I have a Tulikivi Soap Stone heat retaining ovens [0] in my home. It stores about 60kWh and releases it gradually over 24+h. The problem is that it's power is

I have a Tulikivi Soap Stone heat retaining ovens [0] in my home. It stores about 60kWh and releases it gradually over 24+h. The problem is that it's power is about 3kW of released heat. Which is not enough for my home. I still need to use heat pumps as my main heat source (not complaining as they are more efficient anyway). So it's a nice fireplace that retains heat and the cats really love it. But there is a tradeoff between power and efficiency so if you are looking to put one in, do the math and figure out whether it is the right solution for you. They also claim that over 90% of the burning energy goes to heating the home and only 10% is lost. Tho as mine uses inside air I suspect that as cold air is drawn in, it might be less. [0] https://www.tulikivi.com/en/Products/Fireplace_collection https://www.tulikivi.com/en/Products/Fireplace_collection