I listened to the podcast with Elon Musk and Peter Diamandis talking about the $100 million prize for carbon removal. Mr. Musk pointed out that whatever technology is proposed, it has to work to win the prize. That means something has to be built and operated for a sufficient period of time to be convincing that the technology actually works. The pilot scale that is proposed is 1000 tons per year of CO2. That corresponds to roughly 100 lb/hr of a fuel like natural gas being burned and generating that much CO2. In the power industry, that would be a small scale pilot plant. Proof of principle would be done at the bench scale level. Proof of principle would show that the technology might possibly work, but would not be sufficient to provide the type of data needed to scale up a process to large size equipment. A pilot plant could do that, provided it were large enough to minimize interferences imposed on small scale experiments (boundary effects, surface to volume issues, mixing issues, etc.). Typically, in the power industry, there would be another step after a small scale pilot plant to try to learn about scale up problems. Then there would be a small commercial demonstration to be followed by a large scale demonstration. Thus, the level being proposed would be a preliminary step towards full scale up. Even so, such test facilities cost on the order of $1 - 2 million. They are big enough to encounter many of the issues that larger scale plants will have to confront such as startup, control systems, and shutdown procedures. That being said, typically a 30 day, continuous run is usually required to demonstrate that there are no adverse impacts from longer term operation. These might involve build up of unwanted chemicals, fouling of catalysts, corrosion issues, etc. In the CarbonXPRIZE, one team that accomplished a full 30 day run found that they had a film buildup on one of their electrodes which caused a performance degradation. When the electrode was cleaned, performance was restored. That type of data is extremely important for commercial operation. The worst thing that can happen for the introduction of a new technology for commercialization is to have the performance fail after a short period of time at the customer’s plant. In summary, I think the 4 year time period is too short. I have mentioned this before. It will take some time to properly design, build, commission, test, and execute a 30 day run. An extra year is probably required. The proposed size is probably OK, recognizing that a lot more work will have to be done to scale up. Finally, a 30 day, continuous run should be an absolute requirement in order to meet Mr. Musk’s statement that the technology “must work”.