Tim Gebhart (left) and Ralph Dull (right)

On March 30th, 2009, when I asked Mr. Dull for his email address, he just grinned at me and said, “I’m illiterate when it comes to computers.”  Well, I’m here to tell you that his self-proclaimed lack of computer savvy hasn’t stopped him from making great technological advances in the application of green energy at Dull Homestead Farms.

As a Brookville resident, I heard a lot of buzz around town regarding the new wind turbines when they were installed in May of 2004.  Us locals were all familiar with the Dulls because many of us (and our kids) worked there in the summers, detasseling corn.  When I called Ralph to request an in-depth look at what they were doing, he was glad to give me the full tour of what he has now named The Future Energy and Conservation Center.

Wind Turbines at the Dull Homestead

As a representative of an engineering company, there were obvious things I hoped to see.  Primarily I was interested in how the turbines and their respective electronics were configured, and tied into the power grid.

The six wind turbines are each mounted at 120 feet in the air.  Each turbine produces an average of 9,500 KW of three phase power each year, according to Mr. Dull.  In the original installation, each turbine was tied into a grid-intertie power processor which produces a 240 volt alternating current output.  This output power is then fed through a turbine production meter, and then into one of the farm’s electric load panels.  If at any time the power being produced exceeds the power being used, it is automatically fed back into the utility’s grid.

Power Processors

This move to be green hasn’t been without problems.  Mr. Dull shared that his primary post-installation difficulty focused in on complications with the power processors.  Since each processor (see picture) is fully powered by a wind turbine, it require a constant 8 m.p.h. wind for about 2 minutes just to initiate its electronics.  As such, inconsistencies in the wind can cause the respective controller to reset, restarting the cycle.   One other negative he stated in addition to the controls is that the Brookville location is not optimal for wind energy generation. He suggested that the further north you go, the cleaner wind you get.

Close Up Picture of Two Fuel Cells

The direct electrical output from a wind turbine has a voltage that varies wildly withrespect to wind speed, which is the reason for the power processors.  With the recent failure of one of the processors, Mr. Dull redirected the electrical power from that turbine to a system that generates hydrogen from water.  When used in this application, the wide swings in voltage had no negative effect.

Several fuel cells were on display in the energy center that used the hydrogen as fuel to create electricity.  One of the fuel cells on display was generating enough electricity to run a small electric motor.

There were a variety of other energy innovations being used at the farm including a corn stove, and a corn bio-fuel system they used to dry grain.  He also said they are pursuing state grant money to add solar panels to the facility.

This article was authored by Tim Gebhart of Tri-Tech Engineering.  Tim is a Certified Energy Manager and Certified Energy Auditor through the Association of Energy Engineers.  For more information on energy engineering, you can email us by selecting “Energy Engineering” under our web site’s CONTACTS tab.  If you have questions or are interested in more information on this article, please post your comment below.

Tri-Tech has been involved in the engineering for a variety of energy-savings and energy-recovery efforts for many of their large industrial and institutional clients. Energy projects have included ice storage systems (for off-peak electrical savings), cooling water conservation (vs. once-thru cooling water), energy recovery ventilators (for large areas of assembly), and heat recovery from oven flue exhausts (as discussed hereafter).

Oven exhaust heat recovery for large food processing manufacturers is an area of Tri-Tech’s expertise.  Related efforts have included the engineering for various baking processes in several plants nationwide. To accomplish energy savings in these baking processes, heat is recovered from each oven’s flue through an air-to-air heat transfer system.  The recovered heat is then re-introduced into the same oven’s combustion air intake.  The first costs for this type of system is expensive and should be justified through an energy savings analysisis.  Typically the energy savings associated with smaller ovens will not quickly justify the project.

Tri-Tech engineers visit the site and take various readings at the equipment where heat recovery and energy savings are desired. This information is used to determine the feasibility and estimate the payback (or return on investment). The recovery effort requires an up-front capital expenditure which includes preliminary on-site testing, energy savings calculations, feasibility reports and cost estimates, engineering and installation drawings, and mechanical equipment installation and commissioning. During commissioning, additional testing is performed to verify and quantify the actual operating baseline for the system.

For more information on heat recovery engineering, you can email us by selecting “Mechanical Engineering” under our web site’s CONTACTS tab.  If you have questions or are interested in more information on this article, please post your comment below.