In early October, construction was completed on a solar energy system at Whitesides Dairy near Rupert, Idaho. This is the first dairy operation to install a solar energy system of this size in the state of Idaho. Carl Simpson, CFO for Silk Road Solar and Silk Road Environmental, based out of Kennewick, Washington, helped coordinate, design and install the system. Simpson also helped organize and write grant applications that helped to make this project feasible. Simpson initially met Steve and Brandon Whitesides, owners of Whitesides Dairy, on a trip to look at their dairy’s digesters, which were shut down. He had thought of purchasing and restarting them in the future. On a following trip, Simpson mentioned Silk Road’s solar energy systems.

“We were going to use the solar systems in conjunction with the digesters to warm up, digest and produce bio-gas that would be used as an energy source on the dairy,” Simpson says.

Simpson later returned to the Whitesides’ dairy to specifically show them the solar energy system. Instead of continuing with the digester idea, the use of solar energy was shifted to a different area on the dairy.

“I wanted to look into cost savings, especially in our fuel and heating expenses,” says Steve Whitesides.

The solar energy was planned to heat the water used in the clean-up process between milking cycles. Once the Whitesides approved the installation, Simpson began to scope out and design the project.


Cows are milked three times a day and a clean-up is required between milking cycles. Each clean-up cycle uses nearly 330 gallons of hot water. In total, the dairy was using 1,000 gallons of water for clean-up every day and heating that water to 165 degrees Fahrenheit utilizing propane. Heating the water using propane was costing the operation approximately $30,000 per year.

The solar energy design includes setting up 30 individual panels, with 20 vacuum tubes in each panel. Each tube is vacuum-sealed to prevent heat loss when radiation is absorbed from the sun. A copper solar heat pipe inside each tube moves the energy from the sun to the panel’s header, where the heat exchange takes place. If a tube happens to break, water does not leak out because it stays in the header.

The system has five solar runs with six panels on each of the runs and five separate pumps to pump the water out to the panels from the boiler room. After the water has passed through the panel headers, it returns to the boiler room. Digital thermostats are used to validate the energy produced by measuring the temperature on the cold water going out as well as the hot water coming back on that same line.

With help from Simpson, the Whitesides applied for two grants: one from the USDA as part of the 2008 Farm Bill and a grant from the Treasury Department.

The USDA has a grant available to producers through the Rural Energy for America Program (REAP), if they install renewable energy systems or make improvements to increase energy efficiency. If the producer meets the eligibility requirements, the grant covers up to 25 percent of the project’s cost.


Also, in 2009, the American Recovery and Reinvestment Tax Act was created to stimulate jobs and promote economic recovery. However, this act also promoted the installation of renewable energy projects and assured reimbursement payments from the Treasury Department as a payback for a portion of the project’s expenses. Producers can either use this as an investment tax credit, which would exist beyond the end of 2010, or fill out the grant application form upon completion of the project. This grant, summarized in section 1603 of the act, is scheduled to expire at the end of this year.

Exploring grant options was one of the processes for the Whitesides’ project. However, a key factor for Silk Road Environment when designing these projects is matching up the operation’s energy usage with the amount of energy the system will create.

On October 5, performance tests conducted on this system indicated an unexpected result. Even on a foggy, overcast day, over one million British thermal units (BTUs) of energy were created, while the panels were estimated to create only 900,000 BTU.

Additionally, Simpson points out that for each panel that is installed, one ton of carbon is offset each year. For the Whitesides’ project, it means that for the life of the system, 30 tons of carbon will be offset each year. Over the course of 20 years, 600 tons of carbon will be diverted.

The entire cost of installing this system was $40,000. However, Simpson says that these solar projects are scalable to meet the individual energy needs of each dairy.

“One of our key values as a company is to make these projects affordable,” Simpson says. “We are doing it to help the dairymen and help the environment by offsetting the carbon amount released.”

These solar energy systems have a warranty of ten years but are expected to last 20. This specific project is expected to pay for itself within a year. The dairy owners will then have 19 years where they will not need to buy propane, which will equal more than half a million dollars in savings. Maintenance should be minimal, including keeping the glass tubes clean so that they function properly, which is done by rinsing them off with a water hose.

Simpson believes that by repeating the process of installing these systems at other dairies, milk and cheese processing plants or other related businesses, a significant amount of the carbon impact would be taken out of the supply chain of dairy products.

Simpson hopes to continue installing these solar energy systems at other dairy operations while sending producers to the USDA to request REAP grants for their energy projects.

“I grew up on a farm so I have some good kinsmanship for how hard these dairy farmers work,” Simpson says. “I just like the idea of helping them financially and also environmentally to make their businesses better.” PD

For more information, contact Carl Simpson at or (208) 577-6537

PHOTO: These solar energy systems have a warranty of 10 years, but are expected to last 20. This specific project is expected to pay for itself within a year. Solar panel photo courtesy of Carl Simpson.