Integrating solar energy and climate research into science education
This paper analyzes multi-year records of solar flux and climate data from two solar power sites in Vermont. We show the interannual differences of temperature, wind, panel solar flux, electrical power production and cloud cover. Power production has a linear relation to a dimensionless measure of the transmission of sunlight through the cloud field. The difference between panel and air temperatures reaches 24ºC with high solar flux and low windspeed. High panel temperatures that occur in summer with low windspeeds and clear skies can reduce power production by as much as 13%. The intercomparison of two sites 63 km apart shows that while temperature is highly correlated on daily (R²=0.98) and hourly (R²=0.94) timescales, the correlation of panel solar flux drops markedly from daily (R²=0.86) to hourly (R²=0.63) timescales. Minimum temperatures change little with cloud cover, but the diurnal temperature range shows a nearly linear increase with falling cloud cover to 16ºC under nearly clear skies, similar to results from the Canadian Prairies. The availability of these new solar and climate datasets allows local student groups, here a Rutland High School team, to explore the coupled relationships between climate, clouds and renewable power production. As our society makes major changes in our energy infrastructure in response to climate change, it is important that we accelerate the technical education of high school students using real-world data.
Plain English discussion
Vermont has an ambitious comprehensive energy plan with the goal of meeting 90% of the State’s energy needs through renewable resources by 2050. Part of this is a transition to a distributed renewable energy power system, based on solar power and wind farms. The State has become a leader in the transition towards a renewable energy system. Recently, Rutland Vermont achieved its goal of becoming the city with the most solar power per capita in New England. This is the context for our analysis of solar power and climate by a Rutland High School team, advised by climate scientist, Alan Betts.
Solar arrays measure electrical power production, but some arrays also monitor the incoming solar flux and other meteorological parameters, such as temperature and windspeed. This means we can now calculate how the solar flux drives maximum temperature and the diurnal range of temperature, and how clouds reduce the solar heating of the surface, as well as electrical power production.
Betts, A.K., J. Hamilton, S. Ligon and A.M. Mahar (2016), Integrating solar energy and climate research into science education. Earth’s Future, 4, 2-13, doi:10.1002/2015EF000315.