Hardcore DIYer who finally got his feet wet....

[MrDodge]

Good Day All, First meaningful post here.

After 5yrs. ( yes, 5 yrs.) of contemplating I finally took the plunge into renewable energy. Honestly, I didn't do it to save on monthly energy, save the planet, get the tax credit, or to stick it to the POCO. I did it because I find it interesting, very interesting. About 6 yrs.ago I happened by a YouTube video of a pop can solar heater and didn't believe a minute of it, just not possible. A month later I proved myself wrong with my own DIY upgraded screen collector which is still running strong.

Back then I priced everything up for a small solar array (around 5k watts) but it just wasn't practical, electric was cheap $.07 a kwh delivered. Fast forward to now rates are still low @ $.09, which is why I went a different route than the average consumer. I took a chance on bankrupt Suniva 265w panels @ $.50 a watt paired with used m190's @ $45 ea. The only part of my 4k system with a warranty is the Envoy. If it doesn't hold up I'm ok with it because WalMart sells tv's for more than I have invested, under a $1 a watt installed.

Many thanks to the seasoned pros and hobbyists for all the informative threads especially ground mount over a roof mount. Array.jpgSide.jpg

[J.P.M.]

Welcome to the neighborhood.

Wonder if you got the same rush I did when I got meaningful heat out of my first solar thermal collector.

[MrDodge]

Thank you for the welcome JPM,

Looking back the term, fascinating euphoria, would probably suit me better. I'll never forget it. It was only 8 degrees out the first time it ran and continued nonstop for over 5 hrs. producing a 30 to 40 degree temp rise. I just couldn't believe over a 110 degree split from one side of the plexiglass to the other and that it kept running. Still amazes me.

Unfortunately in my area only a handful of sunny days per month in the winter.

[J.P.M.]

Thank you for the welcome JPM,

Looking back the term, fascinating euphoria, would probably suit me better. I'll never forget it. It was only 8 degrees out the first time it ran and continued nonstop for over 5 hrs. producing a 30 to 40 degree temp rise. I just couldn't believe over a 110 degree split from one side of the plexiglass to the other and that it kept running. Still amazes me.

Unfortunately in my area only a handful of sunny days per month in the winter.

Yea, my ah ha moment occurred Nov. 1976 in Buffalo, NY. The rest is history.

[MrDodge]

If I may ask, after 40 yrs.do you still have a collector in service?

[J.P.M.]

If I may ask, after 40 yrs.do you still have a collector in service?

Well, since you ask, sure do.

Yea, I still have equipment that uses the sun to generate energy, but not the original. I set my first design on fire in the back yard during a stagnation test the following Aug. (1977) while using top & bottom booster mirrors. That design was my first and had a lot of flexibility to change things like absorber material, flow arrangement and pattern, number and type of glazings, etc. I even had a double glazed arrangement where the cooling air passed between the two glazings before it got to the absorber as sort of a heat recovery scheme and as a way to lower the top loss coefficient. Turned out to be a bad idea because the inner surface of the glazings fouled quite easily and for that reason had limited application. Nice try. No cigar.

I was sorry I pyroed that collector. I learned a lot from it besides how to lower the kindling temp. of wood.

I mostly quit my job as a sales rep/peddler of industrial equipment and with the help of a wife who could give Job lessons in patience, returned to univ. the following Sept. with the goal of a B.S.M.E. degree. Long, boring story.

Now, I've got a solar water heating system with 2 selective surface collectors that supply about 90-95 % of my annual DHW load and a storage/piping design that has a lot of flexibility via parallel flows, valving and instrumentation to (re)confirm what I learned and practiced as a working M.E., P.E. in power systems and conventional energy generation equipment and systems such as boilers, heat exchangers and pressure vessel design, both thermal and mechanical.

I also have a 5 kW PV system that I've got dialed in pretty good as to performance including the rate and effects of fouling with the help of a Davis Pro II + weather station about 5 ft. north of the array that takes and records data at 1 min. intervals. I've learned a lot and had a lot of fun with all that stuff.

I'm not done yet, but with only 5 years into it, I envy you for the potentially satisfying discoveries you have yet to make.

Respectful suggestion: Learn the basics and then get a copy of Duffie & Beckman, " Solar engineering of Thermal Processes" for the basics of solar energy. Do it right. You will not regret it. Don't waste your time on U-tube garbage or doing stuff half assed. That's a B.S. waste of time way to do it.

Good luck. Stay curious.

Take what you want of the above. Scrap the rest.

[MrDodge]

Good to hear thermal harvesting is still in your heart and installed on your property. It is in itself very, very interesting and for the most part free less the countless hours you spend just thinking how you could make it just a lil better, (fairly certain that's where the mirrors you mentioned came into play}.

I'm certainly only a novice but nearing retirement I look forward to piddling with thermal in the the future. Thanks for the literature suggestion because when it comes to the science of it, I have no clue, I just know it works and works well.

Regards

[J.P.M.]

Good to hear thermal harvesting is still in your heart and installed on your property. It is in itself very, very interesting and for the most part free less the countless hours you spend just thinking how you could make it just a lil better, (fairly certain that's where the mirrors you mentioned came into play}.

I'm certainly only a novice but nearing retirement I look forward to piddling with thermal in the the future. Thanks for the literature suggestion because when it comes to the science of it, I have no clue, I just know it works and works well.

Regards

Fun, but far from free, either in $$ or more maintenance than most folks want to give them. .

To be clear, I like my solar thermal, not the least reason being that because of entropy considerations, it's about 2-3 more efficient at providing energy than my PV system. My PV system turns about 17-18 % of the solar energy that hits it in a year to electricity. My solar thermal system turns about 45-55 % or so of the solar energy that hits it in a year into useful heat.

However, and for the most part, active solar thermal is usually best used in moderately warm climates, and is most likely marginally cost effective or less so in colder climates, as well as requiring more maintenance and babysitting.

As of this time, for DHW applications in reasonably moderate climates, a heat pump water heater powered by well designed PV is most likely more cost effective and easier to service and maintain than solar thermal, probably close to being on a par with the solar thermal on an energy collected per solar aperture area basis if the heat pump can run at an annual C.O.P. of something like 2.5 or so.

I'm keeping what I have and like it, but I'm probably more eccentric and other directed than most, but if I had to start again today, I'd heat my H2O with a heat pump, but not if I was still living in the Northeast U.S.

For colder climates such as found there, natural gas is hard to beat as a heating source in terms of fuel and equipment costs, availability and ease of use, and for the colder parts of the region, also probably beats a heat pump for cost, both in equipment and fuel.

BTW (and more boring stuff), the mirrors were part of a method to determine/SWAG the overall collector loss coefficient. With no flow, all the solar energy input becomes losses (with the input measured/estimated with a hand held pyranometer I had at the time and an irradiance modeling algorithm I wrote in FORTRAN IV). At those conditions it's possible to get a 1st order approx. of the collector loss coeff. per degree of temp. diff. between the collector absorber temp. and the ambient air temp. That info is one piece of the puzzle needed to estimate collector thermal efficiency.

[bcroe]

However, and for the most part, active solar thermal is usually best used in
moderately warm climates, and is most likely marginally cost effective or less so in colder climates, as
well as requiring more maintenance and babysitting.

As of this time, for DHW applications in reasonably moderate climates, a heat pump water heater
powered by well designed PV is most likely more cost effective and easier to service and maintain than
solar thermal, probably close to being on a par with the solar thermal on an energy collected per solar
aperture area basis if the heat pump can run at an annual C.O.P. of something like 2.5 or so.

My conclusions as well, here in a colder climate. PV solar has the farther advantages of being more
universal in use, and possibly quite remote in locating.

Taking this to a larger scale, I am working on conversion to all mini split heat pumps for heat and
cooling, which have the advantages of quite good C. O. P., extreme effective outside temp range,
and decentralization. The electrical supply part of this (expanded distribution and metering) is
already finished, more on the mini splits later. Bruce Roe

[solarix]

I applaud your DIY initiative, but be aware that Suniva panels have a track record of bad solder joints inside the J-box. You can fix that your self too - just dig down through the sealant inside and resolder them. Suniva went bankrupt for more reasons than the "unfair trade".

[MrDodge]

BTW (and more boring stuff), the mirrors were part of a method to determine/SWAG the overall collector loss coefficient. With no flow, all the solar energy input becomes losses (with the input measured/estimated with a hand held pyranometer I had at the time and an irradiance modeling algorithm I wrote in FORTRAN IV). At those conditions it's possible to get a 1st order approx. of the collector loss coeff. per degree of temp. diff. between the collector absorber temp. and the ambient air temp. That info is one piece of the puzzle needed to estimate collector thermal efficiency.

Sir, that paragraph tells me you've probably forgotten more than I'll ever know about harvesting energy from the sun.

solarix, thanks for the heads up. I'd researched that very issue before committing to the installation. I even bought a couple of extra 190's and a DC amp clamp. I'm just sittin around waiting for something bad to happen! Hopefully I'm prepared.