OK, we admit, we're a long way from a carbon-free grid—but when we have one, what's the most efficient way to use that energy to fly planes? This question is explored by an interactive tool ...

But the performance can vary widely, even among hybrids. Below, we spotlight the 10 most fuel-efficient cars based on Consumer Reports’ overall fuel-economy test results.

Most hot tub manufacturers and dealers ... How do solar-powered hot tubs compare in terms of energy efficiency? Solar power is a great source of energy, but the amount of available sunlight ...

Enter some basic information below, and we’ll instantly provide a free estimate of your energy savings ... It has the highest efficiency rating of any residential inverter we've seen.

These systems are more efficient than most baseboard or forced ... a big difference in lowering energy bills and potentially reducing emissions from your heating source. The IRA offers 30 percent ...