Sun fired pots with solar panels? Sort of…
While the creation of pottery takes a good deal of energy for mining, processing, making and firing, ceramic vessels have the benefit of being long-lasting and not harmful to the environment when disposed of. However, any use of renewable energy in the process is good, so we decided to invest in solar panels to contribute to our energy use, particularly in the the kiln firing.
We fire our pottery just once, by allowing the clay to dry out, applying the glaze and then firing it. The standard way of firing ceramics is to fire the items twice; first a biscuit firing, then a glaze firing. Raw glazing doesn’t quite use half the energy of the standard firing method, because the firing is done over a longer period of time, but it does use less energy.
Our electric kiln has a slightly larger capacity of an old style galvanised dust bin. The firing cycle uses 64kWh. Data from our solar panels for 3 years shows the average daily electrical generation is 6.25kWh. This means we can fire the kiln every 10 days with energy derived from the sun.
Naturally it isn’t that straightforward. We can’t say we fire the kiln directly from the sun, but if the National Grid is viewed as a bank, we can say we put energy in the bank, save it up and withdraw it to use later.
Solar panels themselves take energy to create.
It is also useful to think what 64kWh of electricity means. According to Ofgem, the medium ‘Typical Domestic Consumption’ of two profile classes UK household use around 8 kWh or 11 kWh of electricity per day. This means we use between 6 and 8 days worth of electricity used in a UK home for one firing. (According to Ofgem, UK households also use around 33 kWh of gas per day).