The heatpump i'm considering has a input of 2.5 ish kW, which might be taking the concept of "one large dump load" too far...
Which heat pump do you have in mind? A 2.5kW seems to be a 15A type?
Note: I have been looking at various heat pump, but I could not find real technical information.
I was looking at some 5kW 240V (75 gallon - with a 3/4" water inlet)
It seems that the 5kW is the electrical heating that can be used to get quick hot water, but can be disabled.
About the compressor, I could not find consumption information.
I just imagine that the compressor consumption might be similar to a refrigerator or freezer?
I would be very interested to know if you have any consumption and in-rush current information for your heat pump
as I would like to determine what kind of inverter I would need.
I'm having a hybrid PV/mircohydro system installed to power an off grid camp/resort. I'd like to use any excess power to heat water. In a perfect world I'd like to run an air to water heat pump to do so.
I'm curious to know in what part of the country and for how many months your resort will be open?
If open only during the summer, to heat water, I wonder if a gas would be more economical (using a big 100 Gallon propane tank).
Do you have an idea of the water consumption you need. I just wonder if an On-Demand (propane or electric) water heater
instead of a water tank would be simpler and more efficient. I believe that Heat pumps are slow to re-heat large amount of water.
By the way, are you completely off grid, in this case how much daily electrical consumption do you need?
Are you providing an electrical plug to each user for at least lighting purpose?
Since you may have only 6 hours of sun in the summer, how much battery storage do you have
to provide power at night and in case of cloudy days.
based on my initial research i only see guidance of about running a dump load from the charge controller of which I'll have 1 for the microhydro and another 2 for the PV and from either I believe the dump load would need to be DC.
question:
Is there anyway to combine excess generation from any or all sources, bypass the battery bank and covert to AC to power something other than a restive heat element (i.e. the compressor on a heat pump)?
My approach would be to charge the batteries first, and then to run the heat pump as long there is enough solar production.
So the idea is to have the batteries used only as a buffer in case of some clouds, and to keep them as full as possible otherwise.
But my situation might be a little bit different. I'm in a building where I want to use solar energy for lighting
instead of using the grid to lower the elctricity bill. The daily consumption is around 15kWh, mostly at night.
If the batteries are too low, I can switch back to the grid, something that might occur in winter when the days are short,
with bad weather and low solar energy available, and longer night consumption.
For the hot water, there are already two 75 Gallons water tanks in series using natural gas.
The monthly consumption is about 300 Therms (at $2 a Therm), so something I'd like to improve.
I plan to add an heat pump to pre-heat the water, using excess of solar energy, except maybe during the winter,
and use the natural gas heaters mostly when the demand is high.
I might run the heat pump as a supplement to pre-heat the water,
using the grid, all the day long, or only earlier in the morning before sunrise,
but I would need to perform some experiments to see if this would be cost effective.
I plan to use a small inverter for lighting and a larger Inverter for the heat pump, that I could turn off.
I don't have yet installed a heat pump, so the big issue that I have in my current design is to determine
the heat pump consumption, but heat pump documentations are very poor in this regard.