The Economics Make Sense…Now
During 2009, the combination of solar electric prices dropping by 30% + and the arrival in the marketplace of cost effective super high efficiency European heat pumps makes it possible to design and build net zero energy homes that are cost effective and cash positive day one. By that we mean that the monthly cost of the solar system included in a standard 30 year mortgage will usually be less than the utility bill the home would generate without the solar system. The NZE Certified process itself may cost $1,500- $3,000 in addition to what is already required for a project, but those cost are recovered very rapidly in energy savings.

Is a Net Zero Energy Home Expensive?
Your Net Zero Energy home will use very efficient appliances, lighting, windows and HVAC to dramatically reduce the electric load of the building, however, most of these devices and methods are required by the California Title 24 energy code already. The solar systems will add 2-4% net to the cost of the building but will eliminate a utility bill and often will be immediately cash positive.

How Exactly Does The Utility Billing Work?
The way you pay your utility bills changes when you own a solar electric system. The first difference is the meter. The utility will put in a "net meter" that measures how much energy is being produced compared to how much is being used. For example, if more energy is used than is produced by the PV system, the meter may read a positive number. You can look at this positive number as you owing money to the utility. However, it is apparent that some months are much sunnier than others and therefore produce more energy. Further, the winter months force one to consume more because of the outside temperature as well as how early it gets dark. Because of these factors that change throughout the year, the utility company adds up the monthly readings over the course of one year before billing the customer. So instead of paying a monthly bill, you only pay at the end of the year. This means that if you produce as much as you consume over the course of the year, you will owe no money regardless of the individual months that you used more than your PV system produced.

Sample House: For the following questions consider our NZE Certified sample house. The house is 2300 square feet insulated with R-30 in the roof, R-19 in the walls and R-19 in the floors. It has Energy Star qualified windows and appliances, uses 90% high efficacy lighting, has an Energy Star heat pump, and will use a 6.2 KW PVT system to achieve Net Zero Energy. The standard house is considered as a house with the same square footage, floor plan and insulation as the NZE Certified sample house, only it just barely beats T-24.

How Much Does the Solar Electric System Cost?
The original price for the 6.2 KW system can be about $50,000. California utility and government incentives make the solar system for this sample home very affordable. First, the New Solar Homes Partnership offers a $2.50 per watt rebate. For this system that equals a $15,500 cost reduction. Further, there is a 30% uncapped tax credit that will take away another $15,000 off the original price. After these two rebates, the total cost of the Solar Electric system is $19,500. If you wanted to add the cost to your 30 year mortgage, assuming 7% interest, it would only be $130 per month. This amount is less than the calculated total utility bill without solar!

What if I produce more energy than I use?
As of now, the best case scenario for a home is to produce as much energy as it uses. There are no benefits to producing more that it uses. However, there are already feed in tariffs that do apply to many commercial utility customers. These tariffs allow the customers to actually sell back the extra energy their system produces to the utility companies. The sell back rates will be a fixed, non-negotiable price over an extended period of time. Some counties in Florida actually have a feed in tariff program that buys back all of the energy produced by a commercial or residential system at a higher rate than they sell energy for. This gives utilities customers a great advantage by putting in a PV system. In California, they are working to propose a similar system come January 1, 2010.