Looks like LK of SD21C has come up with a sun theory of value based on an admittedly amusing caricature of the labor theory of value. While this theory might provide insight into how a solar deity might account for the exploitation of his energy release, it doesn't seem all that useful for understanding capitalism as an actually existing social system:
The source of most energy that reaches the earth is clearly the sun. Without the sun and the energy it provides, there wouldn’t be any production of any kind.
Energy can be embodied in raw materials and we can measure human work as energy expended and machine work in terms of energy expended too. So therefore all commodities must have a “physically-necessary sun energy” value. All commodities are just embodiments of the “physically-necessary sun energy” required to produce them. We can even – unlike the hopeless Marxists – use a real homogenous unit to calculate energy straight from the natural sciences: the joule.
Certainly, the mythologizing "ruthlessly exploiting the poor, oppressed and innocent sun" might make one admire the odd coincidences required for life on earth. What the labor theory of value is intended to address was the social relations required to explain capitalism. What the labor theory of value states, very simply, is that all value is brought into production through human labor, and that all labor can be measured (and therefore, compensated for) in units of time.
Since the social relations of capitalism have a class that sells its labor into production and a class that extracts rents on capital, it would make sense to focus on the contribution and compensation of those classes in the analysis of production.* Since labor originates capital, it follows that if we are to quantify our social relations in something other than money used to represent it in exchange, it may as well as be the only input in production created by humans (since human labor is the only thing that creates value by bringing it into production).
So when it comes time to analyze the potential for exploitation in production, either all of the revenue generated by firms is equal to the compensation to laborers of everything used to produce it, or the labor power of workers is not being paid the full value of its expenditure. For classical political economy, this discrepancy is a rent extracted from the fundamental uncertainty of capitalist production and distribution.
A solar theory of value would make no sense because the sun is not a moral agent capable of engaging in the social relations of capitalist production. Long live solar socialism.
* It is crucially important to remember that the present capitalist system precludes many forms of labor power which undoubtedly contributes to the process of production. Perhaps the most obvious (and perhaps most gendered) is the care labor required for social reproduction - raising, feeding, cleaning, etc. Historically, we could consider overdue reparations for slavery as well as the persistent premium extracted in the form of discriminatory pay. Some may also consider the work done by beasts of burden as a form of labor exploitation, though this theory hasn't been pursued much by professional economists.