We have been doing ceramics evening classes for the last three years and had been considering getting a small kiln for some time so that we could fire work at home. We had been put off by both the start up cost and the potential running costs. Some research revealed that we could get a hobby kiln that would run from a standard household 13amp socket and had a peak rating of 3kW. I did some calculations about firing schedules and realised that on sunny days between April and September it would be possible to fire the kiln pretty much entirely from the solar power. It would need the kiln to be started first thing in the morning so that the peak load coincided with peak output of the solar panels. Our system generates more than 3.5kW during the middle of the day at this time of year (if it is sunny) which is more than enough.With the summer months coming up we decided to go for it and have now purchased the kiln below.
 |
| Our shiny new kiln ! |
The next step is to do a test firing of the kiln, the only problem is it hasn't stopped raining for the last three weeks and the few sunny days have been during the week. I did give the kiln a very short run up to check that everything was in working order, the picture below shows the kiln controller in action.
 |
| The kiln controller during a short test |
We are busy making some work so that we have something to fire once the test firing has been done. The test firing is recommended for the new kiln as the elements will burn off their protective coating and the kiln will have had a "burn in". The test firing involves heating the kiln up at a rate of 150C/hour until it reaches a temperature of 600C at this point it will be heated up at full power until it reaches the target temperature of 1050C. The test firing should take around 6 hours so I am planning to start the kiln at around 8am one morning as soon as we get a suitable sunny day.
The longest firing we will are likely to need is when we glaze stoneware which requires a top temperature of 1240C, this requires an initial rate of 180c/hour until it reaches 500C and then at full power until the target temperature. This should take somewhere between 6 and 7 hours to complete so the 8am start should still be fine. I might have to start the kiln a little earlier when the days get shorter in late August and September.
I will post some more reports once we have had a chance to fire the kiln for real, this should be in the next couple of weeks. I am going to check how much power we draw from the grid during the firing by taking meter readings before and after the firing, hopefully it won't be much.
We need to work hard now to create some work to be fired but that is the fun bit !
