- Solar power
Solar power creates heat or electricity using the sunshine. It can also be used for passive cooling and heating of structures. There is a number of ways to use solar power, from the direct conversion of radiation to processes such as photosynthesis. Large solar farms can provide enough power to entire communities and make the communities self-sufficient.
- Nuclear power
Nuclear power harnesses the energy of atom fusing and splitting. Some scientists do not consider it to be an alternative energy source. Others believe that any energy that does not come from fossil fuels and does not create fossil fuel pollutants is an alternative energy.
- Wind power
Wind power comes from windmills that can be placed in locations with a lot of wind. The United States has plenty of such locations.
- Geothermal power
This power can take heat from the planet and deliver it to buildings and structures or convert the heat into electricity. Geothermal power is available is very large quantities, but it is difficult and expensive to produce compared to other types of energy. This being said, heat pumps use geothermal energy, so this kind of energy can be very practical on a micro level.
- Biomass and wood
Biomass includes corn, mulch, sawgrass and so on. To get energy out of these materials, it is possible to burn them in the raw form or convert them into solid or liquid fuels. Wood is the most popular biomass and a lot of people all across North America use it to heat their homes.
- Hydrogen fuel cells
Hydrogen fuel cells create power from hydrogen by combining it with oxygen. Hydrogen does not have any carbon, so the exhaust is water. This energy has an amazing potential, but there are some major issues with the technology.
- Electric cars
Electric cars use only electric power. The power comes from batteries. Currently, the batteries are heavy and cumbersome, but battery technology keeps getting better and better, which is why more and more electric cars are becoming a great choice and can compete with conventional cars.
- Hybrid cars
Hybrids typically use a combination of electric energy and energy that comes from an internal-combustion engine. When a car does not need a lot of power, it switches to the electrical mode. When it needs a lot of power or when the batteries are low, the car uses the internal-combustion engine.
Hydropower is generated by dams with high-pressure water flows. Such flows spin turbines, which, in turn, create electricity. Hydropower can be used on both macro- and micro-levels.
Biofuels are made of biomass, for example, corn. Today in the United States most of the gasoline has at least some corn ethanol in it. Biofuels consume a lot of energy when they are created, but they do lower the dependency of the United States on foreign oils. It is possible to use biofuels on their own and also mix them with fossil fuels.