50W would appear to be a maximum, the article shows a meter at 20W which is presumably total power from the wall socket. Once power consumption gets low enough

50W would appear to be a maximum, the article shows a meter at 20W which is presumably total power from the wall socket. Once power consumption gets low enough it should cease to be a consideration. Everybody will have their own threshold for "low enough", but I personally wouldn't stay awake at night over 20W.