HoursSystem Cost
| Solar Thermal | Photovoltaic | ||
| Low Initial Cost – $5000-6000 | High Initial Cost – $10,000-50,000 | ||
| Return On Investment | Return On Investment | ||
| Fast Pay Back, 2.5-4 Years | Long Pay Back, 8-14 Years | ||
| Initial Cost | $6,000 | Initial Cost, Typical 3 Phase Buildup | $36,000 |
| Hawaii Energy Rebate | -$750 | ||
| Subtotal | $5250 | ||
| Tax Credit 65% | -$3,412.5 | Tax Credit 65% | $23,400 |
| Net Cost | $1,737.5 | Net Cost | $12,600 |
| Avg Monthly Savings | $80 | Avg Monthly Savings | $135 |
| Cost/Avg Savings | Approx 21 Months | Cost/Avg Savings | Approx 93 Months |
| Or 1.8 Years | Or 7.8 Years | ||
| To Get Your Net Cost Back | To Get Your Net Cost Back | ||
| Thermal Solar Saves More | Solar Photovoltaics Save You | ||
| In Years To Come. | Less At Time Goes By. | ||
| Here’s Why: | Here’s Why: | ||
| Say the typical system can save $50 per month at first. When the kwh rate doubles in 10 years, your thermal solar system will save you $100 per month and still makes 120 gallons of hot water a day. | Most P.V. panels come with a 25 year warranty for 80% output. So expect a 10-15% loss in performance in 20 years. The good news is P.V. panels should last about 50 years and still have an output of 65-75% efficiency. Inverters are expected to last 10-15 years; twenty year extended warranties are also available and is probably a good idea. | ||
So, by the time a photovoltaic system pays you back once for your investment, a Solar Thermal hot water will have paid you back 7 times!
We do recommend photovoltaic systems, but we also recommend that you start with a solar thermal hot water system first. This way you are able to reap the rewards and get paid back while or before you are ready to install a photovoltaic system.