Off-grid solar in Maine

Sun data: NASA POWERSized for December#38 of 51 for winter sun

The short version

In Maine's darkest month, December, panels tilted toward the sun get about 2.5 peak sun hours a day, from 2.1 to 2.6 depending on where you are. Sized for that, a typical off-grid home needs about 17 panels and 4 batteries; a cabin, 4 panels and 1 battery. Flat panels, like on a van roof, get 48% 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 Maine

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

Panels, batteries and cost for each kind of setup in Maine
SetupPanelsBatteriesAbout
Off-grid home 17 × 410 W 4 $10,000 – $12,000
Backup for my house 4 × 410 W 2 $9,000 – $11,500
Tiny house 8 × 410 W 2 $6,000 – $7,500
Cabin or shed 4 × 410 W 1 $4,000 – $5,000
RV, bus or skoolie 8 × 410 W 2 $6,000 – $7,500
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 (1.3 h) and are capped by roof space, so they lean on driving and a generator in December. Costs are the gear only.

Sun in Maine, month by month

Tilted at latitude Flat. December gets 48% of the sun of the brightest month (5.2 h). Size for December and the rest of the year has spare.

Across Maine

Darkest-month sun differs by place. The 11 ZIP areas range from 2.1 hours in the 047xx ZIP area to 2.6 in the 039xx ZIP area. That's 25% more panel output for the same panels.

Winter sun in Maine and the nearest states
StateDarkest month, tiltedFlat
Maine2.51.3
New Hampshire2.41.4
Vermont1.81.1
Massachusetts2.71.5

Common questions

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

Sized for Maine's darkest month (December, about 2.5 peak sun hours on tilted panels), a typical off-grid home needs about 17 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 Maine get in winter?

About 2.5 a day in December on panels tilted at latitude, and 1.3 on flat panels (NASA POWER, at the state's center of population), ranging from 2.1 in the 047xx ZIP area to 2.6 in the 039xx ZIP area.

Does off-grid solar work in Maine in winter?

Yes, if it's sized for December: that month gets about 48% 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 Maine's 2020 Census center of population and at each 3-digit ZIP area. Method and downloads.