Green Lancaster header displaying a picture of an Amish buggy, and corn field, horses in a field, cows being milked, and windmills.

Case Study > Woolen Mill Farm: The Epitome of Sustainability


Woolen Mill Farm:

The Epitome of Sustainability


Wind Power

Solar Power

Geothermal Power



When one thinks of south-central Pennsylvania sustainability usually does not come to mind. Jay McGinnis and his wife Jennifer are the owners of Woolen Mill Farm and their farm is perhaps one of the most sustainable and eco-friendly places in the entire area.

Jay always had a fascination with wind mills since he was a child. That fascination lead him to completely revamp his entire estate. The wind mills might not be generating electricity for him, but his photovoltaic tubes certainly are. His basement also houses a geothermal system that helps to heat up his home.

Wind Power

wind mill

Woolen Mill Farm has three different windmills. Of those three, two of them serve actual purposes. The purposes of those two windmills has changed since they were first erected on the farm though.

The power windmill originally ran up until the advent of gas powered engines. Jay's family obviously replaced the function of that power windmill, and it is now used to churn their homemade ice cream. The windmill also functions to grind corn.

The second windmill on the farm, the aeromotor windmill, was first used to pump water for Jay's family to use. It is now being used as an air compressor. The air pressure that it generates is being used to power Jay's air tools in his studio.

The last windmill has no function other than an aesthetic one. It can generally be used to gauge wind speeds and the direction that the wind is flowing from. It is rather simple in that all one would have to do to measure the speed and direction would be to just gaze upon the blades of the windmill and watch how fast the blades are spinning. The windmill has a "tail" on it, so that it acts as a buffer to the wind and rotates depending upon which direction the wind is flowing from.

The idea of using wind to power all of a person's needs in south central Pennsylvania would not be a feasible one. As Jay had stated in our interview, this area simply doesn't have the proper wind speeds to generate a significant amount of usable kilowatt hours. He had said that in this part of Pennsylvania we generally only receive wind speeds at a class two level. (J. McGinnis, personal communication, October 3, 2009)

The wind speed class levels vary from zero to a class seventeen. Those speeds can range from a slight breeze to hurricane force winds. Jay had stated that to properly use wind energy, the wind speeds would have to be at a sustained class 8 level. Class 8 wind speeds can range from thirty-four to forty miles per hour. (J. McGinnis, personal communication, October 3, 2009)

There are some parts of Pennsylvania that could potentially harvest the wind. There are no "excellent" areas of PA to harvest wind, but there are some areas where the wind speeds are "fair" or "good." Those areas are in the northern and central areas of PA. (Provey, 2009a)

The United States as a whole does not have a lot of excellent areas to harvest wind for power purposes. The central parts of our country, from North Dakota all the way down to the central parts of Texas are areas that can be deemed as "good", "fair", and even some isolated spots of "excellent" wind speeds. (Provey, 2009a)

The Northwest parts of the United States have many areas that can be deemed as "excellent" spots for wind harvesting. The problem with those areas though are that are also plenty of spots that receive little to no capable wind speeds. (Provey, 2009a)

The likelihood of the United States to go completely wind powered will never happen, at least in our lifetimes. The United States Department of Energy does have a goal for wind power though. Their current prediction is to have at least twenty percent of our national energy come from wind farms by the year 2030. (Provey, 2009b)

In 2007, 35% of all new energy generation installations were for wind. The exact amount of new megawatts was 5,200 MW. (Provey, 2009b) Adding to that astonishing figure was another first for wind energy, in September of 2008 the United States surpassed Germany to lead the world in wind energy production. (Provey, 2009b)

2007 and 2008 saw a vast improvement in wind production. Wind production in the United States had doubled in a mere two years. That statistic is perhaps one of the best things a consumer can possibly hear. Considering how the cost of fossil fuels has increased to a ridiculous level, the average consumer could benefit greatly from an energy source that leaves no mark on the Earth, and does not spew forth harmful chemicals into our atmosphere.

The majority of people in America have no clue how the process of nuclear energy or clean-burning coal plants produce energy. The potential for wind energy is astounding. Not only is wind energy an almost untapped resource, but in producing more wind farms our economy could possibly see a creation of over 500,000 jobs by 2030 according to the United States Department of Energy if they can reach their goal of achieving 20% of the national energy from wind.

Along with creating hundreds of thousands jobs for our country, there would also be an influx of over 1.5 billion dollars to local communities annually. (Provey, 2009b) Imagine if all the old manufacturing companies that sold gears for automakers would completely switch to producing gears for wind turbine makers. That incredible turn around would force job growth.

One of the major arguments against harnessing wind energy is the massive size of the turbines. One tower is approximately three hundred feet tall and the blades on top of the turbine are each about one hundred and twenty five feet tall. Importing those parts from other countries would just be too expensive on a major scale, but manufacturing those parts domestically would open up the job market dramatically. (Provey, 2009b)

Solar Power


Woolen Mill Farm also utilizes solar energy. Jay had originally installed solar panels on his roof, but has since installed photovoltaic tubes. The major difference between the tubes and panels is the efficiency of each to collect the Sun's radiance.

The process of harnessing the Sun's energy is rather complex, but basically what it comes down to is the photovoltaic modules, basically the panels, collects the radiance from the Sun and then converts that into DC current. (Livingston, & Hollis, 2005) The "cells" that you see inside of the panel are the photovoltaic modules.

There are two types of modules that a user can purchase. The first type is a crystalline module. The crystalline module comes in two types as well. The first type of crystalline module is the monocrystalline module. (Livingston, & Hollis, 2005) The monocrystalline module has either blue or black cells that do not cover the entire face of the panel. Usually there is at least a little bit of the white paneling showing on the corners.

The second type of crystalline module is the polycrystalline cells. The polycrystalline cells are cut in a rectangular pattern that completely covers the panel. (Livingston, & Hollis, 2005) The cells generally are sparkly blue in color and are more aesthetically pleasing. The monocrystalline and polycrystalline modules are both covered in tempered glass and are encased in an aluminum enclosure.

Both types of crystalline modules have around the same efficiency, and the only factors that can influence a buyer would be the availability of the product, the price of the product, and whether or not the buyer wants a uniform panel set-up or one in which the white breaks up the set.

The other type of module is the amorphous module. (Livingston, & Hollis, 2005) The amorphous modules have not been around for as long as its crystalline brother, and they also suffer from poor durability especially in the first and second generations. Aside from those two facts amorphous modules are the future of photovoltaic paneling. The process of installing the amorphous module is very different from that of the crystalline module.

Amorphous modules are standing-seam, thin-filled laminates that are bonded directly on a metal roof. (Livingston, & Hollis, 2005) Amorphous modules have two distinct advantages over crystalline modules. For one they are not as affected by the heat of the Sun as much as the crystalline modules are. Granted all types of solar collectors are affected by heat, the hotter the temperature becomes the less efficient the collector becomes.

Another advantage that the amorphous module has over the crystalline module is that partial shading does not affect how much energy is being collected. (Livingston, & Hollis, 2005) In crystalline panels if one cell is blocked then none of the other panels can collect either. Basically crystalline modules can be likened to a series circuit. Amorphous panels are connected in a web-like manner, so that if one part is being blocked by shade it can easily bypass that area. (Livingston, & Hollis, 2005)

Photovoltaic tubes and the panels essentially use the exact same technology to collect energy from the Sun. Panels have been around for decades, but they have suffered from the cost it takes to manufacture them and also because of their flat design. The new design that is being used by the tubes allows the user to collect the Sun's radiance from every angle imaginable.

Photovoltaic tubes also cost less to manufacture. The old standard of solar energy was that the user would obtain more energy based on the size of the panel, it is an easy to understand concept in that the more area that a panel has translates into more energy collected.

The major issue with that idea is that solar panels are not cheap to produce. The parts of a panel are expensive to manufacture and to increase its size will inevitably increase production cost. Photovoltaic tubes on the other hand are generally smaller and contain less of the expensive parts to manufacture.

Jay's photovoltaic tubes are made up of glass and they are vacuum sealed. The tubes also have a rather ingenious way of dealing with the heat that is generated by the Sun. Inside of each tube is a thin copper strip that collects the heat. That copper strip transfers the heat that is collected to a tank full of anti-freeze. The tank that the anti-freeze is collected in has probes that measure the temperature of the anti-freeze so that as the anti-freeze is being circulated it can monitor it and potentially shut down if the temperature gets at an unsafe level. (J. McGinnis, personal communication, October 3, 2009)

Another way that Jay keeps sustainable is that the heat inside the tank is pumped throughout his house to cut down on the cost of heating his house. There is also a wood furnace at Woolen Mill Farm that can potentially generate heat for his house. The furnace is tied directly to the same tank that the photovoltaic tubes are tied to. (J. McGinnis, personal communication, October 3, 2009)

One of the biggest issues in solar power is whether to stay "grid-tied" or to be "off the grid". It would be anyone's dream to be completely self-sustainable and be "off-grid." The problem with that idea is that unless you are living in an area that has almost an unlimited amount of sunshine, eventually you will run out of energy, especially in the winter months. Another problem with being off the grid is the issue of how to store the excess energy that you are generating. The only feasible option would be to have a system of batteries connected to the panels or tubes. Although that seems like a great idea, having batteries tied in to the system is extremely complex.

Batteries also are expensive to upkeep, they must be replaced every five years or so, and they are not very efficient at storing a surplus of energy. Adding to those problems is what is inside of each battery. Batteries contain many harsh chemicals and heavy metals that are extremely harmful to the environment. (Livingston, & Hollis, 2005)

So the best idea would be to stay tied to the grid. This does mean that the electric company still will have a hold on your home, but in almost every state the companies have a process called net metering.

Net metering is quite possibly the best thing for someone who is using solar power for the bulk of their electricity. For the majority of solar users their panels or tubes will generate a surplus of energy during the sunny summertime months, but run a deficit in the winter months.

Many of the states that offer net metering will actually buy the surplus of energy that is being produced by the panels or tubes. The catch is that the companies will not buy back your excess energy at the standard retail price. (Livingston, & Hollis, 2005)

Instead of selling back the energy to the electric companies, Jay exchanges that excess energy to the electric company and they in turn give him credit to use. He can then power his house during the winter months without having to worry about how much sunlight is being collected. (J. McGinnis, personal communication, October 3, 2009)

The most important aspect of utilizing solar power is to determine how much energy you actually use in a month. After that is figured out you must cut out all of the frivolous expenditures of electricity. It does not have to be anything drastic like removing all the TVs, but just the little things. For example unplugging appliances that are not in use, unplugging a computer if it is not going to be used for a while, and turning off the lights in a room if no one is inside. Essentially, just use your head and eventually you will not even think twice about having to unplug an appliance or TV, or turning off the light.

Solar power not only presents the United States with an unprecedented limitless source of energy but it provides an opportunity for the world as a whole to cut back on pollution that our current source of world energy is producing.

Fossil fuels are currently the cheapest and easiest means to provide energy. Everyone knows that fossil fuels will not last forever though. The current technologies for collecting solar energy are just too expensive to be used on a massive scale however. The cost of producing silicon-based photovoltaics to generate electricity is still around five times as expensive as the same electricity that is being generated from fossil fuels. (Cass)

The process of manufacturing photovoltaics has seen a steady decline in the cost it takes to make them. From 1995 up until 2005 the actual cost of producing photovoltaics had seen a decrease of 5.5% each year. (Cass) According to The European Commission, if every home owner in Europe that had a south facing roof would install solar cells, then they would generate enough energy to meet the entire continent's energy needs. (Cass)

Utilizing solar power is an expensive step in trying to maintain a sustainable lifestyle. However, depending on which state you live in and whether or not they offer net metering, the system could actually pay for itself!

As energy prices continue to climb to unprecedented levels, the more affordable having a grid-tied system becomes. The most important things to keep in mind when determining whether or not to go with solar power are actually very simple. First off you would need to find out if the state you live in offers net metering. If they do not then you would have to find out what other options are available to you by going off the grid.

One of the most common ways be off the grid and still maintain your system would be by using batteries, but as mentioned earlier there are many drawbacks. Aside from the batteries being inefficient and harmful to the environment, they would also take up a whole lot of space.

The best way to stay off the grid and maintain electricity throughout the winter months would be to have either a gas powered or diesel powered generator. Both of those generators are harmful to the environment because of the emissions they produce.

Another factor to keep in mind when determining to go with solar power is what the average amount of sunlight in your area is. The easiest way to determine that value would be to visit After finding that value you must also figure out how much shading there will be on the cells.

Keep in mind that even partial shade covering can have very drastic effects on the power collected from the panels. This fact is extremely relevant if you are going to install crystalline modules. If even three percent of one of the modules is covered in shade then there will be a fifty percent power loss. (Livingston, & Hollis, 2005) If shade is going to be a factor then it would be prudent to purchase either amorphous modules or photovoltaic tubes.

eSolar, a company that has been around since the 1980's, recently did a demonstration in an area northeast of Los Angeles. They had built a facility called Sierra and that facility housed 24 thousand mirrors on twenty acres of land. The mirrors were all focused on water filled boiler units that where placed on top of towers. (Roberts, 2009)

The temperature inside the boilers reached a staggering 850 degrees. The steam that was generated by the mirrors was then used to power a turbine that generated electricity. (Roberts, 2009) eSolar proved that there are many ways to harness the Sun's energy. They proved that just by using the Sun's heat they could combine current technology (the turbine) with new sustainable ideas.

Geothermal Power


Woolen Mill Farm has one more trick up its sleeve. Jay utilizes the temperature of the Earth to help in heating and cooling his home. That process has been termed geothermal heating/cooling.

Geothermal heating has actually been utilized by humankind for over ten thousand years, as archaeological evidence has proved. (Calahan, 2007) The Paleo-Indians from North America have used the geothermal heating as a healing process in the many hot springs around their area and in the 1800's businesses and homeowners piped hot water into their houses. (Calahan, 2007)

Basically the idea of using the Earth as a heat source is not a new one, but has been with us since humans could walk upright. In more modern times, France had actually harnessed geothermal water to heat 200,000 homes. (Calahan, 2007) Three decades later in the mid-nineties a man by the name of Carl Nielson became the first one to develop a ground source heat pump for use in his home. (Calahan, 2007)

Geothermal heating has become one of the most cost-effective ways of heating and cooling a household. The actual process of installing a geothermal system is complicated from a structural standpoint, but the design is rather simple.

Today there are many different types of geothermal heat pumps, but the actual geoexchange system consists of three main elements. The first component is the ground connection system. Depending upon whether you are trying to heat your home or cool it down, the Earth can act as either a heat sink (to displace heat) or as a source. (Calahan, 2007)

The ground connection system is comprised of either high density polyethylene or polybutylene pipes that are fused together thermally. (Calahan, 2007) Those pipes are called the the ground loop and that loop is what is used to transfer or extract heat from the ground. Those pipes can be placed either deep underground or in a lake or pond, depending on what is available.

The second component of the geoexchange system is the heat pump system. A heat pump works in much the same way as a conventional air conditioner or radiator in a car. (J. McGinnis, personal communication, October 3, 2009) Basically the heat pump is what is transferring the heat into and out of the house.

The main idea behind the heat pump is that through the help of a refrigerant, the heat exchange can take place. The primary principle of heat exchange is that heat energy will always flow from the highest temperature down to the lowest one.

The third component of geoexchange systems is how the heat is distributed. This part is the simplest and easiest to install. Heat distribution in geoexchange systems is exactly like is in other distribution systems. The heat from the geoexchange system uses a series of ductwork just like in other homes and businesses. (Calahan, 2007)

At Woolen Mill Farm, Jay is using a close-looped system to heat and cool his home. The idea behind a close-looped system is that the piping used in the ground connection system forms a continuous loop. (Calahan, 2007) That continuous loop acts as the heat exchanger. The pipe is run underground and then connected to an indoor heat pump in his basement.

Inside of the pipe is an anti-freeze solution that circulates the hot or cool energy throughout the system.

A close-looped system is extremely versatile in the ways that the piping can be laid out. The easiest and most common way to lay out the pipes would be in a horizontal manner. Usually the pipes would be entrenched in about four feet of dirt. (Calahan, 2007)

Typically in a 2,000 square foot home you would need anywhere from 1,500 feet to 1,800 feet of piping. If there is not enough area to lay out the pipes horizontally then the pipes could potentially be dug deep down in the Earth in vertical manner. The pipes would have to be dug at least 125 to 150 feet underground though, which could end up being a bit expensive. (Calahan, 2007)

The third variation of the close-looped system would be to have the pipes submerged in at least six feet of water at its shallowest.

The other type of loop system that can be installed is the open-loop system. Unlike the close-looped system where the pipes are all pressurized and under the ground, an open-loop system uses groundwater from a conventional well as the heat source. (Calahan, 2007)

Since the system is not in a continuous loop the used water must be discharged after each use. The water does not become polluted in any way so that when it is time to discharge it, the water can simply be dumped in a stream, pond, ditch, etc. (Calahan, 2007)

In terms of maintenance and performance, both the close-looped system and the open-loop system function about the same. After a prolonged period however, the close-looped system will end up requiring less maintenance solely due to the fact that it is a sealed and pressurized system.

A case study done in Tennessee by members from ASHRAE uncovered some potential problems in using a geoexchange system. The original goal of the experiment was to have fully sustainable housing and they would then monitor what was going on in each house.

One of the houses was supposed to be using the excess heat from the compressor during the cooling season to heat up all the water in the house. To their dismay that process never occurred.

Which brings up one of the biggest issues facing geothermal power: installation mistakes. As it turned out the workers who had been in charge of working out all of the plumbing in the house had made a very large mistake: "The inlet and outlet water lines from the desuperheater exchanger and the hot water heater were not plumbed correctly and needed to be reversed." (Christian, Atchley, Richards, Moon, & Childs, 2006)


There are many ways to lead a sustainable lifestyle. Woolen Mill Farm is a prime example of how technology is progressing towards a cleaner way of living. Fossil fuels may still be the cheapest way to harness energy, but at what cost?

This site was cresearched and written by Joe Lawrence,, a student at Millersville University of Pennsylvania

© 2007 Millersville University. All Rights Reserved.