Redwood City Solar Power Home Save money and the environment while you enjoy energy independence A solar energy system was designed for a beautiful 3,500 square foot house overlooking the San Francisco Bay. This system included forty-eight 120 watt solar modules installed on the south roof (at the existing roof pitch) and north roof (at a reverse pitch facing south). A total of 5,760 watts of peak power generating capability is provided (based on manufacturer output ratings). This system provides about 23 kwh of energy per day or about 8,200 kwh per year -- after taking into account various real-world efficiency losses. Total costs of the solar energy system were $54,910, including all equipment and installation. We applied for and received a $21,553 rebate from the California Energy Commission, and the homeowner will receive an additional $5,004 tax credit from the state. Net costs to the homeowner were therefore $28,354. Based on current residential E-1 electric rates, a 7% discount rate, 30 year system lifetime, 5% annual electrical rate increases (top electric rates in California have actually increased at an average of 5.5% per year), and 42% combined California and Federal tax rates, this system will save the homeowner $1,888 per year with a Net Present Value of $12,441. According to the Appraisal Institute, energy saving improvements will increase your home's value by $20 for every $1 reduction in annual energy usage. In this case the value of the home was increased by $37,760 in current dollars -- more than the net cost of the solar energy system itself! Moreover, by financing the purchase of the solar energy system at an interest rate of 6.5%, the Net Present Value of the system increased to $21,553! This improvement results from the fact that the return on your investment from the solar energy system when it is financed exceeds the cost of the financing itself. On a cash basis, this customer's electric bill went down by $157 per month, and their after tax loan payment went up by $116. Their monthly positive cash flow was therefore $41. These savings do not take into account several important factors: Distributed solar energy power is a renewable energy resource and very kind to the environment. Renewable solar energy system improvements add significantly to the value of your property without any increase in the assessed value in most municipalities. Cash flow savings are likely to be hundreds of dollars per month if you were to install a solar energy system in conjunction with other energy saving devices - and then refinance the entire package at a lower interest rate.