So an Urbie, 30 tons at 32.4 kph provides 345.88 kwh.

Thus the Leenex 60 gives us 345.88.

Thus 345.88/60 = 5.7646 kwh for every engine point.

Vlar 300 = 5.7646 x 300 = 1729.38 kwh.

Average US household uses 11,000 kwh a year.

Assume a mech engine runs 3 hours a day, not 24 as you have to maintain the engine too. You wouldnt run your SUV 24/7 to power your house.

Engine point 5.7646 x 3 = 17.2938 kwh per day.

17.2938 x 365 = 6312.237 kwh for the year.

Vlar 300 = 300 x 6312.237 = 1,893,671.1 kwh in a year.

Divided by 11,000 = 172.15 homes a year. All from the engine of an Orion or a Dragon.

Not bad for something that you arent running 24/7.

thats my very guessimation maths today. Now back to thinking about things.

One thing you didn't take into account is that that the 30-ton Urbie can get up to 32.4 kph in at most 10 seconds. This time frame is actually far less since the Urbie can go from standing still to 32.4 kph, while an Urbie that was walking at a speed of 3 the previous turn can also cover the same distance.

So you are going from 0 m/s to 9 m/s, for a mass of 30,000 kg, so you are basically adding kinetic energy (aka work) to the Mech, so the equation is 1/2 * mass (in kg) * change in velocity (in meters/second)^2:

1/2 * 30,000 kg * (9 m/s - 0 m/s)^2 = 1,215,000 J = 1.215 MJ

Since this was done over a period of 10 seconds, Power = Work/Time, so this becomes 121.5 kW

This is assuming perfect efficiency from the fusion engine to the myomer muscles, from the muscles to the terrain, and that you have the full ten seconds to come up to speed. If you can get up to speed in 1 second, the power used is 10* higher (since it is being needed 10*faster) so the power is 1.215 MW. If the myomer efficiency is only 50%, that means half the energy going into the myomer is being converted into heat, so the power going in is twice as much, making it 2.43 MW. Assuming a 60-rated engine, that puts each point as ~40.5 kW. Assuming the average home uses 11,000 kWhr per year, that is ~1000 kWhr per month, or 33.33 kWhr per day, or 1.4 kWhr per hour.

So 40.5kW / 1.4 kW per home = ~29 homes per point of engine. Assuming a basic 10-rated engine, that is 290 homes that it can support.

The other problem is that energy weapons can damage or melt solid plates of armor. Using the Large Laser as an example (since it damages exactly half a ton of armor), that is 500 kg of material that is damaged enough to no longer be combat viable. Assuming it is just firing at a sheet of iron, where iron needs 126 kJ/kg, then 1 ton of iron just melted would be 126 MJ, and half of that is 63 MJ per Large Laser shot. Assuming the fusion plant can provide that power every 10 seconds, that is 6.3 MW for the fusion reactor. You should be able to make a 30-ton wheeled vehicle with a 10-rated fusion engine, and at least 1 Large Laser in it, meaning that is at least 6.3 MW from a 10-rated engine, aka at least 630 kW per point of engine rating.

Taking that same 6.3 MW10-rated engine, and the same need for 1.4 kW per home, and you get 4500 homes that can be supported.

(The underlined kwh is a measure of total energy, not power generation (1 kwh = 3600 kJ). Also, since the reactor is only running 3 hours per day, you will need some way to store the power for the other 21 hours.)

What are power amplifiers, exactly? Are they additional generators powered by a motor power take-off?

From

sarna and the Tech Manual, I've figured them as a form of capacitor/transformer/battery setup.

The problem is that a Power Amplifier array for 100 Small Lasers (50 tons total mass) would take up 5 tons. This provides enough energy for each Small Laser to fire once (aand the Power Amplifiers then get recharged from the ICE or Fuel Cell).

You then get into the Battlearmor Small Laser. Same damage and range as the 3025-era Mech-scale Small Laser, but the batteries for the BA Small Laser take up 160 grams and provide 30 shots (corrected 4th printing, p348). So Power Amplifiers would need to mass 5 tons to provide each of the 100 Small Lasers with a single shot, but enough BA batteries to provide a total of 120 shots would need only 640 grams. If I want to give each Small Laser 1000 shots, that is 640 kg, still less than the 5 tons needed for Power Amplifiers.