[Origin]

The problem is electromagnetic energy is massless and therefore cannot be described in MKS units

Sure it can.
For a massless photon it's energy is:  E = hf.  Where h is 6.626 x 10-34 Joule-sec and f is frequency.  So the result is in joules.

[acsinuk]

Yes,   E = hf. but what length or area dimension are you measuring in.  Energy must occupy a volume it cannot be described physically without volume in cubic Metres x,y,z especially as it has no mass in Kg. Time in Seconds is relative.
 MKS has a problem describing electricity and electro-magnetic light.

[alancalverd]

Is there any sort of practical example,

See reply #13, or try switching the light on at night when the wind isn't blowing. Right now, 16% of what comes out of the wall is generated by E = mc², as it has been for about the last 50 years.

[alancalverd]

MKS has a problem describing electricity and electro-magnetic light.

The function of the system of units is not to describe anything but to rationalise its measurement. What properties of electricity and electromagnetic radiation are not measured in SI units? ("MKS" was consigned to obsolescence in the last century)

The rest of your post was nonsense.

[Bored chemist]

electromagnetic energy is massless

That's a matter of perspective. Light has no rest mass, but it has relativistic mass.

[Janus]

Yes,   E = hf. but what length or area dimension are you measuring in.  Energy must occupy a volume it cannot be described physically without volume in cubic Metres x,y,z especially as it has no mass in Kg. Time in Seconds is relative.
 MKS has a problem describing electricity and electro-magnetic light.

Energy is a property.  It makes no more sense to say that energy must occupy a volume than it does to say weight must have a length.

[acsinuk]

Physicists needs to physically measure something in terms of its length, weight, time taken etc but fundamental electro-magnetic energy cannot be measured in those units and to use their mechanical energy equivalents is just misleading.

Matter is just made up of electrical charges held apart by magnetic spin inertia in an x,y,z, volume enclosure. How can we measure the 3D electric dynamic forces inside an atom and in which direction they are acting?

[Bored chemist]

Physicists needs to physically measure something in terms of its length, weight, time taken etc

One of the etceteras is the magnetic permeability of free space which was defined as something like 4 pi * 10^-7 Henries per metre by defining the ampere as
" that constant current i which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed r = 1 metre apart in vacuum, would produce between these conductors a force F equal to 2 x 10-7 newton per meter of length ".

So the thing you see as a "problem" was solved decades ago.

The use of things like this
https://en.wikipedia.org/wiki/Kibble_balance
Show that we quite definitely can, and in practice do, measure things in such a way to make this
" fundamental electro-magnetic energy cannot be measured in those units "
absurd.

[Bored chemist]

Matter is just made up of electrical charges held apart by magnetic spin inertia in an x,y,z, volume enclosure.

That's not even wrong.
https://en.wikipedia.org/wiki/Not_even_wrong

[alancalverd]

Physicists needs to physically measure something in terms of its length, weight, time taken etc but fundamental electro-magnetic energy cannot be measured in those units and to use their mechanical energy equivalents is just misleading.

Energy has dimensions ML²T^-2 and is conserved. That is one of the most fundamental statements of physics. So it doesn't matter how you measure it, a joule is a joule.

Matter is just made up of electrical charges held apart by magnetic spin inertia in an x,y,z, volume enclosure.

is meaningless drivel, however you read it.

[acsinuk]

In theoretical physics we need to try and explain what quantum energy consist of and its relationship to matter and electricity

Thus, the modern understanding of mass, as per quantum field theory, supports the postulate that mass is derived from the density and intensity of field excitations.

[alancalverd]

In theoretical physics we need to try and explain what quantum energy consist of

It is energy, quantised. Energy is a conserved quantity. Nothing theoretical at all.

[Bored chemist]

In theoretical physics we need to try and explain what quantum energy consist of and its relationship to matter and electricity

No.
What we need is for you to grasp that energy is energy.
The kinetic energy of a cricket ball is quantised.
Energy is all "quantum".
It's just that the effect is usually unnoticeable except with small things like electrons.

[acsinuk]

Electro-magnetic energy is fundamental energy has the formula = V*A *Cosineϴ*Time.
But if Cosineϴ is zero then even with volts and amps present we have no power energy only quantum power energy

[paul cotter]

You are mixing power engineering with quantum theory and confusing yourself in the process.

[Kryptid]

Acsinuk, you are starting to speak in regards to "New Theories" material in the main part of the forums. Please don't do that.

[Janus]

Electro-magnetic energy is fundamental energy has the formula = V*A *Cosineϴ*Time.
But if Cosineϴ is zero then even with volts and amps present we have no power energy only quantum power energy

That formula refers to  specific situation when you are dealing with an alternating current and a circuit with either capacitive or inductive reactance.  In such an instance, the voltage and current can be out of phase with each other, the difference in phase angle is what you are taking the cosine of to get effective  power usage of the circuit.  If the circuit were purely resistive, than there is no phase difference and you can just multiply volts times amp to get watts and then that by time to get energy usage.
 It has nothing to do with the "fundamental energy" of electromagnetic energy.

[acsinuk]

AC electricity moves at the speed of E/M light and is massless just like photons. So 50/60 cycle per second domestic electricity could  just be very low frequency E/M light. 
Further problem is particles cannot accelerate to light speed without a huge amount of energy being pumped in.
So we need to rethink how we visualise electricity and the parameters surrounding photons inside a conductor.

[alancalverd]

Not "we", just you. Inventing absurdities does not advance understanding: a basic textbook might.   

[Bored chemist]

So we need to rethink how we visualise electricity and the parameters surrounding photons inside a conductor.

Can we start that "rethinking" process by realising that the photons are outside the conductor.
You can verify that fairly simply.
The speed of a signal down an insulated cable depends on the refractive index of the insulation.

If you didn't know that, it shows that you don't know what you are talking about...