Hybrid Solar, grid tied solar pv with batteries

[SunEagle]

I second SunEagle ... I think most people approach solar in general, but definitely hybrid systems, as some sort of magic bullet that will not only give them backup power, but also save them money. There is no saving money in a hybrid system. There is recovering some part of the investment, but among solar options, it is the lowest of recoveries, if one can really say there is even a real recovery of the investment. There are legitimate reasons to for someone to use hybrid, but none of them are green (money/environment).

Asserting that a $45k system pays for itself the first time the power is out for a week... seriously? I mean... Is there anywhere in the world that power is that expensive? I suppose if one earns $45k+ a week, that could be possible, but is otherwise just hyperbole.

Some continuous manufacturing process can cost millions if it shuts down unexpectedly. That includes PV servers, continuous web machines, solid state component manufacturing, long term heating process, etc. So having immediate and seamless backup power will easily pay for itself if it can eliminate even one outage.

As for most home or small company systems the loss of power is not that expensive to their business, but maybe the one that ncs55 mentions could cause a major loss of money if it suddenly stopped and stayed down for days.

[gmanInPA]

I second SunEagle ... I think most people approach solar in general, but definitely hybrid systems, as some sort of magic bullet that will not only give them backup power, but also save them money. There is no saving money in a hybrid system. There is recovering some part of the investment, but among solar options, it is the lowest of recoveries, if one can really say there is even a real recovery of the investment. There are legitimate reasons to for someone to use hybrid, but none of them are green (money/environment).

Asserting that a $45k system pays for itself the first time the power is out for a week... seriously? I mean... Is there anywhere in the world that power is that expensive? I suppose if one earns $45k+ a week, that could be possible, but is otherwise just hyperbole.

[SunEagle]

With all of the things you have said. You guys really don't like Hybrid systems that is for sure. And sunking, you are way biased and not necessarily correct with your evaluation. The last one I sold was just at $45,000.00 turn key. It came with the XW 6048, distribution panels with breakers etc., 3 classic 250's, 25 265W Solar World's, 3 MS PV6 with disconnecting means and breakers on the roof, 16, 6V Crown solar batteries, custom thermal blocked battery box with acid catch, complete critical load extraction and equipment, SCP,Gen control, and combox. Let me tell you, I was not laughing all of the way to the bank. It is a challenging installation. And you do not make as much as you would think. It sells back to the grid every day, has no problems and the customer never runs out of power when the grid goes down. He has a gen for backup, never had to use it yet.( and a hybrid system does not require a gen for extended periods of outage ). He pumps water out of a well and lives normally and can live fine if the grid never comes back. He lives at the end of a transmission line that SDG&E will shut power off every time the wind picks up and looses power frequently. He has had the grid down for over a week at a time. To most that want these systems, the first time the grid fails, it is worth every penny that they spent and they will tell you that. This is not the kind of system that you just go out and peddle either. People come to you, if they want it and there are a lot of these in San Diego County and for all different kinds of reasons. The Tesla powerwall is a joke and will never even come close to what a well designed hybrid system will deliver when the grid goes down. Neither will a gen and batteries and or the SPS from your Sunny Boy.

Most uneducated people can be easily swayed into purchasing a hybrid system that is way over priced and not really needed. Based on Sunkings experience that has happened a lot and he trys to get people to start thinking about wasting their money.

As you have pointed out there are both people with real needs for a hybrid and good systems that can be purchased but as I have read those are few and far between compared to what some of the "sellers" try to push people to get like the powerwall.

So while Sunking may be not 100% correct in his statements he is probably closer to 98% considering the crap that people have tried to sell the unknowing who want to be "free" from their POCO and go "green"

[gmanInPA]

Some of us like hybrid systems very much! Many here, including myself (a hybrid system owner) just want to be sure to point out some of the cons as well as the pros. As a Schneider XW owner, I had to chuckle that your customer has had zero issues, especially with the combox and AGS. Maybe they've not really tried so much with them yet. They're not huge problems, but those two devices are quirky to say the least.

I'm not an installer, but if I were, I would definitely see an opportunity in hybrid systems, though probably less profitable and more time consuming than setting up grid-tied systems I imagine.

For me, one big upside, at least with my AHJ and POCO, is not needing anything other than an electrical inspection since the system is all on a branch circuit.

[ncs55]

With all of the things you have said. You guys really don't like Hybrid systems that is for sure. And sunking, you are way biased and not necessarily correct with your evaluation. The last one I sold was just at $45,000.00 turn key. It came with the XW 6048, distribution panels with breakers etc., 3 classic 250's, 25 265W Solar World's, 3 MS PV6 with disconnecting means and breakers on the roof, 16, 6V Crown solar batteries, custom thermal blocked battery box with acid catch, complete critical load extraction and equipment, SCP,Gen control, and combox. Let me tell you, I was not laughing all of the way to the bank. It is a challenging installation. And you do not make as much as you would think. It sells back to the grid every day, has no problems and the customer never runs out of power when the grid goes down. He has a gen for backup, never had to use it yet.( and a hybrid system does not require a gen for extended periods of outage ). He pumps water out of a well and lives normally and can live fine if the grid never comes back. He lives at the end of a transmission line that SDG&E will shut power off every time the wind picks up and looses power frequently. He has had the grid down for over a week at a time. To most that want these systems, the first time the grid fails, it is worth every penny that they spent and they will tell you that. This is not the kind of system that you just go out and peddle either. People come to you, if they want it and there are a lot of these in San Diego County and for all different kinds of reasons. The Tesla powerwall is a joke and will never even come close to what a well designed hybrid system will deliver when the grid goes down. Neither will a gen and batteries and or the SPS from your Sunny Boy.

[gmanInPA]

I threw this flowchart together to help people who are just starting to consider solar to figure out what direction to head in. It is by no means exhaustive. I'm open to suggestions for edits, but I think it consolidates some of the main ideas.

[gmanInPA]

A recent example of other good reasons to have at least a generator, or a generator and batteries:

From the attached story link:

"“It is only a matter of the ‘when,’ not the ‘if’—we’re going to see a nation-state, group, or actor engage in destructive behavior against critical infrastructure in the United States,” Rogers, who is also director of the National Security Agency, said in a speech March 2."

All that to say that planning on power outages being greater in severity than they are today is a reasonable and prudent approach for any homeowner. Does that necessarily mean batteries? Of course not. But batteries would be a potential additional 'force multiplier' in such circumstances.

[gmanInPA]

I've said this elsewhere, but will say it here too....

If one has any financial goals in considering a hybrid system, unless that goal is to spend a lot of money - it's probably not going to happen. Unless a prospect has some very wild POCO rates with a ToU rate plan that is extremely worthwhile, load shaving is probably not going to be a good incentive on it's own. If anything, it's just a way to recapture a small percentage of your investment into solar. FWIW, my inverter manual is very clear that peak load shaving is not advised or worthwhile unless all of your loads are on the inverter, which is impractical for an average home.

With that said, is it reasonable for people to have non-financial goals for investing in a hybrid system? Sure it is! Are there advantages to such systems? Sure there are. There is no requirement that things always make financial sense.

As a hybrid system owner - one of those wackos who spent money on such - there were two main advantages to going with a hybrid system. Other prospects would need to determine if those advantages are worthwhile:

1) Uninterrupted power (on protected loads). Unlike a generator, battery-based inverters immediately switch over using their built in ATS. I am not aware of a generator that can do so as quickly - if they exist, I'd be interested to know more and if they're cheaper than batteries.

2) Stretching fuel. To run on a generator while grid-down requires running the generator any time you want power (unless you have PV and a grid-tied inverter that makes some of that power available). Batteries and PV are a fuel multiplier (a very expensive fuel multiplier). With a hybrid system - you only burn fuel and run the generator to recharge the batteries.

What helped me conclude what I wanted was to ask myself how I would want to operate in a 14 day outage. Is that number reasonable? Sure - just ask people who lived through Hurricane Sandy or Katrina, or ice storms, etc. One doesn't have to look hard to find reports that grid outages are on the rise in the US, though in fairness, only 5% of US outages are > 4 hours.

If we lost power for 14 days, our critical loads would run off PV for up to 5-6 hours per sunny day (placing no load on a generator, or a battery). Of course, hurricanes aren't usually fair sunny weather, but most of that time would be post-hurricane and average weather. When the sun wasn't available, it would then utilize our batteries. When the batteries were eventually depleted (for us, about .8 - 2.5 days or so), then the generator would kick in. The generator would run for approx 45m-4h (depending on a few variables), shut off, then begin to use PV and/or battery power again until the batteries were once again drawn down to the point of needing to be bulk charged. With our generator, that equates to about 4 gallons of fuel per day (worst case). If I were to run my critical loads off a generator for 24 hours, that would require 24 gallons of fuel, and most of it would be wasted because of my loads pattern. Without the batteries, if I decided to run on generator for 24h, I would need 336 gallons of fuel. But maybe I am willing to conserve and run it 12 hours a day.... 168 gallons for the 14 days. With my setup, I can get by on 56 gallons.

For my interests, these things are an advantage. I had several colleagues who had a very difficult time finding fuel during hurricane Sandy. Those that did had to make daily trips to re-stock on fuel for their generators. They waited long hours and got gouged. For me, the battery pays for itself after only one such event, or several smaller such events because I can continue to work vs spending my day on a resupply mission. That was just a hurricane. If there were a situation where people were truly freaked out, then it can become downright dangerous to resupply.

Some other advantages:

1) Options!!! A hybrid system can run on grid, battery, PV, generator power. That is one more option than a grid-tied system (battery), and one more option than an off-grid system (grid). To be fair, that option comes at a price - more money invested, more maintenance, more time.

So who would most benefit from a hybrid system?
1) Those who are just really bothered by the prospect of having solar power that doesn't work (not very much anyway) when the grid is down.
2) People interested in being prepared for the unexpected
3) People who need large-scale uninterrupted power.
4) People who want peace of mind about having long-term power without massive amounts of fuel stored.
5) People who would like to know they can live off-grid if there is a need to do so, but would prefer to live on-grid the rest of the time.

To be clear - the advantages above have don't really require any PV. You can can these things with just a generator, a hybrid inverter, and a battery bank. The PV just further stretches (potentially) the fuel by relying on solar power when it is available.

[jflorey2]

3. Peak Shaving, this is more for commercial applications . . . .

Agreed. Peak shaving/load shifting won't make economic sense for residential systems until two things happen:
1) Real time pricing (i.e. pricing per hour rather than fixed prices by time or by kwhr)
2) Lower cost batteries.

At this point I'm glad companies like Tesla are working on such systems, because when the above two things happen the hardware will be ready to go. Until then they are more toys than ways to save money.

[Sunking]

So what is hybrid solar? Well the definition I favor is simply, a grid- tied solar panel system with battery storage. There has been quite lot of talk about Tesla's new power wall battery and this may lead to a rise in hybrid systems in the near future.

So why have a Hybrid solar power system? As the battery's are still quite expensive to me there are few circumstances or scenario's where it might make sense

I have to agree, pretty much a waste of money for such little benefit.

To start with the Hybrid Inverters Inverters are more expensive than a Grid Tied Inverter. A good 4000 watt GTI will run you around $1100 to $1500. A 4000 watt 48 volt Hybrid around $2200 to $2500.

With a hybrid Inverter is going to require you to require you to install an Emergency Breaker Panel, and running or rerouting your existing home wiring to Critical Loads and is very limited in power. It will require a licensed electrician in most case and very expensive. That alone is going to cost mid/high 4 digits and can go to low 5 digit cost.

Is going to require a significant battery cost of 4 digits, and battery replacement ever 4 to 6 years. What really is bad if you used those same batteries in a Off-Grid system where they are used every day, the Kwh cost is roughly 4 to 10 times more than buying it from the POCO. So even if you do intend to sell back to the POCO at night from your batteries is terrible foolish. Think about it. It cost you 60 cents per Kwh to make a Kwh, and you sell it for 15 cents. Is that a problem for you? However used as Emergency power, will the Kwh cost of the batteries is beyond astronomical when only used once or twice a year during an outage. Easily into hundreds of dollars per Kwh. Not too mention extremely limited amount of power consisting of a few lights, refrigerator, TV, fan motor on heater, and a few receptacles.

A hybrid system still requires a generator for extended outages of more than a few hours.

On the other hand a conventional Grid Tied System with a pad mounted Emergency generator cost 1/2 that of a hybrid system installed.

Conventional allows you to run everything in your home like nothing happened. You get to sit back in hot summer time and watch all your neighbors suffer while you drink ice cold lemonade or you favorite brewsky.

Your Kwh fuel cost are reasonable.

Much more environmentally friendly.

More reliable.

No rewiring your home.

When you look at the big picture, there is no comparison. It would be rare circumstances where a Hybrid system would be a batter choice. For the vast majority the only persons happy with Hybrid Inverters are the company who sold it and installed it for you. They are laughing all the way to the bank. Not only that, it just keeps on giving them more of your money as you replace your batteries.

[solar pete]

Hi All,

So what is hybrid solar? Well the definition I favor is simply, a grid- tied solar panel system with battery storage. There has been quite lot of talk about Tesla's new power wall battery and this may lead to a rise in hybrid systems in the near future.

So why have a Hybrid solar power system? As the battery's are still quite expensive to me there are few circumstances or scenario's where it might make sense.

1. Critical Loads, that is where in the event of a grid-outage (blackout) you still must have power to run critical loads, this could be to power a medical device or critical infrastructure like servers etc. If this is the case you need to determine how much power you need as a minimum and for how long. This is difficult as who knows how long a black out will last, a generator will also be required in this scenario.

2. Wanting to reduce your night time grid usage. Now while this is very doable in many instances it just wont make financial sense. If you are charged at a high rate per kWh (kilowatt hour) you could look at the viability of shifting your night time usage to your batteries. The thing to remember here is you need to size your solar pv array to be large enough to both charge your batteries and run the house loads during the day time. NOTE, even though you might get say 8 or 10 daylight hours a day that is not how solar isolation is measured, best to think of it as you only get 4 or 5 usable day light hours in summer and maybe half that in winter. You do not want to be in a situation where you are forced to charge your battery's from the grid as this is defeating the purpose of having battery's in the first place. Each situation will be different that is why you need to talk to an experienced solar pro as this needs to be planned and designed correctly.

3. Peak Shaving, this is more for commercial applications as I see it and depends on how a customer is billed for their electricity consumption. Commercial customers who have large mains feeds can be billed with a type of sliding scale that is determined by how much peak power the poco (power company) needs to deliver. For example we have a supermarket client who has a 100kW system on their roof, over the last year this has both reduced their bill and we suspect (yet to be tested) reduced their peak demand. Its possible that if we add battery storage to the existing PV system we could further reduce peak demand thus decreasing their overall bill. Its still early days with this scenario but its getting closer to reality the cheaper the storage options get.

So what equipment do you need to run a hybrid solar system? Well the same as a normal solar pv system with the addition of a battery/batteries and either a hybrid inverter or a charge controller (CC) and perhaps a BMS (battery management system) .

So this is a new stickie so please comment/correct/improve etc

Here is a link to a large hybrid solar panel system. http://s12.photobucket.com/user/pete...?sort=3&page=1


Cheers