Got Solar!

[JoeS]

ed5000, I think it's a great energy-saving idea to use the solar collectors and water heater tank as a pre-heater with storage! The tankless using only 1kW is a HUGE consumption reduction. Hope this scheme continues working for you and I trust you have some automatic controls for not overheating the water that comes from the collectors (uncontrolled and at a very low flowrate my pool solar collectors are great at generating steam on a summer afternoon).

Yes, the Climate Change Credit it nice and offsets the monthly meter fee (another PG&E profit center) which had doubled a couple of years ago.

Now that May 1 has come and PG&E's revised 2019 summer rate structure has kicked in (peak of 46.4¢/kWh, at least for me on their E-6 tariff) we really need to pay attention as to when we do the laundry or charge the cars. Due to PG&E's wacky scheme, I am always above 100% of baseline (due to generation, not consumption) which kicks me into their highest tier for the entire month so my lowest nighttime rate is 27.2¢/kWh. Happily, as I generate the consumption $$ decrement at this high rate as well so my net is always in my favor, dollarwise.

PG&E has declared Chapter 11 as a result of their potential liabilities for those wildfires and there is talk of their rates doubling!

As it is, most of us are now purchasing our power from a Community Choice Aggregator (CCA) (in my case, Silicon Valley Clean Energy), with PG&E only providing the distribution. SVCE not only provides clean/renewable electricity but also pays me at market rates for what I export. :mrgreen:

Suffice it to say, I haven't had to pay for my electricity since 2006 and, on top of that, with SVCE taking over a couple of years ago I received a check for $430 from them last year and expect around $740 this year.

My solar panels amortized themselves years ago...

 

[Don]

Hope this scheme continues working for you and I trust you have some automatic controls for not overheating the water that comes from the collectors (uncontrolled and at a very low flowrate my pool solar collectors are great at generating steam on a summer afternoon).

I have no overheat protection on my system. My 40 sq ft panel will get 110 gallons of water up to 150 or 155 degrees on a cloudless day in the summertime, but I've never had any problems with anything getting too hot. I do have a mixing valve on the tank outlet which mixes cold water with what's coming from the tank and I have that set at 115 degrees so we never have scalding water anywhere in the house

The little circulation pump in the system only runs when the collector temp on the rooftop panel is 15 degrees higher than the warmest point on the storage tank, so it cycles on for a couple minutes every 10 or 15 minutes, depending on how hot the water in the tank already is and how bright the sun is shining

It's 100% solar for 9 or 10 months every year and I have a time clock with 120 volts on the upper element that I use in the dead of winter when we have more cloudy days. It's been working pretty flawlessly now for 12 or 13 years

Don

 

[ed5000]

ed5000, I think it's a great energy-saving idea to use the solar collectors and water heater tank as a pre-heater with storage! The tankless using only 1kW is a HUGE consumption reduction. Hope this scheme continues working for you and I trust you have some automatic controls for not overheating the water that comes from the collectors (uncontrolled and at a very low flowrate my pool solar collectors are great at generating steam on a summer afternoon).

Yes, the Climate Change Credit it nice and offsets the monthly meter fee (another PG&E profit center) which had doubled a couple of years ago.

Now that May 1 has come and PG&E's revised 2019 summer rate structure has kicked in (peak of 46.4¢/kWh, at least for me on their E-6 tariff) we really need to pay attention as to when we do the laundry or charge the cars. Due to PG&E's wacky scheme, I am always above 100% of baseline (due to generation, not consumption) which kicks me into their highest tier for the entire month so my lowest nighttime rate is 27.2¢/kWh. Happily, as I generate the consumption $$ decrement at this high rate as well so my net is always in my favor, dollarwise.

PG&E has declared Chapter 11 as a result of their potential liabilities for those wildfires and there is talk of their rates doubling!

As it is, most of us are now purchasing our power from a Community Choice Aggregator (CCA) (in my case, Silicon Valley Clean Energy), with PG&E only providing the distribution. SVCE not only provides clean/renewable electricity but also pays me at market rates for what I export. :mrgreen:

Suffice it to say, I haven't had to pay for my electricity since 2006 and, on top of that, with SVCE taking over a couple of years ago I received a check for $430 from them last year and expect around $740 this year.

My solar panels amortized themselves years ago...

Right now for control I use one of those Watts circulator pumps with a time clock on it (came with a water saver kit for preheating your hot water line) and set it for 10 am to 4 pm. After 4pm the neighbor's redwood tree shades that side of the house. And then I move a 2'x4' piece of plywood around in front of the panel to try and keep the water temp around 130 degrees, at least for now. I've also ordered a Miso solar hot water controller that should come in any day now.

That's great news about the CCA. At least your getting something from your system. I wish I installed my system sooner! Here our CCA is East Bay Community Energy.

 

[ed5000]

Hope this scheme continues working for you and I trust you have some automatic controls for not overheating the water that comes from the collectors (uncontrolled and at a very low flowrate my pool solar collectors are great at generating steam on a summer afternoon).

I have no overheat protection on my system. My 40 sq ft panel will get 110 gallons of water up to 150 or 155 degrees on a cloudless day in the summertime, but I've never had any problems with anything getting too hot. I do have a mixing valve on the tank outlet which mixes cold water with what's coming from the tank and I have that set at 115 degrees so we never have scalding water anywhere in the house

The little circulation pump in the system only runs when the collector temp on the rooftop panel is 15 degrees higher than the warmest point on the storage tank, so it cycles on for a couple minutes every 10 or 15 minutes, depending on how hot the water in the tank already is and how bright the sun is shining

It's 100% solar for 9 or 10 months every year and I have a time clock with 120 volts on the upper element that I use in the dead of winter when we have more cloudy days. It's been working pretty flawlessly now for 12 or 13 years

Don

That's a nice setup you have there. I can see how the 110 gallon tank gives you some "working room" along with the time clock for the winter months.

I found a good book at my local library called "Solar Water Heating" by Bob Ramlow that I really like so far. I'm trying to decide exactly how I'm going to set my "preheater" up.

 

[JoeS]

It's beginning... not only had PG&E already raised the rates on March 1 of this year (I don't remember the percentage), and was quickly followed by another one on May 1, the following is from my latest CCA's BOD agenda packet regarding the generation portion of the rates (generation costs had been going down due to renewables):

"PG&E is now projecting a weighted average 3.5% increase in generation rates for July 1st from March 1st, versus the 6.5% decrease that had been anticipated. Although the May 1 rate change was expected, PG&E unexpectedly included 6 other changes including decommissioning costs for Diablo Canyon in the generation rate change."

All the more reason to go solar!

 

[ed5000]

A little update here. Recall that I have a 27kw electric tankless water heater that took gobs of power to heat water in my house and I had since added a 4' x 8' Alten solar thermal collector to my old 50 gallon water heater that was still in line with the tankless heater but without the gas connected. Since then I have been doing a little shopping:

1. I found two Alten 3' x 8' solar collectors on Craigslist Free section. I couldn't help myself.

2. I found a brand new 80 gallon solar storage tank with a single electric heating element for $280 on Craigslist. The contractor that sold it didn't know it was solar until we opened it. He sure didn't want to negotiate the $280 after that!

3. A Mysol solar controller for $58 on Amazon.

4. Food grade glycol antifreeze. $65 on Amazon.

5. Misc. plumbing, expansion tank, thermal well. About $200.

6. Dual temperature digital readouts. Two for $13 each on Amazon.

I then mounted the solar collectors on the garage roof and swapped out the gas water heater with the new 80 gallon storage tank and connected the plumbing (and pump) to each.

After that I connected the solar controller and temp sensors and mounted the digital readouts on the wall in my garage.

The results have been pretty good. When I first got it going in mid January I was getting tank temps of at least 80 degrees but with our rainless February I was routinely getting 120 degree temps. Now in March, I easily get 120 degrees excepting when it rains here in Northern California. It will be interesting to see what summer brings. I might have to install an anti-scalding valve if it gets warm enough.

I can easily spend and hour watching my digital temperature gauges. I have 7 temp sensors with 3 on the solar controller, one each on the solar fluid supply and return and one each on the cold water in and hot water out. It's very hypnotizing!

 

[JoeS]

Congratulations on putting that contraption together! Yes, very soon the temperatures will be able to get dangerously hot so make sure you have some way of limiting the upper temperature as well as having an overpressure relief valve (one probably came with the tank). A blown pipe spewing steam and boiling glycol or water will not be pretty...

Now, if there was some way of capturing that excess heat and turning it into electricity... hmm, a mini steam-engine? :roll:

 

[ed5000]

Congratulations on putting that contraption together! Yes, very soon the temperatures will be able to get dangerously hot so make sure you have some way of limiting the upper temperature as well as having an overpressure relief valve (one probably came with the tank). A blown pipe spewing steam and boiling glycol or water will not be pretty...

Now, if there was some way of capturing that excess heat and turning it into electricity... hmm, a mini steam-engine? :roll:

Thanks, and yes the tank came with a relief valve but no relief valve on the glycol loop (yet). I think I'll add one.

If I had one of those mini model steam engines I would tempted to hook it up to my spare panel. It might be fun to watch!