I find the renewables / energy efficiency thing overall interesting.
What stands out is that we have such different circumstances, needs and properties that the best answer for each of us varies widely.
There will need to be a mass customisation in future, tailoring solutions from a toolbox full of different components.
For youngsters who gain the knowledge to design and / or the trade skills to install solutions for us all, there's a living to be made I'm sure.
Meanwhile enthusiasts (who I suppose now include me) try to figure it out for ourselves, and put a bit of our money where our mouths are.
I can't spare the space for a 3 ton tank in the garden, but I do have an under-stairs cupboard.
I'm now in the thick of moving my hot water tank down there. The old tank has an immersion inserted through the top and accepts 4.5kWh of energy before it's thermostat tops out. That turns out to be enough for a good bathtub or shower.
The new tank is 180L. It's the largest that will fit the space and I found one with an immersion about 3/4 of the way down which is good because I am keeping my gas boiler and so there's a coil in the bottom quarter of the tank. Assuming 135 L effective capacity and a 65C temp rise (10 to 75C), the new tank will absorb 10.2kWh of surplus solar via the immersion heater.
I get 5.5 to 6kWh more storage than today. That much battery storage seems to cost at least £1500. My new plumbing project will cost less and last longer so it works for me.
But if and when they make the sand battery type storage cost effective I'd expect to be able to fit 30 to 50kWh of capacity in that same under-stairs cupboard and I really don't see why it should cost much more to make than an expensive hot water tank.
What stands out is that we have such different circumstances, needs and properties that the best answer for each of us varies widely.
There will need to be a mass customisation in future, tailoring solutions from a toolbox full of different components.
For youngsters who gain the knowledge to design and / or the trade skills to install solutions for us all, there's a living to be made I'm sure.
Meanwhile enthusiasts (who I suppose now include me) try to figure it out for ourselves, and put a bit of our money where our mouths are.
I can't spare the space for a 3 ton tank in the garden, but I do have an under-stairs cupboard.
I'm now in the thick of moving my hot water tank down there. The old tank has an immersion inserted through the top and accepts 4.5kWh of energy before it's thermostat tops out. That turns out to be enough for a good bathtub or shower.
The new tank is 180L. It's the largest that will fit the space and I found one with an immersion about 3/4 of the way down which is good because I am keeping my gas boiler and so there's a coil in the bottom quarter of the tank. Assuming 135 L effective capacity and a 65C temp rise (10 to 75C), the new tank will absorb 10.2kWh of surplus solar via the immersion heater.
I get 5.5 to 6kWh more storage than today. That much battery storage seems to cost at least £1500. My new plumbing project will cost less and last longer so it works for me.
But if and when they make the sand battery type storage cost effective I'd expect to be able to fit 30 to 50kWh of capacity in that same under-stairs cupboard and I really don't see why it should cost much more to make than an expensive hot water tank.
