GVFX programming for load leveling

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billvon
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GVFX programming for load leveling

Post by billvon » Tue Aug 18, 2015 7:59 pm

We're working on using a GVFX 3648 for utility load leveling - charging during surplus times (midnight to 4am) and discharging to the grid during peak load (6-10pm.) I am assuming we can make a discharge happen by disabling the charger then setting SELL RE VOLTS to (for example) 48 volts, and charge by setting SELL RE VOLTS to some high value (60 volts?) and enabling the charger again. Does that make sense?
--bill von

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Re: GVFX programming for load leveling

Post by Jorge Guzman » Wed Aug 19, 2015 9:23 am

Hi Bill,

It could work if you don't want this to be automated. The mate does have a "Grid-Use" feature, which allows you to connect/disconnect from the grid based on time of the day.
When you intend to charge the batteries from 12-4 just turn off the sell feature vs. when you want to sell during peak times, you turn it back on.

by the way the new mate rev will allow you to automate three different input modes when using an FXR or Radian based on time of the day, ie. 12-4 (Generator/Backup) 6-10 (Grid-tied) this will be fully automated.

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Re: GVFX programming for load leveling

Post by larrywa » Wed Aug 19, 2015 9:24 pm

billvon wrote:We're working on using a GVFX 3648 for utility load leveling - charging during surplus times (midnight to 4am) and discharging to the grid during peak load (6-10pm.) I am assuming we can make a discharge happen by disabling the charger then setting SELL RE VOLTS to (for example) 48 volts, and charge by setting SELL RE VOLTS to some high value (60 volts?) and enabling the charger again. Does that make sense?
This was raised after Tesla Car company announced their ridiculously expensive new battery to do the same thing.

Have you actually done the accounting on this economy?

The amount you save would only be the difference between the on peak and off peak rates to the maximum amount f energy you use each day during a time. If you discharge cycle your battery every day and wear it out after 1000 cycles (about 3 years) will the money saved even pay for a new battery bank?

So far, any calculations I have seen find batteries much more expensive than grid power at any rates charged in North America. With these peak shifting schemes you would only be using the difference in rates between peak and off-peak and batteries, charging circuits, and inverters have big losses. Usually about 40% or more if you measure the actual exergy of your system.

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Re: GVFX programming for load leveling

Post by Ampster » Thu Aug 20, 2015 10:50 am

billvon wrote:We're working on using a GVFX 3648 for utility load leveling - charging during surplus times (midnight to 4am) and discharging to the grid during peak load (6-10pm.) I am assuming we can make a discharge happen by disabling the charger then setting SELL RE VOLTS to (for example) 48 volts, and charge by setting SELL RE VOLTS to some high value (60 volts?) and enabling the charger again. Does that make sense?
I am doing load shifting with a GS4048 and a standalone charger with a timer. I activate the inverter via grid use timers in the Mate3 set to 14:00 to 20:00( Peak rate @ $0.47/kWhr) and charge from 22:00 until 08:00 (Super Off Peak @$0.11/kWhr). Those are summer differentials and during the 9 months of winter the peak is $0.37 with the same super off peak of $0.11/kWH. My initial savings calculation was $800/year and the system cost $8,000. After 3 months my return was reduces to half because my actual loads during the day were less than half of what I had predicted, so my return was reduced to 20 years without factoring cost of money. There are losses of 20% that I calculated into my payback. My charger is 92% effiecient and the inverter is about the same. There are negligible losses into Lithium batteries so I haven't experienced the 40% loss referred to by @Larrywa.

I found the grid use times to be reliable except for the hour of DST that they can't allow for. I just set the timers an hour earlier to account for that. Because I had Lithium and was more familiar controlling a charger with a Voltage controlled relay, like I had done with my VW conversion. I used a simple lighting timer in series with the voltage controlled relay controlling a dual pole relay that provides 240v to my charger. That way the charger comes on only during super off peak rates and only if the batteries were slightly below their normal resting voltage.

I have rationalized part of the system cost as backup and that has improved the return but it is still long enough to resemble a hobby rather than a financial investment. I does protect me against further rate hikes and gives me some flexibility that my daytime usage has effectively been shifted to a net rate (after inefficiencies) of $0.14/kWhr
Last edited by Ampster on Thu Aug 20, 2015 1:27 pm, edited 2 times in total.
Drive Tesla Model X and Model 3 which are charged at Super Off Peak rates.

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Re: GVFX programming for load leveling

Post by Ampster » Thu Aug 20, 2015 11:24 am

larrywa wrote:.......
This was raised after Tesla Car company announced their ridiculously expensive new battery to do the same thing.

Have you actually done the accounting on this economy?

The amount you save would only be the difference between the on peak and off peak rates to the maximum amount f energy you use each day during a time. If you discharge cycle your battery every day and wear it out after 1000 cycles (about 3 years) will the money saved even pay for a new battery bank?

So far, any calculations I have seen find batteries much more expensive than grid power at any rates charged in North America. With these peak shifting schemes you would only be using the difference in rates between peak and off-peak and batteries, charging circuits, and inverters have big losses. Usually about 40% or more if you measure the actual exergy of your system.
The Tesla Powerwall is priced at $350/kWh of storage which is cheaper that other standalone Lithium Battery backups. Balqon's backup solution is $500/kWh. On a life cycle basis it blows away Lead Acid. Sized correctly they can last over 5000 cycles. for example I only use about 20% of capacity so my pack has very shallow cycling so life should be in excess of 5000 cycles.

Because the PoweWall operates on the highvoltage DC bus it claims to have round trip losses less than 10% Other Lithium Batteries operating on the AC Bus have 20% losses. On a utility level scale Tesla's PowerPack is going for $250/kWh storage and I believe that price is competitive with a Gas Peaker Plant. Southern California Edison has a contract to purchase a megaWatt of storage to respond to peak demand. The advantage of these container size packs is that they can be positioned where there are grid needs at substations and be be a distributed source of peak generation. Unlike a Peaker Plant, they can be shifted to another location.
Sorry for the digression.
Drive Tesla Model X and Model 3 which are charged at Super Off Peak rates.

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Re: GVFX programming for load leveling

Post by billvon » Thu Aug 20, 2015 4:41 pm

larrywa wrote:Have you actually done the accounting on this economy?
This isn't an attempt to save money; it's an experiment. It's an attempt to validate some control methodologies for real-time control, in anticipation of real time pricing from utilities.
--bill von

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Re: GVFX programming for load leveling

Post by larrywa » Fri Aug 21, 2015 5:50 am

Ampster wrote:
larrywa wrote:.......
This was raised after Tesla Car company announced their ridiculously expensive new battery to do the same thing.

Have you actually done the accounting on this economy?

The amount you save would only be the difference between the on peak and off peak rates to the maximum amount f energy you use each day during a time. If you discharge cycle your battery every day and wear it out after 1000 cycles (about 3 years) will the money saved even pay for a new battery bank?

So far, any calculations I have seen find batteries much more expensive than grid power at any rates charged in North America. With these peak shifting schemes you would only be using the difference in rates between peak and off-peak and batteries, charging circuits, and inverters have big losses. Usually about 40% or more if you measure the actual exergy of your system.
The Tesla Powerwall is priced at $350/kWh of storage which is cheaper that other standalone Lithium Battery backups. Balqon's backup solution is $500/kWh. On a life cycle basis it blows away Lead Acid. Sized correctly they can last over 5000 cycles. for example I only use about 20% of capacity so my pack has very shallow cycling so life should be in excess of 5000 cycles.

Because the PoweWall operates on the highvoltage DC bus it claims to have round trip losses less than 10% Other Lithium Batteries operating on the AC Bus have 20% losses. On a utility level scale Tesla's PowerPack is going for $250/kWh storage and I believe that price is competitive with a Gas Peaker Plant. Southern California Edison has a contract to purchase a megaWatt of storage to respond to peak demand. The advantage of these container size packs is that they can be positioned where there are grid needs at substations and be be a distributed source of peak generation. Unlike a Peaker Plant, they can be shifted to another location.
Sorry for the digression.
A lot of exaggeration going on there. The Tesla 10kWh unit $3500 is for large quantity orders and dealer only pricing. If you only discharge it 20% then you have a load shift capacity of 2kWh per day. With the peak rates you stated at $0.47 per kWh that may gross you $0.94 per day. That is not considering the cost of the energy, the actual equipment and battery losses, ROI losses, energy delivery costs, and even the increase in insurance when the find out,

Those figures above are with 100% efficiency for your electronics. Yes the Lithium batteries are more efficient but you have ignored your electronics. Chargers can be higher efficiency, maybe in the 90-95% but inverters are not. Without doing good research inverters are more like 75-87% efficient. Ever notice your equipment has fans to disapate the heat? Sure you have and that is energy going to waste. In the summer you may have to A/C that heat out again too. In reality those $0.94 per day are going to cost you about $0.32 per day. Energy delivery costs and ROI losses for the money to purchase the equipment in the first place brings this profit down to a very doubtful the differences will ever pay back even just the cost of the Tesla battery in the 10 year lifespan. oooops... ROI losses...there is another $1750 over the ten years (just for the discounted Tesla battery not the other equipment you wear out), that is classically forgotten about by the greenies.

I've been in the electrical energy field for 40 years and I know hype when I see it by simply doing real accounting. I have watched as hundred of installers have convinced home owners to live off the government subsidies. Without them none of this would have ever happened. We won't mention what happens when your insurance company finds out the fire department will likely stand back and watch your home burn when a fire breaks out.

If you want to feel like you are saving the plant then good for you. I hope the carbon footprint of these large batteries, full of nasty chemicals, in the landfill sites doesn't seep through our blindfolds. It is good to create jobs, though.

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Re: GVFX programming for load leveling

Post by Ampster » Fri Aug 21, 2015 8:51 am

If you want to rant, start a thread about Lithium vs Lead acid, or load leveling with batteries, or government subsidies or global warming, or anything else you want to talk about. The Original Poster asked a question about how to program a GVFX. I offerred some options and agreed with you that the payback is long. Did you not understand that?

I have been an electronic hobbyist for 55 years and will continue to enjoy messing around with electrons. My marginal cost of capital is less than 1%. I enjoy finding ways to give me independence from my public utility or from the oil refineries, especially by employing modern technology. No doubt I have an expensive hobby.

To summarize the responses to the OP's original question, there are a number of options, some more expensive and some more efficient than others.
Drive Tesla Model X and Model 3 which are charged at Super Off Peak rates.

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PV:1000W east@45, 600W west@45, 2400W south@19 deg.
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Re: GVFX programming for load leveling

Post by larrywa » Fri Aug 21, 2015 4:42 pm

billvon wrote:
larrywa wrote:Have you actually done the accounting on this economy?
This isn't an attempt to save money; it's an experiment. It's an attempt to validate some control methodologies for real-time control, in anticipation of real time pricing from utilities.
If this "isn''t an attempt to save money" why would you care about "real time pricing from utilities"?

Don't get me wrong. I find this concept fascinating... being in this field most of my life

but the use of batteries to time shift loading is a good concept for utilities and large industry that pay huge amounts for peak grid power (ranges in hundreds of dollars per kWh). They also get huge discounts on equipment.

For a small scale entrepreneur without ANY peak demand billing charge it hasn't been economical using any current battery technology and chargers/inverters. The efficiency is also bad but a more minor factor. The Tesla hype was based on their vehicle charging time-shifting and the market got carried away with the concept stretching it a lot. Tesla's sales department is not attempting to correct the misinformation.

Do you have combination grid meter that you are billed on peak demand? That could sweeten the pot by shaving peaks you pay for for the next year. Of course YMMV.

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Re: GVFX programming for load leveling

Post by billvon » Mon Aug 24, 2015 3:34 pm

larrywa wrote:If this "isn''t an attempt to save money" why would you care about "real time pricing from utilities"?
Because we feel that real time pricing is a likely tool that utilities will use to deal with the problems of an aging pool of generation facilities as well as the unreliability of wind and solar. It has already been implemented in Illinois and is being proposed in several other markets. We'd like to get some experience with the tools people will need to save money under a real time pricing plan.

(Not just with the inverter BTW. This also involves managing other loads - EV charger, pool pump, thermostat - to deal with real time pricing.)
For a small scale entrepreneur without ANY peak demand billing charge it hasn't been economical using any current battery technology and chargers/inverters. The efficiency is also bad but a more minor factor. The Tesla hype was based on their vehicle charging time-shifting and the market got carried away with the concept stretching it a lot. Tesla's sales department is not attempting to correct the misinformation.
I agree that the Tesla model doesn't work. But a cheaper system (for example an GVFX and a lead acid battery bank, or a HV inverter and a retired EV battery pack) will start to become profitable at a certain spread of power prices under the real time model. An intelligent controller would observe power pricing and not try to arbitrage power unless the difference exceeded that threshold.
Do you have combination grid meter that you are billed on peak demand? That could sweeten the pot by shaving peaks you pay for for the next year. Of course YMMV.
No, billed straight DR (domestic rate) which means that I am not billed by TOU at all. We have to track power usage (easy with a smart meter) then recalculate what the bill would have been for either a fixed TOU plan or variable real-time plan.
--bill von

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Re: GVFX programming for load leveling

Post by larrywa » Mon Aug 24, 2015 5:35 pm

billvon wrote: I agree that the Tesla model doesn't work. But a cheaper system (for example an GVFX and a lead acid battery bank, or a HV inverter and a retired EV battery pack) will start to become profitable at a certain spread of power prices under the real time model. An intelligent controller would observe power pricing and not try to arbitrage power unless the difference exceeded that threshold.
Do you have combination grid meter that you are billed on peak demand? That could sweeten the pot by shaving peaks you pay for for the next year. Of course YMMV.
No, billed straight DR (domestic rate) which means that I am not billed by TOU at all. We have to track power usage (easy with a smart meter) then recalculate what the bill would have been for either a fixed TOU plan or variable real-time plan.
TOU is not a demand charge. A demand charge is the peak kW demand load you draw from the grid. This you pay for big bucks and in my area for another 11 months on a depreciating basis. I was not in the billing part of it but I know it worth every penny to shave that peak. Demand billing is usually not applied to residential. I believe in Ontario it may not be legal to bill residential on demand.

I am not on TOU metering. I have requested it being an old grid metering person but I finally got them to admit they cannot supply a meter to accommodate TOU with Net metering with grid-tie generation. Being from metering I knew that and it took years to get them to admit it. I was told they are working on it as our provincial government is demanding it. Then I will probably be sorry :). I like the challenge but I am not sure about my wife that thinks I am obsessed. I have to make some money back from the $30-35K I have spent and will never recover in my lifetime. :) Hell, with the $1800 per annum I lose on just ROI alone not having that money invested I will never break even. But I am still fascinated with the whole thing.

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Re: GVFX programming for load leveling

Post by Ampster » Thu Aug 27, 2015 1:23 pm

billvon wrote: ........
I agree that the Tesla model doesn't work. But a cheaper system (for example an GVFX and a lead acid battery bank, or a HV inverter and a retired EV battery pack) will start to become profitable at a certain spread of power prices under the real time model. An intelligent controller would observe power pricing and not try to arbitrage power unless the difference exceeded that threshold.
........We have to track power usage (easy with a smart meter) then recalculate what the bill would have been for either a fixed TOU plan or variable real-time plan.
Billvon,
I would like to hear more about real time pricing. If I understand it correctly it would require some rate communication in order to try to use pricing to influence demand, or to influence people to shift demand. You mentioned Illinois is actually doing some of that. What has been your experience and how was the grid upgraded to accomplish that?
I just signed up for a Pilot program with SCE in California for a low cost sub meter that will give me a few more hours of flexibillity on when I charge my EV. Part of the Pilot program includes an account with Ohm Connect who sends me information about when to turn things off. These are generic messages that apply for users throughout the public utilities in California. I suspect they are using the Independent System Operator load information. We do have summer incentive programs that allow the utility to install a device on air conditioners and the utility can remotely turn off those air conditioners to reduce load. Those are the beginnings of a smart grid but we have a long way to go in California before we are there.

Feel free to start a new thread for this subject if you think this forum would benefit. Just to be clear, I am not talking about the kind of commercial peak load management that I think larrrywa is referring to . I am talking about load management in the aggregate and load shifting. I realize these can be intertwined and batteries can be used for both.
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Re: GVFX programming for load leveling

Post by billvon » Tue Sep 01, 2015 3:08 pm

Ampster wrote:If I understand it correctly it would require some rate communication in order to try to use pricing to influence demand, or to influence people to shift demand. You mentioned Illinois is actually doing some of that. What has been your experience and how was the grid upgraded to accomplish that?
In Chicago they are doing day-ahead pricing by hour which isn't "true" real time pricing but comes pretty close. The end goal of real time pricing is to be able to change price on the fly and have a market-like response to prices, on (for example) an hour by hour basis. Such load agility confers greater flexibility to use less-dispatchable forms of generation, like solar and wind.
I just signed up for a Pilot program with SCE in California for a low cost sub meter that will give me a few more hours of flexibillity on when I charge my EV. Part of the Pilot program includes an account with Ohm Connect who sends me information about when to turn things off. These are generic messages that apply for users throughout the public utilities in California. I suspect they are using the Independent System Operator load information. We do have summer incentive programs that allow the utility to install a device on air conditioners and the utility can remotely turn off those air conditioners to reduce load. Those are the beginnings of a smart grid but we have a long way to go in California before we are there.
Yeah, I have one of those things too (Ecobee thermostat) and that is a very early implementation of real-time pricing. They guarantee at least a day's warning but presumably that could be modified for short-notice activation (i.e. due to a loss of a large baseline plant.) The customer gets credit for being in the program, so that's at least one form of RTP.
--bill von

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2 x FM80s,
FNDC w/3 shunts,
Mate3 v3.015.005 (works excellent!)
Hub 10.3,
PV:1000W east@45, 600W west@45, 2400W south@19 deg.
Battery:48v @ 130Ahr Crown batteries, deep cycle <$380 for 6.25kWh

ISY994i HA, Insteon, X10, Philips Hue, MiLight bulbs & RGBW strips
WebControl 8 as weather station stuffing
ISY994 variables via REST interface

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Re: GVFX programming for load leveling

Post by larrywa » Thu Sep 03, 2015 3:14 pm

Our utilities wanted to do spot market pricing but the metering would be too complex and the data resolution would be way too much data coming in. I am not sure how fine a time increment they wanted to implement but basically industry would pay the current rate negotiated with other provinces and states. This is based on demand usage mostly which residential customers do not pay.

The politicians always have some hair-brained scheme that can't be technically done or economically impractical.

Look at California. whatever they have down will follow everywhere. They have 30 years of experience ahead of everybody else. Or rates latest increase is at 2:1 peak to off peak so far. After dividing up the costs and splitting up the portions of generation, delivery and service industries the realisation that energy is cheap to generate but the delivery is the big cost. My $35 grid energy consumption usage per month ends up being $150 per month after delivery, line losses, debt pay down, taxes and a few other silly thing they thought up.

As an aside: I am burning up energy this week and it hurts. We have go 29 degrees C (84F) and fog that I can't see across the street. Yeah it's really humid and the A/C can't keep it down in the house. Welcome to Ontario. :)

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Re: GVFX programming for load leveling

Post by tallgirl » Thu Dec 03, 2015 3:19 pm

I wrote code which does that using a pair of GVFX inverters and a Mate firmware level which was only available to me and a few other companies. It works fairy well, but you have to reprogram the "Sell RE" voltage using inverter current as the input to a PID loop.

If you DO decide to do something like set "Sell RE" to 48 volts you'll discover that the inverter will sell every bit of battery it can get its hands on, and then the current will decline (at 3kW -- which is about the long-term limit for a single GVFX3648) and you'll be out of battery.
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Re: GVFX programming for load leveling

Post by mariareese » Wed Jun 21, 2017 2:29 am

But utilities are also not working completely to handle it .. :(

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Re: GVFX programming for load leveling

Post by billvon » Wed Jun 21, 2017 11:53 am

mariareese wrote:But utilities are also not working completely to handle it .. :(
Here in San Diego we have an experimental RTP program that gives day-ahead pricing. Prices range from 8 cents/kwhr at 1am to $1.30/kwhr at 6pm on hot days. Since we do all our EV charging at night - and don't really need A/C yet - it is working for us so far.
--bill von

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