ps I had a quick look and noticed Michael was still using the language of renewables and carbon mitigation, at the time of his book, so he might not yet be on full realisation, imho, it is almost impossible to sort this problem without distinguishing between mathematically negative and positive energy use. This is why I am so critical of the "established science" approach. Hopefully folk will understand it completely by understanding the principle of the Energy Polarity Multiplier Framework (The subject of my book), which goes straight to the heart of the issue, imho.