Stephen Foster’s song may say, “The sun shines bright on my old Kentucky home,” but can solar power really play a big part in our energy mix?
A lot of folks are taking a fresh look at the potential for solar power here.
The sun’s energy can be used locally in two ways.
Sunlight can be converted to electricity in photovoltaic systems. This might be in a small device, such as a pocket calculator, or something a bit larger, such as outdoor patio lights. An even larger photovoltaic system can generate enough electricity to use in an entire building’s wiring to power appliances, equipment, and lights.
Ordinary sunlight can also be used as is (without taking the extra step of converting it into electrical energy) in a variety of situations in homes and businesses. In thermal systems, the heat in sunlight can be used directly to heat water for indoor plumbing or outdoor swimming pools, as well as indoor space heating. And the natural light from the sun coming through properly placed windows or specially designed rooftop portals can take the place of electric lighting.
All these options are being discussed anew as concerns about greenhouse gas emissions and energy costs become more widespread.
Each kilowatt of electricity produced from the sun means that an equivalent amount of electricity did not need to be generated from fossil fuels. For water heating, each bit of energy coming directly from the sun instead of from a fossil fuel also reduces the need for conventionally generated electricity.
That’s important. If enough people begin using solar power for part of their energy needs, that can also change how much electricity utilities need to generate at their power plants. Increased use of solar energy could delay the need to expand older power plants or build new ones. Using the sun’s energy can also be an important strategy to make existing supplies of fossil fuels last longer.
Andy McDonald, coordinator of the Kentucky Solar Partnership, believes putting energy from the sun to good use can be an important step toward reducing our state’s reliance on coal and other fossil fuels for our energy needs.
McDonald says, “I’ve submitted testimony to the Kentucky Public Service Commission about the potential for developing renewable energy in Kentucky. We could be looking at 100,000 homes with solar photovoltaic panels on their roofs or grounds, plus another 100,000 homes using solar water heating systems. I think this is very reasonable by the year 2020.”
But so far, solar power’s been a tough sell here in Kentucky.
Do we really have enough sunlight to make solar energy practical? We have lots of sunshine during the warmer months for our crops and pastures, backyard gardens, and outdoor fun. But on any morning or afternoon clouds can appear, or linger for days. And during the winter months there are many weeks in a row with fewer than nine hours a day when the sun is above the horizon.
A recent U.S. government survey concluded that average amounts of sunlight in Kentucky on a daily basis range from a peak of 5.6 hours in June to a low average of only 2.7 hours of sunshine a day in December. Throughout an entire year, Kentucky only averages 4.5 hours of sunlight on a daily basis.
Experts agree that Kentucky does not have the same kind of sunlight potential as the southwestern desert states of Arizona or New Mexico. Those states, with long periods of clear skies and ample sunshine year-round, are good choices for the kinds of large utility-scale solar arrays that produce electricity in huge quantities. Last month’s column showcased some innovative solar technology suitable for those regions. In those areas, improved devices can produce electricity measured in megawatts, enough to go into the nation’s power grid as a reliable part of the system’s daily operations.
Kentucky’s lower sunlight potential over the course of an entire year makes it unlikely that such multi-megawatt projects will be built here anytime soon.
Instead, smaller-scale local-use solar projects are more suitable for our weather patterns and available sunshine. A rooftop or backyard array of just a few photovoltaic panels can generate enough electricity for a single household on many of the days throughout a year. Other kinds of small-scale solar devices can use the sun’s energy to provide hot water for a household’s daily needs, or warm the water for a swimming pool.
Sunlight as an energy source does work in Kentucky. Solar energy is a valuable option instead of fossil fuels. Sunlight is free. But even with three plusses, folks considering this alternative are still faced with some tough questions to answer before moving forward.
Three key money issues keep coming up:
• High initial cost of solar devices
• Our state’s low average electric rates
• Uncertainty about government incentives
Jeff Hohman, marketing manager at East Kentucky Power Cooperative, which generates electricity from coal for distribution to local electric co-ops in 89 Kentucky counties, says, “The staff at all our local co-ops and our staff here at EKPC were getting so many questions last year about renewable energy options, I decided to do some research. I put together a PowerPoint slide show with lots of information to help co-op staffs answer consumers’ questions.”
In Hohman’s easy-to-understand presentation, each slide looks at a single example. In one, he uses the average price Kentucky consumers pay for electricity, shows the cost of a typical solar energy project, and then gives the estimated time it will take for the investment to pay for itself. He varies the examples by changing the base price of electricity, or by changing the price to buy and install an alternative energy project.
At first glance, the results of all that math are not encouraging.
It can take from 20 to more than 60 years for a home photovoltaic system to pay for itself, according to Hohman’s figures. Kentucky’s extremely low electric rates make solar power systems that rely on photovoltaic technology one of the least appealing options.
But Hohman offers better news for thermal solar power.
“The payback times on solar water heating can be more reasonable, often under 10 years,” Hohman says, “depending on water usage in the household.”
Hohman found the thermal idea so interesting that in 2007 he purchased a solar water heating system for his own home.
Although he and his wife are empty-nesters, when both their college-age daughters returned home for a summer visit, the family made an important discovery.
“When just my wife and I are at home, we’ve never run out of hot water for laundry, the dishwasher, and showers,” Hohman recalls with a laugh. “But on a cloudy day when both our girls were home, we did run out of hot water once. We learned that this is not a quick recovery system, and we do need to plan our day around the available supply of hot water.”
Matching the size of a solar system to a particular household’s needs requires careful thought.
Solar tax breaks
Hohman kept careful track of what he spent installing the new system, and that’s important for anyone considering solar power. Sellers of all kinds of solar power devices and home energy-improvement projects often have examples of payback times that include tax incentives. But consumers need to understand that this line item can change, and be prepared to consult a tax advisor before making a decision.
For Hohman, and others who installed solar energy systems in 2007 and continuing through the remainder of 2008, the current federal tax credit is based on 30 percent of the system’s cost, with a certain dollar amount as a cap. Congress could change these allowances as part of any new energy legislation during the coming months.
The Kentucky Legislature has already added a new incentive for renewable energy. House Bill 2 includes special tax credits that become effective in 2009 for the installation of certain renewable energy sources and projects.
Another recent private program offers favorable loan rates and terms for people who want to borrow the money to add certain renewable-energy features to their homes.
A good place to start learning more about your solar power options is a visit to the Kentucky Solar Partnership Web site at www.kysolar.org.
DEFINITIONS: THE TWO TYPES OF SOLAR ENERGY SYSTEMS
In a photovoltaic system, energy from sunlight generates electricity. This electricity can power lights and appliances, just like electricity from a utility company’s grid.
In a thermal system, the heat in sunlight transfers directly to a liquid. In a typical home, farm, or business situation, the liquid is plain water that can be used for all the same purposes that hot water from a conventional electric or gas water heater would be used.
Next month: Can nuclear power reduce greenhouse gas emissions?