What is Net Zero Energy?


The goal of the California Public Utility Commission is at least 1/2 of all new homes in California to be Net Zero Energy by 2016 and all new homes by 2020. The goal of net zero energy is for a home to produce as much energy as it consumes on an annual basis. Net zero energy is accomplished when the right combination of efficient mechanical equipment, building materials, lighting and appliances are matched with a properly sized solar electric system. Due to California and Federal incentives for solar electric and solar thermal systems and the introduction new super efficient electric mechanical equipment, many new homes can achieve net zero energy status in a very cost effective, cash positive manner without changing the style of your home or your lifestyle within it.

Types of Net Zero Energy Homes


Most new Net Zero Energy homes will be all electric. However, many people choose to use natural gas for cooking, fireplace log lighting or even space and domestic hot water space heating. This is often referred to as Net Zero Energy Electric meaning all the electric use is accounted for by solar.

How Much Solar Electric Required?


While your Architect may be enthusiastic about your new home being Net Zero Energy, they still want it to look great. The free NZEN Energy Calculator allows the building designer to explore the relationship between building size, roof area, orientation, lighting efficiencies, HVAC options, non-standard energy usages and the solar area required. The more advanced and fee based NZEN calculations allows fine tunes the design to include exact space conditioning loads, specific appliances used and lighting design and solar production required. The more efficient the house, the smaller the area required for solar energy production. Very early in the NZEN process your architect will need to know how many square feet of solar panels to plan for. The free calculator will provide this as an estimate. The more advanced process will be as more accurate. In either case it is very likely your architect will have creative ideas of how to accommodate the solar panels without compromising the design. The panels can be roof; ground or trellis mounted and need to face south. Furthermore, they must not be in the shade between 9:00 am and 3:00 pm on December 21. Here are some recent NZEN projects and how many square feet of solar electric was required.

Sq. Ft. of house

Sq. Ft. of solar required

1500 (new, standard eff.)350
2000 (remodel, standard eff.)420
2900 (new, standard eff.)540
4000 (part time res.)360
4500 (new and very eff)720
8200 (new, stand eff.)1600