Estimations of the costs of renewable energy are common in the literature, a review can be found, for instance, in . In most of the studies published so far, the calculations arrive to values that favor fossil fueled plants over renewables. In general, electric power generated by wind turbines is only marginally more expensive than that generated by fossil fuels. For photovoltaic panels, the gap is large, of approximately a factor 5 (see, for instance, ref. 10).
The “solar power agriculture” paradigm offers a way to look at the financial support for renewables which goes beyond the cost calculations reported in the literature. The misleading factor of these calculations lies in the fact of producing a single, static number. However, the cost of energy is dynamic and it varies over the whole lifetime of a plant which, for the case of renewable plants may be very long, typically of a few decades. We saw in the previous section that the “new renewables” produce a positive, and often highly positive, energy return (EROEI). Since energy is worth money, there follows that the financial return from these technologies will be positive in the long run. It may argued on whether other investments will produce a quicker return, but not on the fact that the money and resources placed into the deployment of renewable energy plants will be, eventually, paid back and will subsequently produce a profit. A case could be made that renewables are not only an effective investment but also the safest possible investment since they produce a commodity, energy, which is the basis of human civilization and hence will never suffer market crashes.
However, it doesn’t appear that investors have picked up yet the potential of renewable energy. This may be due to the bad image of renewables which still lingers in the press and in the public opinion. In this respect, it may be worth citing here as an example an article by J. Dvorak : “People still equate photovoltaics with the hippy – dippy 1970s. A recent article in the New York Times showed some hippies in Ukiah, California, with a solar panel outside their yurt-like home with a sod-covered roof. Presumably, the solar panel was used to power a lava lamp.”
Apparently, the promotion of renewable energy done so far has been off target with the emphasis made on the concept that renewable energy is something “soft” as opposed to fossil fuels which, somehow, are “hard”. Switching to “soft” energy, apparently, would change our way of living, maybe carrying all of us to the Aquarian Age, to a higher state of consciousness or something like that. It isn’t clear how the kWh at a domestic outlet can be defined “hard” or “soft” and anyway these concepts don’t go well with investors who are more likely to think in terms of financial returns rather than in terms of holistic happiness.
However, the economic return of renewables looks different when placed within a context, agriculture, which is known to be reliable, solid, and effective. Maybe agriculture never provided such a rapid return on investments as startup companies from Silicon Valley, but everybody understands that we can’t eat silicon. So, there is a logic in investing in agriculture and there are people interested in investments which privilege safety over speed and which also have a certain degree of “ethical” value. Here is where the “agriculture paradigm” as opposed to the “industrial paradigm” can be most useful.
As long as energy production is managed by power utilities, as it is the case today, energy is produced within the “industrial paradigm” since power utilities are industrial companies which have a tradition of generating energy from the combustion of fossil fuels. In the industrial paradigm, the capital is provided by shareholders and companies will normally choose the road that leads to the fastest return on investments. In “solar power agriculture”, however, the situation is different and the focus moves from capital to land. The question that a stock market investor asks is “how can I increase the value of the capital I own?” while the question that a farmer or agricultural operator asks is “how can I increase the value of the land I own?” The answer to the latter question is to produce something on the land: it may be crops, it may be wine, it maybe wood, it may also be electric power in the paradigm if solar power agriculture.
Large financial resources could be unlocked and utilized for the diffusion of renewable energy as soon as the concept of solar power agriculture becomes an accepted paradigm. For instance, the budget of the European Union for “rural development” in the period 2000-2006 is of approximately 50 billion euros. It is worth noting that in the 2003 document describing the EU agricultural policies , the world “energy” is not even mentioned, although there is one picture showing 19th century windmills. If governments realize that agriculture can be supported in an effective manner by means of the concept of solar power agriculture, part of these resources can be utilized for the diffusion of solar energy in farmlands; this benefits not only farmers, but all the sectors of society.
It remains to consider how fast renewable energy could develop in order to cover the targets outlined here. This depends on the amount of financial resources that can be reasonably allocated to renewables and that may be estimated from the historical record. During the 1990-2000 decade wind power grew at an average rate of 22.4% per year and photovoltaic of 28.9% in the countries belonging to the OECD (Organization for Economical Cooperation and Development) . According to the BP statistical energy review  the growth of wind power worldwide was of 29% from 2001 to 2002, with the wind share of total global electricity supply increasing four-fold since 1996, to 0.4% in 2002. In those countries where wind technology can be considered as “mature”, the data  growth rates higher than 20% have been observed over at least one decade as for instance in Denmark (22.0% yearly) and in Germany (62.9% yearly). As a comparison, the highest rate of growth of crude oil production was 7% yearly for the period from 1930 to 1971 .
At a yearly growth rate of 20% and starting with 0.5% of the present supply, renewables could grow to produce the equivalent of the electricity produced today by fossil fuels in 30 years. This is, obviously, just an order of magnitude estimation. However it shows that renewables have a considerable potential to replace fossil fuels.