Curious to know what an investment in solar looks like?
Google’s Project Sunroof – an online solar estimator – can give you an estimate of the cost to install a system and years until payback. Estimates provided by Google’s Project Sunroof are based on current electric rates. Future changes in rates will impact the estimated net savings and payback. Project Sunroof is not functional for all of Idaho Power’s service area, so we’ve provided three Project Sunroof examples of a typical home below.
 The Jones’ House |
 The Zhang’s House |
 The Jackson’s House |
|
|---|---|---|---|
| Average monthly electric use: | 500 kWh | 1,000 kWh | 1,950 kWh |
| Average monthly bill: | $45 | $90 | $175 |
| Solar system size needed: | 3.75 kW | 8.25 kW | 15.75 kW |
| Estimated upfront cost: | $13,300 ($3.55 per watt) | $27,500 ($3.33 per watt) | $51,000 ($3.23 per watt) |
| Net cost after tax credit: | $8,400 | $17,200 | $31,900 |
| Upfront Payment (no financing, no interest fees) | |||
| Simple Savings1 calculation | |||
| Estimated payback: | 17 years | 16 years | 14 years |
| Total 20 year savings: | $1,500 | $5,800 | $14,800 |
| Net Present Value1 calculation | |||
| Estimated payback: | Beyond 20 years | Beyond 20 years | Beyond 20 years |
| Total 20 year savings: | -$1,700 (loss) | -$1,600 (loss) | -$293 (loss) |
| Loan (financing that includes interest fees) | |||
| Simple Savings1 calculation | |||
| Estimated payback: | Beyond 20 years | Beyond 20 years | Beyond 20 years |
| Total 20 year savings: | -$6,400 (loss) | -$10,300 (loss) | -$15,100 (loss) |
| Net Present Value1 calculation | |||
| Estimated payback: | Beyond 20 years | Beyond 20 years | Beyond 20 years |
| Total 20 year savings: | -$4,200 (loss) | -$6,800 (loss) | -$9,800 (loss) |
*Average monthly bill costs are based on Idaho Power residential Schedule 01 rates as of 11/1/2018. System production estimates are from PVWatts default system settings for Boise ID. All other estimates regarding cost and payback are from Google’s Project Sunroof, which are based on current electric rates. Future changes in rates will impact the estimated net savings and payback. Project Sunroof uses a 20-year loan term and 6.6 percent interest rate. Actual costs, system production and tax credits will vary. For a personalized estimate, Idaho Power recommends getting several bids from certified installers.
1Why does Project Sunroof provide two different 20-year values?
Simple savings, or the payback method, and net present value are different ways of looking at the long-term value of a purchase. Payback tells you how long it takes to recoup your money. Net present value determines if it is a good financial investment compared to other things you could do with your money—like earning interest in your bank account or investing in stocks and bonds.