The barrier is 26 degrees not 30.. over 30 things just turn out as bad as they can get. You have to include active cooling.. hence A/C.. and your cost just doubled. I recommend to shut down indoor growing in Summer, if you do not have a fully isolated room to work with, cooling cost will drive you nuts otherwise. Cooling is less efficient compared to LED diodes.. so the biggest factor of a perfect setup is the cooling.. and if you want to run 'perfect', A/C is imperative... as you will also run it during winter to keep it at 20... if you run a commercial setup. Is a huge difference to produce yourself some weed to smoke or produce top quality material.
What size tents you want to run? I can give you an estimate of your power cost. With the estimate of power consumption you can design the solar setup to bridge your tent(s). You will put a lot more in as the household would need. So once load shedding stops.. you will have a over dimensioned setup. As indicator, a 2.4x2.4 tent will eat about 48-96 kwh a day (no A\C cooling, with A/C double it)... normal house hold uses 10-20 kwh per day, depending if it has a pool and solar geyser.
A 288 Quantum Board will set you back 25-30$US.. plus cooler and the driver.. cooler and driver you can use on other boards if you change. 4 QBs 100$.. is not the biggest investment for a test run (1.2x1.2 tent). As said, if you want to go perfect, you don't need a Lux meter.. you need a PAR meter (science doesn't guess.. hard facts or is just toying around anyhow). You want perfect weed, you have to stay below 26 degrees at all time, best 20 dead flat... just to get that dialed in, you will spend 1000's of $ till you have the right A\C setup with the control units handling all automatically. If you plan to go nuts.. I would honestly suggest to also go additional CO2 to get maximum harvests from that expensive setup. So you will run 2 cooling circles. One for the plants and one for the lights. I would in this case also go hydro and not soil, makes your life easier feeding wise.. and at least 4 2.4x2.4 tents to make it run even. What means.. you will have high costs learning to grow the plants. Every fuckup will set you back around 50-100k in cost you have to cover next harvest.. you hopefully get.
So if you say.. naa, no A\C.. why bother for the light so much? As said, get a grow light from a known producer. Now you know that your light is a working one.. then learn to grow the plant and get your weed tested. Most growers are shocked to find out.. average potency is 12%... not 20 or 30%... average private grower test results are a lousy 12% You get 20% from a strain able to produce 30%.. then you can say: OK, i know what I do, now lets build a perfect setup and see if I can reach the 30%. And yes.. people reach that.. so the target is set.. reaching it is a totally different story.. and you will practice for years till you get there.. perfect setup or not, at the end it counts how happy you keep your plants, the setup helps you, but you have to make every decision yourself.. your setup will not prevent mistakes you create
Is why i said.. don't overthink.. would start with a setup you know works and not a new invented wheel.. also use a known fertilizer brand and proper genetics. You know your tools work, only one to blame for a fuckup is yourself, no excuses. Is like you want to build the perfect F1 race car but never driven a race car in the first place. Light is the engine... not the driver. Best car and a shitty driver will end with bad lap times... hence 12% thc content on average.
Not so easy when a new generation diodes comes out. More efficient.. less draw.. so you add diodes to reach same draw for your driver or you have to add a dimmer.. if your driver can't handle a dimmer.. new drivers for your setup. Then, if you add diodes or not, you have to remeasure your hanging scheme with a PAR meter to have em in the right area again (Proper grow lights give you the hanging distance for each stage). If you would hang em just same as before, you would waste your efficiency gain. So only rule.. never ever buy old diodes for a grow light, that is hyper short minded as the 50$ you save on the diodes will get eaten by Eskom in 1-3 months and after that time your 'awesome' deal delivers less light and uses more electricity... for the next years. Why not shot in your leg just for fun? ^^
The interesting part of growing is that in a lot of cases the first run comes out rather nice and the next runs after more as fails, what confuses people. The reluctance of the first run and just follow orders on the fertilizer bottle gets to the right result. Next run people simply start to over-care and things turn sour suddenly. "But i watered more regular"... yup, they never got the dry phase needed.. "But i defoiled much better this time"... no, you defoiled constantly and kept the plant confused. A little change can have nasty results even you don't notice them. That is why i say... use your knowledge and the information you gained in your research and just start. If you never grew indoors, I would start with a smaller size tent.. 1.2x0.6 is a perfect tent to learn the ropes and understand what the plants tell you. You see your plants pray, you know you do things right.
Na, is fresh air exchanges, so the capacity going in and out the tent. I would say you need to shift at least the same capacity inside the tent. I combined my intakes with plant ventilation but you need another 4 40cm desk fans at least in a 2.4x2.4.. beside the 2 150mm inline silent fans going in (if you go cheap on inliner's, you will hear your tent room on the other side of the house during night). With 2 going out, 4 total. Mine sounded like a turbine factory till i exchange the cheapos with TD-500 silent inliner's.. ~15k Rand gone just for the new air exchange in and out the tent. But worth it, you can easy talk in the room now. The desk fans make it about 2 years till you have to get new ones. A grow room is a running project, the bigger, the more gear you run which can fail.
So cost: Power for lights, air circulation, cooling and gear controlling the setup plus heat mat(s) for cloning box(es). Fertilizers (each run has a certain cost), cloning gear/seeds, air purifiers (carbon filters or ozone generator) and all the side gear like UPs and DOWNs, test kit calibration solutions and grow medium (soil, coco, rock wool, clay pebbles,... endless). Beside the toys you need.. Pen for pH, ppm, EC and the quantum flux PAR meter. If you go for quality.. just those 2 tools can easy set you back 12k Rand... and depending how you grow, they are both simply a must.
Go soil with a biological fertilizer, get your lights from a grow shop (no not anything HID related, they love to sell it as it looks cheap, it isn't) and start growing some weed 18 weeks after you started your journey, you know a lot more about everything in regards to growing indoors. You will not reach perfection till your learned the ropes.. is why I say, don't overthink, just start, you put enough thought into light.