Solar Electric – Initial Planning

I have some big plans in mind, and this post is just to get the rough idea down and keep a record of what should ideally happen and how.  But yes, the plan is to install solar panels on the house.

First, let’s hit the high-level numbers.  I want to budget $30k for the install.  This should give me a a $ loan payment for 5 years.  This should eliminate my $200/mo electric bill, so the cost is net $450/mo for 5 years.  There is a 26% tax credit for solar electric, so that should wipe away 1 year from my loan.  The end result is a $50 cost for 4 years, then $200/mo savings for the next couple of decades – let’s be real, for the rest of my life.

Now, some details on those numbers.  In most people’s lives, the two big debts are house and car.  Ideally, you want to have some sort of break between car loans where you actually still use your car without paying for it.  I do have an active car loan, but that car is my secondary car and I am still getting by on the car that preceded it.  So I can be assured of a long time before I will need another car loan.  So once that car loan is paid off, I will be free to begin another 5yr commitment.

It was my plan to go solar when that car loan was ended, but I was concerned about the sunset of the federal tax credit for solar, which is very soon.  I have recently had a fortunate windfall that can pay off my car loan, should I choose to use it for that.  Because I am debt-adverse, I will do so, regardless of those that say to drag out low-interest loans and invest the difference.

So, with car loan eliminated, I will need to gather quotes from solar contractors and decide on what is available to me.  With what tools are available to me, I was able to determine that my home electric usage ranges from 1200 to 1850 kWh per month, with an average of 1490 kWh.  That’s roughly 50 kWh/day.

According to Project Sunroof, a $200/mo electric bill means I would need a little over 16kW in solar to cover my bills.  From other sources, I found my roof has a max capacity to deliver 20kW in power.  One site says I need 50 panels to get 15kW.  Another says 30 panels will get you 10kW.  One metric cited is that it costs about 75 cents per watt, so 15kW is about $11k in panels (I assume no labor or connective bits).  Another site says ~$30k will get you ~14kW.  So far, we are still in the ballpark.

This does not cover any battery storage on site, which is enticing to me, but could be prohibitively costly, and some of what I’ve read suggests either you have storage or you feed the excess to the grid, not both.  That’s for the experts to educate me in.

Then the real battle becomes dealing with multiple sales people all wanting to sell you a product and a service.  That will be for a later post.  For now, I think this covers all the basic numbers.