# Electricity Transformers and power

Since Power = V*I increasing voltage reduces current and so it is better to have a higher voltage. My question is, since voltage is potential difference i.e. joules per metre, increasing the voltage also increases the heat lost so why is this beneficial?

In addition to this, since we are trying to make the transfer of electricity more efficient and this means moving more electricity with less heat loss. Power is the heat loss per second and since we're dealing with a fixed power wouldnt we want to increase current rather than voltage so that we move more electricity in less time?

I know that my reasoning is wrong somewhere so can someone clarify why this is wrong and provide background information about voltage/current etc. as well as any relevant maths to back it up. Thanks in advance

• Careful with your units: voltage is measured in $[Volt]=[J/C]$. A potential difference only performs work when it moves charge, hence $P=UI$, i.e. both a potential difference and moving charges (i.e. a current) are needed. It is the current which causes a voltage difference along a conductor (rather than between two conductors), which leads to resistive aka "$I^2R$" losses. That's why we are trying to decrease the current when we are transmitting power over long distances. Commented May 21, 2016 at 20:44
• Does this answer your question? physics.stackexchange.com/questions/248229/… Commented May 22, 2016 at 16:46