Values via RSS feed?

I wonder if there is a way to retrieve values via an RSS feed. An energy company in my town publishes live sun measurements (W/m2) and I thought I would use it as a light sensor to trigger indoor/outdoor lights on/off.

In theory yes, but what you are requesting is non-trivial and I would not choose Vera as the platform to do it.

RSS feeds are actually summarized data, in XML format, served via HTTP. It is entirely possible , to use Vera and LUA/LUUP code to make HTTP requests.

local status, result = luup.inet.wget("", 5)

It’s even possible to parse/process the returned information to some extent. But to do this, you’ll need to be able to program using XML, LUA and more.