Words of Wisdom

I’m in the planning stages of building a new house (1,500-2,000 sq ft) and I’d like to make it as close to a zero-energy home as I can.
How close to zero-energy are the homes you’ve built and what were the costs for the solar system? Can you give me any detalis on the system you’re using?
Since you’re on your third house, are there any words of wisdom you would offer to someone who is planning a real world solar home?
Each of the three houses are zero energy houses. Each of the houses are capable of operating in a grid-tied mode or stand-alone mode. Each of the houses have used different systems in different combinations so that the most efficient and economic approach can be identified. Both the 2002 and the 2007 house are using BP Solar panels. They are both solid, multicrystalline systems. The 2005 house incorporated UniSolar amorphous panels. They were used in combination with a standing seam copper roof to make the roof more visually appealing.
The solar thermal systems have been variations on the same general principal. The 2002 and 2007 houses both use evacuated tubes for heating water for the house. The 2005 house used a student designed system that worked in combination with the solar panels and the copper roof to produce hot water.

One of the building technologies incorporated into the 2005 and 2007 houses are Structurally Insulated Panel Systems (SIPS). These wall and roof systems have basically double the energy efficiency of traditional construction methods.
The cost of the 2007 system is about $50,000. While this may seem to be a large price tag, much of this is due to the need to perform as a stand-alone system while at the Solar Decathlon in Washingtion, D.C. The panels are about $25,000, the balance of system (inverters, charge controllers, combiner boxes, etc) are around $10,000, and the battery system us $7,500. The retail cost of the the solar thermal system is not available at this time, as we are finalizing some design issues with our system.
The most important consideration is to make upfront decisions about your goal for the project. Do you have a specific budget that the entire new house meet? Do you want a zero energy home no matter what the cost? Do you want to use more efficent materials and appliances and utilize a smaller solar system, or do you want to use farily standard materials and appliances and use a larger solar system?
Our decision as a team has been to concentrate on make the entire house energy efficient and then sizing the solar system to suit our needs, rather than the opposite approach.
Another suggestion is to work with someone that has experience with design the system. (We are happy to help as time allows.) The primary reason for this is to get maximum bang for your buck. Someone that is familliar with the modelling simulations, new building technologies, and cost benefit analyze can recommend which strategies will best suit your individual project and budget.
If you are interested in more details on the 2005 house, the plan sets are available with a $500 donation. Please see the blog entry for the form. Thanks and keeping sending us your questions