Alaska Solar Energy Generation Exploration- PART 1

Utilizing the NREL's (National Renewable Energy Labratory) PVWATT calculator I was able to determine the potential Solar Energy available at our own home in Anchorage, Alaska. The tool is available for use here:

Taking approximately 5 minutes over coffee this morning, I was able to determine that we could generate 4,618 kWh of energy each year which they say is worth on average about $639. This is with several assumptions, including a 10:12 roof pitch, South orientation, a 5kW sized systems and some inefficiency due to dirt, clouds, snow, etc. 

So what does that mean? 

Utilizing some quick google sleuthing, a 5 kW system is about 400 sqft and would cost in the neighborhood of $11,000. So at $639/ year that results in a pretty long payback of approximately 17 year. It's worth it to consider the lifespan on these panels, among other questions.

Can I utilize all this power to offset my current usage and does Alaska allow net metering? Yes it does; we utilize Chugach Electric. Without too much investigation and math they are willing to pay about $.03970 per kWh; for my 4,618 kWh that would net me a paltry $183 and change, yikes!  I called Chugach electric and their incredibly helpful customer service gave me my total energy usage in 2015: 8,761 kWh with a total cost of $1,513.38. Compared to my potential generation of 4,618 kWh total usage of 8,761 kWh doesn't look so bad. 

Is this the best location and orientation? I recalled some recommendations on static solar arrays that are worth some theoretical testing on the PVWatt calculator. Latitude plus 15 degrees in winter or minus 15 degrees in summer. So for winter we are looking at 61+15= 76deg (fairly vertical), and in the summer 61-15= 46 degrees (about 12:12 roof slope). 

In part 2 we'll compare these rules of thumb with the NREL's tool to determine an optimal angle for fixed installation.