Improve Supply Source Reliability
The Western US is facing supply shortages of SCMs.
The primary SCM is fly ash, the main residual from coal burning power plants. Production has diminished as coal plants close or convert to natural gas. Significant additional closures and conversions are scheduled, creating a bigger deficit in an already constrained market.
78% of the fly ash sold in the Western US comes from 6 Power Plants. By 2025, Four of these will no longer produce fly ash!
Concrete producers facing contract delivery issues, Higher cost, capacity limits, variable quality and poor performance.
The entire industry acknowledges an additional and imminent replacement SCM is needed. The clear front runner is natural pozzolans. They can extend the current fly ash supply through combination, and are likely to become the biggest element of any replacement.
"Fly Ash Current and Future Supply, 2016"
“... fluctuations in supply caused by events such as those previously mentioned compound the likelihood of future shortages.
To mitigate the effects of a fly ash shortage, the construction industry has the option to use other SCMs and admixtures allowed by Caltrans Standard Specifications.” . . . “One of the primary obstacles to replacing fly ash is the large volume that would be required to fill a supply shortfall. Based on expert industry representatives and data available from USGS, natural pozzolans have the greatest single potential supply volume.”
Mapped: The world’s coal power plants
Carbon Brief, May 2018
Globally, 200GW of coal power generation has closed due to a wave of retirements across the EU and US. Another 170GW is set to retire by 2030 and 13 of the world’s 77 coal-powered countries plan a total phaseout.
Meanwhile, electricity generated from coal peaked in 2014, so the expanding fleet is running fewer hours than ever. This erodes coal’s bottom line, as does competition from gas and renewables.