Small scale solar power is extremely practical for domestic use. In the UK many businesses will in fact install solar panels free on your roof in exchange for the excess energy they produce being sold back to the grid by them. You get as much energy as you need from them for free which can add up to a lot. Think how much you spend on electricity and heating. This type of panel is solar PV which is a very thin panel which can be fitted to a rooftop.
Larger scale solar power is generated in hot regions, for instance the south of Spain and Africa. It works by setting up mirrors to heat up a boiler full of water and generating energy from the steam. It is thought this will be an excellent source of energy in future.
Wind energy is produced from wind turbines that are positioned in areas where there are consistent winds. You often find many wind turbines close together and this is called a wind farm. Wind turbines have increased in size over the years as the engineering has improved and now they can be several hundred feet in height. Domestic wind energy is possible though only viable in high wind areas such as the Scottish highlands.
Offshore wind refers to wind farms in the ocean. The turbines are attached to the sea bed out to sea. They can be much larger than on land and also the winds are faster and more consistent. Salmon farms are often positioned round the base of these turbines. In future it may be possible for large floating platforms of wind turbines to generate electricity out to sea.