Well it looks like the electric showers are out of the equation. (At least using more than one is)
I spoke to our Suppliers engineering department who gave me some surprising information.
They said that domestic mains supply is only guaranteed to a maximum of 15Kw !!!!!!. (Although by my calculation with a 100A supply fuse this should carry at least 22Kw max), and the only option to run more than one 10Kw shower simultaneously is 3 Phase. However, because of the rating of our local transformer which supports our cottage and next door, this would require upgrading and the cost would be thousands rather than even hundreds.
So I think what we will have to do is to go with mains thermostatic showers and a 300ltr cylinder fed by a pumped 100gallon breaker tank, and allow for the possibility that I may need to add a further secondary breaker tank at a later stage if needed for extra volume. (We have the space to do it and adding the second tank would be relatively easy).
I spoke to our Suppliers engineering department who gave me some surprising information.
They said that domestic mains supply is only guaranteed to a maximum of 15Kw !!!!!!. (Although by my calculation with a 100A supply fuse this should carry at least 22Kw max), and the only option to run more than one 10Kw shower simultaneously is 3 Phase. However, because of the rating of our local transformer which supports our cottage and next door, this would require upgrading and the cost would be thousands rather than even hundreds.
So I think what we will have to do is to go with mains thermostatic showers and a 300ltr cylinder fed by a pumped 100gallon breaker tank, and allow for the possibility that I may need to add a further secondary breaker tank at a later stage if needed for extra volume. (We have the space to do it and adding the second tank would be relatively easy).