I'll put this in another light, DC is great but only meant for short distances. Otherwise Edison would have cornered the market and Nikola Tesla would have never invented AC.
You would require a HUGE Copper Cable to carry that amount of DC 500' and I won't even mention EMI/RFI... Goodness Gracious! BTW, DIYsolars guesstimate is LOW, it would require trenching, serious conduits and more.... HINT: I converted Wood Saw Mills to Solar and you wanna see serious DC !
In such instances, the vast majority of people will put together a Powerhouse with Inverter(s) and usually batteries & related and then send AC to home/Shop which can travel great distances with Much Cheaper Thinner Copper.
The historical problem with DC over long distances has been the high cost of converting the Voltage. It's very easy, and relatively cheap, to build AC transformers to convert very high voltage power (best for long-distance transmission) to "intermediate" Voltages (such as 24 kv) for distribution to very small "neighborhood" transformers, providing 120/240 single phase for most home uses over very short distances. If it hadn't been for the inability to "transform" the voltage easily, DC would have won.
AFAIK, the longest point-to-point power line in the USA is high-voltage DC (The Pacific DC Intertie). It runs at +/- 500 kv (1000 kv between two poles, that's definitely HIGH VOLTAGE). The conductors are only 1.6" in diameter (they're steel cored ACSR), and the configuration requires only two conductors. DC is definitely not "meant" for only short distances.
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So I've argued with your history and labeling of DC as only a short-distance solution. But in THIS vastly smaller configuration, it all depends on the Voltage, and his DC array almost certainly provides power at more than 240 volts (perhaps about 600 volts, if separated into two parallel strings of Series panels). The problem with converting to 240 Volt single phase AC at the Array is the need for bigger wires with more current. Your "create a power house" idea is good, for AC, but requires two transformers: One to BOOST the A/C Voltage far above the 240v which is normally provided by Solar Charge Controllers, and the other to DROP the A/C Voltage back down to 240v at the house. Depending on how high you go between those transformers, you can greatly reduce power loss. But that second transformer is GRID-TIED, with all kinds of ugly equipment qualification and Utility interconnect hassle. And going higher than 600-700V get into very expensive wire.
DC running at only 600 Volts is about 30 amps, with the array properly arranged as parallel groups of serial panels to reach that voltage. I do see a few SCCs which can handle more than 600 volts MPP (while also handling significantly higher disconnect voltage values). Such as this one
https://www.ecodirect.com/ProductDetails.asp?ProductCode=Fronius-Primo-15-0-1-TL. And wire rated for higher voltages is very costly as well. But keep in mind that all the Voltage Drop will occur before reaching the SCC, if it's converted at the house. I tossed this into a calculator and got only 3.2% Voltage drop (19.2 Volts lost 581 Volts net) using 8-AWG copper in PVC conduit.
If the utility wouldn't allow that particular SCC (or any other which could handle 600 Volts on the DC side), you could theoretically switch down to 400-480 Volts nominal MPP max and just increase the wire size to AWG-6.
I think that DC long runs, running at high panel voltage to a house-mounted SCC, is the winning configuration in this case.