Here in Southern California we are fortunate to have the sunshine nearly all year long. Are you ready to put the sun to work for you? The combination of falling prices, financial incentives, and increasing environmental awareness makes solar power a tempting option for running your home. In some arrangements, you could even sell some of your unused power back to the utility company — a nice switch indeed.
Residential photovoltaic (PV) solar energy systems have four major components:
- Solar panels – They absorb the sunlight and convert it to energy.
- Controller – Controllers regulate the flow of electricity.
- Batteries – When the electricity is not in direct use, it is stored in batteries.
- Inverter – Inverters convert the battery energy into the proper voltage for standard power outlets.
How do you go about deciding if solar power is right for you, and if it is, how do you decide on the system to install?
Check for roadblocks – Solar panels are frequently installed on rooftops. These can be quite large depending on your needs, and not everyone finds them aesthetically appealing. Check for any neighborhood covenants or city ordinances that preclude or limit solar panels, and make sure that you can acquire any necessary construction permits to have the work done.
Set your goals and tolerances – What do you want to operate with your solar power? You will need to answer some basic questions to select the proper type and size of system. Questions include: Do you want to power individual components such as a water heater or an A/C system, and do you require backup on these systems (either with a battery or the power grid)? Do you want to tie into the grid and use the solar component to save money when possible? Do you want to go completely off the power grid, and if so, what backup plans or potential outages can you tolerate?
Evaluate your needs and site capabilities – Start by checking your past utility bills for usage in kilowatt-hours (kWh). Examine the average and the peak usage — peak usage is more important in sizing your system if you are going completely off-grid. You may also consider whether your usage is higher than it should be, and make an effort to conserve overall consumption. Next, investigate the size of the system that you need to install to meet your needs. A nice generic solar project estimator can be found here along with pricing from that vendor. Choose the type of connection,
percentage of power to supply, your general monthly usage, and your peak sun hours by geographical location as shown on an adjacent graph, and you will get a good initial estimate of what you need. Finally, do a site analysis. Is your roof large and strong enough to handle the physical size of the panels you need, and if not, are there any other installation options? Are there shade considerations that might make your installation less efficient? Bring in a vendor for a professional opinion before proceeding with any complex installation.
Run the numbers – Start by calculating the annual savings, based on the estimated power output of your system and the rate you currently pay for electricity. Be conservative and only use 80 percent – 90 percent of the estimated output to account for inefficiencies with inverters and other changes over time. Now total up the costs. Total all costs for the panels, installation labor, taxes, and any other initial costs, and then subtract any tax incentives from your local utility or state programs. There is even a federal rebate for solar installation under the Residential Renewable Energy Tax Credit (currently extended through December 2016). Add in any maintenance costs over time (either estimated or as part of a service contract), and subtract any estimated resale of unused power back to the grid. The break-even point is when the savings over time equals all your costs (ignoring the time value of money and fluctuations in utility rates, but you can add those assumptions if you wish). Ten to twenty years is not an uncommon payback period. (However, keep in mind that a solar installation may also increase the resale value of your home.) Beyond twenty years, you have to concern yourself with the obsolescence of the solar equipment and whether it can be retrofitted. Costs vary greatly, but a very crude estimate for an average home system is in the range of $10,000-$15,000 for the base system and from $20,000 to $30,000 installed. Quotes may be given on an installed per-watt basis.
Choose a vendor and system – Research vendors that operate in your area and check with your local utility for recommendations. Make sure that any vendor does a thorough site analysis and customizes the system to meet your needs. Do not forget to verify maintenance requirements and who is responsible for them. Some companies offer lease options, where they basically install and maintain the system and sell you the solar power at a reduced rate. You do not own the equipment in that case, nor do you receive the subsidies. Do the same sort of cost-benefit analysis before choosing the lease route, and read the fine print carefully with respect to rate increases.
If you are going completely off-grid, you may want to consider installing Tesla’s new Powerwall battery to serve as your emergency backup system. They are not cheap, but depending on your needs, they can serve as a solar-based backup system to eliminate the need for a backup generator.
Try some preliminary calculations and see if solar power is a reasonable investment for you. Solar panels can save you money in energy costs, increase the value of a home, and help you do your part to conserve the planet’s resources. Unless you live under a black cloud, why wouldn’t you at least investigate the possibilities?
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