Written by Joyanna Laughlin for Time to Build a Houseplans Blog
Solar panels or photovoltaic? It’s the same thing. What most people call solar panels are the modular, silicon-based, flat-plate photovoltaic (PV) panels that turn sunlight into electricity, says Ben Uyeda, designer, co-founder of ZeroEnergy Design and FreeGreen.com, and director of HomeMade Modern. A solar electric (a.k.a. photovoltaic) system includes a group of PV panels, inverters [pieces of equipment that convert direct-current (DC) electricity generated by a group of PV panels into alternating-current (AC) electricity that can run your appliances], a mounting system and other equipment.
Additional types of solar energy systems include flexible solar photovoltaic films (used on metal roofing systems, boats, recreational vehicles, etc.) and solar thermal systems, which produce hot water to supplement your home’s water heating system, says Alan Spector, architect and owner of Lafayette, New Jersey-based Spector Associates Architects.
Understand your energy usage
In order to figure out how much energy you need to power your home using the sun, you need to know how much energy you use. This means understanding how much energy it takes to do things like heating your home or making a cup of coffee. According to Estimating Home Appliance and Energy Use on the U.S. Department of Energy’s Energy.Gov website, it takes between 1,800 and 5,000 watts to dry a load of clothes, between 1,200 and 1,875 watts to dry your hair, and 900 to 1,200 watts to brew a pot of coffee. Energy consumption has to do with personal habits, says Kirpal Johnson, an energy consultant for San Mateo, California-based solar installation company SolarCity. Leaving doors open and lights on or running the furnace or air conditioning a lot increases energy consumption. Performing a home energy audit can help you to find out what your actual numbers are. There are tools online to help you do it yourself, and there are also private companies, as well as some public utilities, that will do it for you.
Once you’ve decided to include a PV system in the design of your new home, Uyeda recommends having your general contractor get bids from subcontractors, and Spector adds that it’s a good idea to compare three bids from qualified installers. Research the installers to make sure that they are legitimate companies, and to understand the contract you are signing. “Educate yourself on the company, and inform yourself about the contract,” advises SolarCity’s Johnson. “Homeowners need to be involved at an active level and engaged with the process and the numbers,” Johnson says.
Check the numbers
The installer you select to design your PV system should provide you with an exact calculation of the amount of energy your system will produce, Spector says. You can verify the numbers the installer gives you by using websites such as the National Renewable Energy Laboratory’s PV Watts Calculator.
Buy brand name equipment
Most PV panels have similar conversion efficiencies (the rate at which the panels convert sunlight into electricity). Make sure that your PV panels and inverters are established brand products with good warranties, says Spector. Uyeda recommends telling your general contractor and installer what you are looking for (including good warranties on the equipment) and letting your general contractor and installer pick the brand. Some major solar panel brands include SunPower, Kyocera, Sharp, Yingli, LG and Canadian Solar. And SolarCity recently purchased Silevo, a manufacturer of high-efficiency solar modules, which means they are getting into manufacturing solar panels, a business that is currently dominated by Chinese companies. And SMA, Outback and Fronius are established brands of inverters.
Solar works in cold climates
Solar systems are not just for people in very sunny places. Solar also makes sense in cooler, northern climates. “The important thing is proper orientation to the sun and the amount of sunlight the location receives,” Spector says. “Germany is the world leader in solar, PV and it has only moderate sunlight.” Spector owns a 3,163-sq.-ft., home in New Jersey with a 5-kw PV system that provides 65 percent of the home’s electricity needs and powers Spector’s electric car, a Nissan Leaf.Uyeda designed his own 1,200 sq.-ft energy-efficient home, which is currently under construction in Boston, and he is having a 4-KW PV grid-tied system installed to provide a portion of the home’s electricity needs and to power his Nissan Leaf — the exact amount depends on how much he drives the car. “If you are building a new home in a cold climate,” he says, “solar shouldn’t be the first thing you think about. Consider the building envelope first (orientation, insulation, and energy efficiency). Don’t spend a lot of money on solar to heat an inefficient home.”
There are several options, including buying your PV system up front (which might cost $20,000 or $30,000, says Johnson), rolling the cost of the system into your mortgage like Uyeda is doing with his home, or leasing your system from a large installer like SolarCity. Uyeda prefers packaging the cost of his PV system into his mortgage because the money he would have spent on gas is now going to increase the value of his home, which is a tangible asset. The main benefit of leasing is that you can get a PV system on your home without paying any money up front, Johnson says. Solar City installs the system, insures it, monitors its performance, and handles repairs and maintenance. You sign a 20-year contract with SolarCity, and they take a percentage of your energy savings over the life of your contract. Whichever financing option you choose, going solar can be a simple process and you can soon be on your way to lower energy bills and contributing toward a cleaner environment.