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 ...


14

Operating one cooking appliance would be more efficient. Using your two-pot method, to maintain the boiling water once it is transferred to the cooking pot, you'll have to first bring that cooking pot up to temperature. During that time, the system inefficiencies are in effect for two systems, and heat and energy are being lost. The heat being radiated ...


11

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 ...


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 ...


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


7

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 ...


7

As soon as you have moving parts, you can no longer have it maintenance-free. Moving parts wear out eventually. On the height pressure issue your panels will probably be on your roof and your reservoir somewhat lower. We can probably disregard the height pressure for operational reasons but if you ever get air in the system you will want to be able to ...


7

You measure the temperature of the water going in to the solar panel, and the temperature coming out, and the rate of flow through. The power produced is then a simple calculation of multiplying the specific heat capacity of water, by the rate of flow, by the difference between return and flow temperatures. The energy produced is the integral of power over ...


7

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 ...


6

There's various options depending on the level of accuracy desired. To be most useful to a general audience, not just this question's asker, I'll mention a couple rough methods: The way you should track your energy choices in general is fairly simple: monitor your energy bills monthly, before and after making the change (in this case, before and after ...


6

Thermo-siphon works surprisingly well when feasible. If it is feasible to move the physical location of the reservoir placing it above the collector(s) will cause the water to circulate on it's own. Placing simple diaphragm valves in the reservoir will make the water circulate only when the panel temp is higher than the reservoir. If you can achieve ...


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.


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 ...


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

Use a common (commercially available) electric pump. Home made ones can be problematic, as Chris writes. The solar pumps are available in various power. Even with a very small pump you'd want to install a controller with (at least) two temperature probes on the panel and in the tank to turn the pump on and off. I'm using a 45W pump with throughput of 2 ...


5

If you have a basement you can install a ground loop. It may not be available in your area, but "remote dive" boring equipment comes small enough now that it can be brought in through your front door. Obviously groundwater and underground utilities are concerns, but it's still possible. I don't think I'll ever understand people's carbon fixation, but if ...


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

Given that you have natural gas heat I have a hard time imagining that there is a lot you can do there. There are likely some additional constraints given the historical value of the house. I think in many cases it is more important to preserve historical character than to try to fully decarbonize but that's at least partly a personal preference. Here are ...


4

Based on personal experience, I agree with Zach's conclusion that the dedicated water boiling kettle is more effcient than the stove. My 1500W electric kettle boils a liter of water about 2-1/2 times faster than a covered pan on my stove's 2100W element (4 minutes versus 10 minutes)... and more than 3 times faster than the stove's smaller 1600W element). ...


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

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

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 ...


2

A water boiler or hot water tap are the most efficient ways to heat up water since they are insulated, keeping all of the heat in the container and water (and not the air). I would say that your best bet is heating water with the water boiler, pouring it into your pot, and cooking on the stove from there. Some heat would be lost to the container in 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

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 ...


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