Solar Energy – a Special Case

The term solar energy means not only the direct radiant energy of the sun, but also its stored forms – plants, animals, fossil fuels.

The sun’s radiant energy is not a resource, but the result of throughput of a resource – that being the sun’s matter. This is apparently non-renewable and its depletion will ultimately mean the extinction of life on earth.

However: (i) this depletion will take such a long time as to be, for all practical purposes from a human point of view, eternity; (ii) there is nothing we can do about the throughput rate anyway.

At the point where the radiant energy is available for consumption, before further links are added to the throughput chain, it has no price, since no human agency or throughput of terrestrial resources is involved in bringing it to this point.

The human agency comes in when the radiation is to be converted to electricity or higher-grade heat, or used to bring about desired chemical reactions apart from natural ones. Terrestrial resource throughput also is required by this human terrestrial extension of the solar-matter throughput chain. So a money price must appear.

Money price is only associated with human-initiated resource throughput. Much terrestrial resource throughput arising from solar radiation has always taken place independent of the human race.

Most of the radiant energy reaching the earth from the sun, that is all except the portion lost through reflection and re-radiation, already serves essential needs for life and economic activity. It goes into:

(i) Maintaining the temperature of the biosphere within the range necessary to allow life to evolve and persist;

(ii) Driving the weather systems which allow fresh water to irrigate land masses;

(iii) Enabling processes of photosynthesis, weathering, decomposition and numerous biochemical reactions on which all life completely depends and without which no coal, oil or gas would have accumulated.

Human throughput chain-links can be added without necessarily interfering with item (i). Capturing the energy and doing something else with it on its way through to becoming heat, need not affect the earth’s dynamic heat balance, provided that the amount of reflected or re-radiated radiation is not thereby affected. Even if it is, this need not be bad provided the biosphere is maintained within a certain temperature range; shifts up and down this range will merely alter climate patterns and relative proportions of species.

Drastic changes in local climates could take place, however, if really large numbers of solar collectors became concentrated in a large city, where vast amounts of higher-grade heat would be generated from radiation that would otherwise be reflected away to the atmosphere and space. This problem still lies in the future.

Item (iii) should not be interfered with at all; it would be if large area solar collectors were permitted over areas that were anything but true deserts.

It is often said that solar energy is free, unlimited and non-polluting. None of this is true.

It is only free until it is harnessed, then a money price must appear as discussed above.

It is not unlimited. The rate of flow and concentration of radiation have a limit that we cannot affect one way or the other. And there must be a limit to the harnessing of the radiation, not only because of considerations discussed above, but also because of limits to the terrestrial resources whose throughput is entailed in the process of obtaining heat, electricity and fuel from solar radiation.

It is not pollution free, because the just mentioned terrestrial resource throughput would result in degraded matter that would be toxic or obstructive and would require reconstitution into renewed wealth.

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