Day 6 - Bioheat and Power

On Saturday we took two field trips, finished the biodiesel lab, and took the first round of data from the switchgrass ethanol lab.

We arrived Saturday morning at Cornell's Lake Source Cooling & Heat Exchange facility.  A research institution, such as Cornell, has an incredible demand for cooling.  Cornell has a lot of research labs, equipment, and offices that all depend on cool air to create an optimal environment for experiments and researchers.  This creates an enormous energy demand if the school were to use traditional electric air handling.  Instead, the school takes advantage of the thermal properties of deep lake water.  Cornell is situated on the banks of the largest (lengthwise) Finger Lake, Cayuga Lake.

Lake Sourced Cooling Facility

The Lake Source Cooling facility takes deep, cold water from the lake and draws it in to a facility that simultaneously brings warm water from the school down to the banks of the lake.  Inside the facility, heat exchanging metal plates allow the heat to transfer from the warm school water to the cool lake water.  The now cooled school water is pumped back to the school's air handlers for air conditioning, and the warmed lake water is placed back in the lake at a shallower depth so as to not disrupt the thermal properties between bathymetric layers.

Cooling Loop

Our tour was led by Mr. Tim Peer, a professional engineer and the plant manager.  He showed us each part of the plant and described how the physics and logistics of the plant functioned.

Mr. Peer explaining the heat exchanging plates

By switching to lake sourced cooling in 2000, Cornell University has saved over 25 million kilowatt hours annually and has seen an 86% reduction in energy consumption for cooling over that time.  The school does maintain standard electrical refrigeration plants on campus that are only turned on at times of extremely high demand and these chillers only pick up the difference that LSC cannot.

Chiller plates from above (darker color pipes come from campus, lighter pipes hold lake water)

63" diameter intake pipes that stretch out to 250' deep lake water intakes

Later in the day we visited the Cayuga Lake Nature Center to see a woodchip boiler that is used to heat the center's main lodge.  Act Bioenergy installed the .5 million btu/hour unit in the fall of 2009.  The unit is capable of providing the heating needs of the center at about 25% the cost of propane.  They can house a month's worth of wood chips on site and run the boiler for a week without reloading the 2 ton hopper.  A 10-wheel truck delivers hardwood chips with <30% water content once a month at a cost of $500.

Kevin Lanigan, Cayuga Nature Center's caretaker, describing the woodchip boiler

Hopper that holds a week's worth of woodchips

Hopper and boiler shed at Cayuga Nature Center

Lastly, we finished the biodiesel lab and gathered preliminary data.  Here are a few photos:

Unwashed biodiesel overlying the glycerine byproduct

 

Aerating washed biodiesel to encourage mixing