All Power Labs addressed technical challenges through an iterative process of physical testing and refinement. This approach enabled the team to implement a distributed testing approach proving and maturing individual components, then integrating all systems together to better understand how all components work together. The development of the Powertainer flare represents a good example of this process. The flare uses an automated mixing system to control the stability of combustion inside the flare. The team designed and assembled the flare as a standalone system to isolate the testing of the automated mixing system. After understanding and confirming the flare’s performance, the project team installed it on the Powertainer for further testing and refinement.
The non-technical challenges focused on regulatory, interconnection, and permitting requirements, which were complex and costly considering the scale of the project installation. Some of the complication relates to non-standardized air quality permitting requirements that make permitting simpler in some jurisdictions and more difficult in others. Others include flat rate permitting costs for systems regardless of the system’s size. Unless regulatory requirements change, it will be difficult and expensive to prove the performance and viability of a gasification system when connected to the electric grid, especially for small, distributedscale projects. Exacerbating the issue is the reality that small-scale, portable biomass generation equipment is new, compared to established technology; and that regulatory requirements are not suited for this specific architecture and portable project model.
Project Results
The project team completed and demonstrated the Powertainer prototype. The final product included changes from the original proposal. Site and regulatory challenges prevented the project from operating the Powertainer at its intended site in Placer County, with grid interconnection. Instead, the project team conducted the final performance testing at the All Power Labs facility in Berkeley, without an interconnection.
During the 40 hours of off-grid performance testing, the technology met the majority of the performance targets set in the testing plan. However, it is worth noting that the Powertainer was not able to reach the expected electrical output of 150-killowatt during this test period. The team expects that the lower electrical output is the result of a pressure drop caused by “bell packing” (which is where producer gas is choked off and does not flow consistently through the cross section of the gasifier restriction) in the gasifier’s ash-removal system, preventing an adequate amount of gas to get to the engine. The team thinks this issue can be resolved by improving the grate basket design in the gasifier’s ash removal system to enable the spent char to exit the system without inhibiting gas flow.
Despite some design issues, the Powertainer demonstrated its ability to use forestry biomass waste to create portable clean renewable energy. Through the project, the Powertainer demonstrated many competitive advantages, such as its small-scale design, portable architecture, capital cost, fuel flexibility, and production of electricity and biochar. This multimodel design maximizes the climate impact value of this technology, making it a unique carbon-negative emissions technology. The Powertainer is still in a prototype testing stage and requires additional testing and refinement before the technology will be ready for commercial deployment. Changes in regulatory and permitting requirements would facilitate the deployment of the Powertainer product.
