August 1, 20232 yr Based on the West Coast of SA and neem some insights please. Currently I am heating my 2 geysers (1 x 100l - 3kW element) (1 x 200l - 4kW element) with Evacuated Tube systems with a Solar pump (each). I have to run the electric element in the morning to cater for the first bathers and offset the nightly temp losses (about 5 - 7 degrees, depending on how hot the water was at sunset). The 20 tubes on the 100l is working well, and can heat up the geyser to 50 degrees twice a day [8h00 shower and 13h00 shower], even during current winter conditions. I use about 2 kWh from the grid to get this geyser to 55 degrees for the first shower to offset nightly temp losses. The 20 tubes on the 200l is however not so lucky, as roof placement is not optimal (I used the only available spot), and heats up to about 45 degrees max in the day (only 1 x 6h30 bath drawn). As such, I use about 4.5 - 6.5 kWh grid power to heat the 200l geyser for the morning bath. I want to see how I can get some long term saving on heating this geyser. The options I see (If you have more options, or if I understand the setups incorrectly, please let me know) are: 1) Install GeyserWise PTC ACDC Element. Install 2 additional 500W panels on West side, which will supply DC power to the DC part of the element in the afternoon. This should assist the evacuated tube system in getting the water to about 60 degrees (assumption). Thus, with 7 degrees (max seen so far) loss overnight, the water will still be at 53 degrees, hot enough for the bath. Also, as the AC part of the element is now small enough (2 kW), I can connect it to the essential side of the 5 kW Sunsynk inverter, and run it in the afternoon when I have excess PV power. Batteries are full again on a cloudless day between 13h00 and 14h00, so ample excess energy wasted. My concern with this approach is that it will drain my batteries too fast for the early morning bath and shower. 2) Connect the 200l (4 kW) geyser to the non-essential side, and feed excess power to the AC element in the afternoons. This way I can "blend" power from Eskom and excess PV power (CT coil to be moved before I can do this) and boost the geyser in the afternoon. My concern here is that I still have to use grid power, as my spare capacity (generation - current load) in the afternoon will not fully carry the 4 kW element. 3) As above, but replace the 4 kW with a smaller (2 or 3 kW) element, and in such case I can run it purely from excess PV power in the afternoon for a few hours. My concern with this scenario is that I still might need to top it up in the morning, and then it will take longer (double the time for 2kW and extra 50% for 3kW) because of the smaller element.? As such, I have seen that there are a lot of brialliant people in this forum, and someone can more than likely either give advice on the options abive, or come up with a better suggestion that I have not even considered.
August 1, 20232 yr i Have been searching for a lower watt element for some time now and finally found a 1000w 220v element today in stock for under R700 incl shipping. Its not cheap but still less than geyserwise element. It will be cheaper than extra panels.
August 1, 20232 yr Author 2 minutes ago, Off Grid Farmer said: i Have been searching for a lower watt element for some time now and finally found a 1000w 220v element today in stock for under R700 incl shipping. Its not cheap but still less than geyserwise element. It will be cheaper than extra panels. Hi Off Grid Farmer. Thank you. Sounds great. Perhaps share with others where you got it, as someone else might have the same requirement. I have to be a bit selective though, as I also have very hard water. So, normal elements last about a week with my hard water. The stainless ones from Geyserwise is reported to handle hard water well. The problem with too low a wattage element is also that it lengthens the time to heat the water. In my case, I just want to boost the tubes a bit, preferably by using excess PV power or new panels and a combination AC/DC element. Still open to suggestions.
August 2, 20232 yr 13 hours ago, 007 said: Hi Off Grid Farmer. Thank you. Sounds great. Perhaps share with others where you got it, as someone else might have the same requirement. I have to be a bit selective though, as I also have very hard water. So, normal elements last about a week with my hard water. The stainless ones from Geyserwise is reported to handle hard water well. The problem with too low a wattage element is also that it lengthens the time to heat the water. In my case, I just want to boost the tubes a bit, preferably by using excess PV power or new panels and a combination AC/DC element. Still open to suggestions. I got the element from acdc Germiston for R580. AcDc element is stainless steel. We also have hard water but i use a ion exchange filter system to soften the water. So what you need is a pre heat system. It would be better to use a 2000w element and use the excess pv power.
August 2, 20232 yr Author 2 minutes ago, Off Grid Farmer said: I got the element from acdc Germiston for R580. AcDc element is stainless steel. We also have hard water but i use a ion exchange filter system to soften the water. So what you need is a pre heat system. It would be better to use a 2000w element and use the excess pv power. Thank you. With the info received I am starting to lean more and more to that.
August 2, 20232 yr 53 minutes ago, 007 said: Thank you. With the info received I am starting to lean more and more to that. Leaning more and more towards installing water filtration system? I'm not sure if that will be any cheaper than just installing Geyserwise PTC element and get the flexibility of using both AC and DC to heat your water. I don't work for Geyserwise but in my honest opinion, it is always true when they say ''you get what you pay for'' . PTC element is very different from a normal element and plays well with my batteries. we are almost at the end of winter, my 48kg gas bottle which was bought beginning of February this year is still in use, that is six months later and no complaints about hot water from anyone in my house. Does it work? YES, would I have achieved the same with the normal heating element? Absolutely NO. Is it expensive? That is relative, in my view, it is worth every cent. Would I recommend it? Big YES with a smile 😁
August 2, 20232 yr Author 1 minute ago, hoohloc said: Leaning more and more towards installing water filtration system? I'm not sure if that will be any cheaper than just installing Geyserwise PTC element and get the flexibility of using both AC and DC to heat your water. I don't work for Geyserwise but in my honest opinion, it is always true when they say ''you get what you pay for'' . PTC element is very different from a normal element and plays well with my batteries. we are almost at the end of winter, my 48kg gas bottle which was bought beginning of February this year is still in use, that is six months later and no complaints about hot water from anyone in my house. Does it work? YES, would I have achieved the same with the normal heating element? Absolutely NO. Is it expensive? That is relative, in my view, it is worth every cent. Would I recommend it? Big YES with a smile 😁 Thanks Hoohloc. I am based on the "Weskus", and not seeing anybody around here that sell them. Geyserwise have offices in Cape Town, but not sure if they will sell directly to the public. On your setup, you say it plays nicely with your batteries. Do you have the DC portion connected directly to the batteries, and how does this affect "charging" details from the inverter?
August 2, 20232 yr 2 minutes ago, 007 said: Thanks Hoohloc. I am based on the "Weskus", and not seeing anybody around here that sell them. Geyserwise have offices in Cape Town, but not sure if they will sell directly to the public. On your setup, you say it plays nicely with your batteries. Do you have the DC portion connected directly to the batteries, and how does this affect "charging" details from the inverter? I bought mine directly from them, so they do sell directly to the public. Yep, connected to the same point where you connect your Inverter battery input/output on the Battery isolator
August 2, 20232 yr Author Do you have a smart breaker installed to manage on/off times? Also, I would assume your batteries are 48-52V, and the specs of that element is 72V. Does that work, and it is just a bit slower?
August 2, 20232 yr What most people fail to see is that everyone can heat up any element they want with excess PV. Hell! you can even heat up 4000w element with excess PV, but if you need hot water in the middle of winter at 05:00, then what? Let's make it more interesting, you have loadshedding at 00:00 and power doesn't come back after two hours as expected because of some funny reason. How is the 2000w standard heating element going to help you? If you have power, you will draw from the grid, which is ok, but if you have to rely on your battery? how long will you power that element before draining your batteries and still have a nice hot shower in the morning? will it be more cheaper to get more batteries? or PTC element
August 2, 20232 yr 12 minutes ago, 007 said: Do you have a smart breaker installed to manage on/off times? Also, I would assume your batteries are 48-52V, and the specs of that element is 72V. Does that work, and it is just a bit slower? Check this post
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