Note that electricityMap has been working w/ marginal signals just recently (2021), and they compete with WattTime (which does marginal signal estimations for some time).
In any case, they conclude the marginal signal is good for short term decisions, and also in regions with low renewable sources. In my understanding, if the marginal signal does not go down in the long-term, it means the electrical system still depends on brown energy [1].
Implicitly, they also say that what WattTime does is not “assessable”. Physically speaking, there should have a way to estimate it. It is not like energy comes out of thin-air, and I guess that’s what WattTime tries to estimate.
In any case, they conclude the marginal signal is good for short term decisions, and also in regions with low renewable sources. In my understanding, if the marginal signal does not go down in the long-term, it means the electrical system still depends on brown energy [1].
Implicitly, they also say that what WattTime does is not “assessable”. Physically speaking, there should have a way to estimate it. It is not like energy comes out of thin-air, and I guess that’s what WattTime tries to estimate.
[1] https://www.pnas.org/doi/full/10.1073/pnas.2116632119