Thermal Energy Storage: The PCM- Eutectic Solution

Energy use has always been one of the costs of doing business, and like taxes, is an expense that will probably never go away. Unlike taxes, though, energy expense is something over which the business owner can exercise great control, providing that the best technology is sought after and utilized.

For example, in order to reduce the energy costs and environmental impact associated with heating and cooling, businesses have many options, but only a few that will yield substantial savings. By storing energy for subsequent reuse, "Thermal energy storage" (TES) technology encompasses the best of those options.

TES offers building owners a way to substantially reduce energy costs by using electric power- available during cheaper off-peak time periods- to create ice or chilled water that can be stored and later utilized during peak electricity hours.

The three most efficient storage systems are as follows:

A) Chilled water: Requiring larger tanks. B) Ice: Requiring complex and inefficient low-temperature chillers. C) Eutectic salts: Requiring smaller tanks than chilled water systems.

Of the three systems, those utilizing eutectic salt solutions are the most advantageous. The reason for this has to do with the nature of the salts.

Being salt-based, a modified eutectic solution- better known as Phase Change Material (PCM)- contains additives which encourage crystal formation and stabilization of the mixture.

The result is a solution that- unlike ice or chilled water- has a melting/freezing point above or below 0 C (32 F). This property gives the PCM a thermal energy storage range from 164 C (327 F) to 114 C (173 F). In short, this range gives a machine operator the ability to freeze the solution at a temperature other than 0 C.

In a factory environment, PCM systems:

Cost less to maintain. Use less energy than ice systems. Take up less storage space than chilled water systems, resulting in low media costs. Can be installed as part of a retrofit without having to replace existing chillers.

Due to the corrosive properties of salt-based eutectic solutions, plastic piping and corrosion- resistant tanks are used to distribute and store PCM's, resulting in a more environmentally friendly solution, from a maintenance standpoint.

Financial incentives for business owners can take many forms, inside and outside the walls of the building. Many municipalities offer rebates to companies that substantially reduce energy usage.

The city of Austin, Texas has a Power Saver program which offers:

Rebates of up to $300 per KW of energy reduction (for qualified participants). A Feasibility Study incentive of 50% of the cost of a Feasibility Study. Up to $7,000 for new and existing construction (based o the Study application).

The savings realized by participation in energy reduction plans can help offset the cost of resulting retrofits or other building projects.

In the long term, changes made on the factory floor will not only increase productivity and profitability, but show your employees and the community that your business is doing its part to use energy resources responsibly.

Learn more about this author, Dan Hiland.
Click here to send this author comments or questions.

---

Add your voice

Know something about Determine the best sources of energy for the future?
We want to hear your view. Write now!