Concentration of CO2 in the Atmosphere

Decarbonizing Heat

To see the article as it appears in print, please load the pdf file HERE.

Making 24/7 onsite renewable heat and power practical

G.E.T. Staff

As we work to move away from fossil fuels for heating and electricity, inexpensive bulk energy storage can make electrifying heating cost-effective. A new thermal storage system from the Norwich Technologies (NT) research and development (R&D) team is poised for commercialization. Based in White River Junction, Vermont, NT has frequently appeared in G.E.T.’s pages and posts. NT is a leader in clean energy solutions for our communities and is introducing their new thermal storage system to the market in a new spin off company called Durion. Durion’s mission is to fully decarbonize commercial and industrial energy loads by providing 24/7 onsite renewable heat and power.

Durion offers a practical, economical, ready-to-use system for 24/7 solar thermal electricity and heat. At the heart of breakthrough is Durion’s proprietary HeatTrap™. It represents the culmination of several years of research and development by the NT R&D team. In their own words:

The Durion’s HeatTrap system uses pressurized hot water in steel pipes to store large amounts of energy simply, efficiently, and inexpensively. We leverage a large existing supply chain to be able to deploy bulk storage cost effectively using primarily steel and water. Bulk inexpensive storage allows Durion to compete with fossil fuel heating at the commercial and industrial scale.

The HeatTrap™ is an elegant solution that consists of an ordinary large diameter steel pipe manufactured by the same companies that supply pipes to the gas and oil industry. This pipe stores hot and cold pressurized water in a closed loop, with an internal traveling separator piston that keeps one end of the pipe at maximum temperature and pressure while isolating not-yet-heated water at the opposite end. The separator piston is a patented technical engineering innovation, developed by the NT R&D team in part under a Department of Energy grant. It is a critical component that enables Durion to minimize system cost.

The working temperature is 300ºC (~570ºF) at 85 bars (~1,230 psi) – with the high-pressure keeping water a liquid at above standard boiling temperatures. The system is modular – more pipe means more capacity – and typically would be sized for 15 or more hours of storage. It can be scaled to deliver between 200 kW to 20 MW of power, thermal or electric or a combination. The high working temperature allows power generation using Organic Rankine Cycle (ORC) engine generators. The system is fully automated in operation. The bulk thermal storage is very low cost, allowing commercial and industrial customers to save money in comparison to retail heat and electricity.

The ideal customers include those who have process heat needs throughout the year (such as food processors like breweries) and organizations requiring 24/7 heat and power (such as a hospital.) As it begins to offer its product, Durion has identified interest from food producers like breweries and greenhouses. They are also finding that suppliers and partners from the oil and gas industry infrastructure supply chain are enthusiastic about this new opportunity to apply their existing skills, labor and procedures toward a new clean energy market.

For most customers, Durion provides a no-upfront-cost option that includes all engineering integration work as well as ongoing operations and maintenance for the system. In the no upfront capital cost program, the customer experiences no upfront capital costs and is guaranteed savings through a pay-as-you-go power and heat purchase agreement. Durion packages their systems in three configurations.

Durion Heat provides 24/7 thermal energy for industrial process heat needs. Energy is generated by electric heating (via the grid or photovoltaics (PV)), or by concentrating solar power (CSP) installed on site or nearby land.

Durion Power provides customers with fully-renewable reliable 24/7 electrical power. Energy is generated with a combination of PV and CSP collectors installed onsite or nearby, with thermal energy stored in the HeatTrap system for on demand delivery as electricity using ORC engine generator technology.

Durion Heat and Power is the company’s most comprehensive product, delivering both electricity and heat from a combination of onsite PV and CSP. It delivers the lowest total energy rates by maximizing the system’s efficiency.

Durion expects early deployments in the northeast will be to supply 24/7 heat using off-peak electricity from the grid and/or PV systems for electric heating. With the HeatTrap thermal storage, electricity can be used for heating when it costs the least, then stored for use when needed. This will allow commercial and industrial users to switch from dependence on fossil fuels for their energy needs, improving their resiliency and climate impact by escaping supply and price volatility. With PV they can fully decarbonize their operations. With the current mix of grid power, they can achieve significant onsite emissions reductions.

With the proliferation of solar as the low-cost way to generate electricity, there is an increasing interest and need for storage options. Utilities are also experimenting with rate structures to encourage more off-peak power consumption. Durion believes the simplicity and economy of their storage system will make it an attractive option for industries seeking energy cost savings and resiliency as they pursue energy independence and aggressive climate impact reduction goals.

Learn more about the Durion thermal energy solution at


Durion’s system in operation at its field test site in partnership with the Department of Energy (DOE) and the University of Louisiana. The proprietary technology can store energy for up to 15 hours to be used directly for industrial process heat applications 24 hours a day, seven days a week. (Durion)

Leave a Reply

You can use these HTML tags

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>