19

Let's look at how much electricity and money can be saved by using solar thermal to heat a cylinder of hot water, rather than by using an electrical resistance heater. Assuming a 100% efficient resistance heater (that's near enough to real values), and ignoring tank losses during the heating period. 180 litres of water is near enough 180kg. The specific ...


12

Someone has done it. A majority of the electricity I buy comes from geothermal energy †. Of course, I live in the Pacific Northwest of North America, which puts me close to a tectonic plate boundary. This presents good conditions for extracting geothermal heat (since the earth's crust is thinner at such boundaries ... making shallower wells productive). ...


9

Consider using a flow through core of some sort. For example: Wrap several layers of chicken wire around about 4 to 8 feet of 24" diameter cardboard concrete forms from the hardware store (Depending on how tall you want to make it). Wrap several layers of black poly tubing around the chicken wire and cardboard tube. Use baling wire to tie the black poly ...


8

Unless she's actually using the 1-2 litres of tea each time, there's more savings from simply boiling less water. We bought a small electric kettle with a flat bottom and glass walls to encourage people to boil the one cup of water they actually want, and that has worked reasonably well. If you can make 10 litres of boiling water and insulate the container ...


8

The stabilisation energy rate will be exactly exactly equal to the rate at which energy is lost. Assuming the tank is closed, so there are no evaporative losses, there are two other ways energy is lost. Firstly, from conductive losses through the surface of the tank. That will depend on the thermal conductivity of the tank, and on difference between the ...


7

Here's the simplest way to do conversions like this: 180 liters * 45 degrees Celsius = 8100 kilo-calories. Google knows how to do conversions: 9.41400 kilowatt hours And it knows how to do arithmetic: 2.8242


6

Water has a heat capacity of 4.1814 J/g which means that 1 gram of water requires 4.1814 Joules of heat to increase 1°C. The definition of Watt is Joules / second so the formula you need is: heat capacity * mass * temp. increase / time in seconds I'm assuming the water was at 30 degrees before you started heating it, just like the room. Since water boils ...


6

In older kettles with an exposed heating element it does matter. If the element is not covered with water it will overheat and burn out. With newer kettles without an exposed heating element you may risk reducing the useful life of the kettle as a certain amount of water will be required to absorb and dissipate the heat produced by the heating element.


5

The heat loss will be proportional to the surface area. If you boil ten litres, one litre at a time (rather than all ten litres at once), there's typically a lot more surface area, so the heat loss will be higher during boiling, so it will take more energy. However, once boiled, it will then lose energy. So if you're boiling water for consumption many hours ...


5

I agree with Fred in that it seems logical that a minimum amount of water would be required to help prevent overheating by the element. It's likely though that the manufacturer has specified a fairly conservative minimum amount of water to use. When using a kettle with a concealed element with less that the minimum recommended amount of water, you could ...


4

The glib answer is to use less energy. The best way of doing that is fixing the fabric of the house - massively increasing insulation, massively decreasing air permeability (and as a result fitting a ventilation system). There is no technical-wizardry answer. The simplest solution is best (but unfortunately outrageously expensive).


4

There's another reason for minimum water levels: when the steam is used to trip the temperature sensor, a certain minimum amount of steam (or rate of steam delivery) is required. This will depend on the contact between the water and the element, so will be more of an issue for exposed elements. I find that you can get away with quite a bit less than the ...


3

I am not aware of any modern washing machines (at least in the UK) that still have a hot water feed. One reason is that modern machines don't actually use that much water, so even if you had it connected to a hot tap, it would be filled mainly with the cold water that's been standing around in your pipes, unless you have a particularly short pipe run to your ...


3

TL, DR Solar thermal with a gas burner for peak demand. Possibly improved isolation. First, you need exact data on how much heat you need, and when, during the year and during each day. This should help you get an idea if the insulation of your house can be improved. Once you have the numbers, ask here for a first orientation. Without seeing the house (...


3

A. It's energy efficient to boil exactly that amount of water which is actually needed for tea preparation. To heat more water means some water is not used and heat will be wasted into the air. B. But if you need to prepare for example 5 liters of the tea at once, it is more effective to heat it at once, and not to heat it 5 times 1 liter, due to ...


3

They can be the same thing; the terms have overlapping meanings. A seawater heat pump is a specific type of water-source heat pump that uses seawater. Water-source heat pumps can also use fresh water, e.g. from a lake or river. The source is the first part of the meaning of "water-to-water". The second part means that the destination for the heat is ...


3

I suggest a square wooden frame with a pyramid-shaped frame rising from the corners. Fill the triangular sides of the pyramid with glass or "perspex". A bit of trig is needed to work out the angles. If you work with a bit more precision and use the perspex, you could dispense with the pyramid frame and just glue the panes together. The wooden base allows ...


3

Indeed, hot dry rock geothermal may not be widely utilized, but it may be so not only because of novelty and cost, but also because there are plenty of water-based geothermal resources that are still underutilized, and those could be a lot easier to get to. As an example, let’s look at Idaho — state in north-western US in the Rocky mountain region. In 2008 ...


3

Others have already suggested low flow fixtures and reducing water usage, but here are a few other ideas, from least to most expensive: Turn down your water heater. The U.S. Department of Energy recommends a setting of ~120 F / 50 C. Many water heaters are set at the factory to 140 F / 60 C, which can increase the standby losses (energy spent keeping the ...


2

Take the temperature of water going into the tank. Let a hot water tap run after sundown when the solar panel is inactive and until the temperature is stable at intake. To measure this you'll have to buy one of those digital outdoor thermometers that have a sensor with a cable. Tape the sensor to the incoming water pipe. Put some insulation on top of the ...


2

The regulations are still in flux as recently as 23 September 2013, with the Renewable Heat Payment Plan (RHPP) extended to offer one-time grants to households through spring 2014. The ofgam website and RHI website provide good resources on the latest regarding the RHI domestic programme. The eligibility guidelines are quite long to cover the variety of ...


2

Put the broccoli in a microwave safe bowl with a few tablespoons of water, cover the bowl with a microwave safe top (ideally maybe a glass lid, but if plastic, don't let it touch the food!). Then microwave it. Guaranteed less energy, and you don't lose significant nutrients into the water you'd be boiling it with either of the other two ways.


2

For heating water, you're far better off looking at solar water heaters, which take thermal energy from the sun to heat water. The power conversion formulae for converting sunshine into electricity and then electricity into heat is about 80% less efficient than just taking heat from the sun and putting it directly into the water. This is in no small part ...


2

Depends on where you live but heating with electrical heating is likely the worst thing to do. Odds are some portion of grid's power comes from thermal sources and typical efficiency from heat to electrical power are around 50%. Unless the source is near 100% thermal energy free, heating with electricity is a double whammy: It takes twice as much thermal ...


2

Reducing the amount of water being heated will also reduce the mass of water that is storing heat within the unit, and possible make it even less efficient. You might actually get better results keeping it full. The best way to answer your question is with one of those plugin energy meters, but you say you don't have one. Does anyone you know, or ...


2

You could definitely switch to an efficient gas boiler system with proper controls to run "cleaner" and more efficiently. Depending on gas/oil prices in your area, this may or may not be economically beneficial (short or long term). Varying with your current setup, electrical prices in your area (and their generation method) you could also change about ...


2

For everyone to know, the process was developed by and is now known by the name of Jean Pain Composting process. The man used the technique to heat water for house heating and hot water needs. [...]raw materials of Pain's compost heap were saplings, branches, and underbrush Question also addressed on our prefered network ;) Would a Jean Pain heater work ...


2

I'm glad you found that the extra information about the problems of cooling down your chimney pipe. That is the first point I was going to make in this answer (and I'll make it anyway). You do not want to cool your chimney exhaust gases. Chimneys rely on a temperature difference between the exhaust gasses and the surrounding environment to create the ...


2

With today's prices, it's cheaper to install PV panels and generate electricity, then just use a standard electric water heater. This has the advantage that it actually works better in the winter when it's cold out. Plus any surplus energy generated can be used for other purposes. Surplus heat from solar thermal systems can be a problem in some cases ...


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