Off-grid solar in Texas

Sun data: NASA POWERSized for December#8 of 51 for winter sun

The short version

In Texas's darkest month, December, panels tilted toward the sun get about 4.0 peak sun hours a day, from 3.5 to 5.2 depending on where you are. Sized for that, a typical off-grid home needs about 11 panels and 4 batteries; a cabin, 4 panels and 1 battery. Flat panels, like on a van roof, get 30% less that month.

Answer a few taps in a guide and every page like this shows the numbers for your own setup. Start

Every setup, sized for Texas

Each guide's usual answers, with Texas's December sun. Tap one to change the answers to yours.

Panels, batteries and cost for each kind of setup in Texas
SetupPanelsBatteriesAbout
Off-grid home 11 × 410 W 4 $9,000 – $11,000
Backup for my house 4 × 410 W 2 $9,000 – $11,500
Tiny house 5 × 410 W 2 $5,500 – $7,000
Cabin or shed 4 × 410 W 1 $4,000 – $5,000
RV, bus or skoolie 5 × 410 W 2 $5,500 – $7,000
Van 4 × 200 W 3 $6,000 – $7,500
Just emergencies or camping 4 × 200 W Power station $3,500 – $4,500

Van and RV numbers use flat-roof sun (2.8 h). Costs are the gear only.

Sun in Texas, month by month

Tilted at latitude Flat. December gets 66% of the sun of the brightest month (6.1 h). Size for December and the rest of the year has spare.

Across Texas

Darkest-month sun differs by place. The 49 ZIP areas range from 3.5 hours in the 775xx ZIP area to 5.2 in the 799xx ZIP area. That's 49% more panel output for the same panels.

Winter sun in Texas and the nearest states
StateDarkest month, tiltedFlat
Texas4.02.8
Oklahoma3.72.4
Louisiana3.72.6
Arkansas3.52.2

Common questions

How many solar panels do I need to live off grid in Texas?

Sized for Texas's darkest month (December, about 4.0 peak sun hours on tilted panels), a typical off-grid home needs about 11 panels (410 W each) and 4 server-rack batteries; a cabin about 4 panels and 1 battery. Your own loads change this; the guides size it for you.

How many peak sun hours does Texas get in winter?

About 4.0 a day in December on panels tilted at latitude, and 2.8 on flat panels (NASA POWER, at the state's center of population), ranging from 3.5 in the 775xx ZIP area to 5.2 in the 799xx ZIP area.

Does off-grid solar work in Texas in winter?

Yes, if it's sized for December: that month gets about 66% of the sun of the brightest month, so a system sized for December has plenty the rest of the year.

Data: NASA Langley Research Center POWER Project, long-term monthly averages at Texas's 2020 Census center of population and at each 3-digit ZIP area. Method and downloads.