Spanish utility Iberdrola has commissioned the 225 MW / 210 GWh Valdecanas pumped hydro energy storage (PHES) project in Spain’s Extremadura region. For context, Spain’s average daily electricity generation is around 650 GWh, and 210 GWh of storage depth would cost $80 billion if built out in the form of utility-scale lithium-ion batteries. Instead, the Valdecanas project’s battery component will be just 15 MW / 7.5 MWh, and the investment cost has been so small, due to using pre-existing reservoirs and only adding three 83 MW turbines plus pumping systems, that it’s gone unmentioned. We estimate this project’s capex at no more than $300 million. The company has stated that its Conso II pumped hydro project in the Sil basin,…