How much water can a 400 watt heater heat to 60 degrees.?

Question

If I stick a wind turbine on my house with an output of 400W then attach that to an element how much water could i expect to keep at 60 degrees.

Please assume that the 400watts from the turbine is constant.

Additional Detail:
The hot water storage tank is insulated.

The hot water is heated to 70 by a gas boiler. When the water cools to 60 the boiler kicks in.

The idea is that during windy periods the turbine might prevent the boiler from starting or at least reduce the amount of starting.

The tank holds about 150-200 litres.

Thanks for the answers already.

Answer 1

There will be losses, identify these please.

Answer 2

Utilizing a 400 watt wind turbine to heat water means that:
1)You'd better have good wind speed if you want a hot shower
2)The high windspeed should be 24/7
3)Better not plan on having too much hot water available.

If you are in an off-grid application and are looking for ways to heat water, solar heating is probably a better solution. It requires less maintenance and is a direct convertion of energy to heat so can be a very efficient means.

It may be that you could utilize your wind turbine to charge a battery bank that supplies electricity to your house/cabine, etc. When the battery bank is full, the charger/load controller diverts the excess electricity to a heating element located in the insulated solar hot water tank. This means any excess power or power you don't use for electrical needs automatically supplements your heated water supply.

Answer 3

How much time do you have? 60 degrees Celsius or Fahrenheit II assume the former, since 60F is rather low) . What is the ambient (air) temperature? You say "keep at 60 degrees" what is the water being kept in, how well insulated. Do you want to heat additional water, from what starting temperature?

One watt is one Joule per second, the specific heat of water is roughly 4000 joules/degree K/kg (actually a little higher, I rounded down to make the math easier). So 400 watts could raise the temperature of 1 Kg (1 liter) of water 1 degree in 10 seconds. If the water started at 20° it would take 400 seconds to raise 1kg of water to 60°, or, very roughly, 10 liters per hour, but maintaining the temperature depends on the losses which are unknown. For comparison, a typical domestic electric water heater is about 4kw.

Answer 4

If you have water in a perfectly lagged tank, you could keep it at 60 degrees indefinitely.

But, if you are talking about heating it up, assuming the initial water temperature is 10 degrees, you have to heat it up by 50 degrees.

The energy needed to heat 1 kg of water by 50 degrees is given by 4200 x 50 = 210000 Joules.

So at 400 W it will take 210000 / 400 seconds

= 525 seconds, just under 9 minutes per kilogram

A typical hot water tank might contain 100 kg of water, meaning a total heating time of about 900 minutes = 15 hours

You might be better to use the turbine to pre-heat the water before it gets to your normal water heater.

Answer 5

the most usual arrangement is to put the output of the wind charger into a tempering tank. the tempering tank pre-heats the water going to the main HW tank, and in this way reduces the load on the main tank when HW is flowing. the tempering does not work at any particular temperature, it can run anywhere from 10 degrees to a safety cutoff set at 70 degrees or so. the resistive heating element does not care about the cycles either, anything from 1 to a 1000 hz will work so you don't need an inefficient inverter circuit just to heat water.

Answer 6

Your 400 watts of power can heat up as much water as you want. The difference is that the time to heat it will be longer or shorter, dependent on how much you wish to have at 60 degrees.

Answer 7

Use VIT =MCT
WHERE VI =watts
(400 x time)/ c x 60-0 =mass in kg

Answer 8

depends how long u leave the element in the water