how much is the DOD of the battery overnite
Well at the moment i'm planning for a 30Ah load. I want to limit the DOD to 30% for prolonged battery life. Going by that, I'd need a battery rated at around 100Ah. Therefore, assuming an average daily insolation of 6 PSH a 200W solar panel should be enough to charge a battery (That doesn't take into account batt efficiency etc).
What I'd like to end up with though, is an open source MPPT that can be adjusted to suit any kind of application or requirement.