03-19-2023, 10:54 PM
My setup is similar to Leilanidude. I don't remember how much I paid for it because tax credits and energy rebates paid the majority of it. I remember calculating the payback period being 3 years. Likewise, I don't normally have the breaker on. I don't need the elements turning on when the sun is about to come out and heat it for free.
During the few times per year that we do need to turn the breaker on, we only need to run it for about 5 minutes before getting in the shower or whatever. It's not like when I lived in Alaska and the water going into the water heater was 38 degrees and it took forever to get hot. Figure that the water in the tank is still going to be around 100 degrees when it's "too cold" and the water coming from the catchment tank is 70 or whatever, there isn't a huge spread in temp difference. Giving the water heater a 5 minute head start is all it needs to effectively be an "on demand" hot water heater. And then after the shower, kill the power to the breaker again.
The solar water heater does actually kick on and create some hot water when there is no sun, depending on what type of cloud cover we have. Obviously it doesn't make as much as quickly as in sunlight but it can add a day or two before we run out.
The solar hot water heater can also be turned up so the water lasts longer. It supposedly shortens the life of the tank, but if one knew dark weather was coming they could turn the temperature way up to bank it, and then turn it back down to protect the life of the tank. I have turned ours up to 160 degrees for the purpose of filling a utility sink with hot water for scalding turkeys, and then of course turn it back down after butcher day. I try to keep it set about 130 during summer and 140 during winter but there's been a few years I forgot to turn it down for summer.
During the few times per year that we do need to turn the breaker on, we only need to run it for about 5 minutes before getting in the shower or whatever. It's not like when I lived in Alaska and the water going into the water heater was 38 degrees and it took forever to get hot. Figure that the water in the tank is still going to be around 100 degrees when it's "too cold" and the water coming from the catchment tank is 70 or whatever, there isn't a huge spread in temp difference. Giving the water heater a 5 minute head start is all it needs to effectively be an "on demand" hot water heater. And then after the shower, kill the power to the breaker again.
The solar water heater does actually kick on and create some hot water when there is no sun, depending on what type of cloud cover we have. Obviously it doesn't make as much as quickly as in sunlight but it can add a day or two before we run out.
The solar hot water heater can also be turned up so the water lasts longer. It supposedly shortens the life of the tank, but if one knew dark weather was coming they could turn the temperature way up to bank it, and then turn it back down to protect the life of the tank. I have turned ours up to 160 degrees for the purpose of filling a utility sink with hot water for scalding turkeys, and then of course turn it back down after butcher day. I try to keep it set about 130 during summer and 140 during winter but there's been a few years I forgot to turn it down for summer.