(08-20-2024, 01:39 PM)matt.thompson05@gmail.com Wrote: Has anyone installed a battery backup on either their whole house electrical panel, or on a propane/gas fueled radiant heat system?  We're looking at Tesla Powerwall, but it's very expensive and there is an added cost due to our 400 amp electrical meter.  We have a plug-in whole house generator, but we would ideally like to have an automatic backup up the heating system (which requires VERY little electricity) and possibly the well pump.  Thanks!

(08-21-2024, 11:14 AM)John G Wrote:

(08-20-2024, 01:39 PM)matt.thompson05@gmail.com Wrote: Has anyone installed a battery backup on either their whole house electrical panel, or on a propane/gas fueled radiant heat system?  We're looking at Tesla Powerwall, but it's very expensive and there is an added cost due to our 400 amp electrical meter.  We have a plug-in whole house generator, but we would ideally like to have an automatic backup up the heating system (which requires VERY little electricity) and possibly the well pump.  Thanks!

I haven't seen your system but I have done what you're asking about, if yours is the same.

The circulation pump on the hydronic heat requires very little power, as you suggest. When I tried to run ours directly, using relatively low-tech generators, such as the one in an RV or the budget kind you can find at Harbor Freight, the circulation pump was unhappy about the "semi-sinusoidal" waveform those produce. The output of many inexpensive battery backup UPS systems is the same. If your heat system is similar to ours, typically using a pump made by Grundfos or Taco, it has a synchronous motor and needs a true sine wave to run correctly. I ended up with a dual-conversion type UPS backup that puts out a clean sine wave. It works just fine from the generator's funky output. Generator power in, clean power out for the heat, and it will run the heater for quite a while from a good battery too. About 90 watts to run the heat as I recall.

FYI you need a more robust power supply to get the well pump started, far beyond the capability of the affordable battery backup for the heat. However the well won't be nearly as picky about the generator power.

• Xcel energy is giving an upfront rebate for whole house battery installations ~$5000
  
• Colorado has a tax rebate of 10%
  
• Federal rebate is 20%
  
• Whole house batteries can be set up to store energy when the energy costs are the cheapest. You can set them up to use battery power when demand is the highest.  This will save you money on your monthly power bill.  
  
• If you already have solar, they will charge from your rooftop generated power as well.  During multiple day off grid situations like we experienced recently, your panels will charge your batteries provided they aren't covered with snow.
  
• Most battery companies are providing a 10 year warranty where the capacities are guaranteed to be 70%.  Ten years from now, battery replacement costs could be a lot cheaper and maybe even better energy density.
  
• A whole house generac generator with a clean sine (utility grade) output can run $7k