Net Zero Roadmaps

...showing non-existent "roads".

The Paris Accords established a global goal of achieving Net Zero CO2 emissions by 2050. Essentially this global goal was a “roadmap” leading from wherever to a single destination. Individual nations then established specific goals, not all consistent with the global goal and some ignoring it completely, reflecting their “differentiated responsibilities”.

Achieving the global goal would be a huge project conducted over a 35-year period at enormous expense. However, unlike much smaller projects routinely conducted by governments and the private sector, the Net Zero by 2050 projects were not the subject of detailed engineering plans, schedules and budgets, but rather just “roadmaps” and “scoping plans”.

Governments began advancing along their “roadmaps” from different starting points and at very different paces, most inconsistent with achieving the global goal on schedule. The nations pursuing the goal with the greatest “ambition” soon began to discover that many sections of the “road” to Net Zero were actually under construction or even non-existent and that the “tolls” on the existing “roads” were far higher than anticipated.

Massive expansion of renewable generating capacity resulted in periods in which generation exceeded demand, resulting in negative electricity pricing to clear excess electricity. Periods of reduced solar and wind availability also resulted in periods in which most demand was shifted to existing conventional generation sources which had to be maintained to compensate for the intermittency of renewable generation, but generated reduced annual output and required higher electricity prices to maintain profitability. This issue resulted in increased electricity prices overall, rather than the reduced prices which had been forecast.

The obvious solution to large variations in renewable generation output is electricity storage. The “ambitious” nations at the forefront of the renewable transition discovered that, while short-duration storage (2-4 hours) was commercially available, it was extremely expensive and subject to spontaneous fires which were difficult to extinguish and emitted both air and soil pollutants. Intermediate-duration (1-5 days) and long-duration storage (weeks to seasonal) were limited to pumped hydro systems which were both geographically and politically limited and had a roundtrip efficiency of ~75%.

Several nations began investigation of the potential for intermediate and long-duration storage using “Green Hydrogen”. However, they rapidly discovered that production of Green Hydrogen” required the availability of large quantities of pure water and huge quantities of additional renewable electricity, and that the roundtrip efficiency of Green Hydrogen storage was less than 50%.

Another section of non-existent “road” was the technology to achieve significant inertia on a grid powered primarily by inverter-based generation sources. There has been no demonstration that grid-forming inverters would provide sufficient inertia to carry the grid through instances of minor instability, such as the inverter instability event which triggered the recent blackout on the grid serving the Iberian Peninsula. That grid still retained some steam turbine and gas turbine generation, but apparently either the magnitude of inertial or its location on the grid was insufficient to stabilize the grid and prevent the blackout.

Still another section of missing “road” is the dispatchable emission-free resources (DEFRs) which could offset the need for additional storage. The most likely candidate for DEFR capacity is small modular nuclear reactors (SMRs) which are under development but not yet commercially available.

It is far from certain that the missing sections of ‘road” shown in the various nations’ roadmaps would be completed in time to meet the Net Zero by 2050 goal. However, it is far from certain that meeting the Net Zero by 2050 is necessary or even desirable.

Originally published here.