Comments on: Domestic Hot Water Solar Installation, Part I

By: Liz

Liz — Wed, 26 Sep 2007 06:08:04 +0000

Liz…

Just wanted to drop a note to let you know what a great site you have. It is a great resource and a great place to drop by….

By: Solar Domestic Hot Water for my house | Hudson Valley Solar

Solar Domestic Hot Water for my house | Hudson Valley Solar — Tue, 04 Sep 2007 15:49:53 +0000

[...] invest in some of that technology for my own use. To that end, I spent the weekend installing a Solar Domestic Hot Water (SDHW) system on my roof. I posted the information on my other blog, here is a little bit: If the saying [...]

By: Jay

Jay — Tue, 04 Sep 2007 02:07:57 +0000

More importantly, how is my ladder?

By: Paul

Paul — Mon, 03 Sep 2007 18:36:35 +0000

Thanks, Todd. That is interesting about the larger rafters in new houses. I suppose over the years some improperly build 2X6 rafter roofs have failed, so they increased the size to compensate. Probably has something to do with a law suit. The other factor is perhaps more accurate wind data. This area used to be a 70 mile per hour basic wind speed, but now it is a 90 mile per hour basic wind speed.

By: Todd

Todd — Sun, 02 Sep 2007 23:18:52 +0000

Paul,

Nice job on the solar panels! I have to agree with you, working in the attic is one of my least favorite jobs. It’s also amazing to me to see how older houses are framed with 2×6 rafters. Those houses stand up to the snow and wind loads quite well yet today’s codes require roofs with 2×10 and 2×12 construction….hmmm….such a waste! Anyway, nice start on the project and I look forward to seeing how it all comes out.

By: Paul

Paul — Sun, 02 Sep 2007 19:40:25 +0000

Jen, a number of things… Concentrated solar power is more efficient, no doubt about it. However, as you said, it takes control out of the individual and puts it back into big business. Secondly, as more and more people become interested in solar power, both photovoltaics and solar thermal, the incentive for corporations to develop more efficient products will become larger. Right now, photovoltaics offer between 9-16 percent efficiency, solar thermal, such as the system that I am putting in, is about 60 percent or so. Both of these can be improved upon (and to some extent have been in the laboratory).
The good thing about photovoltaics and small wind/hydro is the distributed power generation. If enough of these systems are installed, the need for more conventionally powered (e.g. fossil fuel) generating plants will decrease, as will the need to string high tension power lines all over the place. Right now, there is a fight about a high tension power line project in the Delaware river valley, about 35 miles south of here. The reason why it is needed is because the New York metro area continues to grow and need more power. The solution, according to the power line proponents is to generate the power out by Rochester and send it down these lines. First, that is terribly inefficient. Second, a beautiful and historic area will be ruined by a set of huge towers. Third, if NYC wants more power, let them generate it down there somewhere. Imagine if every building in NYC had a couple of kilowatts of solar power installed on it. That might do the trick.
The only way we can stop these mega corporations (or in this case, the US department of energy) is if we all stand together and speak very loudly.
Um, ahem, well, thanks for the comment.

By: Jen Wolf

Jen Wolf — Sun, 02 Sep 2007 15:00:14 +0000

Paul, you totally rock for getting up there and doing it. I’m math impaired, not to mention I’m not comfortable climbing around on roofs, but you’re reminding me that as a kid, I had no such problem: I worked one summer in the early 1970s with my best friend’s dad building a PV system in his backyard at his place on the Chesapeake Bay. He had built a tower out back that we had to climb up, and we worked up top in the blazing sun. A retired nuclear physicist with no intention of sitting around, he’d turned his considerable brain power to solar research and was experimenting with a combined PV/hot water system. I helped him build the prototypes from scratch. Solar systems for the consumer were pretty expensive back then and he was trying to build something affordable that did double duty. He continued his research until he passed away, some years ago, now, and I honestly don’t know what became of his research, but it sure was an education and an inspiration for me. He was the guy who first turned me on to the notion and the possibility of energy independence at the individual level. I’ve heard some guys saying, recently, that rooftop collectors are the wrong way to go, that it’s hopelessly inefficient and we should invest in mass collectors. I can see the efficiency part, but then individuals are still tied to the grid. They haven’t yet convinced that individual collectors are a bad idea.

By: Paul

Paul — Sun, 02 Sep 2007 11:03:31 +0000

Hi Sarah, I did consider making the collectors myself, but I decided not to because
1) I wanted the system to last. These collectors have a 25 year guarantee. We are in a pretty tough climate in the winter time and durability is important.
2) The manufactured collectors have higher efficiencies, which is also important in the winter months for at least getting some use out of the system.
3) They look better

I estimate I will save about 25 to 30 percent on the electric bill, which is between 3000 to 3500 kWh per year. Our last electric bill was 0.142 per kWh, which means a savings of $426 to $497 per year.

By: Sarah

Sarah — Sun, 02 Sep 2007 08:40:27 +0000

Hi there. Great project. I’m into alternative energy but alas, not a homeowner, as you know. Probably you wrote about this already, but I have two questions for you:

1. did you consider making the collectors yourself rather than purchasing them?
2. you must have a way to figure out how much energy you’re saving by giving your hot water a boost, right?

Cheers from Vienna!