TIDAL/WATER POWER

pANATRAK CIVILIZATION

The home planet of the Panatrak, Patinar, is densely covered in islands, so much so that there are only a few areas of land more than a few hundred miles from the sea, consequently, the sea has played an extensive part in the Panatrak’s evolution, and in one aspect has provided a power source only realized by humans within the last few hundred years of its civilization.

Patinar, in addition to its myriad of islands and archipelagoes, also has two large moons, which exert a powerful tide on the planet, often generating tidal fluctuations in excess of four metres. From the earliest days the Panatrak have used these tides for a lot of their industrial work, and until recent times with invention of fusion, and the restoration of the planet to a more natural state, tidal power generation was key in civilization’s power supply.

The tidal power systems can be observed as far back as 15000 yrs ago, where coastal lakes were transformed into artificial salt-water lagoons by digging connecting channels to the sea. The changing water levels between sea and lake drove simple water wheels, often used to grind flour from fruit or grains. Where rivers were available these were preferred for this simple water wheel technology, but the smaller coastal islands simply did not have large enough rivers, or their flow was sporadic, and the fresh water too precious and scarce to waste, so this lagoon technology was used instead.

The next step in the design technology was to effectively damn narrow isthmuses between islands, this greatly expanded the available energy, as the capacity of the seas is far greater than the small lagoon systems. These structures were often built across relatively shallow straits, and very few ancient structures (first of these designs started to appear 8000 yrs ago) are more than 10 metres tall. The structures themselves look like great dams, a bridge of stone between islands (a function they also served, though mostly only for cargo, as the citizens themselves are avian), but like the first systems, narrow slots house drive wheels. These horizontal axis water wheels were soon replaced by completely submerged vertical water wheels, a sort of predecessor to turbines.

The problem with simple water wheels is that they could not efficiently deal with the changes in water height, the paddles often had to be metres long to cope with the variety of different heights, and the different velocities as one got closer to the axis reduced their performance. The successor to this design was the over head turbine, something that the extreme tidal range allowed, so that depending on the direction, water cascading over a tidal wall would drive a turbine. To make full use of this design wheels were set up either side of the wall to catch flow in either direction, still these designs were hardly more efficient, and had to have elaborate designs to allow for venting of water and other functions.

The successor to the large and small wheel technologies, was the creation of simple turbines, that sat in tunnels below the water surface, and harnessed the flow of the liquid, these turbines revolutionized the ‘dam’ technique allowing more efficient collection of power. The plane of the turbine would lie perpendicular to fluid flow, and the energy transmitted by mechanical linkage to the surface, often at right angles to the ground.

The more successful turbine technology flourished (5760 years ago), and soon replaces conventional wheels, in both dam and lagoon style power generation projects. This kind of technology would be the corner stone of power generation until the fusion era. Patainar does not have abundant supplies of fossil fuels, despite being well covered in biota, the rapid movements and destruction of landmasses meant that large reserves did not form, so energy was predominantly acquired from turbines, where as heat was extracted from burning firewood.

The electrical revolution saw the disconnection of mechanical linkages from many turbines to be replaced by electrical generators, at a similar time we begin to see turbines independent of tunnels being spread in isthmuses acting like under water wind turbines. The problem with tidal technology is that although the prime locations can generate power almost continuously, they may not be able to generate constant amount of power during the day.

In the more isolated early communities who were entirely dependent on tidal generation (bigger islands used biomass to fill in tidal shortfalls) had designated electricity periods, where citizens restricted their own use to preserve power for communal facilities (hospitals, refrigeration etc.) these times of electricity restriction were circulated in yearly booklets, though in some more drastic communities electricity for civil and public services were on completely different systems, and the public system shutdown when energy needed to be conserved.

The biggest competitor to these type of turbine systems was the exploitation of geothermal which would slowly replace most of the purely producing turbine systems (some turbine systems, because of their antiquity, were kept on as historical monuments). And geothermal systems would be rivaled at a later time by fusion power, though like on Earth geothermal is still not quite obsolete as its power is clean and free, and also provides many other things than just electrical power (mineral salts, and hot water etc.).

The greatest modern impact of this past era of harnessing tidal power, is the way it shaped Panatrak society. Most of Panatrak settlements and cities are in close proximity to old sites of power generation, and even their current architecture has been greatly influenced by these past structures.