Grid tie solar, net metering, home to grid, vehicle to grid

[mbsieg]

I'll start a new thread to try to recover. Bob's. I'll go out and take some pictures of the solar system that I installed a few years back at my house. It is 15,120 watts of solar, a solark 15k, sunny boy 7.7, and 30 KWH of SOK lithium server rack batteries. I am also able to leverage the 131 KWH battery in my Ford lightning as backup also.
I started out as just grid t ie to eliminate my electric bill. The original system cost between 6 and 7k. Since the original system, the economy/ politics changed so much I wanted I wanted backup. So I added that last summer. I produce excess power of about 1,000 kWH a month. I can easily run my house on the power that I produce and store in the batteries.

 

[chowderman]

it's all a nice idea - however almost/all "public utilities" are controlled by "commissions" - their rates are approved/set by "commissions"
- and it varies quite widely - so what happens in your area is not the same as all areas.

most utilities are "forced / required" to buy any excess power you produce. but what they pay varies from near nothing to 'very profitable' (according to some of the posts here.) in my area they pay you what you pay them (last I investigated) - and the buy/sell rate is the same 24x7

peak metering is not done everywhere. usually where there is an ability to meet the demand - either by generation or transmission limitations. some locations customers get a $ break if the electric company can remotely control your usage - shutting off a/c or dryers or other high(er) demand appliances (significant rewiring required....)

without specialized equipment or rewiring, the utility cannot identify car charging activity and selectively manage it.
an EV charge could recognize a signal sent thru the wires to control it - that will happen first in places like CA where they simply make it illegal to sell or operate a charger that does not "obey" external control.

bottom line - for anyone interested , , , you must thoroughly investigate how it is "regulated" in your specific area and don't forget to suss out what your utility is intending to do. not all utilities are fond of buying back power from individual sources - some want to eliminate it, some want to deduct "transmission and distribution charges"
bottom line^2 - next year you may find selling back is eliminated or greatly price-reduced - and all the payback/profit calculations are not holding up . . .

these problems are not new - in the 60's my father ran the mechanical department at a block sized department store. the local power company would call to request they shut down some/most of their a/c in 'bad times' - not because they couldn't generate the power - they had turbine power generator sets to meet any surge - but because the transmission wires were fixing to melt down . . .
in the 90's I did a consulting gig at one their generating plants - one coal fired boiler, one natural gas fired boiler, and 24 turbine gen sets in the side yard.... thirty years, same problems . . .

 

[mbsieg]

"Now lets say someone had a 30 kw battery pack in their house, and daily filled it, and sold back 100% of the power in it, at 5 cents a kw, they would make $1.50 a day.
They had had to buy the power to begin with, or pay for an expensive solar system, not to mention buy the pricey battery pack.
How the heck does a person make money doing that.

Lets lowball the price of the solar, and battery at only $15,000 which I'm sure is too low, but lets just pretend.

That would require 10,000 days, or cycles, which is far longer than the battery pack will last, just to break even.



Even if some power company will pay you 1p cents a kw, and good luck getting 5 cents, much less 10 cents, but lets pretend for fun.
That is still 5000 days, and cycles.
The battery is junk by 5000 cycles and has to be replaced, and you never made a nickel.

So I'm very curious about how people are making all this money selling power to the grid."


Above is a Quote from PGBC

First thing first, in the situation you talk about there's absolutely no reason to have batteries. They gain you absolutely nothing. A few reasons batteries get into the equation is if you are a prepper, frequent power outages, or you have a time of use plan with lower rates off peak and higher rates on peak.

Second scenario. Your electricity utility allows grid tie solar. You install a solar system basically large enough to cover your needs. Smaller households 10 to 15 thousand dollars. Larger households the sky's the limit. You use the grid as your battery. Sunny days when you are producing you. Overproduce and use that overproduction on cloudy days and at night. Basically reducing your bill to the monthly base fee. If you produce enough extra, you can cover that base fee. Some companies will credit some companies will write you a check.

Scenario 3 your electric company is set up with time of use. Your electricity during the day costs .25 cents a kilowatt hour higher than your electricity at night. You put in a grid tie system with batteries. Solar is an option. If you want it. You fill your batteries at night at the low off peak rate, and discharge your batteries (to power your house) during the day during the higher on peak rate. Some utilities will pay you a premium to discharge during peak demand times to the grid.

 

[power1]

Power companies usually pay the same for the power you sell to them that they can produce or buy it from other power companies. The price they pay usually depends on where the power they are buying is com ing from and how it was produced. For instant, many times during the spring hydroplants produce dump power. They have to dump the extra water the dam holds back so they give the power to the company for free.

 

[m1west]

I'll start a new thread to try to recover. Bob's. I'll go out and take some pictures of the solar system that I installed a few years back at my house. It is 15,120 watts of solar, a solark 15k, sunny boy 7.7, and 30 KWH of SOK lithium server rack batteries. I am also able to leverage the 131 KWH battery in my Ford lightning as backup also.
I started out as just grid t ie to eliminate my electric bill. The original system cost between 6 and 7k. Since the original system, the economy/ politics changed so much I wanted I wanted backup. So I added that last summer. I produce excess power of about 1,000 kWH a month. I can easily run my house on the power that I produce and store in the batteries.

I have built an off grid solar system at my cabin. You can see the build in my cabin remodel thread. Have 2400 watts of solar panel with 24kw of lithium batteries sourced from a Nissan Leaf, midnite controller and a 10,000 watt inverter. During the day I can run anything, microwave, 110v electric hot water tank, water pressure system etc. Never runs low. At night I can run lights water pressure system microwave and TV. I have a 24V system that full charges at 30V and low level alarm at 19V. in the morning cam usually around 24V. Im not using all that power, but the inverter has parasitic drag just from being on that pulls quite a bit and is a flaw in the system. I have been thinking about getting a smaller inverter to switch to at night to help out. So I have experience with solar and storage batteries. I plan to add a electric refrigerator after I get the interior finished and likely add another battery pack for it. The system operates about the same winter or summer. Cloudy weather effects it some but smoke in the air really effects it. Been considering some wind power for bad weather and night charging, but would have to get another controller to do that. So running your house on stored energy is possible, but you lose a lot of power in the conversion.

 

[mbsieg]

I have built an off grid solar system at my cabin. You can see the build in my cabin remodel thread. Have 2400 watts of solar panel with 24kw of lithium batteries sourced from a Nissan Leaf, midnite controller and a 10,000 watt inverter. During the day I can run anything, microwave, 110v electric hot water tank, water pressure system etc. Never runs low. At night I can run lights water pressure system microwave and TV. I have a 24V system that full charges at 30V and low level alarm at 19V. in the morning cam usually around 24V. Im not using all that power, but the inverter has parasitic drag just from being on that pulls quite a bit and is a flaw in the system. I have been thinking about getting a smaller inverter to switch to at night to help out. So I have experience with solar and storage batteries. I plan to add a electric refrigerator after I get the interior finished and likely add another battery pack for it. The system operates about the same winter or summer. Cloudy weather effects it some but smoke in the air really effects it. Been considering some wind power for bad weather and night charging, but would have to get another controller to do that. So running your house on stored energy is possible, but you lose a lot of power in the conversion.

Awesome setup you have! You are exactly right. The higher voltage you can store the energy at the better the conversion is. Also keep an eye on the efficiency of the inverters. They can very wildly by what style they use. The solark I run claim s 96.5%

 

[m1west]

Awesome setup you have! You are exactly right. The higher voltage you can store the energy at the better the conversion is. Also keep an eye on the efficiency of the inverters. They can very wildly by what style they use. The solark I run claim s 96.5%

The efficiency of the inverter is a non issue during the day, When the sun goes down the inverter will drag your battery pack down even if you don't use any electricity in the cabin. It has a sleep mode that turns it off until it senses a electrical draw then it wakes up and turns on. That also has a flaw in it, takes a pretty good draw to turn it on, Just turning on the lights isn't enough likely due to them being LED. Thats why I am considering wind because it always windy up there at night and when its cloudy and raining. Problem with wind is the controller just can't shut the power off like solar because it would spin up and self destruct in high winds, so you need a diversion load, like making hot water, there are also large resistors. When I'm not there I could tie the blade so it can't spin. I think I just talked myself into doing that.

 

[power1]

What ever happened to those power cells they were trying a few years back? I read somewhere that many of them are still being used but not much info about them now days.