>home appliances should be aware

You mean IoT installed into wallplugs and whitegoods appliances, pool pumps, heaters, washers, heat pumps/air conditioners, hot water systems, etc.

Yeah. If there was only an IoT standard that worked to allow for usage to be monitored and devices to be switched on/off in a standard way ... sure.

There are "appliances" like HomeAssistant.io and OpenHAB and Domoticz out there to micro-manage these peripheral home devices and monitor consumption/excess/PV generation, and rulesets that can trigger responses and excess/egress of energy,

but it's too complex for the Inverter/Solar managers to take care of usually.

it's better to spend the energy directly than to sell it cheap now and buy it expensive later.

As long as feed-in tariffs are artificially high (e.g. anything not noticeably below 1:1), neither xkcd:927 nor total absence of standards are what is keeping solar-aware consumption from happening.

PS: I absolutely don't want the subsidies to go away, I want them restructured into better subsidies that do not nullify other important incentives.