Everything Solar Forum

Interested in anyone's thoughts on this:  a potential client is planning to have a heat pump installed for both heating and cooling, and discontinuing his gas services (yay!).  He's wanting me to factor in how this will affect the needed size of his solar power system (he wants to cover as close to 100% of his usage as possible) and what his estimated savings/costs would be given this switch to a heat pump.  Any suggestions on how to go about predicting energy usage and cost with the heat pump?  

That's a great question! @Richard Strömberg may be able to answer this!

I recommend looking at the CCF monthly totals on their gas bill, converting to mmBTUs and then to watt-hours. Assume that the efficiency of the heat pump will be 2 to 2.5 more efficient than the NG heating system. An easy way would be CCF>>Btus>>kWh *50%.

1 CCF of nat gas has 103,800 Btus.
Divide Btus by 3412 to get kWh. So for each CCF of NG, the energy equivalent is 30.422 kWh. Divide that by 2 to get your electrical energy estimate for a heat pump.

-Rich

Wow, Richard, this is super helpful!  Thank you so much!

I upgraded in '22 when I decided to go all electric. I had a 2.7 kW array since 2008. When I had to upgrade to 400 amp service, the electricians brought in a solar guy who helped me replace the old with a 5.125 kW array. I have a 4-ton FMC4800AL in the basement that heats and cools. For the month of August, as of the 27th, I have consumed 566 kW; I have generated 592 kW from the solar. I have imported 361 kw from the grid, and I have exported 351 kW to the grid. I have a 100 volt lithium ion set up in the basement so my freezer and wifi and a few other systems never go down . . . or haven't yet. I hope this helps.

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Robert Kloos
Pastor/Administrator RETIRED
The Community of Saint Peter
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Adam -

Several years ago, Dave Hrivnak, who posts here from time to time, pulled together several ASES members to write a book called "Driving to Net 0."  I wrote Chapter 1, which addresses some of your question and is visible in its entirety by clicking the "Read sample" link on Amazon's site:

https://www.amazon.com/Driving-Net-Stories-Carbon-Future/dp/0692143831/

Please feel free to contact me directly at dave (dot) erb (dot) avl (at) gmail (dot) com if you'd like to discuss this in more depth.  Best,

Wow, Dave, you are awfully kind!  Thank you so much!  I will check this out and reach out to you if I have any questions!  I'm not sure how, but if I can ever be of service to you don't hesitate to let me know how.  adampaulrossi@gmail

Roger, thanks for that clarification, Stuart!