Frequently Asked Questions

Is the Cube for sale yet?
No, the Cube is not yet for sale. However, there has been tremendous interest in buying single and multiple units. Therefore, Redox is considering interested early adopters who have applications for hundreds or thousands of Cubes. Send your expressions of interest to the email address.

Does Redox sell internationally?
No, the Cube is not yet for sale. Furthermore, before expanding internationally Redox intends to first enter markets within the United States. We are, however, interested in hearing about interest in different countries. Send your expressions of international interest to the email address.

How can I become a distributer for future Redox products?
Redox is not yet ready to contract with distributers, but we are interested in hearing from potential future distributors. Send your expressions of interest to

Does Redox have any products that are smaller than 25 kW?
No, the first Redox Cubes will be rated at 25 kW. Redox chose the 25 kW size to address a market which is currently underserved and also to take advantage of certain economies of scale with respect to certain commercial off-the-shelf components that make up the system. In the future, we may consider scaling down systems to as low as the 1 kW size.

Does Redox have any products that are larger than 25 kW?
No, the first Redox Cubes will be rated at 25 kW. However, the Cube is designed to be interconnected to address power needs greater than 25 kW. In the future, we may consider scaling up systems to sizes larger than 25 kW.

Does Redox plan on making any mobile or portable products?
While our technology has many advantages such as a high power density that would allow us to develop products for mobile or portable power applications, Redox is currently focused on stationary power products for distributed generation.

Does the Cube produce AC or DC electricity?
The Cube produces DC and can be configured for different DC output voltages depending on the application and size of order. AC power requires an inverter, which can be added externally if desired.

How much will electricity cost when the Cube uses natural gas fuel?
The cost of natural gas, which varies considerably throughout the United States and the world, is the major factor when trying to determine an average price for generating electricity. However, given the high fuel to electricity conversion efficiency the cost will be lower than utility/grid electricity.

What is the overall efficiency of a Redox Cube system?
Efficiency depends on the application and load profile. On average, we estimate that the overall system fuel to electricity conversion efficiency will be from 50% to 60% in most applications. In combined heat and power (CHP) configurations the efficiency will be in excess of 80%.

Is the Redox Cube environmentally friendly?
Yes, the Cube is highly efficient and has additional environmental benefits because of the advanced solid oxide fuel cell technology inside. Unlike gas turbines or internal combustion engines, the Cube has negligible NOx, SOx, and CO emissions and a more constant efficiency across partial loads. Moreover, due to the Cube’s high efficiency the system produces much less CO2/kWh than competing combustion based options. In the future, Cubes could even be configured to run on biofuels making this a net zero CO2 source of electricity.

Can the Redox Cube use fuels other than natural gas?
The current Cube system is designed to run primarily on natural gas, but the units will also work with propane. While all fuel cells can utilize hydrogen, solid oxide fuel cells (SOFCs) can also use a variety of hydrocarbon fuels such as gasoline, diesel, and sustainable biofuels. The Redox SOFC is no exception, and therefore future system designs may allow for the use of a wider choice of fuel options.

What is the anticipated lifetime of the Redox Cube?
Under most operating scenarios a system such as the Cube should last for 10 years or more. Right now there is insufficient test data to validate this so initial systems will be sold with a warranty to alleviate any lifetime concerns.

At what temperature does the current Redox fuel cell technology operate?
It operates at ~650 °C (1,200 °F).

What are the advantages of the Redox technology’s lower operating temperature?
Lower operating temperatures allow use of lower cost materials, thus, reducing capital cost. Lower temperatures also dramatically improve system lifetime. Redox is working to lower the operating temperature even further to ~400-500 °C while maintaining high power density to add features that will make Redox Cube even more robust and versatile.