As fuel prices rise, renewable energy systems are increasingly moving to the mainstream of public awareness. But renewable energy sources are not a monolith, and thus the systems designed to utilize them can be extremely diverse.

Technically, there are only two sources of renewable energy: solar radiation, and geothermal heat. While this is true, energy from the sun can take many forms, and be captured in many different ways. Some of these include active solar energy, passive solar energy, wind energy, and biomass energy. Many of these have notable energy generation plants; wind turbines are a common sight on gusty mountain ridges in many parts of the world. However, several of these can be captured and used at the scale of one building. The three most common sources for this scale are active solar, passive solar, and geothermal.

Single-building active solar energy systems are perhaps the most widely known facet of renewable energy generation. They often take the form of solar panels mounted on rooftops or in open yards. These arrangements of photovoltaic cells use silicon to convert the sun’s rays into electrical energy for use in the home. There are often local or federal subsidy programs in place to support homeowners in obtaining these systems, which can have high up-front costs and sport up to a 20-year payback period. Regular maintenance can help a solar panel system pay for itself much sooner, as clearing the dirt and debris from the glass surface allows the maximum amount of light to penetrate into the photovoltaic layer.

Passive solar generation is less acknowledged as a renewable energy system, but in fact many are using it without even knowing it. An example of passive solar energy is shutting the blinds at night to keep the heat in, and opening them during the day to let sunlight in, thereby heating a residential house. Passive solar energy systems generally collect solar heat directly at the location it’s intended to be used, thus cutting down on losses involved with transporting the diffuse energy. Passive energy systems are commonly used to heat swimming pools, and such systems consist of a large black tarp (since black reflects less light than other colors and therefore retains more light energy as heat). A pump moves the swimming pool water underneath a winding pipe system that contacts the hot tarp, thereby heating the water with almost no electricity needed.

Finally, geothermal systems are a good choice where bedrock permits. In areas where the intense heat of the earth’s center can be accessed via areas of hot water, a steam turbine system can be installed below the surface. The rising steam will turn the turbine which produces electrical energy for residential use. This method is more viable outside of urban centers, where the stability of the ground is not so critical for packed-in multi-floor building foundations.

All of these methods represent ways that homeowners are taking charge of their own energy production, lowering their energy bills and helping the environment at the same time. Would one of these renewable energy systems be the right choice for you?