Using alternative energy

Solar is way easier to afford than it used to be. It is not, however, free or easy.

Solar energy for homes can be passive—the original design of the house allows the house itself to act as a solar collector, or active, with solar collectors providing hot water, space heat, or electricity. Passive solar generally requires a new house. We'll look at the cost of active solar.

For the first time, governments at the federal, state, and local levels are subsidizing solar on a large scale. Let's look at an example of a solar hot water heating system installed in Maryland in either of two counties (information provided by Geoff Mirkin at Solar Energy World, a solar installer).

Original cost $10,000
Federal 30% tax credit -$3,000
MD state grant -$2,000
Montgomery County or Howard County property tax credit -$1,500
Net cost to the homeowner  $3,500

This system would provide savings of $500 to $600 per year, paying for itself in six or seven years.

Now look at the cost of solar collectors for electricity (photovoltaic cells)

Original cost $33,000
Federal 30% tax credit -$9,900
MD state grant -$4,150
Montgomery County or Howard County property tax credit -$5,000
Net cost to the homeowner $13,950

This system would provide savings of $2,372 per year, with payoff in 5.9 years.

These figures are considered conservative because they do not incorporate future price increases of conventional energy, which make solar a better and better deal. A turnkey solar installer provides a "solar calculator," on their website at, that estimates the cost for you.

Be aware, however, that with solar collectors, one size never fits all. If you feel ready to at least research the issue, get free estimates from solar installers. There are many factors that change price, such as your average energy use, the area of the roof that gets full-day sun, how the house is oriented, what kind of space heat distribution you have now, and how energy efficient your home already is. These factors, along with what money you can lay your hands on, will also influence which solar energy option makes sense to start with: hot water, space heat, or electric.

Should you do it or not? If you have either money to pay up front, or room in your budget for a loan, and you are going to be in your home for some time, it may make sense to do it. And pretty quickly. These credits and grants could change.

Start by setting up appointments with a few solar contractors (for comparison). You can find them at, North American Board of Certified Energy Practioners, and Find Solar (this information courtesy of another solar contractor, Ardently Green). And check your state and local government web sites to see what incentives are available. Remember that the 30% federal tax credit only works if you are already paying at least that much in taxes. Research into how to add collectors and how to pay for them is the "not easy" part mentioned earlier. You'll need to compare what the installers offer, work out the money you will be paying after incentives, and see how quickly the system pays for itself.

So what the heck are these things on the roof? Hot water solar has been around for 99 years. According to Rick Peters at Solar Energy Services, this is a "very mature technology. Improvements have leveled out" and it is used extensively in other countries. The collector heats up either water (in warm climates) or an antifreeze solution (in cooler climates), then pumps it back to a water tank. If an antifreeze solution is used, a heat exchanger transfers the heat to water. It then flows around your house just like your hot water does now. Rick says that solar hot water typically handles 75% of annual hot water costs, with conventional electric or gas acting as backup. Rainy days and winter cause solar to not cover 100% of energy needs. Other contractors say that collectors can handle 100% of energy needs (though more collectors and storage are needed). This varying information is the reason it is good to talk to more than one contractor, and look carefully at your own situation.

According to Rick, solar space heating works similarly to hot water heating. The solar contractor adds more water storage and more collectors. How exactly that hot water turns into space heat depends on what heating system is in place now. Radiant floor heating and houses with a boiler use it easily. Forced air systems need a coil in the air duct that heats the air, and is "the least ideal condition."

Solar electric is a wholly different technology. Photovoltaic collectors generate electricity directly from sunlight via semiconductors. Electrons in the semiconductors are freed by solar energy and travel to the home's electrical system. Many systems use power as it is made, and require power from the grid when there is no sun. Storing energy in batteries costs considerably more in installation.

Solar contractors stress that you can do much to lower energy costs after going solar. According to Josh Goldberg at Astrumsolar, "further lowering the energy bill [after going solar] by an additional 5 to 10 percent can be somewhat painless. After that it gets harder." (see Lowering expenses for ways to lower energy costs now.)

You can find out more about solar from the Solar Energy Industries Association.