Real solar power, that you can use at night time!
To be fair, wood burning stove versus solar panel is a false comparison, as they perform very different functions, but for some people - who might be considering both from an ecological/economical motive – it can be a genuine conundrum, as, while the pay-off with both kinds of apparatus will extend for decades (although solar panels offer diminishing returns as the panels deteriorate), initial installation costs can be high. (Up-front costs for solar, though, are typically two to three times as much as for a stove installation.)
Photovoltaic solar energy has made huge strides in recent decades, and will probably be a core component of both domestic and wholesale energy mixes in years to come, especially in sunny countries! However, the oft-quoted problem with renewable energy is its intermittent supply and the challenge of storing the energy it gives until it is needed. In this respect, manufactured solar panels will never improve on the synergy of the wood burning stove and the humble tree.
A tree is condensed sunshine. A tree takes sunshine, water, carbon dioxide, and a minimal supply of minerals from the soil. The carbon which it absorbs from the air is locked into the structure of the tree for its lifetime and then into the floorboards, tables and chairs into which it is converted when it is felled. The branches that are lopped during its life and after felling will be used for firewood and the leaves and twigs will be left on the forest floor to nourish the next generation of trees.
Once your firewood is chopped and stored, it will last for years as long as it is kept dry and free of insect infestation. This means that you can buy as much heating energy security as you want (and can afford/ have room to store).
The raw conversion rate of sunlight into useful or latent energy is of course lower for trees than for solar panels – evolution selects for reproduction before growth or anything else - but a tree is a wonderfully complex thing long before it can be considered a crop or a fuel, conferring countless benefits and uses for the planet and its entire ecosystem as well as for its putative owner.
The wood burning stove is of course the ideal vehicle to transform the wood into radiant, sun-like heat, producing warmth, beauty and serenity in a safe and wholesome package. A solar panel, by contrast, is a sterile tool, unpleasant to look at, which brings little or no collateral benefit to its primary purpose.
Put like that, it's an easy choice!