Environmental Engineering Reference
In-Depth Information
Stumbling blocks for renewables
Financial costs
Renewable energies have a very high ratio of capital equipment costs to
the cost of fuel. In other words, the cost of setting up a renewable power
plant - the wind turbines or the solar arrays, for example - is vast when
compared to what will be powering it. In the case of solar or wind power
the fuel cost is zero, and in the case of waste for incineration, the fuel cost
may even be negative (if renewable generators are paid to burn waste).
Over the long term, this will be a relative advantage for renewable
energy producers. Their capital costs are likely to come down over time,
as economies of scale in technology and manufacturing kick in, whereas
the cost of fossil fuels, which will become harder and harder to explore
and exploit, is likely to rise over time. In the short term, however, it is a
relative handicap for renewable-energy generators that virtually the entire
cost of their operations has to be paid up-front in buying the equipment.
This was one reason why renewable investment was hit disproportionately
hard in the 2008-09 recession.
Energy content and convenience
Energy density - or how much energy a fuel carries - is measured by the
ratio of the energy stored relative to the mass of the fuel it is stored in. By
this measure, the energy stored in an atom far outstrips anything else. But
fossil fuels - coal, oil and even natural gas - come at least second.
Most renewables, in the energy stored in proportion to the mass of
wind or tidal current storing it, come in a distant third. Convenience of
transport is related to density: coal and oil are the densest fossil fuels and
the most transportable; gas is the most dispersed and the least convenient
fossil fuel to transport. Most renewables can only be turned into electric-
ity, which can then be transported - though biomass can, at considerable
cost, also be converted into liquid or gas.
Infrastructure
A problem common to all renewables is the need to rethink infrastructure
optimized over the past century for fossil fuels. Because renewables are a
