Peak demand

[Ampster]

Context of this thread:
This person from Canada asks for some help on a case study which which asks him to look at two generator/battery configurations, one with PV and the other without PV Solar. He gets a lot of suggestions, many are outside the parameters of the case study.

I post a link to a source of information that seems to infer that solar plus batteries is becoming economical. It is an economic trend that he could explore in more detail if he found it useful. Disregard the future projections. I believe the costs are real. What does any of your rant have to do with the question that the original poster asked? If you want to talk about the data then talk about the data; What do you not believe about $30 per megaWatt hour quoted in the article? Do you have more accurate costs?

Why do you take this so personal?

FWIW, SPGlobal is the parent of Standard & Poors which has been around over 140 years and employs 10,000 people.

[Mike90250]

Case:

offgrid baseload of 10MWh per day. Peak power demand ( 3 times a day ) reach 13MWh. Genset is able to handle the baseload. How can I calculate or sizing my battery sizing to reduce the peak power demand?

This is not enough info to give you an answer. So you are getting a lot of harebrained ideas that are worthless

1) can the loads be managed & "Leveled" ?
2) peaks happen 3 x a day. What is the duration of the peak ? Are they scheduled
3) What is the recharge source for the peaker battery ?
4) When the big genset is "down" the battery has to supply the base load for 3 hours ?
5) there are going to be un expected outages. Will the battery be called upon to supply that?

This a such a poor exercise.. You were not given enough information to ask meaningful questions, nor do you know enough to be able to separate the green fluff BS from a "Today real world answer".

[Mike90250]

Some offers for energy prices from battery-backed solar arrays in the U.S. Southwest came in under $30/MWh in 2018, while the installed cost for large-scale battery storage only, modeled on a 20-MW system with four hours of storage capacity, dropped nearly 40% to $357/kWh in just one year, estimates Bloomberg NEF.

It's all in the reading of misleading terms.
20-MW system with four hours of storage capacity
What's not said, is it 20MW for four hours, or 5MW for 4 hours - totaling 20MW. imprecise statements meant to allow someone to jump to conclusions.
Then there is the word "capacity". When dealing with marketers, I want to know what can be delivered, not ordered. Is all 20mw usable, or only 60% of it ? 4 ours or 1 or 7 hours ?
I've had years of reading between marketing lines,to find out what is real.

A big clue will be revealed tomorrow, in Australia, where a heat wave is expected and the coal plants being decommissioned (working plants being blown up, not just turned off). But they installed green batteries. If there are blackouts, I count that as Failure, and once the big peaker batteries are dead, how to recharge them in time for the next day ? Gonna be interesting there for the next few days.

But worse, is some professor in an ivory tower, passing out assignments that will lead students down a greenwashed path and 4 years, place them in charge of systems that cannot function.

I am SO glad I'm off grid in California, because the next couple years, I expect to be nightmarish from the double whammy of mandated "green" power, and PG&E going into bankruptcy to avoid the liabilities of the fires they caused the last 2 years from poor maintenance . Their CEO will still get paid astronomical amounts of $$, and consumers get it stuck in their rear without vasoline.

http://www.caiso.com/TodaysOutlook/Pages/default.aspx

I forsee a huge market in homeowner backup generators, and for business too - since PG&E is going to cut regional power in cases of foul weather forecasts.

https://www.pge.com/en_US/safety/eme...utoff-faq.page
> Just like each days weather, circumstances for each Public Safety Power Shutoff will be unique. The outage, which includes the weather event plus restoration time, could last several days. We will only restore power when we are certain it is safe to do so.

If we need to temporarily turn off an electric line for safety, all customers who receive power from that line would be affected. Emergency facilities such as hospitals and fire and police stations typically use generators to remain open.

[bcroe]

Sounds like going back a century before the GRID, when local areas built there own power generation.
I know of a couple such facility locations close by, one is a big diesel plant currently available as a
backup. It was running when I first saw it about 1949.

I do not get it, seems like with dry conditions, wind, and an abundance or combustable stuff, it is a
fire just waiting for a spark. With a infinite number of possibilities, it does not seem right to pin the
spark blame on a particular source. Better to remove one of the conditions above. Bruce Roe

[Ampster]

Here is the study case scenerio that Dwill clarified further down in the thread.

Hello,
Thank you for your reply guys and I am sorry if I was not being specific. Here is my study case scenario:
Case:
The project is looking for a solution to provide to power to an offgrid site located in South-East Saskatchewan (Canada). This site is an unmanned site but is experience power disruption. The site has a power demand of 755A at 480VAC, 3 phase (baseload). This site also experiences peak power demands (3 times a day) which can add an additional 185 A requirement from the service. Each peak can last from 5 seconds to 45 minutes. It is preferred that the battery system can handle the peak. Regarding with the genset, it is preferred that the battery is used to reduce the peak power demand. Maintenance on the genset will occur every 3 months. During this maintenance, it is expected batteries will handle part of the load (275A at 480VAC, 3 phases with no peak event) for 3 hours. The site will still have fuel gen to handle the load during maintenance.
Factor need to be considerate:
Temperature ( Saskatchewan is a really cold place in winter which can reach -35 for 3 months ).but has a lot of sunny day. According to Canadian solar power resource map , Saskatchewan stands with 1336 kWh/kW/yr ( unit).
Genset Configuration:
There are different configuration that can be done this case:
Plan A iesel Generator and Battery . or Plan B: Diesel generator&PVwith battery.
Calculation:
this is the part that it gets mess and I do not know where to start. I will assume (don

Note the reference to Plan A and Plan B. Then he goes on to say that the Calculation "gets mess and I do not know where to start." and was truncated. Here is the balance of that thought:

I will assume ( dont know if it is right or wrong) that my genset will handle the baseload for the whole day and for the peaks and maintenance will use the battery bank. Probably this is not the best way to do it because we have to consider that the battery have a minimun reduce capacity when is discharging.
Baseload :755A x 480VAC = 362.4kVA
Peakload 494.4kVA
Maintenance: 3hours every 3 months ( 275A x 480V) 132kVA
unknown PF ( assuming 0.9)
Efficiency losses in inverter converter and charges control

Having done a few case studies many years ago I assumed that the key issue was to develop two plans, one with Solar and the other without. Both were to include a genset and batteries. A clue to the insolation in Saskatchewan was the 1336 kWhr/kW/yr ratio.

I had no interest in doing this persons homework and having him pass it off as his own. Therefore, I just gave him a recent trend about the cost of batteries and solar as reported by a well known research and reporting company. Whether that has any value for the scale of his hypothetical project in Canada I will let him figure out as part of the exercise. We have not heard from him since then and perhaps the deadline came and went or he resolved the problem on his own.

[Ampster]

It's all in the reading of misleading terms.
20-MW system with four hours of storage capacity
What's not said, is it 20MW for four hours, or 5MW for 4 hours - totaling 20MW. imprecise statements meant to allow someone to jump to conclusions.
Then there is the word "capacity". When dealing with marketers, I want to know what can be delivered, not ordered. Is all 20mw usable, or only 60% of it ? 4 ours or 1 or 7 hours ?
I've had years of reading between marketing lines,to find out what is real.

It may depend on whether one views the glass as half full or half empty. What I took from that article is the macro trend that prices for battery systems are getting below $500 per kWhr. That is a lot better that the $1000/kWhr that SimpliPhi and others are charging for just batteries with no inverter.. My hope is that the commoditization of battery storage continues to give us more affordable alternatives.

But worse, is some professor in an ivory tower, passing out assignments that will lead students down a greenwashed path and 4 years, place them in charge of systems that cannot function.

I agree. It was clear to me the professor skewed the assumptions on that case so that the students would look at PV with batteries as an alternative. At least it was done in the form of a case study where hopefully the students develop some critical thinking skills.

I am SO glad I'm off grid in California, because the next couple years, I expect to be nightmarish from the double whammy of mandated "green" power, and PG&E going into bankruptcy to avoid the liabilities of the fires they caused the last 2 years from poor maintenance . Their CEO will still get paid astronomical amounts of $$, and consumers get it stuck in their rear without vasoline.

http://www.caiso.com/TodaysOutlook/Pages/default.aspx

I forsee a huge market in homeowner backup generators, and for business too - since PG&E is going to cut regional power in cases of foul weather forecasts.

In many ways I envy those of you that are able to be off grid. I am served by a public utility and have not choice about going off grid. All I can do, within reason, is shift as much load off grid as possible.I also want to have backup capability because I am with PG&E in a fire prone area and expect to see some of those brownouts.

There is already a growing market in behind the meter backup generators. Most of those are taking the form of Tesla Powerwalls, LG Chem, Sonnen and others. Many companies are entering the market where traditional generators can't be used because of noise or other issues, particularly in urban or suburban areas. One only has to look to Germany to see that trend. Also, one of the trends in large businesses is to use battery systems for peak shaving to avoid load charges. All of that results in load departure for the Public Utilities. It is a gloomy outlook for them.

[azdave]

In many ways I envy those of you that are able to be off grid. I am served by a public utility and have not choice about going off grid.

Don't pay your electric bill. That will get you off grid faster than anything.

[Ampster]

Don't pay your electric bill. That will get you off grid faster than anything.

My system is not that resilient yet for me to try that. It is an interesting issue though. I will have a chance to test that when my solar installer changes out my main panel in the next few weeks. It was supposed to happen yesterday but someone screwed up the timing so it has been postponed. However I did get a call from PG&E asking for contact information of my installer who was supposed to meet them at the site. He told me that I would be without power and asked if I had a back up generator. I told him that I had a Hybrid Inverter with a UL approved transfer switch. I have pulled the permit for that and the subpanels but have not yet had them inspected because I am waiting for the main panel to be changed and that is on a separate permit.

[peakbagger]

Do a search for Flexgen power systems. Solid state capacitor based generator for surge loads

[solar pete]

A big clue will be revealed tomorrow, in Australia, where a heat wave is expected and the coal plants being decommissioned (working plants being blown up, not just turned off). But they installed green batteries. If there are blackouts, I count that as Failure, and once the big peaker batteries are dead, how to recharge them in time for the next day ? Gonna be interesting there for the next few days.

But worse, is some professor in an ivory tower, passing out assignments that will lead students down a greenwashed path and 4 years, place them in charge of systems that cannot function.

Howdy Mike and All,

Well so far so good down here in OZ with the heatwave, it may have been just pure luck, but we did have another 30megawatt battery come online a couple of days ago, at the start of the heat wave, I havnt noticed any power outages in my area, but I am sure there would have been a few around the state.

Here is a link to our latest big battery, https://www.abc.net.au/news/2019-01-...leted/10718772

[Paul Land]

Don't pay your electric bill. That will get you off grid faster than anything.

Careful with this one, A woman had here POCO disconnected and town tried to condemn her home for doing it.
condem.png

[azdave]

Careful with this one...

Of course I was joking but yes, I've heard that many areas require maintaining connection to utilities that are available. It's been discussed here previously. We can't have everyone going stand-alone now can we?

[SunEagle]

Of course I was joking but yes, I've heard that many areas require maintaining connection to utilities that are available. It's been discussed here previously. We can't have everyone going stand-alone now can we?

It happened here in Florida. Someone tried to go off grid with the property inside a township. The town officials started to charge them penalty fees each day due to not following the town rules requiring electric and water connections.

[Paul Land]

It happened here in Florida. Someone tried to go off grid with the property inside a township. The town officials started to charge them penalty fees each day due to not following the town rules requiring electric and water connections.

I think it happened when i was living down there she was on local news with eviction notice due to condemn notice

[SunEagle]

I think it happened when i was living down there she was on local news with eviction notice due to condemn notice

What I remember was that the property owner was collecting all rain water (they had no well) as well as having solar generate all power. I don't remember if they were still tied to the sewage system or if they have a septic tank.

To get them back they were first charged and then the property was condemned to get them to connect back to city service or just leave.

As we have stated before we try to convince people to first find out what the "rules" are concerning all utilities before they just disconnect and go off grid or try to cheat the POCO. If you break the law the city and POCO will win in the end.