What is the advantage of tidal energy over wind?
Predictability, tides come twice a day and at different times around the coast of the UK
 

Why is tidal energy not used elsewhere in the world?
Where else do you see the tide going out half a mile? The UK has a unique geography with one of the highest tidal ranges in the world and one of our greatest assets.

What tidal range does the UK have?
The river Severn for example, has a tidal range of 15m, Thames 7m, Mersey 10m,Humber 7m.

Is tidal energy different from wave power?

Yes, Tidal energy harnesses the predictable rise and fall of tides while wave power harnesses the kinetic energy of waves generated by wind.

What is the difference between tidal stream and tidal range?
Tidal range uses the vertical difference in water levels between high and low tide whereas tidal stream relies on the kinetic energy produced by a strong tidal current. Tidal stream is a wind turbine under water and requires deep water with high current usually located between islands such as Anglesey in Wales, UK.

Is tidal range energy competitive with other forms of energy?
A recent study commissioned by the British Hydro association that the levelised cost of energy (in line with government assessment) is cheaper than Nuclear power.

Can you use existing hydro technology on tidal range power?
Yes triple regulated Bulb Turbines could be used in the centre of an estuary where the turbine can be set low as the machine requires 6m of head above the turbine. The total energy produced is 30% less than with a Very Low Head Turbine (VLHT).

Does tidal range technology destroy the ecology?
The VLHT is bi directional and generates in ebb and Flow and works on a differential head of 3-6m and significantly reduces the impact on the ecology.

Do you have to build a barrage?
We plan to use concrete caissons sitting on the bed of the estuary and letting the water flow through the turbine opening thereby creating a tidal bar rather than a barrage ( sometimes referred to as a tidal fence) A Barrage would let the water in and hold the water until the tide dropped and then generated in one direction.

What is the difference between a tidal Bar and a lagoon?
A tidal bar would be one side of the triangle in an estuary where a lagoon of generally circular and should not close off an estuary.

How would ships pass through a tidal bar?
A shipping lock will incorporated into the structure.

Does the Very Low Head turbine (VLHT) kill the fish?
The turbine operates at low speed 25rpm and I similar to a water wheel and will not harm the fish. There are no harmful pressure gradients or shear forces in the turbine flow that could stun the fish.

How long does tidal technology last?
Most hydro schemes have an asset life of at least 125 years with
mechanical/electrical refurbishment ever 50 years.

Is the turbine affected by seawater?
The impact of corrosion from seawater is generally around the splash zone where the water is oxygenated. A submersed turbine with the correct materials will have a good life span.

How long Does offshore wind last?
The towers have a life of 60 years but the mechanical and electrical machine has a life of 25 years.

How will the tidal bar be built? 
The seabed will be levelled with stone and steel or concrete caissons will be manufactured in dry docks and floated into position. This is a proven method of construction.

How long would it take to build a tidal bar once consenting and funding are available 3-4 years What power could be generated by tidal in the UK?
The River Severn for example could produce 6% of UK power requirement and utilising all our estuaries 30% of UK power requirements.

Why has this type of power previously been rejected by the government?
Existing technology impacted on ecology and fish mortality and was not considered economical. These issues have generally been mitigated and the VLHT resolves the main objections to tidal range energy overcoming the issues of ecology, fish mortality and economics.

Is anyone else looking to develop tidal energy?
The main hydo suppliers are waiting to see if the government changes its view on the cost of tidal range energy.

Who are the tidal range alliance?
The tidal range alliance is a subset of the British Hydro Association whose members are potential tidal range developers, engineers and suppliers. It brings together various stakeholders interested in developing Tidal range energy.