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I, for one, would be very interested in any write up on your experiences, esp wrt solar. I'm still trying to sort out solar hot water vs panels. We have a fai

I, for one, would be very interested in any write up on your experiences, esp wrt solar. I'm still trying to sort out solar hot water vs panels. We have a fairly high hot water consumption rate. An interesting experiment in Alberta - http://www.dlsc.ca/ http://www.dlsc.ca/

danans 5y ago
> I'm still trying to sort out solar hot water vs panel. We have a fairly high hot water consumption rate. Every situation is different, but generally speaking it makes more sense these days to install ever cheaper PV rather than solar water heating and pair that with a heat pump water heater, at least in typical grid connected scenarios. Perhaps the considerations are different for full off grid setups though.
- jacquesm 5y ago
  This is correct and roughly the installation that I'm planning.
  - danans 5y ago
    A few more bits of useful info for this setup: - Most Heat pump water heaters have a 3000W-6000W backup resistance element used when conditions are too cold to run the heat pump. If you live in an area with long stretches of near or below freezing weather, make sure you install it in a conditioned or semi-conditioned space. - The exception is the Sanden C02 system which can heat water even in sub-zero temps. - Heat pump water heaters draw about 800W / 4A when using their heat pump, although probably more for the Sanden. As with most fixed speed compressors, the inrush/surge current can be as much as 4x the steady current, which is important for sizing the wiring and circuit breakers, as well as sizing max current output of any batteries that might be installed. - Heat pump water heaters have slower recovery times than gas fired water heaters.
jacquesm 5y ago
In a nutshell: panels were still quite expensive when I built my installation, so we choose a double axis movable mount for the panels, two blades of 8 panels each. This allowed for both day-to-day and seasonal adjustment and ensured perfect incidence. In practice that system was the weakest point in the chain, and my new installation will be stationary, I'll spend the extra money from the moving mounts on more panels and end up with a surplus in energy compared to the movable mounts and have a more reliable system. The system I built was totally off the grid, in my new installation, which has neutral net metering I will use the grid as a fake storage device saving a bunch of money as well as space for the installation. The inverters I used were two stacked Xantrex 5 KW each for 240V, in my new installation I will use a Victron 12 KW inverter. The panels will be Samsung monocrystalline, there will be 32 of them, there will be no other source of power. Heating will change from natural gas to heatpump, which will be a major affair because there is only the possibility of a shallow sink/source here, deep ones are not allowed. If you have any specific questions feel free to mail me: jacques@modularcompany.com. As for hot water: I will definitely use all the space for electrical panels and use some electricity for hot water, there are excellent 'instant' hot water sources that are electrically powered now. The hassle of dealing with a system with fluids in it on a rooftop is not something that is maintenance free enough to add value to the house. Those systems tend to be quite fragile and need frequent repairs as well as not being available 'on demand' which with a family can get you to the point where there simply isn't enough hot water.

danans 5y ago

> I'm still trying to sort out solar hot water vs panel. We have a fairly high hot water consumption rate. Every situation is different, but generally speaking it makes more sense these days to install ever cheaper PV rather than solar water heating and pair that with a heat pump water heater, at least in typical grid connected scenarios. Perhaps the considerations are different for full off grid setups though.

jacquesm 5y ago
This is correct and roughly the installation that I'm planning.
- danans 5y ago
  A few more bits of useful info for this setup: - Most Heat pump water heaters have a 3000W-6000W backup resistance element used when conditions are too cold to run the heat pump. If you live in an area with long stretches of near or below freezing weather, make sure you install it in a conditioned or semi-conditioned space. - The exception is the Sanden C02 system which can heat water even in sub-zero temps. - Heat pump water heaters draw about 800W / 4A when using their heat pump, although probably more for the Sanden. As with most fixed speed compressors, the inrush/surge current can be as much as 4x the steady current, which is important for sizing the wiring and circuit breakers, as well as sizing max current output of any batteries that might be installed. - Heat pump water heaters have slower recovery times than gas fired water heaters.

jacquesm 5y ago

In a nutshell: panels were still quite expensive when I built my installation, so we choose a double axis movable mount for the panels, two blades of 8 panels each. This allowed for both day-to-day and seasonal adjustment and ensured perfect incidence. In practice that system was the weakest point in the chain, and my new installation will be stationary, I'll spend the extra money from the moving mounts on more panels and end up with a surplus in energy compared to the movable mounts and have a more reliable system. The system I built was totally off the grid, in my new installation, which has neutral net metering I will use the grid as a fake storage device saving a bunch of money as well as space for the installation. The inverters I used were two stacked Xantrex 5 KW each for 240V, in my new installation I will use a Victron 12 KW inverter. The panels will be Samsung monocrystalline, there will be 32 of them, there will be no other source of power. Heating will change from natural gas to heatpump, which will be a major affair because there is only the possibility of a shallow sink/source here, deep ones are not allowed. If you have any specific questions feel free to mail me: jacques@modularcompany.com. As for hot water: I will definitely use all the space for electrical panels and use some electricity for hot water, there are excellent 'instant' hot water sources that are electrically powered now. The hassle of dealing with a system with fluids in it on a rooftop is not something that is maintenance free enough to add value to the house. Those systems tend to be quite fragile and need frequent repairs as well as not being available 'on demand' which with a family can get you to the point where there simply isn't enough hot water.