Energy from tides and currents: Arranging underwater Tidal Sails

See on Scoop.itGreen & Sustainable News

In the long sprint to find new sources of clean, low-cost power, slow and steady might win the race — the slow-moving water of currents and tides, that is.

Duane Tilden‘s insight:

>The system, developed by a Norwegian company called Tidal Sails AS, consists of a string of submerged blades or sails, connected via wire ropes, angled into the oncoming current. The rushing current generates large lift forces in the sails, and as they are pushed along through a continuous loop, they drive a generator to produce electricity. […]

In their analysis, the researchers found that the maximum amount of power could be generated using blades with a chord length (the width of the blade at a given distance along its length) equal to the separation between each individual blade, that are positioned at about a 79 degree angle relative to the oncoming current, and that move at a speed about one and half times faster than the current.<

See on www.sciencedaily.com

UK government rejects current Severn tidal barrage plans

See on Scoop.itGreen & Sustainable News

Ministers say major changes must be made to the scheme if it is to be revived and given serious consideration

Duane Tilden‘s insight:

>Concerns over the impact of such a barrage on marine life played a major part in the rejection, with the government agreeing with MPs that better studies were needed to establish the effects on fish.

The response was: “It is for the developers to do the necessary work to prove that their design is ‘fish-friendly’ and will not jeopardise the UK’s obligations under the water framework directive and habitats directive. Such studies will need to take account of the wide variation in vulnerability of different fish species arising from to their different morphology, physiology and behaviour.”

The government said Hafren would need to provide much more detailed, credible evidence of the proposal, including a study of the environmental impacts and information on turbines, as well as information on allaying fears of flooding that could be worsened by any barrage. The coalition said it would consider the proposal further if this information was provided, but added that legal hurdles would mean the consortium’s current proposals were likely to be subject to delay.

Ministers reiterated their view that there should be no firm commitments of public financial support – in the form of the “strike price” of a premium for low-carbon power that has been confirmed for wind power and is expected soon for nuclear energy – for tidal barrage schemes until 2019 at the earliest.<

See on www.theguardian.com

Scotland gives green light to Europe’s largest tidal energy project

See on Scoop.itGreen Energy Technologies & Development

Wave power to provide electricity to 40% homes in Highlands as work on building turbines in Pentland Firth gets approved

Duane Tilden‘s insight:

>”This is a major step forward for Scotland’s marine renewable energyindustry. When fully operational, the 86 megawatt array could generate enough electricity to power the equivalent of 42,000 homes – around 40% of homes in the Highlands. This … is just the first phase for a site that could eventually yield up to 398 megawatts.”<

See on www.theguardian.com