A survey by the U.S. Energy Information Administration confirms what most of have seen first-hand: electronic gadgets are using more and more energy in our homes.

The EIA on Monday presented data on energy use in 12,000 U.S. households, which showed improvements in efficiency from better appliances and weatherizing over the past several years, but a marked increase in the electricity load from electronics.

In 1978, about two-thirds of a home's energy went to space heating and 17 percent to electronics. With the proliferation of TVs, DVRs, PCs, and cell phones, electronics in 2005 represented 31 percent of total energy use, with 41 percent going to space heating.

The EIA said that more efficient products, such as EnergyStar appliances, and better construction have helped make homes more efficient. Consumers have also improved the efficiency of homes with steps such as sealing holes and improving insulation. Overall, there has been a 31 percent reduction in energy use per household since 1978, but the electric load has offset some of those gains.

The first federal mandatory efficiency standards for major appliances came into force between 1988 and 1994 but the power use from appliances nearly doubled because of more homes, larger homes, and the increased use of air conditioning.

Very few homes in 1978 had a personal computer, but now 76 percent of U.S. homes have at least one computer and 35 percent have more than one. Larger and more numerous TVs also contribute to a higher electronics load.

Smaller electronics are having an impact as well, with nearly one-third of households having at least four electronic devices, such as cell phones and DVRs, plugged in and charging at home.

There are a number of companies developing products to reduce the plug load in homes, including power monitors and "smart plugs" that cut stand-by power. Home automation tools also promise to let people more easily schedule when to turn off major appliances and electronics instead of manually turning electronics off.