Hydroelectric energy would be the best alternative energy source for a house in Alaska. While solar energy can be a good source of electricity in many areas, it is not a reliable source of energy in Alaska due to the long periods of darkness during the winter months. On the other hand, hydroelectric energy can be generated continuously as long as there is a water source, such as a river or stream, available to power the turbines. This makes it a more reliable and consistent source of energy in a place like Alaska where the sun is not always shining. Additionally, hydroelectric energy is a clean and renewable energy source, making it a good choice for those who are looking to reduce their carbon footprint.