From LoGOs Energía we support the energy efficiency projects and renewable energies, since they do not drain resources nor pollute, and they are expanding all over the world, mainly aeolic and photovoltaic energy.
The most efficient alternatives for heating are the ones that utilize renewable energies, such as aerothermal energy, geothermics, biogas, solar thermal, biomass, etc. and high-performance centralised boilers that function with gas condensation, low temperature and thermal inertia, like underfloor heating.
Regarding cooling systems, whether they are electric or gas-fired, the most efficient option is the heat pump (aerothermal energy, geothermics, etc.).