Eliminate Propane when Adding Solar, or Keep Some Propane Appliances?

[davemill]

Currently propane powers the furnace, tankless water heater, dryer and stove in our 1800 sf home in Santa Cruz, CA (no AC). All those appliances work fine, but we dislike the stove. We are planning to add solar, but don't know how to think about replacing the propane appliances with electric, since those would be among the largest power consumers. It seems like the economical choice might be to keep some of those propane appliances, at least in the short term.

Note: The NEM3 rate plan in CA pays so little for power sent to the grid that the few residential solar projects these days seem to include large battery capacity.

Thanks.

 

[OffGridForGood]

Welcome to the DIY Solar Forum @davemill
There are a lot of CA members here that will help you,
the whole going solar and maybe dropping the Propane is a tough question to answer - "it depends"
Some things going for your are good solar all year around - start by going to PVWatts.nrel.gov and plug in your location and 1kW PV - use your latatude for the PV angle due south and see what your area has to offer during Nov - January (typically the poorest solar months)
Then take your utility bill and see what your consuming now, before the propane shift, as a starting point.
Everyone here on the forum will help you.
Ok did the PV Watts for you for Santa Cruz, 1kW PV array due south tilted to 37 degrees:

January	3.89	95
February	4.86	106
March	5.38	128
April	6.30	143
May	6.22	145
June	6.45	145
July	6.21	142
August	6.33	144
September	6.05	134
October	5.73	135
November	4.72	109
December	3.70	90
Annual	5.49	1,516

 

[OffGridForGood]

What PV Watts tells you is December is the poorest month, at 90kWh per 1kW of PV array, or about 3kWh per day per 1kW of panel array size.
This lets you scale up - say you determine you need 27kWh per day on average, and want to size the array for the worst month (Dec) 27/3 = 9 so you would want at least a 9kW array of PV.

If you are planning to use a roof for PV panels, you can use PV watts to estimate the solar you can expect to get from each roof area, by pluggin in the actual direction it points - ie if not due south, and the pitch of the roof rather than the 37-degrees we started with. Maybe you want to compare a ground mount at 37-degree tilt to a roof area at 18 degree pitch: PV watts let you plug in any combination of 'test' set ups you like and save the results. This can be handy. One caution for PV watts - shade from trees or other buildings etc will dramatically affect the solar potential.

 

[SunDave]

You could keep them, then swap them one at a time so you know what your capacity is. Just over the next few years so you can see how the whole season goes with the next electric appliance.

I put up a small 2kW array for my phase 1, and the nice thing about that is that I have real world data for my location. I know what scaling up 7x (my phase 2) will do. No guesswork.

Good luck with your project. You will get where you want to be if you stick to it.