Some notes on how the singleboard pc (also used by the domoticz software) would become aware of when it's currently an off-peak or a peak-hour:
as mentioned, this is best done using a dynamic system (else it's equally useful to just use plain time switches and not have a singleboard pc running at all to get this done).
For the dynamic system, I mentioned power companies can use a sort of PLC (see https://en.wikipedia.org/wiki/Power-line_communication ) system. That would have the advantage that the power company could use a same power cable to also transfer the data. This might be a bit too complicated for power companies to set up though in retrospect. Probably better is that they just run an rss-server instead. A seperate rss-server would need to be be running per country, or even per power company.
Since it would be dynamic, it could even use a range of prices depending on the power production/demand ratio at that particular moment. The switches the singleboard pc then control can even be set to start/stop depending on the price at that moment, and stopped after a certain delay -this is most useful for say washing machines, ... as else there might be increased wear-). As all ready mentioned though, it's something power companies would need to set up, and since that isn't the case yet, we probably best just make a simpler, static system ourselves. That static system can then also function as an (off-line) back up, even when the dynamic systems are being made.
For the static system: it would be most useful to make this as something that's user-settable (so that the user can change the standard settings to match the off-peak/peak hours his local electricity company set out, exactly). It should be made in such a fashion that even if there's no internet access on the singleboard pc, it can still be used. Similar to the dynamic system, the different switches can be activated/deactivated by the singleboard pc upon reaching a certain price range. Unlike the dynamic system though, there will off course only be 2 prices: that of the off-peak hours, and of the peak hours. These prices are best also made settable.
The singleboard pc tend to use linux as the OS, so it needs to be written in say C++
Any volunteers ?
PS: besides the ability of this program to activate and deactivate power plugs (i.e. via the fifthplay smart energy box hardware noted above), we'll also need special hardware to be able to route power in one of 2 possible directions. This is only needed though for the renewable power plants at home, when we use the simpler system mentioned. For the more complex one (with a battery system), it's not needed, as we can put an activatable/deactivatable switch both before and behind the battery bank.