Solar panel systems come in a wide array of configurations, including panels that mount on a home’s roof and panels that mount on poles outside the home.
grid-tie systems allow the homeowner to sell power back to the utility when their system produces a surplus.
Off-grid systems are designed to provide a home’s electrical supply without the need for a connection to the power grid. Such systems include a battery bank that recharges during the day and provides power for the home at night. These systems are ideal for remote properties.
The high cost of home solar systems once put them out of reach of many homeowners. But in recent years, solar leasing and power purchase agreements (PPAs) have made solar a much more affordable option.
Solar lease agreements allow a homeowner to rent solar systems and avoid the high upfront costs. In a power purchase agreement, the homeowner lets the provider install a solar system on their home and then purchases the electricity generated by the system from the provider. The availability of solar leasing and PPAs varies depending on the home’s location, but both are seen as more affordable options than purchasing a solar system, which can run well into five figures.
You may have also heard of “passive solar” systems which use the sun’s light directly to provide home heating or hot water. Passive solar systems do not generate electricity, but they can be employed to reduce a home’s overall energy use.
A geothermal system employs special pipes that are buried deep underground where the earth’s temperature is constant. Depending on the location, that temperature typically ranges from 50°–60°F, which is warmer than the outside temperature in the winter and cooler than the outside temperature in the summer.
Therefore, a geothermal system can be used both to cool a home in the summer and to warm a home during winter.
When used for home heating, the system works by circulating fluid through the underground pipes to absorb heat. The warmed fluid returns to the surface where it is used to heat the home. There are different types of geothermal systems, but they all employ a similar process of heat exchange.
In the summer, the process is reversed—the fluid absorbs heat from the home at the surface before being circulated underground, where the cool earth acts as a heat sink, cooling the fluid.
Like solar, the upfront cost of installing a geothermal system has been a barrier to widespread adoption of the technology. However, new companies that provide specialized financing have sprung up, putting such systems within reach of homeowners interested in reducing their energy use.