Are they actually making money for you, or is this just for fun?
I ask because I have 2 and have been less than impressed with their stability and function. While I can mine for days at about 2.6 MH/s on each, that's not earning me more than a few pennies worth of coins a month.
I picked up a couple of Antminer L3+ for $99 each and since I'm running an oversized solar panel system I don't have to worry to much about electric costs. At an average of 570 MH/s they're on track to make between $60-90 a month each.
I'm just curious why you want to invest more in them if they aren't really making anything.
Point them at scrypt alt-coins, set it and forget it. The solar thing you have setup is my perfect dream. My apt complex however charges a tiered electric rate.. 0-100 .13kwh, 101-200, .14kwh, 201-300, .15kwh. you see my problem there. So these little guys fulfill my desire to "mine" a few cents, while only costing a few cents. Wife is happy with the minimum noise as well.
I have an apollo also in eco mode, but these moonlanders make great gifts to blockchain curious.
Any idea what that U2 component is?