smackaholic should love this

[Mikey]

'holic, I know you really appreciate my magic shade tree that produces about 9,000 kWh of clean solar electricity every year and was 30% paid for by schmucks like you.

You're gonna love this one.

This is my new 4 kW, 8 kWh battery that will store excess solar power to be used later instead of exporting to the grid. It will discharge during the peak pricing periods in the afternoon to keep my bill as low as possible. If not fully charged at night it will top off when the rates are low. Eventually I'll configure it so that, if the power goes out, I can still use my solar in the daytime and discharge the battery when the sun isn't shining.



This is my new WiFi programmable thermostat that I can control remotely from my phone.



Coming later this week is my new level 2 car charger that will work in conjunction with the battery to charge my car, four times as fast as my current power cord, during the most advantageous hours of the day, usually late at night.

Total cost to me:
$0.00

Total cost to CA ratepayers:
Not gonna say

I just have to switch over to a TOU (time of use) rate with SDG&E and let them look at my data for a year to see how all my "smart home" stuff affects my usage in a statewide study. Then I get to keep it and do whatever I want with it.

Besides the free equipment, I get to geek out over reams of cool new data.

[Shlomart Ben Yisrael]

bourgeois

[Mikey]

bourgeois

I prefer a nice Rhône style blend.

The batterie is German, BTW...I might have to toast it with some Riesling.

[Left Seater]

Will the battery run the normal household load? If so for how long?

As for you thermostat, does SDP&G have the ability to change your thermostats setting during periods of high electricity use?

[Mikey]

Will the battery run the normal household load? If so for how long?

As for you thermostat, does SDP&G have the ability to change your thermostats setting during periods of high electricity use?

It should be able to run the normal household loads, without AC, for maybe six or eight hours during a power outage, especially if we shut down non-essential loads.

At first it won't be configured for that, though. It's meant to be the gateway to a sort of personal micro-grid where it optimizes the combination of direct solar, stored energy, and electricity from the grid to take advantage of time of use (TOU) rates. They're going to TOU in residential tariffs around here where on-peak rates in the afternoon could be three times the off-peak rates.

Eventually, when the study is over, I can re-configure it to where it still does the optimization but it will never go below 85% or 75% or 50% of full charge, so that it can act as backup storage. With most solar PV you are interconnected and "synched" to the grid so that if the grid goes down so does your solar. This is so, if the grid is not energized, you're not feeding power into it and electrocuting anybody out there who might be working on fixing it. The on-board inverter in the battery system can cause the system to isolate from the grid in case of an outage so that I can run off solar during the day, recharging the battery with excess production in the afternoon, and run off the battery at night. If it's fairly sunny I can probably run indefinitely while disconnected. I might go and get a few more batteries to give me more capacity. The system is easily expandable. The most expensive part is the controller and interfaces.

We've been thinking of getting a backup gas generator for power outages. During the fires around here the past 10 years when the power goes out it seems like half the houses have generators. With this system we might not need one.

As for the thermostat, I don't think they can change the settings. That's not the point of the study. We were on a set-back program about 10 years ago where they could raise the setting by 5 deg during a high demand event, but we could always override and just not get the credit. That program was pretty much the suck but we got a couple hundred $$ every year for a few years for participating.

I'll have to say - I probably (no, definitely) would not buy one of these right now if I had to pay for it. The payback is just not there - they're not cheap. But the time is coming when they may be standard equipment and I like the idea of being at the front of the curve so I can figure the shit out in advance.

[smackaholic]

Rack you, you hi tech welfare whore, for getting others to buy you stuff. Good thing your state is awash in extra cash to be able to do this.

Is it a lithium battery?

I know Musk is using them for his powerwall thing. I still don't get the economic sense of using Li-ion for stationary uses. But that's because you don't worry about economic sense when somebody else is footing the bill.

I do get the idea of non centralized storage, but it would seem to me that doing it on the subdivision level or maybe town level would make more sense than individual residences, especially if the resident isn't paying a nickel of it directly.

[Left Seater]

Sounds pretty cool and like you are getting over on your neighbors.

I am surprised liber CA would go to the tiered pricing. Charging the most in the afternoon often puts more of the bill on those at the lowest levels of income. Families with young kids, elderly, shift workers etc. I think it is the right approach to bill more when demand is at its highest, just surprised CA would think that as well.

I also think it makes sense to store the commodity yourself if you have the means and can acquire it at a discounted rate. In your case power. In other cases water. Battery storage is where we need the innovation. If batteries could hold more charge we would see far more setups like this even without the solar panels. One question though, do you worry about battery degradation if it is only being discharged to 50% or so?

We have far too many trees for any kind of solar, but they do a great job of keeping our house cooler than it otherwise would be. Cutting them down and putting in solar would be a lose lose. We do however have a stand by generator that can power the full load of the house including the AC. It ties into the natural gas and it is awesome.

[smackaholic]

Don’t get too connected to trees. A cat 7 hurricane will be along in short order to turn them into firewood.


Sent from my iPhone using Tapatalk

[Imus]

There are no Cat 7 storms. In face there are no Cat 5s. It is all hype to get fed money

[Mikey]

In face there are no Cat 5s.

Your brain appears to have experienced at least a Cat 6.

[Dinsdale]

One question though, do you worry about battery degradation if it is only being discharged to 50% or so?

NiCad batteries should be nearly discharged before recharging.

Lead-acid batteries should be kept as close to fully charged as possible.

Lithium-ion batteries don't give a shit either way.

[Imus]

In face there are no Cat 5s.

Your brain appears to have experienced at least a Cat 6.

I never did LSD.

[Goober McTuber]

In face there are no Cat 5s.

Your face looks to have been through a volcanic eruption along the lines of Krakatoa, 1883. Quickly followed by some minor nuclear testing.

[Mikey]

One question though, do you worry about battery degradation if it is only being discharged to 50% or so?

NiCad batteries should be nearly discharged before recharging.

Lead-acid batteries should be kept as close to fully charged as possible.

Lithium-ion batteries don't give a shit either way.

All true. You can supposedly discharge a Li-ion battery all the way down and leave it for weeks without damage. Not so with lead acid.

Looking at the manufacturer's website for the unit I got they supposedly use Lithium Iron Phosphate, a different animal than any of them. Similar to Li-ion but slightly lower energy density. The big advantage is that they don't heat up and have fewer safety concerns than Li-ion which tend to explode on airplanes.

Looking at the batteries on the inside of the box, though, this looks a lot like a Sony Li-ion battery. Don't know why, but I can't really complain.

[Mikey]

Sounds pretty cool and like you are getting over on your neighbors.

I am surprised liber CA would go to the tiered pricing. Charging the most in the afternoon often puts more of the bill on those at the lowest levels of income. Families with young kids, elderly, shift workers etc. I think it is the right approach to bill more when demand is at its highest, just surprised CA would think that as well.

I also think it makes sense to store the commodity yourself if you have the means and can acquire it at a discounted rate. In your case power. In other cases water. Battery storage is where we need the innovation. If batteries could hold more charge we would see far more setups like this even without the solar panels. One question though, do you worry about battery degradation if it is only being discharged to 50% or so?

We have far too many trees for any kind of solar, but they do a great job of keeping our house cooler than it otherwise would be. Cutting them down and putting in solar would be a lose lose. We do however have a stand by generator that can power the full load of the house including the AC. It ties into the natural gas and it is awesome.

Around here, tiered pricing and TOU (time of use) are actually sort of opposites. The traditional residential rate is a tiered rate. In this rate you have a baseline monthly allowance that you get at a fairly low cost. Or relatively low cost - San Diego has the highest rates in the US besides Hawaii IIRC. Once you exceed tier 1 you go to tier 2, tier 3 and eventually tier 4, all at escalating costs per kWh.

A few years ago the tiers were:

Tier 1 up to baseline
Tier 2 up to 130% of baseline
Tier 3 up to 200% of baseline
Tier 4 above 200% of baseline

The total costs including transmission, generation and any other fees were about $0.16, $0.18, $0.33 and $0.35

A few years ago they started squeezing the tiers so that Tier 3 at 130% and above was paying almost $0.40.

Now tier 1 is up to 130% tier 2 is up to 400% and above 400% you get a "high usage" charge and they get you for $0.55 per kWh at that rate. Tier 1 is $0.27 in the summer and tier 2 is $0.48.

When we got our magic shade tree the strategy was to try and offset enough usage to stay in tier 1 but not be a net exporter. The cost of Tier 1 couldn't justify the solar investment, but Tier 3 and 4 definitely could (our baseline is about 400 kWh/month in the summer).

So that's tiered rates.

TOU is when they charge more in the on-peak period (all afternoon) and less off-peak. They want to get everybody on to TOU but can't really force you. All new solar customers have to go to TOU, even if you're expanding an existing system.

To participate in this program I have to go to the TOU rate and not go back. You can see the rates I'll be paying below, and that there's a big incentive not to use any power from 4 pm until 9 pm, especially in the summer. So, the battery charges up at the lowest rate after midnight, the solar starts kicking in during the morning, and you draw down the battery during the on-peak period. It makes you think about when you use all that electricity and maybe start scheduling things a little differently.

[Mikey]

You might be wondering (or not) why the peak period is from 4 pm until 9 pm when it used to be usually from like noon until 6 pm.

The reason is the duck curve, and it's the reason they need to push battery storage in California. Basically, we are saturated with solar during the afternoon and they need to do something with it. It's gotten to the point where they have actually paid Arizona to take the excess generation on a few occasions.

[smackaholic]

One question though, do you worry about battery degradation if it is only being discharged to 50% or so?

NiCad batteries should be nearly discharged before recharging.

Lead-acid batteries should be kept as close to fully charged as possible.

Lithium-ion batteries don't give a shit either way.

I agree with the first two, but from my admittedly limited knowledge on the subject, Li-Ion don't much care to be run into the dirt either. They are more forgiving to it, than lead-acid, but they do prefer staying above 50%.

I have been told that running my phone down to nothing affects battery life. I also have read that EVs typically limit Li-Ion battery discharges to something a good bit higher than full discharge.