30 years ago, while sitting in my high school drafting class I first envisioned a totally solar powered home. Of course at that time, it was only a dream and all of the things needed to achieve this weren't readily available or even developed outside of some NASA laboratories. Through NASA, solar electric systems currently know as PV system have emerged and have finally made it mainstream. This is were you can place PV panels on the roof of your home and generate all of the electricity needed for your home. Now, almost all of the electric companies in the US allow for what is called net metering. This is where the solar panels on your roof are directly tied into your electric panel and when you produce more energy than you consume, the excess energy gets fed back into the grid and you get credited for the energy produce. This is the cool part, by doing this you can generate enough electricity during the day that puts energy into the grid and then at night when the sun isn't shining you get it back. You get to use the electrical grid as your battery for storing the energy you produce and then when you need it, you simply take it back. While the procedure for doing this varies greatly, from not only state to state but electric company to electric company, most if not all will be doing this shortly. All of the larger ones already do this and have been doing this for years. Some even give you grant money to help pay for the system, as much as 50% of the cost. The other factor that has made this a very practical approach is the new energy bill initiate earlier this year. The federal government now gives you a tax credit of 30% of the total installed costs of the systems. Not only Solar electric, but solar thermal and geothermal systems as well. previously they had a $2,500 cap on the amount eligible for the credit and on system costing upward of $30-40,000. Another thing that has made this more practical, is the reduction of costs for the systems themselves, the panels now cost 1/2 of what they cost only 2 years ago.
How much does it cost to build a Zero Energy Home?
This is the big question I get all of the time, and most people want a sq/ft cost of doing this. What I can tell you is that it can be done for under $200 sq/ft and maybe even as low as $150 sq/ft. The last home I just completed, entails all of the systems needed to achieve this, short of the PV system and the construction cost came in just under $150 sq/ft. (more about this house)The energy demands for this house are so low that making the leap to zero energy may not be the practical approach. Before we even start to build a home, during the design phase, we do what is called energy modeling were we can predict the energy demands for the home in any giving climate. While I like this approach, it uses data from a variety of sources to figure things like heating and cooling demands along with the typical electrical demands on any home based on occupancy levels. Now I need the real data, the energy bills from a home occupied for a year to determine if the model was correct and to design the PV system to meet the real needs. I feel pretty confidant that the PV system needed to make this a true zero energy home will cost around $25-30,000. Here is some quick math to determine practicality of adding this system to a home with an annual energy costs of $1,500.
cost of system $30,000
federal tax credit -$9,000
MA state tax credit -$1,000
final cost without grant money $20,000/annual energy cost $1,500 = 13.33 Yr payback @ current cost
factoring in inflation in energy cost, the real payback is somewhere around 10yrs or less if energy costs rise dramatically.
If you are interested in building a zero energy feel free to contact me ecobuilder@aol.com
