Enough Sun In Idaho For Solar?

Yes, we absolutely have enough sunshine in Idaho for solar systems to pay for themselves in a reasonable time frame.

Idaho has latitude between 42° N to 49° N
We get lots of sun at these lattitudes, particularly with our clear skies, and upland desert ecosystems.
- You can verify this by visiting this .gov website with a searchable database: National Renewable Eneregy Laboratory: Solar Radiation Database, where meteorologists measure the sunlight over time.
Boise gets about 4.5kWh/m²/Day - more than enough for a solar system to make sense.
The whole state objectively gets lots of sun.

What about the snowy winters and smokey summers?

Snow and clouds will partially impede the panel’s energy production. Cloudy or smokey weather still has lots of diffused light for the panels to be useful, and properly designed system will accommodate these coniderations.

Will my solar array require snow removal?

Probably not; of course it depends but here are some considerations:

Snowfall slides very easily off of solar arrays angled 30° of arc or more from the ground.
An efficient angle of arc for solar arrays at our lattitude is ~45° from the ground.
Panels heat up quickly in the sun and the snow will typically slide off without mechanical intervention.
When to worry about snow: IF you have really heavy snowfall (Sun Valley, McCall etc.) AND a flat roof, then it is time to get a ground mounted system or plan on shoveling.

Three ideas to consider:

Winters are often very sunny in Idaho.
Solar panels produce more energy in colder weather:
Grid-tied solar systems produce heaps during the summer and bank up credits with the utility for the winter.

This section is for those who want to dive too deep into this temperature idea:

Solar panel temperature coefficients:

A solar panel temperature coefficient is a measurement that indicates how much a solar panel’s power output decreases for each degree Celsius increase in temperature, essentially showing how well a panel performs in hot conditions.

A negative temperature coefficient (typically ranging from -0.2% to -0.5% per °C) means that as the panel gets hotter, its power output decreases by that percentage per degree. A LOWER temperature coefficient means the panel is less affected by heat and performs BETTER in high temperatures.

Importance: When choosing a solar panel, a lower temperature coefficient is desirable as it indicates less power loss in hot climates, like Idaho in the summer.

Conclusions

It is generally very sunny in Idaho in the ways that are important for solar panels to produce properly. Your sales rep is probably right about this one.

Good luck with your solar panels!
Thomas Lansing