A Wisconsin cheese company with abundant local sawmills, was interested in assessing the cost-effectiveness of using biomass to replace their natural gas consumption.  The project would enable the company to reduce its natural gas purchases by approximately 600,000 Therms each year (enough to heat 650 homes) and significantly reduce expenses.  The project remained stalled over technical questions and financing.

CleanTech Partners was able to accelerate the project by:

• Providing technical assistance

• Identifying and applying for USDA funding which was granted

• Offering $350,000 in subordinated debt funding

Melting costs can make or break a metal foundry. The process not only consumes enormous amounts of energy, its level of efficiency is critical to the control of quality, composition, and the physical and chemical properties of the final product. Stack melter furnaces, which use flue gases to preheat the charge materials, can significantly improve energy efficiency in melting and producing castings. By installing stack melter furnaces, a foundry can reduce its operating costs, through both energy savings and reduction of metal losses.

CleanTech Partners facilitated the installation of an aluminum stack melter furnace that is saving the foundry approximately $165,000 per year. The project had been stalled due to lack of financing, but CTP's participation revived it. We worked with the technology supplier to determine the viability and applicability of the technology, and CTP funds financed all the purchase and installation costs not covered by a separate Focus on Energy grant.

Field measurements of actual flows and temperatures were compared to original heat exchanger design specifications. Modifications which increased flows closer to design improved heat exchanger efficiency, and reduced heat exchanger plugging. Also, modifications were made to keep the hottest water from blending with tempered water before being pumped. These were fairly simple piping and pumping modifications to the existing process. 

The net effect was an initial estimated savings of $88,000 with an optimized savings potential of $194,000.

Field measurements of actual flows and temperatures on recovered water systems have uncovered unknown valve cross tie’s which were compromising the amount of recovered heat. Modeling of the system provided economic impact, which led to the support for improved field labeling and for actual process measurement displayed in an operator control room.

Economic Impact: $75,000 with an optimized saving potential of $111,000.

The field evaluate also highlighted the value of a seasonal recovered water strategy to optimize tempered water recovery during the shoulder and winter months. Personnel changes have created a lack of awareness of the optimum configuration of these heat recovery systems. 

Dryer steam systems tend to operate with very high pressures, leading to high pressure condensate containing a large amount of flash steam, when pumped to a lower pressure collection tank. Field observations followed by actual field measurements and condensate system modeling quantified the extent of the wasted steam. It further quantified the economic value of reinstating a previously isolated portion of the steam system. It also provided an alternative option for beneficial use of the lower pressure flash steam with a system specifically designed. 

Economic impact of waste reduction $736,000 on one paper machine and $570,000 on the other. 

Mill conversions inherit legacy equipment which was designed for an original process which is now very different. Energy efficiency of water reclaim, fiber reclaim, and steam system energy were identified and quantified through on-site measurement and process reviews. Water, stock and waste handling systems are typically left out of the rebuilds, but provide energy and operational opportunities once measured and modeled for current uses. Quantification of the energy implications provided an economic benefit for the project scope and prioritization within always limited personnel and financial resources. Converted sites are usually ripe with energy and operational optimization opportunities, again identified and quantified through on-site measurement with modeling.