. It has also dropped the cull rate 25 percent, meaning that some heifers born to the herd can be sold for cash rather than being put into milk production. At $2,000 dollars per calf, the change in cash flow is significant. Add in the $75,000 dollars no longer spent on wood shaving style bedding annually, and the economic advantages are obvious.

Andreas Herr, Norswiss Dairy: "They're not tremendous profit centers at this point. What makes the profit for the farm is what happens after the manure gets separated, we collect the solids and we are able to bed the cows and make them more comfortable."

An additional bonus to its cash flow is the ability to trade digested liquid waste as a fertilizer to neighboring farms in exchange for silage. Since the 800 acre production produces only 40 percent of its annual forage needs, the acquired silage helps meet feed demands.

The digester was built through a partnership with Dairyland Power Cooperative of La Crosse, Wisconsin. The synergetic relationship allows Dairyland to buy methane from the digester and burn it in a 800 kilowatt generator installed on an easement at Norswiss Farms. Revenue from the methane sale pays the loan on the construction of the digester, which cost just over one million dollars. The money from the sale of methane is not paid to Herr, but is applied directly to the loan. Electricity is then transferred to Dairyland's electrical grid, which serves 575,000 customers in four Midwestern states.

Thirty miles away in Bruce, another methane generation project is preparing to expand.

At the Timberline Trails Landfill, 3,200 kilowatts of electrical energy are being generated using methane gathered from this 50 acre landfill. Perforated pipes penetrate the pile of trash, drawing out enough methane to power nearly 3,000 homes.

Bill Konvicka, Waste Mangement: "The strengths of the plant is we take the gas off the hill which is a greenhouse gas and we turn power out of it. That's the biggest thing. We produce electricity for the grid locally and we can use it locally."

The Timberline facility is composed of individual cells which can generate methane at a steady rate for up to 15 years after being closed. This facility has a methane production life of over 40 years. For Dairyland, the steady methane production of Norswiss and Timberline are attractive features.

Company officials claim a steady supply of methane from a digester or landfill eases the load on coal or gas fired energy plants, allowing the utlity to meet peak energy demand.

William Berg, DPC: "...they're there when we need them virtually 24 hours a day and therefore we can afford to pay more for that type of resource than we can for something that won't necessarily be there when our members are demanding electricity."

A stable supply of methane also is financially attractive. In 2006, a near doubling in the cost of rail delivery of coal forced Dairyland to increase its energy rates for the first time in nearly 20 years. Transportation now represents over 70 percent of the utility's coal cost. $30 dollars worth of coal now costs an average of $75 dollars to ship.

And Dairyland is bullish on the future of renewable energy.

William Berg, Dairyland Power Cooperative: "If you're talking 20 years out there is a fairly good likelihood that maybe as much as 25% of our energy could be coming from what I would term non-traditional types of sources. The further you go out that number is bound to increase."

The evolution of the renewable energy marketplace has brought Norswiss a digester to produce bedding without a dramatic up front cost. Waste solid bedding benefits both the cows and the bottom line.

Herr: to be able to sustain and to renew your own bedding and make your own bedding on a daily basis you're not relying on somebody else's whim whether or not they want to sell you something makes a big difference.

For Market to Market, I'm Peter Tubbs.

 


Tags: alternative energy dairy electricity Energy/Environment news Wisconsin