| Solar power energy systems are not inexpensive. | | | | Many states and local jurisdictions offer rebates, tax |
| That said it's important to compare them within | | | | credits and other types of incentives to homeowners |
| context of other types of home improvement projects. | | | | for installing residential photovoltaic and solar domestic |
| Home buyers and realtors view a solar photovoltaic or | | | | water systems. To view a comprehensive database |
| solar hot water heating system as a significant | | | | of the incentives available for renewable energy visit |
| value-added improvement - similar to adding a deck or | | | | At the Federal Level, you can take advantage of a |
| remodeling your kitchen. Plus unlike a deck or kitchen | | | | 30% tax credit (of up to $2,000) for the purchase of a |
| remodel, you also gain one-up on your power bills. | | | | residential solar system at least until December 31, |
| Solar power systems often get an additional financial | | | | 2008. |
| boost as well: many jurisdictions and utilities across the | | | | Step 6: Run the numbers |
| USA offer attractive financial incentives to drive down | | | | Although the cost for a solar PV system will depend |
| the upfront capital costs associated with a solar | | | | on the size of the system you intend to install, your |
| power system. | | | | electricity rate, the amount of kilowatt hours you |
| Here are some foolproof ways to estimate the cost | | | | expect to generate, and the state/local rebates/tax |
| of a solar photovoltaic or solar thermal system and to | | | | credits that may be available, the formulas for |
| figure out if a solar energy system makes sense for | | | | calculating the returns are pretty much the same. |
| you. Let's start with a home photovoltaic (PV) system. | | | | For those who appreciate having the formulas, use the |
| Step 1: Estimate your home's electricity needs | | | | ones listed below to do a quick ballpark estimate of |
| To get started, it's good to have a sense of how | | | | how much a solar photovoltaic system might cost you. |
| much electricity you use. You'll have a better point for | | | | Retail Price for Solar Photovoltaic System |
| comparison if you find out how many kilowatt hours | | | | + Building Permits |
| (kWh) you use per day, per month, per year. Your | | | | - $2,000 Federal Tax Credit |
| utility bill should include that information. | | | | - State or Local Tax Credit or Rebate |
| Of course, the utility bill will also display your costs and | | | | - Utility Rebate or Other Incentive |
| many utilities include a graph that displays how your | | | | = Net Investment |
| monthly energy use/cost varies throughout the year. | | | | Kilowatts of electricity generated from PV per yearx |
| That helps you estimate where your highest energy | | | | Kilowatt hours used per year |
| use is and at what time of year. | | | | = Annual Kilowatt energy from the PV system |
| New Home Construction | | | | Annual Kilowatt energy from the PV systemx Current |
| If you are constructing a new home, then you'll need to | | | | Residential Electricity Rate |
| estimate your demand based on the type of | | | | = Annual $$ Saved |
| equipment you plan to install and your home's square | | | | Yearly Excess PV Energy Producedx $$ credit |
| footage. The pross call this "your load". | | | | applied per watt |
| To figure out your anticipated load, create a table to | | | | = Annual Value from Net Metering |
| record the watt use for each appliance. Each | | | | Of course, a more accurate assessment can be |
| appliance - be it a water heater, electric light, computer, | | | | made by a pro. Work with a solar power contractor to |
| or refrigerator - should have a nameplate that lists its | | | | size and price the right system for you. As is true with |
| power rating in watts. Or you can get the information | | | | any major purchase, don't hesitate to ask for several |
| from the manufacturer's website. | | | | bids from different contractors. |
| Some labels list amperage and voltage only; to obtain | | | | Many solar power providers will provide you with a |
| watts multiply the two together (amperage x voltage = | | | | comprehensive estimate. Helpful information to know |
| watts). In another column, record the number of hours | | | | includes: |
| each appliance is expected to operate. Then multiple | | | | - Total cost to make the system operational (labor |
| the watts and hours together to estimate watt-hours | | | | cost for design and installation and equipment costs) |
| used per day. Since it's hard to anticipate all electric | | | | - Equipment (Make and Model) |
| loads (it may get tedious scouting out every toothbrush | | | | - Warranty info |
| and mobile phone cell charger), you might want to add | | | | - Permit costs, if needed |
| a multiplier of 1.5 to be safe. | | | | - Tax, where applicable |
| Step 2: Anticipate the future | | | | - Federal tax credits |
| In 2005, average residential electricity rates across the | | | | - State or local jurisdiction tax credits or rebates |
| USA ranged from about 6 to nearly 16 cents per | | | | - Utility rebates |
| kilowatt hour depending on where you lived. Average | | | | - Expected Renewable Energy Certificates or Net |
| retail and commercial electricity rates have increased | | | | metering credits |
| roughly 30% since 1999 and the upward trend will likely | | | | - Expected operation and maintenance costs |
| continue especially as costs for the coal and | | | | - Projected savings |
| hydropower used to generate that electricity rise as | | | | Solar Thermal (also called Solar Hot Water) |
| well. So think about your home electricity needs and | | | | Solar thermal systems capture the sun's energy to |
| present and future cost in relation to one another. | | | | heat water and are one of the most cost-effective |
| Step 3: How much sun do you get? | | | | renewable energy systems. They are used to heat |
| The Florida Solar Energy Center has conducted a | | | | hot water tanks and/or a heating system. A solar pool |
| study to examine how a 2-kW photovoltaic system | | | | heating system is another type of solar thermal |
| would perform if installed on a highly energy efficient | | | | system designed specifically to heat a pool or hot tub. |
| home across the continental USA ( | | | | Generally it's worth investigating the economic viability |
| The study accounted for all factors that impact a PV | | | | of installing a solar hot water system if you have an |
| system's performance such as the temperature | | | | electric water heater with utility rates of at least 5 |
| effect on the photovoltaic cells, the amount of sun | | | | cents per kilowatt hour and have tax credits or |
| peak hours in various regions, and the efficiency of | | | | rebates available. (It may even be worth changing out |
| inverter to convert solar derived energy from DC to | | | | a gas-powered water heater if your costs are at least |
| AC. | | | | $8/million BTU). |
| As the study implies, solar photovoltaic systems work | | | | The formulas for costing out a solar water heater |
| just about anywhere in the US. Even in the Northeast | | | | system are similar to estimating the cost for installing |
| or in "rainy Seattle", a pv system can pencil out if | | | | solar PV system. Many solar energy professionals can |
| designed and installed properly. In New York or New | | | | help you determine what system might work best for |
| Jersey, a one kilowatt system should produce about | | | | you. |
| 1270 kilowatt hours of electricity per year, in Seattle, a | | | | Heating Your Swimming Pool with Solar Power |
| one kilowatt system should produce about 1200 | | | | Although few jurisdictions provide financial incentives |
| kilowatt hours per year. In the Southwest, of course, | | | | for using solar energy to heat a swimming pool or hot |
| those ratios will be much greater. | | | | tub, in general, using solar power to heat your pool is a |
| Solar contractors in your area can help determine the | | | | "no-brainer" from a return on investment standpoint. |
| best size for your solar photovoltaic system. | | | | The electricity used to heat a pool during the swimming |
| Step 4: Size your system | | | | season often amounts to the same amount of energy |
| In general, solar photovoltaic systems sized between 1 | | | | that homes-without-pools consume over a year. |
| to 5 kilowatts are usually sufficient to meet the | | | | Combining a solar thermal system to generate heat |
| electricity needs of most homes. One advantage of | | | | for the pool with a solar thermal pool cover to retain |
| grid-tied systems is that you can use solar PV to | | | | the heat generated can further maximize efficiencies |
| supplement or offset some of your electricity needs; | | | | and extend your swimming season. |
| therefore you can size your system to match your | | | | Most installers recommend that a solar collector used |
| budget and always add to the system later if needed. | | | | to heat a pool is sized at roughly half the square |
| Also as a side note, here's a rule of thumb to | | | | footage of your pool surface area. Solar thermal |
| remember to help you estimate the physical space | | | | panels typically last 10 - 20 years and come with a |
| your PV system might need: one square foot yields 10 | | | | 10-year warranty. |
| watts. So in bright sunlight, a square foot of a | | | | How long it takes to break even on the cost of your |
| conventional photovoltaic panel will produce 10 watts | | | | solar power pool system depends on where you live. |
| of power. A 1000 watt system, for example, may | | | | In California or other parts of the Southwest, you'll |
| need 100 - 200 square feet of area, depending on the | | | | break even in 1 to 3 years but places as "far north" as |
| type of PV module used. | | | | Canada, a solar pool heating system pencils out over a |
| Step 5: Know your rebates | | | | slightly longer period of time. |