Just for the heck of it, I had a PV system quoted for the 10K House to see how much it would cost to take care of 100% of the electrical demand with a grid-tied system. The good people at SunPower Builders gave me an estimate today. We would need about a 5KW array to supply all of our electric. The breakdown in cost is as follows:
- 2,800 Watt System - $28K
- 4,000 Watt System - $39.5K
- 6,000 Watt System - $53.9K
To think that just a few months ago, I thought that offering a PV upgrade option to convert an all-electric home to a zero energy home would be feasible. We are using gas now for both water and space heating and have eliminated A/C and we still can’t come close. We wouldn’t even have enough room on the roof to fit enough solar panels to make it zero energy. This is a bit sobering and a testament to the fact that renewable energy is not the answer.
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Wow. That is depressing to say the least. I knew PV systems were expensive but I didn’t think they were THAT expensive.
indeed
How about a second quote?
The PV system quotes that we have seen to date range from about $7-$10 per watt installed. These are slightly on the high end of that, but within the range.
Remember, it’s hard to build any house for $100k these days, so finding space in such a budget for a PV system is not really an option.
For those of you with larger budgets, consider the local rebates (as high as $5/watt in some states), the property tax exemption for the system, putting it in your mortgage (put 20% down) and getting the tax write-off on your mortage payments (which you can’t do with you normal utility bills) and having no utility bills.
When all is said and done the increase in your mortgage payment is probably close to the reduction in utility bills. This varies according to how you finance, local utilities rates, and incentives available in your state of course (www.dsireusa.org for more on those).
Solar usually makes the most sense after using passive tactics and reducing mechanical consumption. We all wish it was cheaper, but in the meantime it makes sense look at the details and see if it’s right for your situation. You can do this by looking at the total cost of ownership of your house, not just the construction cost.
What Adam said…
This is more of an FYI post for me. I can’t devote a lot of time and research to the subject at this time as it is not remotely feasible for this project. Even if we had better pricing we would still be way out of the ballpark.
The humbling thing is that this size system would only be taking care of our appliances, lighting and ERV. We could create a home that required no active heating or cooling via passive techniques and still need a PV array this large to cover the remaining energy demand.
It seems that refrigerators would be the first appliance to improve. If anyone finds some type of a ground source heat pump powered fridge, let me know…
So the current price of a PV setup is roughly $10,000/Kw? Any idea how this compares to the price last year? Or 5 years ago? It’s not directly analagous, but I remember when hard disk capacity cost about $1/mb, or $1000 for a gig (15 years ago?). Economies of scale and improved technology have pushed costs today to below $1 a gig.
What’s the likelihood of solar following a similar trend?
You can purchase renewable energy credits to offset your house and make it zero energy. Also check out www.halcyonenvironmental.com for other energy saving technologies. There are other energy reduction solutions that should be done to the house before considering PV as the only source of energy. Secondly, you could add solar heat collectors on the side of the home. Renewable energy prices will decrease as production increases and as we keep upgrading the traditional pv panel.
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