Solar Thermal Pasteurization and Refrigeration for Milk and Dairy Products

The economic impact of the Dairy Industry is significant in almost every region of the United States. In fact, for several states, the Dairy Industry is the main economic driver. There are approximately 9.35 million dairy cows in the U.S., collectively producing about 226.9 billion pounds of milk in 2023. This total represents 24,265 pounds of milk per cow each year.

Although the sales of milk are down and margins are lower due to the cost of energy and higher feed prices, the industry is on solid footing to invest in production and reduce production costs. Dairy products are forecasted to continue modest growth.

Fluid Milk Processing is Energy Intensive All Along the Production Line and Supply Chain

Worldwide, the dairy industry has set a goal of reducing GHG emissions and other environmental impacts associated with milk processing. Although the major GHG emissions associated with milk production occur on the farm, most energy usage related to milk processing happens at the processing plant and during refrigerated storage. Refrigeration is a key requirement for the transportation, retail, and consumption of most milk products.

Sustainable alternatives and designs for dairy processing plants of the future are actively being explored by the global dairy industry. The goal is to improve efficiency, reduce costs, and comply with corporate social responsibilities.

Energy Usage in Dairy Farms

Dairy farms use more energy now than they have in the past due to larger farms, increased automation, and 24/7 operations. U.S. dairy farms typically consume 800 to 1,200 kilowatt-hours (kWh) per cow annually. About 50% of this energy is used for milk production equipment, including milk cooling, vacuum pumps, and water heating. Other major energy consumers include lighting and ventilation.

Improving Energy Efficiency in Dairy Processing

Energy efficiency improvements are crucial for dairy processing plants to reduce costs, lower emissions, and minimize exposure to volatile energy prices. Artic Solar provides energy efficiency opportunities for steam systems, refrigeration, anaerobic digesters, and key unit operations involved in processing dairy products.

We have developed an innovative solution to reduce the temperature of milk from the parlor (101°F) to 36°F for transportation by using a drop-on-site, plug-and-play Hybrid Solar/Gas Absorption chiller. These units leverage solar energy, biogas from farm digesters, LPG, and natural gas as backup sources, resulting in significant electricity cost savings for refrigeration. They also offer an alternative to conventional electric vapor compressor systems.

The Hybrid Solar/Gas Chiller Technology

Our high-efficiency, solar-driven Double Effect Absorption Chiller integrates innovative non-tracking Externally Concentrating Parabolic Collector (XCPC) technology (US Patent 9,383,120). A supplemental heater using digester biogas or natural gas ensures high efficiency and on-demand refrigeration/cooling and heating 24/7.

This Hybrid Solar/Gas Dairy Milking Parlor Cooling/Refrigeration product is market-ready. The XCPC Concentrating Solar Thermal technology achieves temperatures exceeding 230°C with 45% efficiency, even in diffused or hazy conditions—performance that market incumbents cannot achieve without tracking or direct sunlight.

A second-generation laboratory prototype XCPC has been successfully tested with a 6.6-ton double-effect chiller at the University of California Solar Lab. The technology continues to improve, with third-generation XCPC units manufactured in Jacksonville, Florida, increasing reliability and efficiency.

Economic and Environmental Benefits

When the XCPC collector is paired with a 30-50-ton double-effect chiller, it reduces life cycle cooling costs to levels comparable with conventional electric systems. The anticipated payback period is 3-5 years, with an even shorter ROI when utilizing farm-generated biogas for continuous operation.

In addition to cooling, the system captures condenser-side heat for water heating used in dairy sanitation, providing additional energy savings. This combined benefit significantly reduces operational energy costs for dairy farms.

Ensuring Dairy Product Quality

Milk quality is critically important to farmers, as bacteria content affects the price they receive for their product. Typical milking processes involve heat exchangers prone to bacterial buildup, which must be cleaned with hot water and chemicals.

Standard water heaters operating at 140°F to 150°F are insufficient for proper sanitation. The XCPC technology generates temperatures exceeding 160°F, ensuring effective cleaning of piping and heat exchangers. This higher sanitation standard improves herd health and milk quality.

Solar Thermal for Dairy Industry Growth

Whether for solar cooling or high-temperature solar thermal sanitation, Artic Solar and the XCPC technology provide cost-effective, high-quality solutions for the dairy industry. Our innovations not only support dairy farmers but also provide savings for milk processors, helping create a healthier and more sustainable dairy supply chain.

Financial Incentives for Solar Adoption

Investing in renewable energy in 2024 is more accessible than ever. The Federal Investment Tax Credit covers 40% of total installed costs. Additionally, the USDA Rural Energy for America Program (REAP) offers grants covering up to 50% of project costs. When combined, these incentives drastically reduce upfront costs for farmers.

Farmers with low tax liabilities can sell their tax credits to third parties. Combining solar thermal and photovoltaic systems significantly reduces dairy farm energy costs, with some projects achieving immediate ROI and positive cash flow in the first year.

Conclusion

Reducing energy consumption, improving herd health, and enhancing milk quality are now achievable realities. Artic Solar’s Hybrid Solar/Gas Chiller and XCPC technology provide reliable, cost-effective, and sustainable solutions for modern dairy farms.