12.1. Market Overview for Solar Thermal Energy

What is the main rationale for detailed market analysis in solar energy field today?

Understanding the current state of the market and future trends will help with the following:  

• Identifying key growth and investment opportunities in the global solar thermal market;
• Identifying key players and stake holders on market and their strategic moves;
• Making decisions with respect to technology development based on history and forecast data
• Develop business strategies based on the latest economy, customer base, and policy related to the solar thermal field
• Dealing with potential issues and restraints
• Minimizing economic risks

Solar thermal energy markets are diverse and range widely in their fields of application. We can identify six main market areas:

• Solar water heating
• Building heating
• Solar cooling
• Industrial process heat
• Thermal power systems
• Solar ponds

Each of these fields is briefly summarized below. Note that each field may have their own trends in market, which depend on local conditions, economy, and policies.

Solar water heating is performed all over the world and is one of the most widely used forms of solar thermal energy. Systems can be active with a mechanical pump, or passive with either a thermosyphon or geyser pump driving the fluid flow through the collector(s). Additionally, collectors can be constructed from a range of materials as simple as plastic sheets, laminated together with no glazing, for pool heating and as complex as multi-layered glass over black copper fins in a black aluminum enclosure.

Solar building heating can also be an active or passive activity. While active solar building heating is very similar in nature to solar water heating, passive solar building heating design results in some creative and interesting architectural requirements that are derived from the use of strategically placed thermal mass and the subsequent aperture requirements to effectively use a building as a solar thermal collector with high heat capacitance. Passive solar building design is a large field that combines meteorology, thermodynamics, fluid mechanics, and human thermal comfort. The Passive House (Passivhaus) Standard is the highest bar that is widely used for designing buildings that use significantly less energy than is required by most building codes. Solar heat gains are one of the required energy inputs to accomplish this level of energy reduction in a building.

Solar cooling has been a field of great interest for many people for many years. The concept of using heat from the sun to drive a cooling process that exists primarily because of that same source, the sun, is very desirable. This is because if solar radiation is not available over some time frame, presumably the loss of that source of heat reduces the cooling loads over that same time frame. Coupling the cooling source’s energy supply to a same driver of the cooling loads enables a balanced system design. Methods for solar cooling include desiccants, absorption chillers, mechanical systems such as Rankine engines, and passive systems.

Solar industrial process heat can range in use case from large textile factories to small rural agricultural processes and anything in between. Any industrial process that requires heat (particularly as steam) can be integrated with a solar thermal energy conversion system to increase the solar utility of that company or individual. This is particularly applicable in cases where a solar thermal system can supplement either an existing heat system such as steam or a process that does not need to run continuously and can instead run in batches when the sun is shining with sufficient intensity to generate the heat required.

Solar thermal power systems are one of the most publicized forms of solar thermal heat. Using solar thermal energy to generate high quality steam for use in a standard electricity generating steam turbine is happening world wide on the scale of hundreds of MWs of power, the largest of which, at 392 MW, is currently the Ivanpah Solar Power Facility in California that we read about in an earlier lesson. These types of systems have been under development for several decades now, and have now started crossing over the levelized cost of energy barrier through cost reductions and economies of scale.

Solar ponds can be used for multiple purposes ranging from active electrical power generation to distilling water and producing salt. Most of the solar pond research and testing for novel applications has occurred in Israel. One of the oldest solar driven evaporative processes is the production of salt, which occurs worldwide and accounts for about one third of the world’s annual salt production.

All of these STE markets have been capitalized on to some extent, but all of them have a lot more room to grow in both research as well as implementation. As energy costs continue to rise, solar energy of all forms may become more attractive in various locations. When working in any field, it is good to know what alternatives and options are available as both competitors in your sector (one solar thermal water heating system versus another) as well as alternative application of your core technology (solar thermal concentrators for power generation versus industrial processes).