PV1
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Re: Got Solar!

Wed Feb 20, 2019 6:47 am

Calculate out your electric bill for 25 years, then compare that to the cost of a solar install sized to meet 100% of your consumption. With solar, you're basically pre-paying for power, and often it ends up being cheaper over the warranty period of the solar panels.
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ed5000
Posts: 167
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: Got Solar!

Thu Mar 07, 2019 10:09 am

greenteam84 wrote:I want to try solar power but I find it expensive

Around here it's expensive with or without solar. I just got my second full month energy bill since installing solar. It was $180 with $150 of it being the cost of natural gas. So about $30 was an electric connection fee and taxes. I usually pay between $220 to $240 in the wintertime so right away, I'm seeing a savings of $40 to $60 per month.

Since I financed my system I have a payment of about $100 per month, so it looks like I might be loosing $40 to $60 per month except for the fact that the fuel for my I-meiv is in there somewhere. I figure this cost to be about $30 per month.

My latest improvement is that I installed an electric water heater this weekend replacing the gas one. This will save $30 to $40 per month in gas charges. The only thing I need to watch for is that I don't draw more electric power than I produce on the roof during the year.

As we move into Spring and Summer, my electric production should go up and my natural gas usage will go down and that should save me more! :mrgreen:
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

Don
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Posts: 2869
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Got Solar!

Thu Mar 07, 2019 4:02 pm

I installed a 4 by 10 foot (AE40) solar water heating panel on my roof 12 years ago with two 55 gallon storage tanks in the basement. Total coast was about $3K but I got half that back when I filed my taxes. It has paid for itself many times over and I figure the electricity it saves me is about the same amount I use charging my EV's. So, even though I don't have solar electricity, I'm still driving pretty much free!

Switching from gas to electric for heating water might just be a losing proposition - Same for gas or electric clothes dryers. Unless your electric rate is very low, gas is probably cheaper. If you use more solar than you're generating, your new water heater may be part of the problem

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

ed5000
Posts: 167
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: Got Solar!

Fri Mar 08, 2019 9:54 am

Don wrote:I installed a 4 by 10 foot (AE40) solar water heating panel on my roof 12 years ago with two 55 gallon storage tanks in the basement. Total coast was about $3K but I got half that back when I filed my taxes. It has paid for itself many times over and I figure the electricity it saves me is about the same amount I use charging my EV's. So, even though I don't have solar electricity, I'm still driving pretty much free!

Switching from gas to electric for heating water might just be a losing proposition - Same for gas or electric clothes dryers. Unless your electric rate is very low, gas is probably cheaper. If you use more solar than you're generating, your new water heater may be part of the problem

Don

I'll have to look into solar water heating. It would go really well with a solar electric system.

I hated to go from gas heating to electric but with electric power that's sort of free, it was too tempting. Plus my gas heater is still hooked up and ready to go. I just have to change some valves and light the burner. This way I'm ready for whatever they throw at me. :lol:
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

JoeS
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Location: Silicon Valley, California

Re: Got Solar!

Sat Mar 09, 2019 3:57 am

ed5000, does your water heater have a heat pump? I have a GE GeoSpring, but it had issues and I've modified it for TOU.
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

ed5000
Posts: 167
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: Got Solar!

Mon Mar 11, 2019 12:41 pm

JoeS wrote:ed5000, does your water heater have a heat pump? I have a GE GeoSpring, but it had issues and I've modified it for TOU.

Sorry Joe, I should have elaborated a little more on this.

I have a tankless 27 kw electric water heater. So no heat pumps on these (that I'm aware of).

The way my house is set up is all our bathrooms and even the kitchen is on the right half of the house. The gas water heater was on the far left, actually beyond the left in our garage which is the left most part of the house. All the water lines run from left to right. So taking a shower or drawing hot water in the kitchen took a really long time and used lots of water. Now less than 30 seconds brings us hot water in the bathrooms or kitchen. So that should cut our water usage and cut our energy cost heating all that unused water. Plus, I've insulated most of the hot water lines which were all uninsulated before.
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

JoeS
Site Moderator
Posts: 3737
Joined: Thu Dec 15, 2011 5:47 am
Location: Silicon Valley, California

Re: Got Solar!

Mon Mar 11, 2019 2:36 pm

ed5000, your tankless water heater is drawing 112.5 amps at 240vac?? :o Wow! Makes our car charging currents seem puny. Just how big is the circuit breaker for this thing?

Good that you relocated the water heater location. When I designed my house, I located my (electric) water heater centrally with respect to the already-grouped plumbing, with very short runs to all the bathrooms and kitchen.

Insulation really helps. After installing my new water heater and insulating the input/output pipes, there is virtually no warmth emanating from that thing and it holds hot water for the entire day as I cut off its power input as soon as TOU partial-peak begins in the late morning, and only turn power back on in the evening. Simply don't do laundry during the day, that's all, especially now that summer rates are about the kick in.

With respect to tankless vs. tank vs. tank+ heatpump, that's a separate discussion...
EVs: 2 Wht/Blu SE Prem., '13 Tesla MS85, 3 156v CorbinSparrows (2 Li-ion), 24v EcoScoot(LiFePO4)
EV Conv: 156v '86 Ram PU, 144v '65 Saab 96
Hybrids: 48v1kW bike
ICE: '88 Isuzu Trooper. Mothballed: '67 Saab (orig.owner), '76 MBZ L206D RHD RV

Don
Site Moderator
Posts: 2869
Joined: Thu May 10, 2012 3:55 pm
Location: Biloxi MS

Re: Got Solar!

Mon Mar 11, 2019 4:32 pm

JoeS wrote:ed5000, your tankless water heater is drawing 112.5 amps at 240vac??


. . . . and no matter when it runs, day or night, it will be using juice from the grid because your solar can't supply that kind of power, can it?

A standard 55 gallon electric heater with a 4 Kw lower element wired to run on 120 volts instead of the 240 it's rated for (only draws 1kw on 120 and will last forever) set on a time clock to only run when the sun is up would be a good option for anyone with solar who doesn't have natural gas. That would ensure you seldom use grid power for heating water . . . .

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2017 Chevy Volt Premier
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1979 Honda CBX six into six

ed5000
Posts: 167
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: Got Solar!

Mon Mar 11, 2019 6:09 pm

JoeS wrote:ed5000, your tankless water heater is drawing 112.5 amps at 240vac?? :o Wow! Makes our car charging currents seem puny. Just how big is the circuit breaker for this thing?

Good that you relocated the water heater location. When I designed my house, I located my (electric) water heater centrally with respect to the already-grouped plumbing, with very short runs to all the bathrooms and kitchen.

Insulation really helps. After installing my new water heater and insulating the input/output pipes, there is virtually no warmth emanating from that thing and it holds hot water for the entire day as I cut off its power input as soon as TOU partial-peak begins in the late morning, and only turn power back on in the evening. Simply don't do laundry during the day, that's all, especially now that summer rates are about the kick in.

With respect to tankless vs. tank vs. tank+ heatpump, that's a separate discussion...

It does have three 40 amp two pole breakers and I have a 200 amp service for the house. I’ve been trying to keep an eye on it. The specs claim it can handle up to 3 showers at once and we only use one at a time so our power draw is lower. The highest I’ve seen close to 70 amps.

I like your idea of a heat pump water heater especially on a time schedule and Don’s idea
of an 120 volt element is great too. I’ll keep them in mind if the tankless doesn’t work out.
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

ed5000
Posts: 167
Joined: Mon Jul 27, 2015 9:22 pm
Location: Castro Valley, CA

Re: Got Solar!

Thu May 02, 2019 12:53 pm

ed5000 wrote:
JoeS wrote:ed5000, your tankless water heater is drawing 112.5 amps at 240vac?? :o Wow! Makes our car charging currents seem puny. Just how big is the circuit breaker for this thing?

Good that you relocated the water heater location. When I designed my house, I located my (electric) water heater centrally with respect to the already-grouped plumbing, with very short runs to all the bathrooms and kitchen.

Insulation really helps. After installing my new water heater and insulating the input/output pipes, there is virtually no warmth emanating from that thing and it holds hot water for the entire day as I cut off its power input as soon as TOU partial-peak begins in the late morning, and only turn power back on in the evening. Simply don't do laundry during the day, that's all, especially now that summer rates are about the kick in.

With respect to tankless vs. tank vs. tank+ heatpump, that's a separate discussion...

It does have three 40 amp two pole breakers and I have a 200 amp service for the house. I’ve been trying to keep an eye on it. The specs claim it can handle up to 3 showers at once and we only use one at a time so our power draw is lower. The highest I’ve seen close to 70 amps.

I like your idea of a heat pump water heater especially on a time schedule and Don’s idea
of an 120 volt element is great too. I’ll keep them in mind if the tankless doesn’t work out.


Well, I made some improvements. I got to thinking about the electrical current draw this water heater uses and I thought why not install some solar thermal to pre-heat the incoming water.

I bought two used 4'x8' flat panel solar hot water collectors but only connected one temporarily to my old 50 gallon gas water heater (gas line disconnected) which now feeds tempered water to the electric tankless heater. The gas water heater is only temporary until i find a permanent storage tank.

The results are very encouraging: during the first shower (there are 6 of us) the tankless came on briefly until the water arrived from the storage tank then remained off for the rest of the shower. The second shower did likewise but eventually began drawing 1000 watts according to our utility power meter outside.

Btw: I just got my latest electric bill and was pleasantly surprised to have a $25 credit. They gave me a $53 climate change credit which I believe is given out only once or twice a year and then my taxes and a little gas usage came out to about $28 in fees before the $53 credit. Amazing, right?
2012 ES, Cool Metalic Silver, no quick charge, no fog lights and no navi but a cold weather package for when it gets 13 below, wait - it never gets that cold here.
"Silver Shadow"

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