"spare energy" is a correct and usable phrase in written English.
You can use it when you want to refer to extra or unused energy, or energy that has been saved. For example: "We tried to save as much spare energy as possible by switching off all the lights when we left the room."
The spare energy went straight to our heads.
They will be used to hold water pumped from a nearby lake using spare energy, in order to create hydro power during periods of high demand.
We interpreted those results as a likely response of the liver to spare energy and provide glucose for the lactating mammary gland during feed deprivation.
This diet is relatively poor in nutrients and provides the koala little spare energy, so the animal spends long hours simply sitting or sleeping in tree forks, exposed to the elements but insulated by thick fur.
National Grid has reassured the government that Britain has enough spare energy capacity to keep the country's TV sets on in the event of England making it to the World Cup final energy secretary said yesterday.
Only a few months ago, when their kin back home were still faring relatively well, the Iraqi Christians of London seemed to have ample spare energy to concentrate on the successful careers that many of them have established in their adopted homeland.
His mother is a special-needs teacher, and saw that, in the kitchen, her son could focus his spare energies while also providing tasty family meals.
Under this scenario, the inhibition of ABC transporters that require ATP hydrolysis to translocate various substrates across membranes would have spared energy required for translation.
Currently, the sugar cane bagasse generated in the plant is consumed for energy production through cogeneration, becoming self-sustainable energy plant, and in some cases spares energy to electricity sales.
In this context, tolerance versus harmless foreign antigens of microbes on body surfaces (see gut, skin, respiratory tract, urogenital tract) or harmless autoantigens is a memory function that spares energy reserves.
Formally, the all-over patterns of the "Light Balances" images give way to a spare, calligraphic energy.
