United Kingdom is the windiest country in Europe, so much so that we could power our country several times over. 
Advantages & Disadvantages of Heat Pumps
This page lists some of the main advantages and disadvantages of both ground source and air source heat pumps. This article mainly focuses on the advantages of heat pumps.
Advantages
Air source heat pumps (Air to Air) have few moving parts, which reduces maintenance requirements. However, the outdoor heat exchanger and fan should be kept free from leaves and debris, if not damage may occur. On the other hand, ground source heat pumps (Ground to Air) have no regular maintenance.
Both air and ground source heat pumps reduce fuel bills, due to their efficiency, the air source heat pump could have an efficiency of up to 330% and a ground source pump could reach 450%, compared with an efficient gas boiler of 90% obviously this is a big difference. When dealing with heat pumps, the efficiency is known as Coefficient of Performance (COP).
With ground source heat pumps there are no corrosion or degradation issues with the buried plastic pipes, consequently there will never be a need to replace the pipes due to degradation.
CO2 emissions from heat pumps are considerably less than gas or oil fired heating systems and due to the low grade energy source utilised by heat pumps are considered a renewable energy source.
Ground Source heat pumps benefit in that, due to the prolonged thermal retention qualities of the soil, they can provide both warming in the winter and reverse cooling in the summer.
Both Air source (Air to Air) and Ground Source Heat pumps can be used in conjunction with other renewable technology, particularly in achieving reduced U values and compliance with the PassivHaus standard
Disadvantages
Air source heat pumps become less efficient at extracting heat from the air when the external temperatures become low.
The cost of equipment, material and installation can be expensive, depending on the type of heat pump installation planned. Preferably ground to air heat pumps would be installed alongside or part of another development to your home.
Due to the coils laid underground, a reasonable amount of land would be needed for ground source heat pumps. This is more of a requirement than a disadvantage.
Air source heat pumps can be noisy, due to the fan and generally are not aesthetically pleasing.
Ground Source heat pumps work best when incorporated within an underfloor heating system, and as such are generally only suitable for properties with a larger floor area.
Other articles you may like:
Advantages & Disadvantages of Wind Turbines