RENEWABLE ENERGY - BASE VERSUS BOOST

Many investors and organisations fail to understand the significant differences between the various sources of harvestable renewable energy and the applications that each type makes possible. Laying aside the complications, the costs and even the environmental implications of the actual extraction, the world of renewable energy can be split into two basic types:

A)  BASE RENEWABLE SOURCES - These occur naturally (e.g. thermal, gravitational) and in such vast quantities that their output CANNOT be affected by climatic fluctuations or human activities.

B)  BOOST RENEWABLE SOURCES - These too occur naturally (e.g. thermal, gravitational) but their output CAN be affected to some extent (or even completely) by climatic fluctuations or human activities.

BASE RENEWABLES

GEOTHERMAL - Massive amounts of heat are produced at the earth's core and, at the most suitable locations in the world, it reaches the surface (or just below) - and from there it can be harvested.

TIDAL STREAM and TIDAL RANGE - The gravitational pull of the moon creates both of these forms of base energy. Their regularity and the variations in the quantities produced can be predicted and documented even centuries in advance - with only some insignificant localised deviations being caused in specific areas (by high winds or ice, for example).

HYDRO - Provided that the source is sufficiently plentiful and its gravitational fall is far enough, this too can in some cases be regarded as a Base Renewable.

BOOST RENEWABLES

SOLAR - Even though the amounts of heat and light produced by the sun can be monitored very accurately at any location, their power can be greatly reduced by a number of natural phenomena (e.g. cloud, fog and rain). When that happens, a boost is required from another source so that a steady supply can be maintained.

WIND - A back-up source (a boost) will always need to be available because periods of high pressure during the winter months often produce long periods of calm - precisely when a maximum energy supply is required.

BIOFUEL - This could almost be classed as a Base Renewable because it is sufficient when the demand for energy is small and there is a comparatively large supply of biofuel (such as wood, manure, agricultural waste etc.). However, the supply of biofuel is usually quite minute compared with the amount of energy required by the general public.

WAVE - As with wind, wave power has great potential and can be fairly predictable in a generalised, long-term way - but it too can suffer from climatic variations and, therefore, a boost supply is required.

Boost Renewables will eventually be able to operate without having to rely on fossil-fuel generation for ‘rapid response’ back-up, owing to the continuing development of energy storage systems (such as Hydrogen production, large VHV batteries and high-capacity efficient Pumped Storage).

It is an accepted fact that environmental problems have frequently resulted from the construction of huge dams for hydro-electric systems, so our future surely depends on the safe, efficient harvesting of the power from geothermal locations and the vast tidal movements.

A personal paper by Paul Hales, Director, Hales Water Turbines Ltd