The Link Between Solar, Wind Power and Groundwater Sustainability

A recent study, led by Princeton University and published last week in Nature Communications, is one of the first of its kind to show that increased use of solar and wind energy can aid groundwater sustainability, an important aim for both taking on droughts as well as boosting sustainable agriculture. While the researchers used California as a case study, the findings could also apply to states like Texas and other countries that are trying to balance groundwater depletion, drought and agricultural output.

Known as the energy-water nexus, the link refers to the water embedded in energy and the energy embedded in water. Consider the amount of water it takes to produce and distribute electricity. As well, consider the amount of electricity used to treat, pump and distribute water. And while solar PV and wind energy resources are virtually water-free, traditional sources of energy—such as coal, nuclear and natural gas—require a significant amount of water to generate power. Depending on the fuel mix for electricity and the level of water stress, the tradeoff could be significant. From California to Texas, recent droughts and declining groundwater levels require more pumping to provide irrigation water for crops.

Agriculture combined with population growth during droughts means groundwater is being depleted at alarming rates. As regions experience more frequent droughts, it requires more energy to pump more water out of the ground as the levels drop. It can take a long time to replenish groundwater, and though it seems intuitive that heavy rains could take care of it, the rain has to fall in the right spot to make a difference. The scenario gets complicated quickly.

Strategic placement of renewable energy could get the biggest water-savings bang for one’s buck. In 2016, I led a study at Environmental Defense Fund (EDG), in collaboration with the Texas Army National Guard, which mapped water stress and the potential for solar, wind and geothermal energy at 60 of the National Guard’s Texas facilities. By overlaying the water data with renewable energy, the lowest-hanging fruit become clear. For example, Fort Bliss Readiness Center in El Paso has both the highest solar potential and the most extreme category of future water stress. Therefore, Fort Bliss is an ideal candidate for protecting water supplies by installing solar panels.

The Princeton-led study’s findings show a clear link between deploying more solar and wind energy and more sustainable groundwater supplies. When looking at long-range forecasting, energy and water planners should look at both resources. California is better placed than some due to its statewide cap-and-trade program that includes a Water-Energy Team of the Climate Action Team to better coordinate carbon reductions from the water sector, whose emissions largely come from the energy used by the sector. Further, the California Energy Commission found that as much energy could be saved through water conservation as through the investor-owned electric utility efficiency programs, but at half the cost. There is a lot of potential to reduce emissions and water demand when the two sectors are looked at more comprehensively.

Energy and water are inextricably linked, so it makes sense that increasing the use of low-water energy resources will decrease the demand on water. The next step is critical. We have the data, now it is up to policymakers in states, regions and countries to consider water impacts when making energy choices and energy impacts when addressing water supply issues. In many places, the two sectors are siloed, within both budgets and policy. Concerted effort could be taken to break down those silos to preserve the water we need for our people and our food.

Image credit: National Park Service