Solar energy - your experience?

[NW-Bound]

I am having Solar installed. Signed the paperwork a few weeks ago and will be installed in November

Getting a 10Kw system with 32KW of batteries with two new LG 16Kw batteries

For me, and everything is different for others, I didnt see the value to ME without the battery back up. That way in the event of a weather or hacker caused outage, I will still have power.

Batteries also allow you to draw off of them at night rather than the grid

I customized the power that stays on with the batteries. Essentially if the power goes out I still have everything except Air Conditioning, Oven and Dryer. So I have heat in the winter and if it is brutally hot, I have a nice finished basement that is always cool...

Time to install a mini-split for a selected area of the house. Then, you will always have comfort.

The above system is about the same as my DIY system, with 7.8 kW of panels and 34 kWh of lithium battery.

I have two mini-splits which cool/heat the 1st level of my house, which has the master bedroom, and the living space (living room, dining room, kitchen, breakfast room, family room). The 5 room upstairs are on the central AC, which does not get turn on much because the rooms are not used.

In the hottest days of summer, my 34-kWr battery can carry the two mini-splits to 8PM to avoid the grid peak rate. If the battery gets fully charged by the late afternoon, it can run the mini-splits late into the night or even till the next day. However, my solar array is not large enough to fully charge the battery while also running the mini splits at top speed already during a hot day.

The inverters that run off the above battery also power the pool pump, and the water heater when I have excess power. They run all kitchen appliances (except the stove), the fridge, and also some lighting circuits. We do nearly all the cooking with an induction burner, 2 microwaves, Instant Pot, air fryer, and a toaster oven, and they run off the solar circuits.


PS. The pool pump and the water heater are used as dump loads. When the temperature is moderate and the mini splits do not have to work hard, I will have excess power built up in the battery. When the battery is full, the charge controllers will go to sleep, and the solar power stops getting harvested. That's when I switch the pool pump and the water heater over from grid to solar to use up the excess power.

There are times during the year, when I ran the pool pump for several hours longer than normal, in order to use up the free power. All this free power may just wear out my pump, so may not be a good thing.

 

[Koolau]

Time to install a mini-split for a selected area of the house. Then, you will always have comfort.

The above system is about the same as my DIY system, with 7.8 kW of panels and 34 kWh of lithium battery.

I have two mini-splits which cool/heat the 1st level of my house, which has the master bedroom, and the living space (living room, dining room, kitchen, breakfast room, family room). The 5 room upstairs are on the central AC, which does not get turn on much because the rooms are not used.

In the hottest days of summer, my 34-kWr battery can carry the two mini-splits to 8PM to avoid the grid peak rate. If the battery gets fully charged by the late afternoon, it can run the mini-splits late into the night or even till the next day. However, my solar array is not large enough to fully charge the battery while also running the mini splits at top speed already during a hot day.

The inverters that run off the above battery also power the pool pump, and the water heater when I have excess power. They run all kitchen appliances (except the stove), the fridge, and also some lighting circuits. We do nearly all the cooking with an induction burner, 2 microwaves, Instant Pot, air fryer, and a toaster oven, and they run off the solar circuits.


PS. The pool pump and the water heater are used as dump loads. When the temperature is moderate and the mini splits do not have to work hard, I will have excess power built up in the battery. When the battery is full, the charge controllers will go to sleep, and the solar power stops getting harvested. That's when I switch the pool pump and the water heater over from grid to solar to use up the excess power.

There are times during the year, when I ran the pool pump for several hours longer than normal, in order to use up the free power. All this free power may just wear out my pump, so may not be a good thing.

Heh, heh, sounds like you need MORE batteries!

 

[NW-Bound]

Heh, heh, sounds like you need MORE batteries!

In the shoulder seasons, when I need no cooling nor heating, my solar panels produce more than I use, and the excess is more than my battery can hold.

But in the mid-summer, in my post above, I describe how my solar panels do not produce enough to charge up the battery when the ACs run non-stop 24/7.

If I add more panels so that I produce enough juice to be able to run the AC through a 24-hr period even in the mid-summer, then in the shoulder seasons I would have even more juice than any battery can hold.

What it boils down to is this: if I build a system that has enough panels to produce enough for the time of year with peak demand, it will have ridiculous excess capacity when the demand is low. Storing that excess capacity will then take a huge and expensive battery. That huge battery is not without use; it will help me coast through a day or two of low sunshine.

It just takes a lot of money. And is that money effectively used?

And seeing that I am a long way from being able to cut free from the grid, I will always need that grid connection. And with the grid connection, once I produce and store enough for the peak period of the TOU rate (24c/kWh for 2PM-8PM), a kWh that I manage to save to use past 8PM is worth only 7c/kWh. The extra hardware to produce the kWh for off-peak use takes 4x longer to pay off.

Now, what about the hardware that is needed to coast through 1 day of low sunshine? How long does that take to pay off?

 

[Freedom56]

We installed our system in October 2012. We acted as the prime contractor and did the design, hired the engineer to generate the drawing and obtained the permits from the city. We purchased Kyocera solar panels and Enphase microinverters from a distributers in New Mexico. We then hired an installer (who now has been in business for over 28 years) to perform the installation which took 2 days. The total cash outlay was about $23K and we received a rebate of $1832 from Edison. We then claimed a 30% tax credit and our net cost was just under $16K. Our electricity bill averaged $3500 per year for 2009-2012. It would be about $4600annually at current rates. Our solar system generates just under 11 MW annually and we consume just over 10 MW. We receive about $100-$200 credit annually So our break-even was about 4.5 years. so for about a $16K initial investment we saved approximately $3500 or and after tax return of 22% annually. We considered contractors who delivery turn-key installations but they were asking $40K and using Chinese panels which we did not want. Most of these solar contractors were in business a few years so I did not see any benefit to using them. The warranty was from the manufacturer not the installer. The bottom line is do your homework. If you roof doesn't tilt south in the range of 165-210 degrees, you will likely be disappointed. Leasing a solar system is a bad idea and could hurt you when you sell your home. Seven other people on our cul-de-sac also have solar systems that they are leasing. Most of my neighbors had nothing but problems dealing with these contractors and their leasing arrangements and found that they really didn't save. Two of the contractors are already out of business. I have yet to meet someone who leased a system and stated that they were happy with their savings. Since we installed our system, electricity is an expense we have completely eliminated at our primary home. If we were installing a system today, it would cost less and generate more power since new panels are more efficient.

 

[RobLJ]

I had a 8,090 W-AC system installed Oct 2019 for 27k, it was a little over a 1/3 oversized since we were planning to buy an EV. It was 18k after the rebate.

We get repaid 81% of retail for excess power, so I'm waiting on buying a battery, probably for some time. The payback is 9 years but that doesn't include gasoline savings, which have been very high (Bolt EV and RAV4 Prime plugin). In two years gas savings will pay for the extra panels, then the payback period starts to drop quicker--if the Bolt doesn't burn up. Our usage is up this year since the yewt moved in last Thanksgiving (he runs a big computer rig as a programmer) and particularly Reno's summer this year was probably the warmest in the record (temps of 95-100 through most of late June through August, very unusual). System produced 16 MWH in 2020; because of the smoky summer this year it will probably run slightly under this for this year.

After the AC burns out, which I expect in 3-5 years, I'll replace with a high SEER or heat pump and reduce the usage.