His more detailed argument is that off grid users aren’t generally array limited and the benefits of his system are in the reduced fusing costs, safety of lower voltages, and reliability of being able to stick with solid state controllers with life-spans >30 years. MPPT requires the use of electrolytic capacitors which crap out after about 10 years give or take based on thermal cycles etc.
Pretty much everything in that is false. I am array limited (and money limited, panels may be relatively cheap but they aren't free, like thousands of $/€ not free, not negligeable IMHO...) and I'm probably not the only one. Also if you start including ecology in the equation it's clearly not a good idea to do that (more panels to compensate higher losses = more resources used).
And again, totally ignoring the wires needed for the low voltage high amperage. Copper is really expensive and often forgotten in the budgets.
Reduced fusing costs? I'd really like to know how if you can give more details please. Physics says it'll be the contrary, or else you're cutting corners and you don't really protect things correctly.
MPPT don't require electrolytics, you can do it without them, it's just a bit more expensive and you need more time spent on the design, but totally do-able. But even without that, electrolytic can last far more than 10 years, you just need the right type and use high quality ones (of course if you use the cheapest you can find in a back alley in China they'll not last long).
It’s still possible to use MPPT chargers with the SBMS, so long as they have remote on off switches that can be controlled by his SBMS so if using MPPT is important to your use case, go for it. In thirty years if your amortized costs are lower than Dacian’s system, you can call him up and give him an I told you so. I doubt he will care.
BMS main purpose isn't to be a controller, it's to be a safety device when the other things crap out. If it can only control the thing that crapped out and can't cut power itself then it's pretty much useless. For example: mosfets in your SCC have short-circuited, battery is in over voltage, what this BMS will do? nothing; it'll try to turn the SCC off but it can't so the battery will continue charging until the cells are destroyed.
Here you go. Measured comparison 9 years ago on a 130W panel (8/4/2011, Santa Barbara, Ca). I used a switch to connect panel either to charge controller or directly to lead acid battery. The battery had a constant load to keep battery voltage from rising (battery voltage range: 12.2 to 12.3V). It appears around noon time MPPT output degrades due to temperature? Ambient temps are around 22C.
MPPT: total amp hours = 63.8
direct: total amp hours = 58.6
MPPT gain = 8.8%
Thank you one million times, finally some real world data
So around 9 % which on my previous estimated system would translate to 1440 W of PV (16000 * 0.09) needed if the no MPPT solution was chosen. At 30 cts/W that's 430 USD which gives you a nice MPPT or two. And again when you add the costs of wires, fuses, etc... you'll save hundreds if not thousands so yeah, I don't see how it's more economical than using MPPTs.
Unfortunately Dacus is giving out false information to hype his product. 10 year life span of capacitors in a MPPT controller??? WTF? My CC is still going strong after 14 years of constant use. Clearly, MPPT has a performance gain over a direct connection, even in summer.
Yep, I tried to give him a fair chance actually, but got too much BS for me to take him seriously anymore.
While I think there are blindspots in his argument, and I think he tends to get laser focused on one particular use-case or factor and not fully acknowledge or consider alternative use-cases/design goals, I definitely don't feel that he is acting in bad faith or trying to hype his product. He is a very disarming and straightforward guy, and strikes me as very honest, even when I disagree with him or feel he is overlooking something.
I'm sorry but someone asked him and he ignored it, I asked him and again he avoided answering the question. And yes, conveniently ignoring everything else in the system while only talking about the SCC isn't a proper way to design a solar system.
I may be wrong (actually I really hope I am for anyone buying from him) but I personally don't trust him anymore. No hate or anything, just I don't trust him, that's all.
All I wanted to do is warn people here to not trust everything you're told and check the numbers and the general sense of something before buying; and then if it's good for you then no problem, go for it