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.

Kiln spy hole showing how hot the kiln gets.

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.

Electric kiln at Butter Wynd Pottery

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).

Solar panels flat roof installation. These contribute significantly to the firing of the kiln at Butter Wynd Pottery

The solar panels