How one farm uses ‘buckshot’ to meet energy needs
By Francis Thicke, Radiance Dairy
There can be many innovative ways to move our farms towards greater energy self-sufficiency. As Bill McKibben has said, rather than looking for a single silver bullet, we should look for silver buckshot—a lot of smaller energy innovations that together can meet our energy needs.
On our farm we have adapted a number of energy improvements from increased efficiency to renewable-energy-generation systems. Experts tell us that energy gains through conservation and efficiency are the cheapest and easiest to achieve. I agree, but since most people find alternative energy systems to be sexier than conservation, I will start by describing the energy systems we have been dabbling with on our farm.
This past year, we installed a 40 kW wind turbine on our farm. It is now producing energy as it should (finally), but if I had it to do over today, I would put my money into solar photovoltaics (PV) instead of a wind turbine for several reasons. First, solar PV prices have dropped by about 75% since five years ago when I applied for the grant that helped fund our wind turbine. Also, solar panels have no moving parts, so are more trouble-free and require less maintenance. Finally, solar systems are at ground level or on rooftops where they are easier to work on. If you or someone on your farm is not willing to climb the turbine tower (it can be more than a little intimidating to climb a 120-ft tower), the cost for hiring turbine maintenance could bust your budget. A wind turbine will have maintenance needs just like other pieces of farm machinery.
My adventure with the wind turbine took many twists and turns. First, complications with the USDA REAP grant resulted in having to rewrite the grant and jump through lots of hoops, causing long delays. However, the grant paid for 25% of the $160,000 turbine cost. The 30% federal tax credit for alternative energy systems also applied to this wind turbine. In addition, the turbine is eligible for depreciation tax credits. All of these reduced our costs substantially. As a result, the turbine should pay for itself in about 10 years.
What greatly complicated my wind turbine installation was that the installer (from another state) sent me an email halfway through the installation saying that he was “choosing to walk away from this project.” And to complicate matters further, the wind turbine factory (in Kansas) seemed to be hanging on by a shoestring and had lost most of its staff with technical expertise. So, I was basically on my own—with the help of a good local electrician. Fortunately, I had not paid the installer the full amount of the contract, so the cost overrun was not too great (not counting my many extra hours of work).
It seems that the wind turbine industry is pretty stable in the smaller turbine size range (20 kW and under) and in the ginormous size range (MW). But, in the 40 kW range, the industry has not been very stable, and there have been more than a few outright scam artists. A farmer friend of mine from Wisconsin paid $125,000 down on a 40 kW wind turbine and never got more than a concrete pad for his money before the company went bankrupt. If you are thinking of getting a wind turbine in that size range, investigate both the factory making the turbines and the installer very thoroughly before proceeding. And, make sure that their cost and payback estimates are based on sound assumptions. (They like to exaggerate).
Now that I have my wind turbine working, I am happy with it. But, there were times when I wasn’t sure I was ever going to get it working. On an annual basis, this 40 kW turbine should produce about 70,000 kWh of electricity, which is about the amount of electricity we use on our farm annually. However, our power company does not allow net metering, so when the wind is blowing and we have more electricity than we need, the power company buys it back at 3.8 cents per kWh. When the wind is not blowing, we pay 10 cents per kWh for electricity. A net metering arrangement would be much more favorable.
Solar and wind systems can complement each other—often when the sun isn’t shining the wind is blowing, and vice versa. However, I would suggest investing in solar first, and then if you are feeling more adventurous, invest in wind.
We have a number of other renewable-energy systems on the farm. About 10 years ago we converted the water system for our grazing paddocks to solar power. We put a 4,000-gallon polypropylene tank on top of the highest hill on the farm, and at the bottom of the hill installed a solar panel on the edge of a pond to power a pump in the pond. The pump fills the 4,000-gallon tank, which gravity-feeds water to small watering tanks in the 60 paddocks spread around the farm. We injected a one-inch polyethylene pipe into the ground about 10 inches deep, connecting the 4,000-gallon tank to all the paddock watering tanks. The system has high capacity, and, even on cloudy days, the solar pump runs fast enough to keep up with over 100 cows drinking water.
We shut down that solar watering system during the winter months, and use two other watering systems located below a pond dike and gravity-fed by the pond that work all winter without supplemental heat. One of these water tanks has a two-foot-diameter tube extending eight feet into the ground beneath it. The geothermal heat from the ground below, in addition to the regular flow of water from the cows drinking, keeps the water from freezing hard. Some ice will crust on the tank overnight during very cold weather, but we can easily break the ice on top when we check the cows each morning.
The other pond water tank uses a constant overflow of water from the pond to keep the tank from freezing. Instead of the water overflowing and making a mess in front of the tank, a standpipe in the back of the tank carries the overflow of water out through an underground pipe to a nearby ravine. It amazes me how a small, constant trickle of pond water can keep that tank ice-free in the coldest weather. These two tanks work well for outwintering cows.
About five years ago, we installed a solar hot water system. We put four solar-thermal panels (each 4’ by 10’) on the roof of our on-farm dairy processing plant. These solar panels are connected to two 120-gallon water tanks that store water heated by the panels, and that feed water into our regular hot-water heater. During summer months the solar panels will preheat hot water to 145 degrees F. This system saves a lot on propane costs to heat water in our dairy processing plant and milkhouse.
Other renewable-energy systems we use include solar-powered electric fence chargers, which also improve flexibility of fencing in our grazing systems, especially for remote pastures that are far from electricity sources. There are some very good solar chargers available today. We also installed a geothermal heat exchanger in our house, with loops of piping in a nearby pond. The geothermal system uses the pond water as a heat source and sink for heating and cooling the house (extracting heat with a heat pump is more energy-efficient than burning fuel).
When we built our house we included a cupola on its top. Inside, the house is open from the roof cupola, through the stairwell, to the first floor. The cupola has windows that we can open by remote control. On summer nights, we open windows in the cupola and on the first floor, causing a strong natural convection current, which pulls warm air out through the cupola and cool air in through the downstairs windows. As a result, we rarely use air conditioning.
Also, we have begun using biodiesel made from waste cooking oil for our tractors. A local organization makes the biodiesel from restaurant and cafeteria cooking oil, and delivers it to our farm.
As mentioned above, often the greatest gains in energy self-sufficiency can come from conservation and improved efficiency. We think that one of our greatest efficiencies comes from our grass-based dairy system—in comparison with conventional confinement dairies. In a grass-based system, after each milking a new paddock is opened for the cows, and the cows happily do the work of harvesting their own forage while spreading their manure right where it needs to be. By contrast, in a confinement dairy system, the cows’ forage has to be harvested mechanically, put into storage, and delivered to the cows for daily feeding. Then the cows’ manure must be collected, put into storage, and eventually taken back out to the fields. All those energy-requiring steps in a confinement dairy are avoided in a well-designed and managed grazing system.
These are exciting times for renewable-energy innovations. Solar prices have dropped dramatically. Many states and power companies are providing economic incentives for renewable-energy installations. However, there are still some significant roadblocks to allowing small-scale, locally owned renewable energy to compete on a level playing field with large-scale utility companies. I believe that in the future we will see renewable-energy systems become increasingly competitive with fossil fuels as costs for renewable energy continue to decline, fossil-fuel costs rise, and states remove roadblocks and provide incentives for renewable energy. Now is a good time to look into how you can make your farm more energy self-sufficient.
Francis Thicke and his wife, Susan, own and operate Radiance Dairy, an alternative energy-powered grass-based, organic dairy near Fairfield, Iowa.
From the May | June 2014 Issue