Zonal versus Nodal Electricity Pricing: the PJM experience | Vincent P. Duane

Today, in Europe electricity prices are determined per (bidding) zone which equals in most cases a country. Under zonal pricing, only transmission capacity limitations between the zones are considered in the market-clearing process. The transmission lines within a zone are assumed to have unlimited capacity. This assumption is more and more challenged; one factor is the changing pattern of network flows due to the integration of renewables. As a result, Europe’s less-than-optimal zonal configuration is becoming a limiting factor for the efficiency of the market integration process.

One remedy could be to build more transmission lines. This option is however costly and takes a lot of time. Another remedy could be to redraw the boundaries of the different bidding zones, a so-called bidding zone review. In the extreme, the zones could be determined so small up to the point that each node of the transmission network is priced; this is nodal pricing. With nodal pricing, limitations on all transmission lines are considered in the market clearing process. Nodal pricing is advocated by many academics as being the theoretical optimal solution. However, many stakeholders in Europe are resisting against a push in the nodal direction.

On the 25th of January, the Florence School of Regulation held a workshop about zonal versus nodal pricing for the electricity markets. In the slipstream of the workshop, Tim Schittekatte interviewed Vincent P. Duane, Senior Vice-President at PJM. PJM stands for Pennsylvania-New Jersey-Maryland and is the largest independent power system operator (ISO) in the US. It operates competitive wholesale electricity markets and the power system serving an area encompassing 14 different states. Since about 20 years ago, nodal pricing is implemented in PJM.

In the interview, Tim questions Mr Duane about how PJM deals with some of the common ‘’European concerns’’ regarding a nodal electricity market: low liquidity, market power, and computational complexity. Looking at the PJM experience, the challenge in switching from zonal to nodal pricing is not really in the economics or technicalities but rather in governance. The interview ends with an outlook to the future. It is argued that if we really want a vision of local energy generation and smart consumption to materialize, we need local prices reflecting the correct value of the different attributes of electricity.