Does Solar Work in Portland?
Solar Now! is brought to you by the City of Portland Bureau of Planning and Sustainability, Energy Trust of Oregon, Solar Oregon and the Oregon Department of Energy.
Q: Does solar work in Portland?
A: Yes. Despite our rainy winters, Portland receives as much solar energy annually as the average U.S. city. Solar is Oregon’s most abundant renewable energy resource. More than 17,000 Oregon households have solar energy systems.
Q: What is a solar energy system?
A: There are two kinds of solar energy systems for home use: solar water heating and solar electric. A solar water heating system preheats the water that goes into your existing water heater, which reduces the amount of gas or electricity your water heater consumes. A solar electric system makes electricity, which means you purchase less electricity from your power company. If your system is producing more than you need, the power company buys the power back from you.
Q: What are the benefits of using solar energy?
A: Going solar means true energy independence — energy is captured right where it is used, at your home. Sixty-three percent of the current supply of electrical power for Portland comes from fossil-fuel burning power plants. Emissions from these plants are a primary contributor to global warming pollution. Traditional electricity and natural gas generation also have impacts on human health, ecosystems and wildlife.
Q: How much do solar energy systems cost?
A: A typical installed solar water heating system costs $6,000-$9,000 before incentives. For a solar electric system, the average cost is $9,000 for each kilowatt (kW). Energy Trust of Oregon provides cash incentives to help Oregonians invest in solar energy systems. These incentives and tax credits can cover as much as half the cost. The costs vary depending on the system size, current market prices for the technology you choose, and the ease of installation. Federal tax credits increased in 2009, providing more cash back to homeowners installing solar electric systems.
Q: Does solar add value to my home?
A: Solar is an investment in your home that will increase in value as energy costs rise. At today’s gas and electric prices, a solar hot water system saves the average family of four $150 - $300 a year. Savings are typically higher for larger families. A 2kW photovoltaic system can trim 15- 20 percent or more off your electric bill. In addition, you are adding value to your home that will be reflected in its resale price. Current sales data show that added resale value is about 20 times the annual cost savings of a system.
Q: What size system do I need for my house?
A: Heating water is one of the largest uses of energy in your home. Residential solar water heating systems can save 2,000 - 2,800 kilowatt-hours (kWh) (100 - 140 therms of gas) per year. That’s 60 percent of the energy used to heat water in an average Oregon home. In the summer, your system may provide 100 percent of your hot water. During the winter months, solar will still heat the water, but not to the temperature recommended for home use. Electricity production is directly proportional to solar electric system size. 1 kW of solar electric panels optimally oriented with minimal shade will produce approximately 1,000 kWh per year in Portland. A typical residential system of 3 kW will supply about 3,000 kWh annually, or quarter of an average Oregon home’s yearly electricity usage (an average four-member household uses 12,000 kWh/year).
Q: Is my house good for solar?
A: Solar works best on south-facing roofs, though east or west oriented low-slope roofs may be suitable as well. There should be little or no shading from trees, buildings, chimneys or roof gables. Remember, locations with no shading in the winter may be shaded by spring and summer foliage, and young trees will grow.
Q: What is added to my house if I install solar?
A: Both solar electric and solar water heating systems use large panels that are typically mounted on your roof. Solar water heating panels, called collectors, are 4 feet x 10 feet. A typical system will have one or two collectors. Photovoltaic panels require 100 square feet for each kW installed. For your solar water heating system, an additional 80 gallon storage tank will be installed near your existing water heater. Solar water heating systems can also be used in conjunction with a tankless, on-demand water heater. Your photovoltaic system will have a wall-mounted inverter, about the size of a large briefcase, and two smaller disconnect switches. These can be located indoors near your breaker panel, or outdoors in a shaded location. A solar meter that measures the electricity generated by your system will be located near the inverter.
Q: I have radiant floor heating. Can I use solar to heat my house more efficiently?
A: During the heating season, we receive the least amount of sun, so using solar energy for winter heating is not ideal in the Willamette Valley. Energy Trust is investigating the effectiveness of solar for space heating.
Q: Can I install the system myself?
A: To qualify for an Energy Trust of Oregon incentive, your system must be installed by an eligible contractor. If you install your own system, you will still be eligible for state and federal tax credits.
last updated September, 2009.
