Maps Dispel Perceptions that Solar Energy is Consistent From Year to Year
3TIER®, a global leader in renewable energy information services, today released maps illustrating how solar irradiance varied from its normal monthly averages across the U.S. from June through August, 2010. The maps dispel a popular perception that solar energy is relatively consistent from year to year and underscore the need for thorough resource assessments prior to investing in solar projects. Variances in solar irradiance, which are caused by short-term weather anomalies, have a significant impact on the long-term economic viability of both distributed and utility-scale solar power development.
“The patterns observed in the solar maps correlate well with the series of weather events that affected the U.S. during these same months,” said Dr. Bart Nijssen, senior vice president of technology at 3TIER. “The variances are quite significant, often in excess of plus or minus 20% of normal. This highlights the need to look beyond basic climatology, or the notion that ‘it’s always sunny here,’ when evaluating a site for development. 3TIER can help developers and financiers quantify and anticipate the variability of their solar resource over the long-term.”
Notable takeaways from the three-month study on solar performance include:
- June: The North Atlantic High delivered unusually high solar irradiance to the eastern seaboard and southeastern states – it was the hottest June on record in Delaware, New Jersey and North Carolina. Meanwhile, an upper-level trough over the northwestern quarter of the country depressed irradiance in the Pacific Northwest and upper Midwest. Record-breaking precipitation was recorded in Michigan and near record-breaking rainfall was experienced in Iowa, Illinois and Nebraska.
- July: As the North Atlantic High continued to drive high irradiance values along the East Coast, Hurricane Alex and Tropical Storm Bonnie reduced irradiance and temperatures in Texas and the Midwest. Coastal California had a persistent marine layer all month resulting in below average irradiance.
- August: Solar irradiance and temperatures remained above average in much of the country. However, in the Southeast higher temperatures combined with higher than average atmospheric water vapor content produced unusually high cloudiness and rainfall, pushing irradiance below its monthly mean. Likewise, parts of Montana experienced above average rainfall and cloudiness, while solar irradiance along the California Coast remained below normal due to persistent morning fog.
The monthly maps for both Global Horizontal Irradiance (GHI) and Direct Normal Irradiance (DNI) and a more detailed summary of the study can be found at: http://www.3tier.com/en/docs/3TIER_Solar_Anomaly_June_August_2010.pdf
“Solar power development in the U.S. is driven more by government incentives than production potential right now,” said Kenneth Westrick, founder and CEO of 3TIER. “However, as the industry matures and policy becomes more performance-oriented, projects will be more rigorously scrutinized for their long-term energy production potential. 3TIER offers a full suite of products that enable that today.”
Based on the most advanced and accurate dataset of global solar resources, 3TIER offers a full range of products that enable project developers to quantify the long-term availability and variability of solar resources with or without observational data, anywhere in the world. Some of 3TIER’s products include:
- Solar Prospecting Tools provide instant online access to annual and monthly GHI, DNI and DIF values at any location worldwide for early-stage siting. 3TIER also provides this information via an Application Programming Interface (API) and in the form of GIS data layers to facilitate efficient broad scale development planning.
- FullView Assessment, which is appropriate for projects in the financing stage of development, provides a more in-depth analysis with reduced error and uncertainty by correcting bias within the dataset based on any available onsite observational data. The analysis also includes data on other atmospheric factors, such as variations in temperature and wind speed, which have a significant impact on power production.
For more information about 3TIER’s solar products please visit: http://www.3tier.com/en/products/solar/.
Founded in 1999, 3TIER is one of the largest independent providers of wind, solar and hydro energy assessment and power forecasting worldwide. People around the world turn to 3TIER when they want the best scientific information to make decisions about renewable energy projects — from the prospecting stage to operations. For more information, visit www.3tier.com.