PV Calculator
The PV Watts solar calculator, created and maintained by the National Renewable Energy Laboratory (NREL), gives a detailed analysis of the expected energy production and its associated value for a given geographical location and system configuration.
TIP use a DC to AC Derate Factor of .95, and 11¢ for the Cost of Electricty.
Solar Pays Back
In an urban environment, it makes sense to stabilize the unpredictable cost of electricity and natural gas with an inexpensive grid-tied solar electric system. The advantages are lower power bills, an increase in your home's equity and stabilizing the electricity supply.
Treasure Valley Solar engineers systems to use the latest racking, panel and DC to AC inversion technology to keep the installation costs at a minimum - and meet the homeowner part way in covering the cost of installation.
We've provided example payback models; one for a homeowner and the other for a small business - these field tested models show how solar pays back - in some cases the payback is less than a year.
Example Payback Models
Commercial Payback Model
This 2.76KW system was installed for $5.79 per watt and has a payback of 4 years including tax incentives and an increase in property equity.
| 2.69KWH System | Year 1 | Year 2 | Year 3 | Year 4 | Year 5 | Year 6 | Year 7 | Year 8 | Year 9 | Year 10 |
|---|---|---|---|---|---|---|---|---|---|---|
| Initial System Cost | $15,976 |
|||||||||
| Property Value Increase | $7,546 | $613.31 | $663.16 | $717.06 | $775.35 | $838.37 | $906.51 | $980.19 | $1,059.86 | $1,146.01 |
| Idaho Tax Deduction | $5,000 | $3,195 | $3,195 | $3,195 | ||||||
| Federal Tax Credit | $4,793 | |||||||||
| System KWH | 2.76 | 2.76 | 2.74 | 2.72 | 2.69 | 2.67 | 2.65 | 2.63 | 2.61 | 2.59 |
| Panel Degredation % | 0.00% | 0.80% | 0.80% | 0.80% | 0.80% | 0.80% | 0.80% | 0.80% | 0.80% | 0.80% |
| System Capability KWH | 2.76 | 2.74 | 2.72 | 2.69 | 2.67 | 2.65 | 2.63 | 2.61 | 2.59 | 2.57 |
| Average Hours Daily Sun for Southern Idaho | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 | 5.5 |
| Calculated Daily KWH Production | 15.18 | 15.06 | 14.94 | 14.82 | 14.7 | 14.58 | 14.47 | 14.35 | 14.24 | 14.12 |
| Yearly KWH Production | 5548.3 | 5503.9 | 5459.9 | 5416.2 | 5372.9 | 5329.9 | 5287.2 | 5244.9 | 5203 | 5161.4 |
| Yearly KWH Consumption at this Residence | 17000 | 17000 | 17000 | 17000 | 17000 | 17000 | 17000 | 17000 | 17000 | 17000 |
| AVG KWH Rate at this Residence | 0.0680 | 0.0680 | 0.0741 | 0.0808 | 0.0881 | 0.0960 | 0.1046 | 0.1140 | 0.1243 | 0.1355 |
| Annual Increase % | 0.00% | 9.00% | 9.00% | 9.00% | 9.00% | 9.00% | 9.00% | 9.00% | 9.00% | 9.00% |
| Calculated Rate | 0.0680 | 0.0741 | 0.0808 | 0.0881 | 0.0960 | 0.1046 | 0.1140 | 0.1243 | 0.1355 | 0.1477 |
| Yearly Power Bill | $1,156 | $1,260 | $1,373 | $1,497 | $1,632 | $1,779 | $1,939 | $2,113 | $2,303 | $2,511 |
| Yearly Payback on Production | $377 | $408 | $441 | $477 | $516 | $558 | $603 | $652 | $705 | $762 |
| Electric Bill Coverage | 33.00% | 32.00% | 32.00% | 32.00% | 32.00% | 31.00% | 31.00% | 31.00% | 31.00% | 30.00% |
| Payback Balance | $15,599 | $15,191 | $14,750 | $14,273 | $13,757 | $13,199 | $12,596 | $11,944 | $11,239 | $10,477 |
| Payback Realizing Federal Tax Credit | $10,806 | $10,398 | $9,957 | $9,480 | $8,964 | $8,407 | $7,804 | $7,152 | $6,447 | $5,684 |
| Payback Realizing Property and Tax Credit | $3,260 | $2,239 | $1,135 | $(59) | $(1,350) | $(2,746) | $(4,256) | $(5,888) | $(7,653) | $(9,561) |
