"carbon intensity" of the grid

[NiHaoMike]

https://carbonintensity.org.uk
The quick summary is that knowing what % of the grid is currently being powered by renewable sources can allow individuals to support renewable energy more by simply optimizing when they use energy. It does not require individuals to invest in their own renewable energy equipment or sign up for a green energy plan, so a great option for those living in apartments, even including shared housing.

Is there something similar for the US?

[richard.cs]

There are also phone apps showing the same data, including half-hourly predictions for the next 48 hours. I did at one point use it as a guide for when best to charge the car. There is a big but coming though...

The data shows CO2 per unit energy for the current generation mix, but what you really care about is the marginal carbon intensity. What happens when the load increases by some small amount? The grid might be currently be 80% wind and nuclear and showing very low carbon intensity, but if those sources are flat-out then any additional load might mean increasing the output of a CCGT plant, i.e. the marginal carbon intensity is that of the gas fired generation that will be increased when you add the load, not the intensity of the rest of the grid. Plugging in an extra load at that moment emits extra CO2 corresponding to generating that amount of electricity from gas.

Granted for any individual domestic customer it's lost in the noise, but I still think marginal CO2 intensity is actually the metric we care about.

[AndyC_772]

I agree; it's not really useful unless there's a surfeit of 'green' energy available at certain times, ie. there's more green power available than is required to meet the entire demand from the grid - and that's not the case anywhere yet AFAIK.

When we had our solar panels installed, we were advised to run heavy loads like the washing machine during the day, when we actually do have more power available on 'our' side of the meter than we'd otherwise use. From a purely economic standpoint, it costs less to use our solar energy when it's available (and not export the surplus to the grid) than it does to sell spare power during the day and then buy it back from the grid at a higher price when it's dark outside.

Environmentally, though, it makes no difference at all. 100% of the power that our panels produce gets used, somewhere, by somebody, and as a result a gas tap can be turned down very slightly in a power station when it's sunny here. It doesn't matter whether they're powering my home, or my neighbours. I can (and do!) feel good about running my plasma TV from "free" electricity, but it's still the case that turning it off would save just as much gas overall as anyone else doing the same.

[f4eru]

it probably makes an environmental difference because locally consumed power incurs nearly no distribution loss, while fossil generation is usually quite far away, and incurs distribution losses.