No abstract

The primary objective of the project is to evaluate the benefits of wind and solar energy and determine economical investment sites for wind and solar energy in Texas with economic parameters including payback periods. A 50 kW wind turbine system and a 42 kW PV system were used to collect field data. Data analysis enabled yearly energy production and payback period of the two systems. The average payback period of a solar PV system was found to be within a range of 2-20 years because the large range of the payback period for PV systems were heavily influenced by incentives. This is in contrast to wind energy, where the most important factor was found to be wind resources of a region. Payback period for the installed wind system in Texas with federal tax credits was determined to be approximately 13 years.

No abstract

Flow visualization techniques were used to study the flows over the Enertech 21-5, Carter 25, and Enertech 44-50. Despite centrifugal effects superimposed on the aerodynamics, tufting (gross aerodynamic behavior) and oil flow (average boundary layer behavior), tests reveal the nature and many of the details of the flows involved. Results were compared to expected flow patterns based on angles of attack calculated from the PROPPC code. Chord Reynolds numbers ranged between 75,000 (Enertech 21-5) to 1,340,000 (Enertech 44-50). The typical low Reynolds number flow characteristics of these airfoils, including laminar separation bubbles, turbulent reattachment, and complete separation were observed. Full or partial reattachment due to tower shadow was observed on each machine. Spanwise flow was observed near the leading edge of the Enertech 21-5. Cyclic radial flow from tower dam effect was also noted.