There would be more than one way IMO. One option:
- Select target surfaces, and set their Sun Exposure field to "NoSun"
- Pick a layer in their referenced construction and make it an internal heat source.
- Link the new layer to a low radiant heating system.
- Calibrate as to achieve your equivalent solar power (q), e.g. intensity, schedule
- Make sure to isolate and subtract the injected heat from your building electric use.
