seeking advice re buying inverter with future considerations

Re: seeking advice re buying inverter with future considerations

Welcome to the forum.

You've got a few problems there. One being the need to power water pumps and refrigeration. Both have hefty demands for start-up current. The pumps may not run so long, but the 'frige is bound to use a fair amount of power per day.

A 12 Volt system would not be desirable here. The combination of high current demands and significant Watt hours use means a 24 or even 48 Volt system will perform much better. I'm not sure of the specs on those panels, but you're really looking at starting over to achieve your goals.

You can in fact have a grid tie system with battery back-up and panels facing every which-way. It just means each array set has to have its own controller to optimize output to the batteries. How efficient would this be? That depends on how much panel you cn have facing in any given direction. If you can't get enough insolation at any time to provide full DC power there isn't going to be anything surplus to sell back to the grid. But it just might be possible to putter along with low number all day rather than a high output peak midday.

As for integrating components, that becomes desirable when you have either multiple controllers or multiple inverters or both. That way they share data necessary to their particular function and improve efficiency somewhat. If it is only one controller and one inverter it is really not necessary for them to be the same. There are many companies that make only one or the other component, and they can be work together fine.

Re: seeking advice re buying inverter with future considerations

No, the Apollo can not be turned in to a GT inverter. There's too much that would have to be changed. If it were possible the extra components would probably add up to the $1000 difference.

Paralleling panels is preferable for reducing shading effect, but it's more a matter of where the shade will fall; if you can keep both of the panels in a string of two free of shade there's no problem. You are correct that the 28 Vmp isn't suitable for directly charging a 24 Volt system. They probably don't have a bypass diode on every cell; there isn't much point in doing that. Usually there is a bypass diode on each cell string, because an individual cell is only about half a Volt. So typically several cells in series have one bypass diode across in case of shading.

At some point you're going to have to decide which way to go. Remember that grid-tie systems need to be done with plans and permits and permission. Since the process is the same regardless of size, a larger system is more worthwhile.

As for back-up power, you need to evaluate how often and how long outages are to see if it's worth investing in battery back-up (pretty expensive) or a good generator (less money for the power delivered).