According to the DOE and other sources, in about 2001, the nationwide average for a home for heating, cooling and hot water was close to about 70%.

Today 6 years later, just heating, cooling and hot water is about 50%.

A larger % is now going to electronic devices, etc... no big suprise.

The 4 largest energy expenses are a home are in this order:

1. space heating
2. hot water
3. lighting
4. cooling

I have 1000 square feet of radiant barrier from here:
Foil Insulation Radiant Barrier - AtticFoil.com $135 delivered for this much.

I will lay it in my attic on top of the regular insulation as it reflects 97% of heat in the winter coming thru the roof and 97% of any heat hitting it downwards that moves up from the inside of the house during heating in winter.

I am also applying 2 full primer coats with the nasa paint additive to all ceilings and walls in the house (1 story with full basement)...only applying to main floor at this time.

Radiant heat loss in winter and gain in the summer is THE MASS MAJORITY of all heating gain and loss (RADIANT) and only a very small percentage is from conduction or convection but unfortunately all non-radiant reflective technologies/insulations only cater to conduction or convection but do zero for radiant! Pretty crazy!

Anyway, the majority is radiant loss and gain and treating those happen to be about the cheapest things you could do to so that you can decrease heating costs in winter (locking heat in the house) and decrease cooling costs in summer (reflecting heat away so it can't get into the house).

Using the paint on the interior and the radiant barrier together in the attic will be absolutely remarkable. Also, in the spring, I'll paint the outside of the house with the paint additive as well.

So these very inexpensive measures take care of the #1 and #4 most expensive parts of energy costs for an average home and they are about the cheapest things you can do.

Now, what about hot water #2? A solar hot water heater is preferred so the sun heats most of the water requiring little to nothing from the grid to heat water. Then have your hot water heater supply hot water to tubing under your floors for radiant heating! In the summer, pipe the city cold water supply through the floors and hot air in the house will be drawn to the colder floor and carried out for free.

This method coupled with radiant barriers and paint additive takes care of #1, #2, and #4 with 1 single system. solar water heater + radiant tube floor heating and cooling. In my opinion and this is the system I am currently designing using currently existing packages and parts.

As far as lighting, I'll use full spectrum compact fluorescents in most places unless I really have to have my full spectrum incandescents, which I love even if they do use a lot of power. I'll do all this until LED lights for normal home use is more cost effective with enough light output.

If we concentrate on reducing #1-4 with as little intervention as necessary, that alone takes care of 50-60% of all home energy use.

By that time, the actual electric use is hardly anything and with simple measures to draw electricity efficiently from the grid, it will then be practical and more cost effective to use solar for the rest of the electricity since electric use will be at a minimum.