The question can't be answered in this form.
The most compact form of engines are hydraulic motors, though.
Compact fluorescent light bulbs are pretty energy efficient and are energy star rated.
thermal/heat energy
Watts is a unit of power, energy / time. Therefore, the energy consumption of a device is the amount of watts, multiplied by the time the device is turned on.
No, the most energy efficient bulbs are LED (Light Emitting Diode) light bulbs.
compact fluorescents are lowest in energy use for most houshold applications
comparative: more compact superlative: most compact
A clutch device enables engagement and disengagement of power from an engine. Most people associate clutches with transmissions and the vehicles they apply to.
The viola is the most compact string instrument.
Women and children did not sign the Mayflower Compact.
Incandescente light bulbs waste quite a bit more energy than most alternatives.
You can determine which appliances are consuming the most electricity in your home by using a device called an energy monitor. This device can be plugged into your outlets to measure the energy usage of each appliance individually. You can also look at your electricity bill to see which appliances are using the most energy based on the increase in your monthly usage.
There are a number of machines that can change heat into mechanical energy. One of the simplest would be an early form of steam engine, with a hollow metal ball filled with water, and two tubes extending from the ball, each with a bend in two opposite directions. One of the most impressive (but complicated) is a Sterling Engine. It's main advantage over a steam engine is how little energy it requires to make it go (There's a version you can buy to place on top of your coffee cup!) -haloeffects