My wife and I recently had solar panels installed at our home. People have been asking me about the process, so I’ve gathered up some of my notes for anyone interested…

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Here are sites the Solar Tour Organizers recommend:

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First, it takes money to make money. So I had to wait until I turned 59½ to get access to my retirement money without penalty.

If you have to borrow the money, things will be different but should still be worth doing while subsidies are available. According to Michelle Knox, who sold us the panels and sits on various solar committees, there is a program coming to subsidize the loans several points or to give a rebate for paying cash.

The easiest thing to do is to invite several sales people over and let them get you oriented to the systems and paying for them. Even if you aren’t that interested right now, I think it’s worth listening to them for 2 hours of entertainment (and to let them practice their spiels).

We listened to:

Straight-Up Solar (314-218-2663); their bid was $25,480.

Tick Tock Energy (217-994-9020); their bid was $30,317.

And went with WindSolarUsa (217-825-4206); their bid was $27,313 and we paid $27,265.

Because of a miscommunication or something, we didn’t get a bid (but should have) from Harvest Energy (877-788-0220 toll-free), who I think put in the system on a farm my brother and I visited. It was a big system like 20 kWh. Ours is 6.8 kWh with 24 panels.

The different companies have different systems with different components. The panels produce direct current and have different ways of getting it turned into alternating current, while using things like Solar Edge Power optimizers.

This is actually the fun part—getting the sales people to explain these things like they’re talking to a ten year old. We went with micro-invertors which turn the DC into AC at each panel. They sit under the panels so you probably don’t want them if the panels are on the roof because you have to pull up the panel to change them.

If you look at the Cost Model attachment (see below), our system would have cost $27,300. But I did a little of the work myself. And the Federal Government’s tax credit is $7,709.

There is also a solar renewable energy credit (SRECs) that will give us $6,846 as we generate power. This credit comes from a pool of money the power companies have because by law they have to generate so much power “greenly”—so they subsidize generators. (We should get another 5 years of SRECS if things go as planned. It’s not a sure thing but would get the payback down to 8 years or so.)

That leaves $11,141 which needs to come from savings on our $90/month power bill. So we will have our money back in 10.5 years—faster if the rates go up or with 5 more years of SRECs.

If you are a business or farmer you can write them off, i.e. depreciate them so payback is much faster. You know if the farmers are jumping in, the money is right.

The panels are warrantied for 25 years, so after they’re paid off we’ll get a return on our investment of about 8.3%. This should put us ahead by $22,295—when I’m 85.

All this takes a while so it’s good to get in communication with the sales people early so you can act quickly if the subsidies are cut or new ones show up.

Anyway, it’s good karma and at the moment a good investment. Also there is a cost for doing nothing both in carbon (karma) and cash.

Solar panel installation

Ron Feltes – 6.84kW Cost Model

Energy Production, Cost, Economics and Environment


  • Solar electric systems rated module capacity (kW dc): 6.84
  • Estimated output year one (kWh/yr): 8,911


  • Estimated installed cost: $27,300
  • Federal Tax Credit or Treasury Grant: $7,709
  • Value of First Year REC Sales: $1,604
  • System cost after first cost incentives: $17,987
  • Value of REC Sales in P.V.: $6,846
  • System cost after all incentives: $11,141
  • Value of year 1 to year 10 power production: $10,345


  • Years to cost recovery (“0” Means > 30 years): 10.5
  • Cash gained over the life of the system: $22,295
  • 25 Year discounted NPV: $5,506
  • Project Profitability Index: 1.3
  • 25 Year IRR: 8.3%


  • CO2 emission reduction per year (tons/year): 7.32

Key Assumptions

  • Cost of System Per kW (dc): $4,000
  • Federal Income Tax Rate: 28%
  • State Income Tax Rate: 7.9%
  • Electricity rate year one ($/kWh): $0.0944
  • Estimated electricity price inflation rate (%/yr): 3.78%
  • Expected output degradation (%/year): 0.75%
  • Discount rate (used only in NPV): 5.0%
  • Annual maintenance cost of gross system cost: 0.25%