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Solar Tracking Payoff Time

There are basically 4 items that can determine a reasonable estimate on solar payback time.  This is both for tracking and fixed systems and this is based on 2018 figures.  Electrical costs are much higher now.  

  • System costs and installation

  • Tax breaks and rebates

  • Price per kWh’s

  • Total kWh’s  the system can produce yearly


“kWh’s" (Kilowatt hours) is the rate of  energy you consume in a given amount of time.  For example:  3000kWh/year, 400kWh/month or 20kWh/day to give an idea. 

Solar production estimates are sometimes based on a yearly average (more in summer, less in winter).  If you live in a hot climate and run the AC all day long, the solar tracking payoff time becomes shorter.  This is because you are receiving optimum solar when you are consuming the most power.


Price per kWh value is stated on your monthly bill.  If you are paying lower than $.10 kWh, solar may not be justifiable unless you are using large amounts of energy in kWh’s per day.


Some Power Companies use a Multi-tiered and Peak-usage Approach


The peak usage program increases the cost around 3:00PM and just about the same time people get home from work.  A static installation stops producing  full power about  3:00PM. But with solar tracking, full power production continues until evening. 


There is also another program called "Demand Charge". This term is a sore subject with the farming industry that depend on  irrigation pumps and other high consumption electrical.  This is a complicated topic meant for another discussion. So let's move on for now.


In San Jose CA, the power company uses a multi-tier program.  Currently, Tier 1 -  .19kWh, Tier 2 -  .27kWh, Tier 3 over .30kWh! They move you up a tier based on your usage.  After 300kWh/Month usage they move you to Tier 2 and so on.   This becomes very expensive especially if you are running an AC or even charging an electric vehicle when peak usage kicks in. However there are some incentives with EV charging and the power company may reduce power costs.

The total usage you consume in kWh’s is another consideration for your solar investment decision. Over 400kWh’s/month is pretty high and you should consider going solar. Plain and simple.


Power Companies do not Like Solar

They say they do, but they don’t.  Power companies continue to find loopholes that make your solar system less useful. It hurts their bottom line. Like we mentioned, some electrical companies impose a high demand/peak pricing program. This can range from 3PM-8PM. This about the time solar becomes less productive for fixed solar installations. And about the same time peak usage goes up. Sure, you may receive net metering credits from solar but there is a commission involved.  You do not receive back the total credit of what you gave to them.  You can save the solar power for yourself by using solar tracking that continues to produce all the way into the evening when demand is at most.


If you don't have solar, at least take measures to reduce high power consumption in your home. But it is hard to do especially if you need to use air conditioning.


What is the Payback Time in Years Using the Suntactics Solar Tracker?


To figure out payback, you will need the 4 the items mentioned:

  • System costs and installation

  • Tax breaks and rebates

  • Price per kWh’s

  • Total kWh’s  the system can produce yearly


In the solar tracking case, we will base it on one solar tracker that produces 1.2Kwatts. For the sTracker, this is the final output after panel and inverter inefficiencies and power losses through wiring and other electrical connections.  There are some other inefficiencies but they are very small. You may say 1.2Kwatts is not enough solar energy for my situation.  This is true but it is pretty much linear.  Use 2 solar trackers or 3 to get you to your power requirements.


Let’s do a solar payback example for the solar tracker:

  • System cost rounded off to $5000. After the 30% Fed credit = $3500. Lets’ be conservative and make it $3800(installed).

  • Price per kWh in the San Francisco Bay Area is about $.24kWh on average as of early 2018.

  • Total yearly average in Northern CA with a 1.2Kwatt solar tracker is about 3000kWh’s/ year.


Payback estimate in years = Total cost / ( Price per kWh * Yearly solar production kWh’s)


Payback estimate in Years = 3800 / ( .24 * 3000) = 5.1 Years. 


The same example using a fixed or roof system:

Now this gets a little tricky.  A solar sales person may state the solar  power offered is 1.2KWatts but may not state the actual power output after all the inefficiencies in the system.  You need to bring this to their attention as it may affect their payoff estimate.  They may be surprised that you are educated.  But most reputable solar companies will know about system inefficiencies and will state the true output.  So we will treat this example as 1.2KWatts output after the inefficiencies.

  • System cost as stated in first example $3800 (After rebates, installed).

  • Price per Kwh in the San Francisco Bay Area is about $.24kWh on average.

  • Total yearly average with a 1.2Kwatt fixed system is about 2100kWh’s/ year.

Using the same formula as the solar tracker:


Payback estimate in years = Total cost / ( Price per kWh * Yearly solar production kWh’s)


Payback estimate in Years = 3800 / ( .24 * 2100) = 7.5 Years.


The solar tracker payback is 5.1 years and the fixed system is 7.5 years.  Solar tracking produces a substantial amount more power over a fixed system.  Fixed systems are wasting precious potential solar energy.  However, a fixed system may be the only choice for you for many reasons. You may not have the room. But we are all in this together, fixed or tracking, both save money either way.



How We Determined our Findings

We used many sources to come up with our calculations. We used PVwatts, other solar calculators, input from our solar contractor connections and distributors.  We also continue to test using real life solar data and measurements.

Price per kWh’s data are given to us from property owners in the area.  Some of the billing statements revealed lower than .24 kWh pricing, but most were over. Some were even higher than .27 kWh pricing.  As described earlier, California uses the multi-tier program. The more you use, the more they take. 

We can give you a pretty close estimate on solar payback time provided you have the price per kWh and total kWh usage.  If your state offers solar incentives, this will also help with the pay back estimate.

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