We spent two months last summer at 56-58N and relied on our solar panels
for much of our daily use. With long hours of daylight you might get less concentrated output, but more low level output accumulated per day, if you're prepared to put a little effort into getting it.
We have two 45W panels
on a gantry aft that can be orientated fore and aft, and two deck
mounted semi-flexibles (45W each) on deck
, and the difference in average output between the two arrays is huge - far more from the aft panels
. We check the angle of the aft panels regularly and can monitor
their output and it's hardly a chore. We also have an 85W flat panel with lashings on it to enable us to mount it to best effect when we're at anchor
- again we move it every hour or so to get the best output. Between the three arrays we gain most of our daily output, to run pumps, lights, laptops etc.
You don't mention whether you already have a wind generator
- in our latitudes where we have plenty of wind
a powerful turbine (we have a Superwind) is well worth having, and on the days that it's wet and windy the Superwind takes up the slack from the solar. We still reckon that solar gives us more bang per buck, but as has so often be said, a combination probably makes most sense.
During the whole period living aboard
we never once ran our engine
to charge the batteries. As it was a windy season we motored far less than usual, so we were really pleased with the set-up we have.