The 35-35 energy equation: understanding Switzerland’s goal of 35 TWh renewable energy in 2035 through the lens of cumulative energy demand

Abstract

In 2023, Switzerland set a goal of producing 35 TWh per year from renewable sources by 2035 and developed three deployment scenarios to reach it through specific technology mixes of renewable energy production. However, current models do not consider the impact of the cumulative energy demand (CED) of those technologies, accounting for production, transport, installation, performance, maintenance, and disposal. This study integrates CED and its related uncertainty using a 90% confidence interval (CI) to compare net energy across three future energy scenarios. The diverse renewable sources scenario yields a median net production of 29.1 TWh (90% CI: [27.7, 30.2]) and requires 6.24 GW of additional capacity to meet the 35 TWh target. The solar PV-focused scenario, with the highest embodied energy due to battery storage demands, has the lowest net output at 25.2 TWh (90% CI: [23.7, 26.5]), necessitating an extra 11.35 GW. The productivity-maximization scenario achieves the highest net production at 30.8 TWh (90% CI: [29.5, 31.7]), requiring 3.68 GW more capacity. In all energy scenarios, increasing gross renewable targets is essential to reach the net 35 TWh/year goal. Optimizing renewable deployment by prioritizing low CED technologies, such as wind, can maximize net energy production. Policymakers should incorporate embodied energy metrics into planning to ensure sustainable and realistic energy transition strategies.