A better way to calculate solar radiation

Oct 15, 2013
A better way to calculate solar radiation

(Phys.org) —Research by Murdoch University, James Cook University and the University of Waterloo in Canada has revealed flaws in the way that the widely-used Ångström-Prescott equation links solar radiation to sunshine duration.

Ångström-Prescott equation is used extensively in providing radiation readings for agricultural, ecological, meteorological and hydrological models.

The new research is contained in a publication voted a Best Paper 2012-2013 by Solar Energy, regarded as the premiere solar and renewable journal in the world, and will be recognised at the Solar World Congress 2013 in Cancun, Mexico in November.

Murdoch co-author Mr Ross Bowden said the research showed that the Ångström-Prescott equation overestimates during overcast and clear periods, but underestimates during partly cloudy intervals.

"The Ångström-Prescott equation assumes that the received on the earth's surface rises in direct proportion to the sunshine duration. However, we have found this is not the case." Mr Bowden said.

"Radiation is well below predicted levels during overcast periods due to clouds being thicker than at other times. The Ångström-Prescott equation assumes a constant cloud thickness.

"Scientists and engineers have noted inconsistencies in the past, but have attributed these to local variations. By putting a wealth of global data together, we've been able to show that this isn't the case."

The group analysed data from 670 sites all over the world as diverse as Nairobi, Vladivostok, Osaka and Miami.

Mr Bowden has worked for Western Power and Horizon Power and is currently a consultant in the energy industry while pursuing his PhD in Mathematics at Murdoch.

Explore further: Ambitious EU targets for renewable energies make economic sense

More information: Suehrcke, H., Bowden, R. & Hollands, T. Relationship between sunshine duration and solar radiation, Solar Energy Vol. 92, pp. 160-171, 2013. www.sciencedirect.com/science/… ii/S0038092X13000911

add to favorites email to friend print save as pdf

Related Stories

Sun emit a mid-level flare

Nov 13, 2012

(Phys.org)—On Nov. 13, 2012, the sun emitted a mid-level solar flare, peaking at 9:04 p.m. EST.

Spain receives ever more solar radiation

Jun 06, 2013

Solar radiation in Spain has increased by 2.3% every decade since the 1980s, according to a study by researchers from the University of Girona and the Federal Institute of Technology (ETH) in Zurich. This ...

Space Image: Sunspots and solar flares

Mar 21, 2012

(PhysOrg.com) -- NASA's Solar Dynamics Observatory (SDO) captured this image of an M7.9 class flare on March 13, 2012 at 1:29 p.m. EDT. It is shown here in the 131 Angstrom wavelength, a wavelength particularly ...

NREL updates solar radiation database

Nov 28, 2012

The U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) and collaborators released a 20-year updated version of the U.S. National Solar Radiation Database, a web-based technical report that provides ...

Recommended for you

Should the Japanese give nuclear power another chance?

11 hours ago

On September 9, 2014, the Japan Times reported an increasing number of suicides coming from the survivors of the March 2011 disaster. In Minami Soma Hospital, which is located 23 km away from the power plant, ...

UK wind power share shows record rise

14 hours ago

The United Kingdom wind power production has been enjoying an upward trajectory, and on Tuesday wind power achieved a significant energy production milestone, reported Brooks Hays for UPI. High winds from Hurricane Gonzalo were the force behind wind turbines outproducing nuclear power ...

Global boom in hydropower expected this decade

18 hours ago

An unprecedented boom in hydropower dam construction is underway, primarily in developing countries and emerging economies. While this is expected to double the global electricity production from hydropower, it could reduce ...

User comments : 0