Doing so will help provide much needed certainty to invest in capital-intensive projects such as power plants that operate for 40 years or longer.

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This is very important because what this goal means is it unleashes a lot of the capital sitting on the sidelines for the lack of certainty that could be invested in America to create jobs, to create these new clean energies.

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With certainty about tax rates, companies will increase their capital expenditures (currently at anemic levels), contributing to a virtuous cycle of jobs and growth.

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Because of the huge capital costs, stretched over many years, companies want some certainty over how much they might be paid for the electricity generated by their plants.

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Interestingly, historically there was usually a premium built into high-quality company valuations, as investors are willing to pay more for their high returns on capital, strong balance sheets, lower risk, and the certainty of their cash flows.

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That certainty has economic value as a hedge, even if the capital cost of wind and solar power stations is, at the moment, higher than that of coal-fired ones.

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