Do we still pass fuel around a belt to switch steam/solar?

[Tinyboss]

It's been a year or more since I played, and I'll probably be at that point later today. Is there a new state of the art for having steam power only turn on as a backup to solar, or is it still the old way?

[Neotix]

Now we have combinators and we have better control over many things. In v.13 we will get electric switch and probably ability to connect almost everything with circuit network. So there will be some new clever construction.

[BlakeMW]

The modern way is to use a smart chest linked to pumps and a yellow inserter taking things out of the chest and a blue inserter putting them back in. The blue inserter is on the main grid (or separated by an accumulator filter), the yellow on dedicated power. When the blue inserter stops, the chest empties. The pumps are set to start pumping when the chest goes below threshold and the steam engines burst into life.

Here's an example from one of my games:
http://imgur.com/nswDjC7

[XKnight]

Or if you want to know exact amount of energy in accumulators you can build something like this:

1.png (1.05 MiB) Viewed 2965 times

and connect this signal to every small pumps before steam engines with condition "<10".

Animation.gif (14.3 MiB) Viewed 2965 times

I am using this build to disable beacons if energy is lower than 30%, and to enable steam engines if energy is lower than 10% or if energy demand is very high.

P. S. You should build electric poles in a strict order, otherwise this build won't work