Progress 08/15/19 to 04/14/20

Outputs
Target Audience:The target audience of this project wascommercial electricity customers in rural locations who stand to benefit directly from the cost-savings, increased electric security and resiliency, and reduced greenhouse gas emissions provided by Pecos Wind Power's PW85 turbine. The PW85 wind turbine is primarily designed for behind-the-meter, single load commercial applications. Rated at 85kW, the PW85 can be installed next to schools and universities, agricultural and industrial operations, remote villages, microgrids, and many other electrical applications. During the Phase I project, Pecos Wind Power succesfully reached this audience and received four letters of intent for future Phase IIIpaid projects (provided by the State University of New York at Morrisville, Grace Farms, Burlington Electric Department, and Northeastern Junior College). Additionally, various stakeholders within the disributed wind industry stoodto benefit from the outcomes of this project through increased understanding of high capacity drivetrains for distributed wind turbines. National laboratories, distributed wind turbine manufacturers, project developers, component suppliers, and distributed turbine end-users all can benefit from the lessons learned throughout this project. During the Phase I effort, Pecos Wind Power shared their technical findings with the Distributed Wind Energy Association through a presentation at their 2020 business conference. Our findings were also shared through a design review which engaged individuals from the National Renewable Energy Laboratory, Aegis Renewable Energy, Buffalo Renewables, and several component suppliers. Changes/Problems:During Technical Objective 1 we encountered an unexpected need to incorporate a blade pitch system into the drivetrain design to minimize our turbine's acoustic noise emissions. Initially, we designed the drivetrain to utilize aerodynamic stall to regulate the turbine's power output - the design did not require a blade pitch system. During a design review with wind energy experts at the National Renewable Energy Laboratory (NREL), we were advised that our initial drivetrain design would emit significantly more noise than what we specified in our product requirement specification. The acoustic noise was the result of aerodynamic stalling of the blades when the turbine reached maximum power. The solution was to incorporate a blade pitching system into the drivetrain that would regulate turbine power output while avoiding aerodynamic stalling. Therefore, we modified the hub, main shaft, and gearbox to allow for an internal pitch rod to actuate the blades from a linear roller screw located in the nacelle. While this was a major unexpected hurdle, it was caught in the early stages of the project and therefore did not have a significant impact on Pecos Wind Power's ability to complete the project on-time. What opportunities for training and professional development has the project provided?The project provided a training opportunity for students within the Renewable Energy Program atthe State University of New York at Morrisville (SUNY Morrisville). During the project, Pecos Wind Power's visited SUNY Morrisville to give a presentation to Dr. Philip Hofmeyer and hisstudents regarding the small-wind turbine drivetrain and PW85 turbine that is being developed under the USDA SBIR Project. As part of a Phase III project, SUNY Morrisville has signed a letter of intent to host a customer demonstration project and incorporate the PW85 wind turbine into the workforce development program within the Renewable Energy Curriculum. How have the results been disseminated to communities of interest?Pecos Wind Power presented the results of the USDA SBIR Project at the 2020 Annual Distributed Wind Energy Association Business Meeting in February of 2020 in Washington DC. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Impact: Distributed wind turbines provide local power generation for buildings and communities. Unlike large-scale wind turbines (>2MW, >300ft tall) used for centralized power generation, distributed wind turbines are typically small-scale (<100kW, <150ft) and well suited for on-site power generation for rural homes, schools, and businesses. They present a unique opportunity for rural electricity customers to significantly reduce their exposure to high and volatile electricity prices. The critical problems that have historically limited the deployment of distributed wind turbines are fundamental inabilities to compete on cost with other sources of generation and achieve a high capacity factor in regions of low wind speed. This USDA SBIR Phase I project resulted in the design of a drivetrain that will support a rotor with a swept area 56% greater than existing best-in-class 85-100kW distributed wind turbines. The drivetrain's improved ability to harness power at low wind speed will enable a breakthrough cost of energy of $0.068/kWh, 43.3% less than today's most cost-competitive small-scale wind turbines and 22.7% less than the average avoidable cost of commercial electricity in the United States. The impact of Pecos Wind Power's technology will yield disproportionate benefit to rural America due to the large expanses of open land with abundant low wind resources. As estimated by the Distributed Wind Energy Association (DWEA), the number of properties nationwide with enough space and wind resources for distributed wind turbines could yield nearly 1,100gigawatts (GW) of power- enough to meet 100% of the nation's energy demand. In addition to lower cost electricity, the PW85 will stimulate rural clean-energy manufacturing and create skilled jobs for rural Americans. The overall goal of this USDA SBIR Phase I project was to demonstrate that increasing capacity factor of distributed wind turbines is a technically and economically feasible solution to providing lower cost of electricity to rural areas nationwide. This goal was successfully achieved through the accomplishment of three technical objectives, discussed below. Technical Objective 1: Design a drivetrain for Pecos Wind Power's PW85 distributed wind turbine that utilizes a 30m diameter rotor with a swept area 56% larger than existing mid-size distributed wind turbine rotors. Major Activities Completed: This technical objective began with the creation of a product requirement specification (PRS) to align the specifications of the drivetrain with the technical needs of customers in rural areas. A computer aided design (CAD) and bill of materials (BOM) was then created for a drivetrain configuration that satisfied the aforementioned PRS. The structural suitability of the design was analyzed using finite element analysis. Lastly, the design was subject to a noise analysis to determine noise emissions. Summary Statistics and Discussion of Results: The structural FEA validated the drivetrain's structural suitability for the extreme and fatigue loading of the 30m rotor. The drivetrain produced lower noise-emissions than current distributed wind turbines.The PW85's noise level was calculated to be 44 dBA at 50m (164ft) from the tower base - equivalent to ambient noise levels for a rural nighttime. Key Outcomes or Other Accomplishments Realized: The key outcome of this objective was a change in knowledge surrounding whether a small-scale wind turbine drivetrain can structurally support the increased loading from a rotor with a swept area 56% larger than existing small-scall distributed wind turbines. The result was a drivetrain that utilizes a three-stage gearbox and an induction generator to cost effectively handle a 95% increase in rotor torque. Technical Objective 2: Validate the drivetrain's performance in a computer simulated environment using the National Renewable Energy Laboratory's computer-aided engineering (CAE) tool for aeroelastic simulation of horizontal axis wind turbines, FAST. Major Activities Completed: A computer model of Pecos Wind Power's drivetrain was created for NREL's OpenFAST wind turbine simulation tool. The drivetrain model was subject to design load cases based on worst case extreme and fatigue load events described in IEC61400-1, the international design guideline for wind turbines. Lastly, as an output from the simulations, the performance and design loads of the drivetrain were compared to analytical predictions. Summary Statistics and Discussion of Results: The simulations showed that Pecos Wind Power's drivetrain enables the PW85 turbine to achieve an annual energy production of 322,446Wh and an industry leading capacity factor of 43% in low annual wind speeds of 6m/s. For comparison purposes, the average fleetwide capacity factor in 2018 of similarly sized distributed wind turbines was only 17%. Key Outcomes or Other Accomplishments Realized: The key outcome of this objective was a change in knowledge surrounding how a high-capacity factor drivetrain behaves in extreme turbulence, changes in wind direction, and wind shear. The computer simulations in NREL's OpenFAST CAE tool provided insight to how the drivetrain's performance and loading increase due to a larger rotor. The simulations verified the ability of Pecos Wind Power's drivetrain to achieve the annual energy production and capacity factor that were predicted analytically. Technical Objective 3: Based on the design and performance of the drivetrain, assess the overall environmental and socio-economic impact that the PW85 will have on rural areas in the United States. Major Activities Completed: A cost model of the drivetrain and PW85 turbine was created. The model considered the cost of materials, labor, logistics, and margin for the turbine equipment, balance of station, and operations and maintenance (O&M). The socio-economic impact was determined by first calculating the PW85's "energy payback period". Pecos Wind Power's impact on rural job growth was estimated by determining the personnel required to achieve 2030 sales targets. Summary Statistics and Discussion of Results: The cost and performance of the drivetrain will enable the PW85's levelized cost of energy (LCOE) to achieve $0.068/kWh, 43.3% lower than the most cost-competitive 85-100kW wind turbine installations in 2018. We found that with an AEP of 322,446 in 6m/s annual winds, the PW85 will require approximately 18 months to offset the energy and carbon emissions that were (and will be) required to manufacture, transport, construct, operate, decommission, and recycle it. Based on average US grid electricity emissions, the PW85 will offset 394,029lbs of CO2 per year, equivalent to taking approximately 31 cars off the road. To achieve Pecos Wind Power's target sales volume of 1,500 turbines/year we will require an estimated engineering and sales team of 16 personnel, a manufacturing team of 35 personnel, and an installation team of 28 personnel. In total, a need for at least 79 skilled workers by 2030. In an effort to co-locate with the market for distributed wind power, these jobs will be disproportionally created in rural America. Key Outcomes or Other Accomplishments Realized: The key outcome of this objective was a change in knowledge about the quantified socio-economic impact that a high capacity distributed wind turbine drivetrain will have on rural America. The R&D resulting from this Phase I SBIR project has indicated the potential for Pecos Wind Power's PW85 distributed wind turbines to achieve an LCOE of $0.068/kWh. Considering the average avoidable cost of commercial electricity in the United States is $0.0879/kWh, the PW85 will bring considerable cost reductions to rural businesses, schools, farms, and communities - a key enabler of rural economic growth.

Publications

• Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Presentation at the 2020 Distributed Wind Energy Association Business Conference. https://distributedwind.org/distributed-wind-2020-agenda/