800M 32mm SWA - could this cause increased electricity bills due to voltage loss

Do have this right - you have half a mile of LV cable and a transformer on your side of the meter?


If that is the case then there would certainly be some losses - 800m of 35mm² would have a resistance of about 1.25mΩ/m so about 1Ω for 800m L & N. Looking at the case where your installation is drawing say 10A, I²R losses for the cable alone would be about 100W. Your 6000kWh suggests around a 3A load on average - so minimum losses in the cable would be around 9W (<80kWh/year). Drawing the same energy at higher power over shorter durations would increase the losses. Eg. drawing 20A for three hours a day (about 5000kWh/year) would mean cable losses of 400W or 1.2kWh/day or 438kWh/year. (But do check my maths!)


The transformer too will have losses - both constant and as a proportion of the load - but others here know much more transformers than me, so best wait for their suggestions.


An obvious check is to place some metering on the load side of the half-mile of cable and transformer - and compare the results with the supplier's meter - a clip-on energy monitor can be had for around £30 and should give you a first approximation quite easily.


   - Andy.

Do have this right - you have half a mile of LV cable and a transformer on your side of the meter?


If that is the case then there would certainly be some losses - 800m of 35mm² would have a resistance of about 1.25mΩ/m so about 1Ω for 800m L & N. Looking at the case where your installation is drawing say 10A, I²R losses for the cable alone would be about 100W. Your 6000kWh suggests around a 3A load on average - so minimum losses in the cable would be around 9W (<80kWh/year). Drawing the same energy at higher power over shorter durations would increase the losses. Eg. drawing 20A for three hours a day (about 5000kWh/year) would mean cable losses of 400W or 1.2kWh/day or 438kWh/year. (But do check my maths!)


The transformer too will have losses - both constant and as a proportion of the load - but others here know much more transformers than me, so best wait for their suggestions.


An obvious check is to place some metering on the load side of the half-mile of cable and transformer - and compare the results with the supplier's meter - a clip-on energy monitor can be had for around £30 and should give you a first approximation quite easily.


   - Andy.