Those interested in getting solar panels for their homes could benefit from a new, interactive University of Hawaii at Manoa website that will provide an estimate of how much solar radiation reaches their rooftops.
"Rooftop solar energy is, I think, going to benefit a lot from this because people are going to get a very accurate estimate of how much solar radiation their rooftop receives," said Thomas Giambelluca, a UH hydrologist and climatologist. "They can estimate the number of panels they need or figure out how much electricity they’ll get from a given number of panels more accurately."
The solar radiation website, along with one on climate in Hawaii and another on evapotranspiration — the process of water going from the surface back into the atmosphere as water vapor — are part of the Geography Department’s Evapotranspiration of Hawaii project. It includes a suite of websites that provide data on the state’s climate and water processess. The department’s Rainfall Atlas of Hawaii is also in the mix, although it was launched about 2 1⁄2 years ago.
"The purpose is to make available the results of a big scientific project whose aim was to estimate the special patterns of evapotranspiration for the whole state of Hawaii, and in the process of making those estimates, we had to make maps of many other variables, and we think those are also useful. So we developed these websites to make it easy for people to get that information either as files or using that interactive map," Giambelluca said.
The information was gathered by a research team of students, professors and scientists, with 325 high-resolution maps made for each evapotranspiration variable, including air temperature, humidity, rainfall, wet canopy evaporation, solar radiation, net radiation and more. Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released into the atmosphere.
Overall, 12,000 data maps were created, covering each hour of the day for each month, each hour of the 24-hour cycle for the year, and average values for each month and the year.
"These data will be used by researchers and people in so many different fields in Hawaii," said Abby Frazier, a climatology doctoral student and member of the research team. "So people working in invasive species and water management, I mean, the data, different layers are going to be interesting for different people, but we’ve gotten so much interest already about all of this data. So solving all kinds of natural resources problems, aiding in that type of research."
According to Giambelluca, evapotranspiration is useful for water resource assessment planning and irrigation management.
"Evapotranspiration is important for understanding our water resources, and so it’s a similar importance to knowing rainfall amounts because the water resources we have are basically a function of the rainfall minus the evapotranspiration. So we need to know both," he said. "And it’s much harder to figure out evapotranspiration than rainfall. There’s never been a whole estimate done for the state before."
The project was funded by the U.S. Army Corps of Engineers-Honolulu district and the state’s Commission for Water Resource Management, Frazier said.
For now there are no plans to update the website as new data come in.
"We think that it’s something that should be updated as we get better data, but right now we don’t have any specific plans to do that," Giambelluca said. "We are trying to sort of streamline the process and put all the software together so that when the opportunity comes we can do it more easily and (cheaper)."
