Hot Water Energy Storage
The high heat capacity of water also means it is a quite effective energy storage. Or - in other words - it can stay hot (in a properly insulated tank) for quite a long time. This also means the 100 liters I need for a bath in the morning could be heated at any time during the day. In particular during the period when we have oversupply of energy (when the Sun shines and wind blows and people are not taking baths and the industrial machines are switched off).
It is a dead simple idea. An I thought it was only where I lived that this idea was not implemented. But it is probably not implemented anywhere (at least on a broader scale). I realized that listening last week to Stacey's Episode 355 of the Internet of Things podcast.
There is a startup (Plentify) in South Africa which aims at doing just this - help you run a water boiler when the energy in the grid is abundant. This is terrible. I mean not Plentify, but the whole state of so called smart energy grids. The simplest ideas, such as energy consumption scheduling for appliances, which are super easy to implement, have not been implemented.
We are flying robots to Mars, space telescopes to peek back in time, last year 400 private jets came to Glasgow to talk about climate change and what? We cannot properly schedule water boilers?
It seems, among all this gadooing (a Polish term for babbling), there is no doing. No action. Probably nobody is truly interested. Boiler companies sell boilers and are happy. Water utilities sell water and are happy too. Energy utilities sell energy and are not really interested in people using less. It is - probably - the time for governments to step in. But governments are more interested in reinforcing themselves as governments rather than do something useful, especially for the climate.
Where in all this is the Entreprenurial State? Or the EU green deal? Why in the era of the all abundant wireless connectivity and software driven appliances we are still in the dark ages of managing the flow of energy?
Well, in Greece each house has a black-painted barrel on the roof. Cheaper than PV+electric and much more efficient. For cooler climate a heat pump would be again more efficient than PV, which are around 30% efficient in optimal conditions
ReplyDeleteYes I agree capturing Energy directly from the Sun (black paint) or the Earth (heat pump) is the way to go, but one is only applicable to places where you have the sun and the other is a fairly complex hardware change.
ReplyDeleteMy point has been that simple scheduling software could enable much more efficient "charging" of hot water tanks. It would also work for heat pumps equally well.
Interesting:
ReplyDeleteI wonder how many homes could store enough hot water for long enough for your use case to be generalised.
I am an investor in Caldera Heat Batteries. We use cheap electricity to heat it up a specially designed core packaged inside a vacuum insulation layer. It's a good way of storing heat.
https://www.caldera.co.uk/warmstone-heat-battery-thermal-storage-for-your-home
Hi Richard, Thanks for bringing the Caldera as a great example of this idea. To give you some perspective: I experienced a 2-day power outage due to the recent winds. The power loss also affected my water supply, as I have my own deep well. When the power was restored after the ~48 hour period, the first thing I did was taking a hot bath. The hot water came from the boiler in my basement which was heated 2 days before. Which tells me two things: my temperature setpoint is too high and the thermal insulation is very good. This reinforces the case - I would love to use any surplus energy to heat the water. The boiler is there, it works, all it needs is a "signal" from the power grid "there is surplus energy now, you can start heating". Which - infrastructure-wise - is super simple today. A small electrical relay box with a SIM card (or connected to my WiFi).
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