Submitted to: National Solar Conference
Publication Type: Proceedings
Publication Acceptance Date: 4/5/2006
Publication Date: 8/1/2006
Citation: Vick, B.D., Clark, R.N. 2006. Large scale deployment of renewable energy by combining wind farms with solar thermal power plants. In: Proceedings of the American Solar Energy Society Annual Conference, July 8-13, 2006, Denver, Colorado. 2006 CDROM.
Interpretive Summary: The amount of CO2 (carbon dioxide) in the atmosphere is increasing at an alarming rate, and most climatologists believe this increase in CO2 is causing global warming. The burning of fossil fuels (coal, natural gas, oil) in power plants is one of the main contributors to the rapid CO2 increase, and replacing most of the aging fossil fuel burning power plants with wind and solar generated electricity should significantly slow the CO2 increase. Wind farms installed at Class 4 wind sites in the Texas Panhandle and Central West Texas have shown that the cost of electricity generated by these wind farms is only $0.04/kWh (currently the cheapest form of new electrical energy). However, the electricity generated by the wind farm during the day does not usually match the electrical load of the utility – in fact; the average is nearly the complete opposite (e.g. the lowest average annual wind generated electricity is in the afternoon when the highest average annual utility electrical load occurs). Also, in Texas, the highest electrical load occurs in the summer which is when the lowest average wind generated electricity occurs. Solar thermal power plants have operated very well in the Mojave Desert in California for fifteen years and a 65 MW solar thermal power plant is currently being constructed near Boulder City in Nevada – although the price of this solar thermal generated electricity is estimated to be about three times that of wind farms in windy areas. Solar thermal power plant generated electricity was estimated for three regions of Texas: Texas Panhandle (Bushland), Central West Texas (Lamesa), and Far West Texas (Presidio and Sierra Blanca). The solar thermal power estimated for Sierra Blanca was estimated to be the same as that at Barstow, CA – close to where 354 MW of solar thermal power plants are operating in California. It was found that combining wind farms with solar thermal power plants in the Texas Panhandle and Central West Texas resulted in a good match to the utility electrical load during the day and during the year, and if some of the electricity was stored then virtually a perfect match could be achieved
Technical Abstract: The installation of megawatt-size wind turbines on 65 to 80 meter towers at Class 4 wind sites in Texas has resulted in the cheapest form of renewable energy ($0.04/kWh). However, wind farm output has a diurnal mismatch to the utility electrical loading. Combining solar thermal power plants with wind farms was shown to result in a good match to the utility loading, and if storage was used then virtually a perfect match could be achieved. The seasonal mismatch for wind farms (i.e. peak load occurs in summer when wind energy is at a minimum) was also improved significantly by combining solar with wind. The peak electrical load during the year is critical to a utility and a wind/solar hybrid was shown to be much better to the utility than a wind alone system for the two regions studied: the Texas Panhandle and Central West Texas.