- The three reservoirs will generate hydroelectric power. They will be linked by a pumped storage system so that they can store energy generated by wind and solar farms in the area when they generate in excess of demand and allow water through the turbines generating electricity when it is needed.
- The project will allow a new not for profit water company Dowr Kernow which will provide competition for South West Water and drive down prices for customers.
- The new reservoirs will better define the border between Cornwall and England, which it is hoped will prevent a cross-border "Devonwall" constituency from being implemented.
Although the required compulsory purchase of the land and buildings will be extensive, the Duke points out he does own quite a bit of it already, and has offered to give an (as yet unconfirmed) discount on new properties in the Duchy's housing development to his subjects who are affected by compulsory purchase.
|The Cornwall-England border, showing the three proposed new reservoirs along the Tamar Valley|
|A closer view of the area, with some detail of the proposals.|
|Reservoir||Total area (km^2)||Average depth (m)||Volume (million m^3)|
The above table shows the area and volume of the proposed reservoirs.
To store energy from renewable generation, a cubic metre of water can thus be raised 50m from Dowrgonna to Lyn Tredamar, which means it gains 1000*9.8*50 J of potential energy, or 20m from Dowrgonna to Lannstevan.
If the upper two reservoirs were emptied there could be 17.8 million kilowatt hours stored by raising water to Lyn Tredamar, and a further 10.6 million kWh by raising water to Lyn Lannstevan.
|There are approximately 1100 properties expected to be below the waterline, which would rise to about 3600 if the 100m water level option was followed for Lyn Lannstevan. However, it was pointed out that this option would lead to the submerging of Prince Charles Close in Launceston, so therefore the Duke doesn't favour this option.|
The cost of the project is unknown, however Prince Charles has assured his subjects, that it will be cheaper than Trident replacement, and less environmentally destructive than a nuclear war.