Published on June 17th, 2008 | by Stephanie Evans

Residential Solar Applications

Utilities across the country are running into some hefty competition, and it is not from a new electric company. People all over the world, with Japan and Germany leading the way, are turning towards the sun for electricity and heating needs. While solar technology has been available for over a century, it is just recently becoming cost effective.

While giant solar power plants, solar powered cars and planes, and sun fueled air conditioners may be the wave of the future, there are several residential applications for solar power available today that can save you money in the long run and mitigate damage to the planet.

Solar Pool Heating

Solar Panels/Photovoltaics

Solar panels, also known as photovoltaics (PVs), take energy from the sun and turn it into electricity using semiconductors such as Silicon. A good deal of time and money is being invested into “thin film” technologies that can coat flat surfaces and do not use Silicon.

Solar has benefits and drawbacks, of course. PV systems have a high upfront cost, about $12,000 and $30,000, depending on the size and the amount of government subsidies available in your state, but generally pay for themselves in six to ten years. Additionally, they:

add value to your home
once installed, require very little maintenance as there are no moving parts

The problem with solar panels is that they are only cost effective in areas that get a lot of sunlight, such as southern California, Nevada, or Arizona. Most systems can generate electricity on a cloudy day, but far from full efficiency. There are systems that can store energy for nighttime use or periods of extended poor weather, but they are very costly, and generally only make sense in areas where the consumer is “off the grid”.

Most research that goes into photovoltaic technology is geared towards generating more efficient solar cells. Current models only collect about 15% of the sun’s rays and take up quite a bit of space. Additional research focuses on concentrated photovoltaics, which use mirrors and lenses to amplify the sun’s energy. However, costly tracking systems are required for the system to follow the sun’s pathway across the sky.

PV customers should not aim to go completely off the grid. The most sensible strategy is to cut your utility bill by about 50%. This makes solar panels more affordable, and you still save quite a bit of money in the long run on your electric bill. At this point, it is not realistic for the average U.S. consumer to power their entire house, day and night, summer and winter, using photovoltaics, though the cost is certainly falling.

Solar Attic Fans

The idea of an attic fan is to vent the hot air that accumulates in your attic, which cools the temperature of your house. The hotter it gets, the harder it works, as it is powered directly from the sun by a small PV panel on the roof. Solar attic fans are generally easy to install, especially because there is no electrical wiring to haul. Solar fans typically cost around $200 more than a conventional attic fan, but as with all solar products, money is saved on your utility bill and you get to feel good about reducing your carbon footprint.

Solar attic fans are not ideal for all households.If there is poor insulation between the attic and the rest of the home, the fan can draw air from the house, reducing energy efficiency and increasing the potential for mold.

Solar Water Heaters

Solar water heaters are thought to be the best and most cost-effective way to transition into solar technology. They consist of two parts, the solar collector and the storage tank. The collector is typically mounted on the roof, and consists of a thin metal box with liquid-filled tubes running through it. As the collector warms, so does the water. Generally, a pump is used to circulate water into an insulated storage tank, where it is stored for later use.

Solar water heaters generally cut water heating needs by about 60%. If the water in the storage tank dips below the desired temperature, utility-provided gas or electricity kicks in to heat it back up.

The cost of a solar water heater that generates 80-100 gallons of hot water per day is generally in the $2,000-$4,000 range. These systems typically save the consumer several hundred dollars per year on their utility bill, making them cost effective in the long run. The cost and savings of a solar water heater are also influenced by the incentive programs of each state.

Solar Pool Heaters

For those who want the luxury of a heated pool without all of the guilt, a solar pool heater is the way to go. They work in a similar fashion as a solar water heater, except the storage tank is the pool itself and the pool’s filter acts as the pump. These systems work best for covered pools, which retain significantly more heat than uncovered models.

There are several issues with the solar pool heater. One is the initial cost, ranging from $2,000-$10,000 depending on the size of the pool. However, it is estimated that the consumer will see a return on investment within two to seven years, depending on how much energy is typically used to heat the pool. The second problem is size: Solar pool heaters take up an immense amount of space, between 50 to 100% of the pool’s total area.

If initial cost and size do not present issues for your situation, the solar pool heater is a responsible way to extend the swimming season into the cooler months. In fact, some countries don’t allow heated pools unless they are heated by renewable energy.

Solar Battery and Cell Phone Chargers

For those who spend a lot of time outdoors away from power outlets, the solar battery charger might be the way to go. There are currently a number of solar powered cell phone chargers on the market that can give you a full charge in two to three hours. They are also quite affordable, generally ranging from $30 to $200. They range in size, but are typically about two to three times the size of the average cell phone.

Unless you are camping, they are not such a practical idea because a standard charger is a good deal smaller, and power outlets can be found almost everywhere. Another issue is that your phone has to be left in direct sunlight for several hours to get a charge, which can damage the phone and its battery over time. Solar battery and cell phone chargers are an interesting concept, but probably not currently practical for most people on-the-go.