How best to heat your log cabin depends on its size and use you will probably not want to bother with a wood burner if you are using your cabin as a home office. Perhaps the most important factor is whether you have power sources available but as with everything the amount you can afford to spend will probably make the decision for you.
The first three suggestions below will require a mains power source but if you are using the cabin as a garden office this shouldnt be much of an issue:
This is the ideal solution in many ways as air conditioners can give you warmth in winter as well and cooling if required in summer. They are also a good idea if you are using your cabin for storing items as you can easily regulate temperature and humidity. You do have to be aware however than they can produce some noise and also require a little space for an outside mounted heat exchanger.
Electric radiators and convection heaters
Electric radiators can be wall mounted or stand alone and linked to thermostats and timers so they switch on if the temperature drops below a certain level or if you have programmed them to go on at a particular time. So if you have a home office you might decide to time the radiators to switch on 20 to 30 minutes before you use the room. Convection heaters tend to warm a room much quicker than radiators and can also be linked with timers or thermostats. They are quite a cost effective solution and can simply be used with a regular power supply.
Oil-filled electric radiators
As above, but oil-filled electric radiators have the advantage that they retain heat longer and can usually be put anywhere in the cabin.
The following suggestions can be used in conjunction with electrical solutions or simply by themselves:
This is a fantastic idea and panels can be mounted on the roof or south facing wall. Although they will only work when the sun is out, this is not as bad as it sounds as even in winter there is a fair amount of sun. If the primary objective is to reduce damp and have some warmth in the cabin then the running costs are basically nothing and they can be left unattended for long periods. Solar heating units can be quite expensive to buy but there are also various DIY versions that can be made from plastic piping and drinks cans! Some may require a small battery to power a fan, but basically they can be left to run all winter and simply unattached when not required in summer. If you have good floor and roof insulation plus dark floor tiles and some form of heat sink (see demo here) the results can be very effective.
These must be professionally installed by a HETAS engineer and along with flue installation they can be quite expensive. However for cool points they are amazing and probably what everyone expects to see in a log cabin (not so much a home office though!). They can also be a little be messy with the accumulation of ash etc and are relatively slow to get going and quite high maintenance in terms of time. They are of course carbon neutral and if you have a supply of wood then very cheap to run.
Bottle gas heaters can be installed outside the cabin to feed a heater or be free-standing with an enclosed bottle. These are not an ideal solution as they require ventilation which partly defeats what you are trying to do as well as issues of vapour and toxic fumes.
When making a decision of how to best heat your log cabin in winter you can of course opt for a combination of the above for a home office we would recommend oil-filled electric radiators alongside a basic solar panel unit.