Climate Change Impacts on Solar and Wind Power
- Apr 14, 2018 5:23 am GMT
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Location and success of solar and wind power facilities depends strongly on climate ― how much the sun shines and how strongly the wind blows over predictably long time periods. If global climate change is now in progress, what is the outlook for solar and wind power as regional cloud and wind patterns adjust to the changing global climate? This summarizes why much more study of these issues is needed as part of risk-management diligence for renewable energy projects.
Climate Change and Renewable Energy: The Circularity Problem
Electric power generation by combustion of fossil fuels emits greenhouse gases (GHGs) which have been implicated as a driver of climate change. Power from solar irradiance ― either from thermal or photovoltaic (PV) conversion ― and wind-driven turbines are being promoted and deployed as zero-GHG alternatives to generation driven by high-GHG combustion of coal and lower-GHG combustion of natural gas.
Location and success of solar and wind power facilities depends strongly on climate ― how much the sun shines and how strongly the wind blows over predictably long time periods. If global climate change is now in progress, what is the outlook for solar and wind power as regional cloud and wind patterns adjust to the changing global climate?
Models for How Climate Affects Solar and Wind Power Potential
At least as reflected in the peer-reviewed scientific literature, serious consideration of how climate change might affect solar and wind power generation has received very limited attention compared with the high degree of attention paid to climate change as a geophysical phenomenon. The tacit assumption in deployment of renewable energy production has been that geophysical support for solar and wind power will continue undiminished into the future.
At the executive level, the climate-related threats to efficiency of solar and wind power involve several effects predicted in various models for global climate change:
- Pole-to-equator temperature gradients (atmosphere and surface) as agents of change for atmospheric pressure gradients
- Atmospheric pressure gradients as agents of change for wind patterns
- Both temperature and pressure gradients as agents of change for cloud patterns and aerosols
The current backbone of climate-change forecasts are general circulation models (GCMs) ― differentiated by focus on either atmosphere or ocean ― which leverage temperature patterns and trends as predictors of fluid circulation patterns. Atmospheric GCMs, as usually employed in climate-change studies cited in the context of energy production, make different approximations for clouds and aerosols (microscopic dust particles or droplets suspended in air). Indeed, cloud and aerosol effects remain key challenges in untangling uncertainties in climate forecasts.
Scientific studies of climate-change sensitivity of renewable energy systems have addressed only certain regions of interest to particular stakeholders. Studies of specific regions have included California USA, Europe, and southern Africa. The following table summarizes the main characteristics and findings of those limited studies.
The main takeaways from the summary table are that:
- Solar and wind power are affected differently in different regions, suggesting that meaningful risk-based assessments of renewable power assets must consider individual locations
- Model approximations ― an unavoidable necessity in all long-range forecasts ― often yield large bands of uncertainties in the results for predicted power-potential changes; an uncertainty level of at least + 15% in solar or wind potential appears typical of current knowledge
- In at least some regions, models predict significant decreases in either solar or wind power potential as a function of forecasted climate-change scenarios
Future application of more sophisticated climate models might help reduce uncertainties in forecast of potential solar and power trends. But until more precise and accurate forecasts become available, conservative planning should incorporate risks of loss in solar or wind potential in some locations.
A Risk Management Perspective
Effective risk management in long-range planning of power-generation portfolios must include considerations of whether generating assets might become derated ― or, in effect, lose generation capacity ― over time. It now seems clear that, in addition to the common considerations of asset age and maintainability, long-term performance ratings of solar and wind power assets should also consider possible effects of climate change in reducing their decadally-adjusted generation capacities.
To upgrade risk management of power generation portfolios, the following provisions are recommended for solar and wind power resources:
- Assess climate-related changes in power potential by location. Available studies have shown notable differences in results according to the region of the world that was studied. If a particular asset location has not been studied for possible climate-related trends, a higher degree of uncertainty should be adopted in assessing climate-related changes in power potential. For conservatism, a risk of 15% loss of power potential between the Years 2014 and 2050 could be a reasonable starting point, pending more informative results from specific studies.
- Assess climate-related changes in power potential separately for solar and wind. Available studies of long-term, climate-related forecasts have shown that, for a given location, trends may be different for solar and wind potential. Accordingly, solar and wind resources should be evaluated independently with regard to climate-related changes in power potential. Model forecasts should be validated and utilized according to whether they inform best about solar or wind attributes.
- Continually review and revise climate-related risk assessments as data and models improve. All climate models involve approximations that contribute to qualitative and quantitative uncertainties in numerical results. Solar power potential is especially sensitive to long-term forecasts of clouds and aerosols while wind power potential is more sensitive to ocean heat-balance models and land use. Current climate models offer incomplete (at best) treatments of clouds, aerosols and ocean-land interactions.
Originally appeared at Geoclime Blogs.