National priorities in the power system transition to net-zero: No one size fits all

Net-zero emissions targets are increasingly being adopted globally. However, there is a disconnect between policy mechanisms, that primarily focus on incentives to reduce emissions, and technological requirements to achieve this aim. In this context, an absence of CO2 removal incentives effectively precludes complete decarbonization, while potentially increasing the cost. Here, we quantify the effectiveness of carbon tax, negative emissions credit, and technology improvements in delivering net-zero targets cost-effectively in the UK, Poland, Texas, and Wyoming power systems. We show that the combination of a carbon tax and negative emissions credit is critical to reaching net-zero targets. From the techno-economic perspective, while all cost reduction is welcome, a further cost reduction of renewable energy is uniquely valuable in minimizing the transition cost. However, even with the availability of electricity storage, dispatchable and low-carbon thermal plants are key to cost-effectively maintaining system reliability, regardless of the costs of other alternatives.