Commercial, Industrial, Solar  -  December 1, 2017 - By William Guiney

Why businesses are turning to solar thermal energy

As corporations continue to sharpen their focus on carbon reduction, interest in using solar thermal collectors to generate the heat needed for industrial processes and applications has grown. More than 4.3 million square feet of solar collectors produce solar heat for industrial processes around the globe generating more than 280 MWth.

Thermal energy and steam are required for industrial processes. From the extraction of raw materials like oil and gas, mining, food and beverage processing, sanitation, commercial laundries and distillation, heat is a vital part of the processing and manufacturing sectors. Why are more and more organizations turning to this technology?

The solar thermal collection technologies are field-proven. In the past 15-20 years, product research and development and improved manufacturing have created a new generation of simple, reliable, efficient solar water heating systems. Modeling tools are available to predict system performance, costs, energy savings and return on investment based on local sun and weather conditions.

Solar heating technologies can pre-heat boilers, re-heat condensate, heat air, evaporate liquid waste or provide a full range of temperatures from 80 to 400 degrees Fahreinheit for manufacturing processes.

There are also collectors on the market which do not require tracking and some can be installed in any climate (absorbing both direct and indirect radiation) to produce industrial process heat for all the applications listed above. The solar thermal system integrates easily with any commercial boiler. The solar array can preheat make-up water to a boiler and/or reheat steam condensate. The technology can heat any type of fluid by using a heat exchanger. The heat exchanger is specific to the type of fluid being heated which means no fluid other than the solar heat transfer fluid is pumped through the solar array. Heat is transferred to the process fluid in the heat exchanger.

All industrial process heat systems will have a solar storage tank. The storage tank can be sized to the daily load as an example; the sanitation for a meat processing facility may use up to 100,000 gallons of 160-180 degree water during the evening sanitation shift. In these cases the storage tank would be sized for 100% of the load or a smaller solar fraction selected by the customer. In some applications a buffer storage tank is used for buildings where all the heat transferred from the solar array in the heat exchanger is used immediately by the facility. Hospitals are an example of large hot water loads during the daylight periods and will typically not have enough roof area for a large solar fraction or percentage of load.

Storage can be inside the building or on a pad outside of the mechanical room. The system designs are very simple and these standard solar thermal designs have been used for years around the globe in many applications.

The operation and maintenance of non-tracking solar heating systems is very low, because they do not require tracking systems and are fixed in position when installed. The only moving parts on the system are the circulation pumps for the HTF and the process fluid being heated. The pumps are controlled by a digital differential controller sensing the heat available in the solar array. Monitoring systems can verify the daily solar production, flow rates and temperatures.

Solar thermal systems:

• can produce temperatures up to 400 degrees Fahrenheit, depending on the manufacturer;
• offer significant reductions in greenhouse gases;
• are cost effective and have great return on investment.

Focused on growing the solar heating & cooling market through reducing barriers and advocating for policies on the federal, state, and local levels, the U.S. Solar Heating & Cooling Alliance, a division of the Solar Energy Industries Association, is a great first stop for additional information on solar IPH applications. 

William (Bill) Guiney has more than 30-years of experience in the solar industry as a retailer, contractor, distributor, manufacturer and educator and serves as president and CEO of Artic Solar Inc., a high temperature solar thermal collector manufacturer and integrator of complete advanced high temperature solar thermal systems for industrial process heat and cooling systems. Previously, Bill was the director of the solar heating and cooling business at Johnson Controls Inc.; his previous positions at the company included program director for global renewable energy development and program manager for the development of the PV and solar thermal business. Bill is the primary solar thermal instructor for both the North Carolina and Florida Solar Energy Centers. He has chaired the Entry Level Solar Thermal Committee for the North American Board of Certified Energy Practitioners, has been active in many states' solar organizations and currently serves on the Solar Heating & Cooling Alliance of the Solar Energy Industries Association.